WO2007033353A2 - Compositions de liaison a des cibles chimiques - Google Patents
Compositions de liaison a des cibles chimiques Download PDFInfo
- Publication number
- WO2007033353A2 WO2007033353A2 PCT/US2006/035968 US2006035968W WO2007033353A2 WO 2007033353 A2 WO2007033353 A2 WO 2007033353A2 US 2006035968 W US2006035968 W US 2006035968W WO 2007033353 A2 WO2007033353 A2 WO 2007033353A2
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- pharmaceutical composition
- binding
- composition
- glucose
- concentration
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Ceased
Links
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
- A61K9/00—Medicinal preparations characterised by special physical form
- A61K9/14—Particulate form, e.g. powders, Processes for size reducing of pure drugs or the resulting products, Pure drug nanoparticles
- A61K9/16—Agglomerates; Granulates; Microbeadlets ; Microspheres; Pellets; Solid products obtained by spray drying, spray freeze drying, spray congealing,(multiple) emulsion solvent evaporation or extraction
- A61K9/1605—Excipients; Inactive ingredients
- A61K9/1629—Organic macromolecular compounds
- A61K9/1635—Organic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polyvinyl pyrrolidone, poly(meth)acrylates
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
- A61K9/00—Medicinal preparations characterised by special physical form
- A61K9/0012—Galenical forms characterised by the site of application
- A61K9/0019—Injectable compositions; Intramuscular, intravenous, arterial, subcutaneous administration; Compositions to be administered through the skin in an invasive manner
- A61K9/0024—Solid, semi-solid or solidifying implants, which are implanted or injected in body tissue
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
- A61K9/00—Medicinal preparations characterised by special physical form
- A61K9/48—Preparations in capsules, e.g. of gelatin, of chocolate
- A61K9/50—Microcapsules having a gas, liquid or semi-solid filling; Solid microparticles or pellets surrounded by a distinct coating layer, e.g. coated microspheres, coated drug crystals
- A61K9/5073—Microcapsules having a gas, liquid or semi-solid filling; Solid microparticles or pellets surrounded by a distinct coating layer, e.g. coated microspheres, coated drug crystals having two or more different coatings optionally including drug-containing subcoatings
Definitions
- compositions useful in regulating the concentration of chemical targets in a fluid relate generally to compositions useful in regulating the concentration of chemical targets in a fluid.
- the invention finds utility, for example, in the fields of medicine and environmental science.
- a toxic substance must be present in an organism at some threshold concentration before any adverse effects are evident. Below this concentration, no such adverse effects are observed. By using this theory it is assumed that tiny doses of a toxic substance will not cause any adverse effects. A toxic substance must be present in an organism at some "threshold" concentration before any toxic effects are evident.
- the health of an organism or ecosystem relies on an ability to maintain healthy concentrations of all of the chemical species that are present within the organism or ecosystem. This principle applies to nutrients, toxins, metabolites, and other chemicals regularly encountered in aqueous environments.
- insulin is secreted by the pancreas in response to rising levels of blood glucose, thereby helping to maintain blood glucose concentrations near 5 mM.
- insulin secretion is impaired or annihilated, and daily injections of insulin are therefore vital.
- State-of-the-art insulin therapy utilizes short and long acting insulins (meal and basal insulins) in various regimens, thereby attempting to maintain glucose levels in the diabetic patient at a healthy level at all times. Tight glucose control is paramount in avoiding long-term tissue damage (eyes, kidneys, heart, etc.) from hyperglycemia (> 10 mM) and acute danger (coma or death) from hypoglycemia ( ⁇ 3mM).
- hyperglycemia > 10 mM
- hypoglycemia hypoglycemia
- unexpected/irregular changes in glucose levels occur almost daily, and these events are not easily compensated for with current state-of-the-art insulin therapy. It has been shown that glycemic variability in diabetic patients may be an important factor involved in the pathogenesis of microvascular complications.
- compositions, implants, formulations, medical devices and methods for modulating and controlling the concentration of a chemical target in vivo or in an ecosystem have a capacity to bind the chemical target present in the ecosystem or the physiological fluid of a living organism in a reversible manner.
- the capacity for binding with the chemical target and the binding constants for the chemical target are designed to maintain the concentration of the chemical target substantially within a beneficial range of concentrations.
- the disclosure describes a pharmaceutical composition comprising a biocompatible binding component.
- the binding component comprises a binding moiety capable of reversibly binding with a chemical target.
- the pharmaceutical composition is capable of regulating the concentration of the chemical target in a physiological fluid of a patient.
- a method of regulating the concentration of a chemical target in a physiological fluid of a patient is also described. The method comprises contacting the physiological fluid with such a composition.
- the disclosure describes a pharmaceutical composition for treating diabetes.
- the pharmaceutical composition comprises a biocompatible binding component capable of reversibly binding glucose.
- the pharmaceutical composition is in a dosage form capable of contacting the physiological fluid of a patient suffering from diabetes for a predetermined length of time.
- the disclosure describes a method for regulating the concentration of glucose in the blood of a patient.
- the method comprises contacting the blood of the patient with a pharmaceutical composition comprising a therapeutic amount of a biocompatible binding component capable of reversibly binding glucose.
- a composition for regulating the concentration of a chemical target in an aqueous environment of an ecosystem comprises a binding component.
- the binding component comprises a binding moiety capable of reversibly binding with a chemical target.
- the binding constant of the binding moiety is complementary to the beneficial range of concentrations for the chemical target in the aqueous environment.
- the disclosure describes glucose-binding composition and medical device capable of reversible glucose binding in the physiological environment.
- this embodiment describes methods of use of the glucose-binding composition and device for the treatment of diabetes, wound healing, tissue regeneration and tissue repair.
- the chemical target can be any other physiological agent, metabolic byproduct, natural compound or a synthetic chemical entity present in the living body or ecosystem.
- the chemical target is a drug, pharmaceutical agent, biological or physiological process altering agent found in or used in a living body or ecosystem.
- the disclosure describes a drug-binding composition that is implanted in an organism.
- the drug is introduced (separately or together with the drug-binding composition) into the organism by conventional medication routes (injection, ingestion, inhalation, etc.).
- Drug circulating in the body after such introduction is bound by the implanted drug-binding composition and subsequently released into circulation when the circulating drug concentration is diminished.
- the specificity, binding constants, capacity and binding and dissociation rates of the drug by the drug-binding moieties can be optimized to achieve desired kinetics of drug delivery.
- a chemical target is an endogenous biologically or physiologically active agent such as hormone, growth factor, cytokine, etc.
- the endogenous factor is present in the living body or ecosystem.
- the binding composition in this case is used as "sponge" for the endogenous agent.
- Such a binding composition may be useful, for example, in concentrating and localizing the effect of the chemical target at the local tissue site where the binding composition is implanted.
- the chemical target can be a toxin or pollutant, or other undesirable agent present in living body or ecosystem.
- the binding composition binds the toxin at the concentration levels that are toxic to the living body or ecosystem and may release the toxin by dissociation when toxin levels fall sufficiently below the toxic concentration levels.
- This disclosure also describes methods of treating diabetes and its complications by improving glycemic control and reducing glycemic variations.
- a glucose-binding moiety refers not only to a single glucose binding molecular structure or moiety but also to a combination of two or more different moieties
- a hydrophilic polymer refers to a combination of hydrophilic polymers as well as to a single hydrophilic polymer, and the like.
- all technical and scientific terms used herein have the meaning commonly understood by one of ordinary skill in the art to which the invention pertains. Although any methods and materials similar or equivalent to those described herein may be useful in the practice or testing of the present invention, preferred methods and materials are described below. Specific terminology of particular importance to the description of the present invention is defined below.
- substantially within a given range over time. By this is meant that the value of the variable remains within the given range at least 90%, preferably 95%, of the time that the variable is measured. Thus the term “substantially within” takes allowance for isolated and relatively short-lived deviations of the value of the variable beyond the limits of the given range.
- living body refers to human or animal body or its parts, organs, systems, tissues, cells, cell cultures, and includes body fluids such as blood, lymph, cerebrospinal fluid, saliva, tears, sweat, or urine.
- the term "ecosystem” refers to a community of plants, animals, and microorganisms that are linked by energy and nutrient flows and that interact with each other and with the physical environment.
- Rain forests, ocean, lakes, rivers, ponds, deserts, coral reefs, grasslands, and a rotting log are all examples of ecosystems.
- the term "beneficial range of concentration” refers to the concentration of a chemical present in the living body or ecosystem at which said chemical is not harmful if, for example, the chemical is a toxin or pollutant; or at which said chemical is therapeutically effective if, for example, the chemical is a drug; or refers to the normal and/or healthy range of concentrations of the chemical if, for example, the chemical is a nutrient such as glucose.
- a chemical target will have a "beneficial concentration” rather than a beneficial range of concentrations in the physiological fluid or ecosystem.
- beneficial range of concentrations is meant to encompass instances wherein the chemical target has a beneficial range of concentrations as well as instances wherein the chemical target has a single beneficial concentration.
- beneficial ranges of concentrations are known in the art for a wide variety of substances found in or added to physiological fluid or ecosystems.
- a binding constant may be described herein as "complementary" to a beneficial range of concentrations.
- the binding constant of a binding moiety is such that, for a composition containing the binding moiety, the equilibrium concentration of a chemical target in the composition is within the beneficial range of concentrations.
- the equilibrium concentration of a chemical target is the concentration at which binding and releasing of the chemical target with the binding moieties is in equilibrium.
- polymer is used to refer to molecules composed of repeating monomer units, including homopolymers, block copolymers, random copolymers, and graft copolymers. Any molecule having at least 2 carbon atoms is deemed to be a polymer for the purposes of this invention.
- prepolymer refers to monomers, oligomers and polymers that can be further used to create a larger molecular weight polymer by crosslinking, polymerizing or otherwise linking prepolymers.
- crosslinked refers to a composition containing intermolecular crosslinks and, optionally, intramolecular crosslinks as well, arising from the formation of covalent bonds. Covalent bonding between two crosslinkable components may be direct, in which case an atom in one component is directly bound to an atom in the other component, or it may be indirect, through a linking group.
- a crosslinked matrix may, in addition to covalent bonds, also include intermolecular and/or intramolecular non-covalent bonds and electrostatic (ionic) bonds.
- crosslinkable refers to a component or compound that is capable of undergoing reaction to form a crosslinked composition.
- Synthetic to refer to various polymers, drugs, toxins or pollutants herein is intended to mean “chemically synthesized.” Therefore, a synthetic polymer in the present composition may have a molecular structure that is identical to a naturally occurring polymer, but the polymer per se, as incorporated in the composition of the invention, has been chemically synthesized in the laboratory or industrially. "Synthetic" polymers also include semi-synthetic polymers, i.e., naturally occurring polymers, obtained from a natural source, that have been chemically modified in some way.
- hydrophilic and hydrophobic are generally defined in terms of a partition coefficient P, which is the ratio of the equilibrium concentration of a compound in an organic phase to that in an aqueous phase.
- a hydrophilic compound has a log P value of less than 1.0, typically of less than about 0.5, where P is the partition coefficient of the compound between octanol and water, while hydrophobic compounds will generally have a log P greater than about 3.0, typically greater than about 5.0.
- Polymers may be crosslinked by either "physical" or chemical means.
- Physical crosslinking differs from chemical crosslinking in that the linkages are typically weaker, of lower energy, and often reversible. Thus, physically crosslinked hydrogels often are deformable mechanically.
- Four fundamental forces have been found to be responsible for producing physical crosslinking: ionic interactions; hydrophobic interactions; hydrogen bonding and Van der Waals forces.
- hydrogels may be intramolecular or intermolecular or in some cases, both.
- hydrogels can be formed by the ionic interaction of divalent cationic metal ions (such as Ca+2 and Mg+2) with ionic polysaccharides such as alginates, xanthan gums, natural gum, agar, agarose, carrageenan, fucoidan, fiircellaran, laminaran, hypnea, eucheuma, gum arabic, gum ghatti, gum karaya, gum tragacanth, locust beam gum, arabinogalactan, pectin, and amylopectin.
- divalent cationic metal ions such as Ca+2 and Mg+2
- ionic polysaccharides such as alginates, xanthan gums, natural gum, agar, agarose, carrageenan, fucoidan, fiircellaran, laminaran, hypnea,
- crosslinks may be easily reversed by exposure to species that chelate the crosslinking metal ions, for example, ethylene diamine tetraacetic acid.
- Multifunctional cationic polymers such as poly(l -lysine), poly(allylamine), poly(ethyleneimine), poly(guanidine), polyvinyl amine), which contain a plurality of amine functionalities along the backbone, may be used to further induce ionic crosslinks.
- “derivative” refers to a chemically or biologically modified version of a chemical compound that is structurally similar to a parent compound and (actually or theoretically) derivable from that parent compound.
- a “derivative” differs from an “analog” in that a parent compound may be the starting material to generate a "derivative,” whereas the parent compound may not necessarily be used as the starting material to generate an “analog.”
- a derivative may or may not have different chemical or physical properties of the parent compound. For example, the derivative may be more hydrophilic or it may have altered reactivity as compared to the parent compound. Derivatization (i.e., modification) may involve substitution of one or more moieties within the molecule (e.g., a change in functional group).
- a hydrogen may be substituted with a halogen, such as fluorine or chlorine, or a hydroxyl group (--OH) may be replaced with a carboxylic acid moiety (--COOH).
- derivative also includes conjugates, and prodrugs of a parent compound (i.e., chemically modified derivatives which can be converted into the original compound under physiological conditions).
- the prodrug may be an inactive form of an active agent. Under physiological conditions, the prodrug may be converted into the active form of the compound.
- Prodrugs may be formed, for example, by replacing one or two hydrogen atoms on nitrogen atoms by an acyl group (acyl prodrugs) or a carbamate group (carbamate prodrugs).
- prodrugs More detailed information relating to prodrugs is found, for example, in Fleisher et al., Advanced Drug Delivery Reviews 19 (1996)115; Design of Prodrugs, H. Bundgaard (ed.), Elsevier, 1985; or H. Bundgaard, Drugs of the Future 16 (1991) 443.
- derivative is also used to describe all solvates, for example hydrates or adducts (e.g., adducts with alcohols), active metabolites, and salts of the parent compound.
- the type of salt that may be prepared depends on the nature of the moieties within the compound.
- acidic groups for example carboxylic acid groups
- alkali metal salts or alkaline earth metal salts e.g., sodium salts, potassium salts, magnesium salts and calcium salts
- physiologically tolerable quaternary ammonium ions and acid addition salts with ammonia and physiologically tolerable organic amines such as, for example, triethylamine, ethanolamine or tris-(2-hydroxyethyl)amine.
- Basic groups can form acid addition salts, for example with inorganic acids such as hydrochloric acid, sulfuric acid or phosphoric acid, or with organic carboxylic acids and sulfonic acids such as acetic acid, citric acid, benzoic acid, maleic acid, fumaric acid, tartaric acid, methanesulfonic acid or p-toluenesulfonic acid.
- Compounds which simultaneously contain a basic group and an acidic group for example a carboxyl group in addition to basic nitrogen atoms, can be present as zwitterions. Salts can be obtained by customary methods known to those skilled in the art, for example by combining a compound with an inorganic or organic acid or base in a solvent or diluent, or from other salts by cation exchange or anion exchange
- analog refers to a chemical compound that is structurally similar to a parent compound, but differs slightly in composition (e.g., one atom or functional group is different, added, or removed).
- the analog may or may not have different chemical or physical properties than the original compound and may or may not have improved biological and/or chemical activity.
- the analog may be more hydrophilic or it may have altered reactivity as compared to the parent compound.
- the analog may mimic the chemical and/or biologically activity of the parent compound (i.e., it may have similar or identical activity), or, in some cases, may have increased or decreased activity.
- the analog may be a naturally or non-naturally occurring (e.g., recombinant) variant of the original compound.
- an analog is a mutein (i.e., a protein analog in which at least one amino acid is deleted, added, or substituted with another amino acid).
- Other types of analogs include isomers (enantiomers, diasteromers, and the like) and other types of chiral variants of a compound, as well as structural isomers.
- the analog may be a branched or cyclic variant of a linear compound.
- a linear compound may have an analog that is branched or otherwise substituted to impart certain desirable properties (e.g., improve hydrophilicity or bioavailability).
- Biodegradable refers to materials for which the degradation process is at least partially mediated by, and/or performed in, a biological system.
- Degradation refers to a chain scission process by which a polymer chain is cleaved into oligomers and monomers. Chain scission may occur through various mechanisms, including, for example, by chemical reaction (e.g., hydrolysis) or by a thermal or photolytic process.
- Polymer degradation may be characterized, for example, using gel permeation chromatography (GPC), which monitors the polymer molecular mass changes during erosion and drug release.
- GPC gel permeation chromatography
- Biodegradable also refers to materials which may be degraded by an erosion process mediated by, and/or performed in, a biological system.
- Erosion refers to a process in which material is lost from the bulk.
- the material may be a monomer, an oligomer, a part of a polymer backbone, or a part of the polymer bulk.
- Erosion includes (i) surface erosion, in which erosion affects only the surface and not the inner parts of a matrix; and (ii) bulk erosion, in which the entire system is rapidly hydrated and polymer chains are cleaved throughout the matrix.
- erosion generally occurs by one of three basic mechanisms (see, e.g., Heller, J., CRC Critical Review in Therapeutic Drug Carrier Systems (1984), 1(1), 39-90); Siepmann, J.
- PCS photon correlation spectroscopy
- other particles size measurement techniques may be applied to monitor the size evolution of erodible devices versus time.
- biodegradable synthetic polymers include polyglycolic acid (PGA) and poly-DL-lactide-co-glycolide (PLGA), crosslinked hyaluronic acid, crosslinked PEG containing carboxylic ester or thioester linkages.
- PGA polyglycolic acid
- PLGA poly-DL-lactide-co-glycolide
- crosslinked hyaluronic acid crosslinked PEG containing carboxylic ester or thioester linkages.
- small molecular weight crosslinker refers to multi reactive group containing molecules with molecular weights between approximately 100 and 3,000 Daltons.
- reagents containing two or more succinimidyl groups are small molecular weight crosslinkers including disuccinimidyl suberate (DSS), bis(sulfosuccinimidyl) suberate (BS 3 ), dithiobis(succinimidylpropion- ate) (DSP), bis(2-succinimidooxycarbonyloxy) ethyl sulfone (BSocOES), and 3,3'-dithiobis(sulfosuccinimidylpropionate (DTSPP), and their analogs and derivatives.
- DSS disuccinimidyl suberate
- BS 3 bis(sulfosuccinimidyl) suberate
- DSP dithiobis(succinimidylpropion- ate)
- BSocOES bis(2-succinimidooxycarbonyloxy) ethyl sulfone
- DTSPP 3,3'-d
- synthetic hydrophilic polymer refers to a synthetic polymer composed of molecular segments that render the polymer as a whole "hydrophilic,” as defined above. Preferred polymers are highly pure or are purified to a highly pure state such that the polymer is or is treated to become pharmaceutically pure. Most hydrophilic polymers can be rendered water soluble by incorporating a sufficient number of oxygen (or less frequently nitrogen) atoms available for forming hydrogen bonds in aqueous solutions.
- Hydrophilic polymers useful herein include, but are not limited to: polyalkylene oxides, particularly polyethylene glycol and poly(ethylene oxide)-poly(propylene oxide) copolymers, including block and random copolymers; polyols such as glycerol, polyglycerol (particularly highly branched polyglycerol), propylene glycol and trimethylene glycol substituted with one or more polyalkylene oxides, e.g., mono-, di- and tri-polyoxyethylated glycerol, mono- and di-polyoxyethylated propylene glycol, and mono- and di-polyoxyethylated trimethylene glycol; polyoxyethylated sorbitol; polyoxyethylated glucose; acrylic acid polymers and analogs and copolymers thereof, such as polyacrylic acid per se, polymethacrylic acid, poly(hydroxyethylmethacrylate), poly(hydroxyethylacrylate), poly(methylalky
- the term "activated" refers to a modification of an existing functional group to generate or introduce a new reactive functional group from an existing functional group, wherein the new reactive functional group is capable of undergoing reaction with another functional group to form a covalent bond.
- a component containing carboxylic acid (--COOH) groups can be activated by reaction with N-hydroxy-succinimide or N- hydroxysulfosuccinimide using known procedures, to form an activated carboxylate (which is a reactive electrophilic group), i.e., an N-hydroxysuccinimide ester or an N- hydroxysulfosuccinimide ester, respectively.
- carboxylic acid groups can be activated by reaction with an acyl halide such as acyl chloride to provide an activated electrophilic group in the form of an anhydride.
- particle surface refers to the total surface including the outer surface and surface created by porosity, texture of the surface, cracks, channels, or other structures available for contact with the components of physiological tissue fluids or tissue surface.
- the particle surface is increased by grafting branched hydrophilic polymers with side chains containing multiple reactive groups and glucose binding groups.
- biomaterial refers to compositions suitable for implantation, contact, ingestion, inhalation, or other introduction into the living body, or interface with the living body.
- the biomaterial can be prepared ex-vivo or formed in-vivo using synthetic or naturally occurring, hydrophilic or hydrophobic, biodegradable or nonbiodegradable polymers, prepolymers, monomers, or minerals.
- reactive moieties at the tissue site refers to nucleophilic groups such as primary and secondary amines, sulfhydryls, hydroxyls and other reactive chemical groups found in physiological fluids and on the tissue surface.
- the reactive moieties available to react with activated groups of the implant can be found on amino acids, peptides, proteins, lipids, proteoglycans, cell surface proteins, extra cellular matrix, cell breakdown components, blood proteins and cells, wound exudates, blood, plasma and lymph.
- implant herein refers to any composition or object placed surgically or otherwise in contact with a human or animal body.
- Such implants can have a diagnostic, therapeutic, or aesthetic function, or can be used as identification, or information storage or processing devices, and include without limitations all know medical implants and devices.
- Said implants can be attached on the outside surfaces of the body such as skin, oral mucosa, teeth, nails, eye, and ear-nose-throat passages, or can be placed inside of pulmonary system, or digestive system, or urinary system, or intestinal tract, or reproductive system, or vascular system, or surgically placed subcutaneously, intramuscularly, intraperitoneally, or in any other location in the body.
- the term “device” refers to any form of the compositions described herein that may be suitable for delivery to an organism or ecosystem.
- the term therefore encompasses embodiments wherein the compositions are formulated as a medical dosage form (e.g., pills, implants, pastes, solutions, etc.) as well as wherein the compositions are formulated in an environmental delivery device (e.g., sponges, particles, solutions, etc.).
- physiological fluid refers to any fluid normally found within an organism such as a human or other animal. Physiological fluids include blood and the various components of blood, cerebral spinal fluid, synovial fluid, saliva, gastrointestinal fluids, urine, semen, etc.
- the "chemical target,” or simply “target,” refers to a compound, composition, molecule, element, ion, biomolecule, or fragment thereof that may be found in or added to a living body or ecosystem. Chemical targets are not limited to naturally occurring substances. The compositions disclosed herein may contain the chemical target.
- Chemical targets include metabolites, nutrients, metabolic breakdown products, toxins, drugs, pharmaceuticals, biopharmaceuticals, drugs of abuse, complexing agents, hormones, detergents, fertilizers, herbicides, pesticides, any other physiological process altering moieties, environmental pollutants, oxidation products, microbial metabolism products, viruses, prions, plasmids, bacteria, cells, yeast cells, fungi, cellular fragments, proteins, lipids, triglycerides, enzymes, proteins, minerals, heavy metals, organophosphates, biological warfare agents, chemical warfare agents, petrochemicals, soluble blood components, vitamins, antibodies, cytokines, growth factors, thyroid hormones, amine-containing metabolic breakdown products, amino acids, ketenes, liver toxins, ingested or inhaled toxins and poisons, tissue necrosis factors, heat shock proteins, anaphylactic shock factors, pharmaceuticals, drugs, biopharmaceuticals, drug analogs and derivatives and their metabolic products, antibiotics, anti-proliferative agents, anti
- the chemical target may be glucose, lactose, lactic acid, EDTA,
- DDT paraquat, styrene, ethylene glycol, aldrin, calcium, magnesium, potassium, sodium, fluorine, cobalt, zinc, manganese, strontium, DNA, RNA, dopamine, serotonin, pyridinoline, deoxypyridinoline, pyridine, carbon tetrachloride, dimethyl nitrosamine, trichlorethylene, carbon monoxide, vitamin A, vitamin D, 17-hydroxyprogesterone, acetoacetate, amylase, ascorbic acid, bicarbonate, bilirubin, ceruloplasmin, chlorine, copper, creatine kinase, creatinine, hemoglobin, iron, lactic dehydrogenase, lead, lipase, zinc, cholesterol, oxygen, carbon dioxide, phosphatase, phosphorus, prostate-specific antigen, albumin, globulin, prothrombin, pyruvic acid, thyroid-stimulating hormone, alanine, aspartate, urea,
- the binding component is generally a composition comprised of binding moieties capable of reversible binding, complexation, or other reversible interaction with a chemical target.
- the binding constants and capacity of the binding component may, for example, be selected to bind the chemical target under physiological conditions of the living body or the natural conditions of an ecosystem. Binding or dissociation of the chemical target to or from the binding component regulates the concentration of the chemical target in the body or ecosystem; the concentration of the chemical target may be reduced, elevated, or simply held constant as a result of this interaction.
- Binding moieties that bind with the chemical targets described herein are generally well known, characterized, and documented in the literature. [00048] Binding moieties will typically bind the chemical target through a reversible interaction. Reversible interactions include covalent bonding, hydrogen bonding, ionic bonding, Van der Waals interactions, and other forms of non-covalent bonding interactions. [00049]
- the binding component may be comprised of a polymer or a combination of polymers. One or more binding moieties may be located along the backbone of the polymer, at the termini of the polymer, on sidechains of the polymer, or any combination thereof.
- Hydrophilic polymers useful for making the binding component include: polyalkylene oxides, particularly polyethylene glycol and poly(ethylene oxide)- poly(propylene oxide) copolymers, including block and random copolymers; polyols such as glycerol, polyglycerol (particularly highly branched polyglycerol), propylene glycol and trimethylene glycol substituted with one or more polyalkylene oxides, e.g., mono-, di- and tri- polyoxyethylated glycerol, mono- and di-polyoxyethylated propylene glycol, and mono- and di-polyoxyethylated trimethylene glycol; polyoxyethylated sorbitol, polyoxyethylated glucose; acrylic acid polymers and analogs and copolymers thereof, such as polyacrylic acid per se, polymethacrylic acid, poly(hydroxyethylmethacrylate), poly(hydroxyethylacrylate), poly(methylalkyls
- the hydrophilic polymers useful for preparing the binding component may be synthetic or naturally occurring hydrophilic polymers.
- Naturally occurring hydrophilic polymers include: proteins such as collagen, fibronectin, albumins, globulins, fibrinogen, and fibrin, with collagen particularly preferred; carboxylated polysaccharides such as polymannuronic acid and polygalacturonic acid; aminated polysaccharides, particularly the glycosaminoglycans, e.g., hyaluronic acid, chitin, chondroitin sulfate A, B, or C, keratin sulfate, keratosulfate and heparin; and activated polysaccharides such as dextran and starch derivatives.
- Hydrophobic polymers including low molecular weight polyfunctional species, can also be used in the binding component.
- hydrophobic polymers herein contain a relatively small proportion of heteroatoms such as O, S, P, N, or combinations thereof.
- Preferred hydrophobic polymers generally have carbon chains that are no longer than about 14 carbons between heteroatoms. Hydrophobic polymers are particularly useful for the binding component when slower biodegradation is desired.
- Polylactic acid and polyglycolic acid are examples of two hydrophobic polymers that can be used.
- the binding component may include a mixture of hydrophobic and hydrophilic polymers.
- the binding component may also contain thermoreversible polymers, which may be useful in forming an implant in-situ. Hydrophobic interactions are often able to induce physical entanglement, especially in polymers, that induces increases in viscosity, precipitation, or gelation of polymeric solutions.
- thermoreversible polymers for example, poly(oxyethylene)- poly(oxypropylene) block copolymers, available under the trade name of PLURONICTM (BASF Corporation, Mount Olive, NJ.), are well known to exhibit a thermoreversible behavior in solution.
- an aqueous solution of 30% PLURONICTM F-127 is a relatively low viscosity liquid at 4 0 C and forms a pasty gel at physiological temperatures due to hydrophobic interactions.
- the binding component may comprise pH responsive polymers.
- polymers that have a low viscosity at acidic or basic pH, and exhibit an increase in viscosity upon reaching neutral pH, for example, due to decreased solubility.
- the stability and reactivity of crosslinkable aqueous polymers can be controlled by appropriate selection of pH.
- degradable esters are stable at pH 3-5, while reactivity for electrophilic- nucleophilic reactions is highest at elevated pHs.
- polyanionic polymers such as poly(acrylic acid) or poly(methacrylic acid) possess a low viscosity at acidic pHs that increases as the polymers become more solvated at higher pHs.
- solubility and gelation of such polymers further may be controlled by interaction with other water soluble polymers that complex with the polyanionic polymers.
- poly(ethylene oxides) of molecular weight over 2,000 dissolve to form clear solutions in water.
- thickening, gelation, or precipitation occurs depending on the particular pH and conditions used.
- a two or more component aqueous solution system may be selected so that the first component comprises poly(acrylic acid) or poly(methacrylic acid) at an elevated pH of around 8-9 and another component comprises a solution of poly(ethylene glycol) at an acidic pH, such that the two solutions on being combined in situ result in an immediate increase in viscosity due to physical crosslinking.
- the binding component may also comprise naturally occurring
- Other natural polymers such as glycosaminoglycans, e.g., hyaluronic acid, contain both anionic and cationic functional groups along each polymeric chain, or covalently crosslinked hyaluronic acid. See, for example, X. Shu, Y. Liu, Y. Luo, M. Roberts, G. Prestwich, Biomacromolecules, 3: 1304-1311 (2002).
- the synthetic hydrophilic polymers useful in the binding component may be a homopolymer, a block copolymer, a random copolymer, or a graft copolymer.
- the polymer may be linear or branched, and if branched, may be minimally to highly branched, dendrimeric, hyperbranched, or a star polymer.
- the polymer may include biodegradable segments and blocks, either distributed throughout the polymer's molecular structure or present as a single block, as in a block copolymer. Biodegradable segments are those that degrade via the breakage of covalent bonds.
- biodegradable segments are segments that are hydrolyzed in the presence of water and/or enzymatically cleaved in situ.
- Biodegradable segments may be composed of small molecular segments such as ester linkages, anhydride linkages, ortho ester linkages, ortho carbonate linkages, amide linkages, phosphonate linkages, etc.
- Larger biodegradable "blocks" will generally be composed of oligomeric or polymeric segments incorporated within the hydrophilic polymer.
- Illustrative oligomeric and polymeric segments that are biodegradable include, by way of example, poly(amino acid) segments, poly(orthoester) segments, poly(orthocarbonate) segments, and the like.
- suitable synthetic hydrophilic polymers include chemically synthesized polypeptides, particularly polynucleophilic polypeptides that have been synthesized to incorporate amino acids containing primary amino groups (such as lysine) and/or amino acids containing thiol groups (such as cysteine).
- Poly(lysine) a synthetically produced polymer of the amino acid lysine (145 MW), is one example.
- Poly(lysine)s have been prepared having between about 6 and about 4,000 primary amino groups, corresponding to molecular weights of about 870 to about 580,000.
- Poly(lysine)s for use in the compositions disclosed herein may have a molecular weight within the range of about 1,000 to about 300,000, for example within the range of about 5,000 to about 100,000, and as a further example, within the range of about 8,000 to about 15,000.
- Poly(lysine)s of varying molecular weights are commercially available from Peninsula Laboratories, Inc. (Belmont, Calif.).
- Other examples of synthetic hydrophilic polymers useful in the binding component are hydroxyethylmethacrylate (HEMA), polyethylene glycol (PEG) and polyglycerol (PG). With respect to PEG, various functionalized polyethylene glycols have been used effectively in fields such as protein modification, peptide chemistry, and the synthesis of polymeric drugs.
- HEMA hydroxyethylmethacrylate
- PEG polyethylene glycol
- PG polyglycerol
- Activated forms of PEG are commercially available, and are also easily prepared using known methods. For example, see Chapter 22 of Poly(ethylene Glycol) Chemistry: Biotechnical and Biomedical Applications, J. Milton Harris, ed., Plenum Press, NY (1992); and Shearwater Polymers, Inc. Catalog, Polyethylene Glycol Derivatives, Huntsville, Ala. (1997-1998).
- the binding component may also comprise thermogelling polymers.
- Examples of such polymers, and corresponding gelation temperatures ( 0 C), include homopolymers such as poly(N-methyl-N-n-propylacrylamide), 19.8; poly(N-n- ⁇ ropylacrylamide), 21.5; poly(N- methyl-N-isopropylacrylamide), 22.3; poly(N-n-propylmethacrylamide), 28.0; poly(N- isopropylacrylamide), 30.9; poly(N, n-diethylacrylamide), 32.0; poly(N- isopropylmethacrylamide), 44.0; poly(N-cyclopropylacrylamide), 45.5; poly(N- ethylmethyacrylamide), 50.0; poly(N-methyl-N-ethylacrylamide), 56.0; poly(N- cyclopropylmethacrylamide), 59.0; and poly(N-ethylacrylamide), 72.0.
- homopolymers such as poly(N-methyl-N-n-propylacrylamide
- thermogelling copolymers may also be used to prepare thermogelling copolymers.
- thermogelling polymers with other water-soluble polymers such as acrylmonomers (e.g., acrylic acid and derivatives thereof, such as methylacrylic acid, acrylate monomers and derivatives thereof, such as butyl methacrylate, butyl acrylate, lauryl acrylate, and acrylamide monomers and derivatives thereof, such as N-butyl acrylamide and acrylamide).
- acrylmonomers e.g., acrylic acid and derivatives thereof, such as methylacrylic acid, acrylate monomers and derivatives thereof, such as butyl methacrylate, butyl acrylate, lauryl acrylate, and acrylamide monomers and derivatives thereof, such as N-butyl acrylamide and acrylamide.
- thermogelling polymers include cellulose ether derivatives such as hydroxypropyl cellulose, 41 0 C; methyl cellulose, 55 0 C; hydroxypropylmethyl cellulose, 66 0 C; and ethylhydroxyethyl cellulose, polyalkylene oxide-polyester block copolymers of the structure X--Y, Y--X--Y and X--Y--X where X is a polyalkylene oxide and Y is a biodegradable polyester (e.g., PLG-PEG-PLG) and PLURONIC(S)TM such as F- 127, 10-15 0 C; L-122, 19 0 C; L-92, 26 0 C; L-81, 20 0 C; and L-61, 24 0 C.
- PLG-PEG-PLG biodegradable polyester
- PLURONIC(S)TM such as F- 127, 10-15 0 C; L-122, 19 0 C; L-92, 26 0
- synthetic hydrophilic polymers that are useful for the making of binding compositions, particles and implants herein include, but are not limited to: polyalkylene oxides, particularly polyethylene glycol and poly(ethylene oxide)- poly(propylene oxide) copolymers, including block and random copolymers; polyols such as glycerol; polyglycerol (particularly highly branched poly glycerol); propylene glycol and trimethylene glycol substituted with one or more polyalkylene oxides, e.g., mono-, di- and tri- polyoxyethylated glycerol, mono- and di-polyoxyethylated propylene glycol, and mono- and di-polyoxyethylated trimethylene glycol; polyoxyethylated sorbitol; polyoxyethylated glucose; acrylic acid polymers and analogs and copolymers thereof, such as polyacrylic acid per se, polymethacrylic acid, poly(hydroxyethyl)
- the binding component may include bioresorbable and/or biodegradable components.
- the compositions disclosed herein may include biodegradable segments and blocks, either distributed throughout the polymer's molecular structure or present as a single block, as in a block copolymer.
- Biodegradable segments are those that degrade so as to break covalent bonds.
- biodegradable segments are segments that are hydrolyzed in the presence of water and/or enzymatically cleaved in situ.
- Biodegradable segments may be composed of small molecular segments such as ester linkages, anhydride linkages, ortho ester linkages, ortho carbonate linkages, amide linkages, phosphonate linkages, etc.
- oligomeric and polymeric segments that are biodegradable include, by way of example, poly(amino acid) segments, poly(orthoester) segments, poly(orthocarbonate) segments, and the like.
- biodegradable polymers suitable for preparing the binding component include albumin, collagen, gelatin, hyaluronic acid, starch, cellulose and cellulose derivatives (e.g., methylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, carboxymethylcellulose, cellulose acetate phthalate, cellulose acetate succinate, hydroxypropylmethylcellulose phthalate), casein, dextrans, polysaccharides, fibrinogen, poly(ether ester) multiblock copolymers, based on poly(ethylene glycol) and poly(butylene terephthalate), tyrosine-derived polycarbonates (e.g., U.S. Pat. No.
- polyesters poly(hydroxyl acids), poly(D,L-lactide), poly(D,L-lactide-co-glycolide), poly(glycolide), poly(hydroxybutyrate), polydioxanone, poly(alkylcarbonate) and poly(orthoesters), polyesters, poly(hydroxyvaleric acid), polydioxanone, degradable polyesters, poly(malic acid), poly(tartronic acid), poly(acrylamides), polyanhydrides, polyphosphazenes, poly(amino acids), poly(alkylene oxide)-poly(ester) block copolymers (e.g., X-Y, X--Y--X or Y--X-Y, R-(Y-X) n , R-(X-Y) n where X is a polyalkylene oxide and Y is a polyester (e.g., polyester can comprise the residues of one or more of the monomers selected from lactide, lactic
- Non-resorbable binding compositions are also within the scope of the invention, and are typically comprised of polymers that are substantially insoluble in physiologic liquids.
- Suitable biocompatible polymers include, by way of example, cellulose acetates (including cellulose diacetate), ethylene vinyl alcohol copolymers, hydrogels (e.g., acrylics), poly(C] -C 6 ) acrylates, acrylate copolymers, polyalkyl alkacrylates wherein the alkyl groups independently contain one to six carbon atoms, polyacrylonitrile, polyvinylacetate, cellulose acetate butyrate, nitrocellulose, copolymers of urethane/carbonate, copolymers of styrene/maleic acid, and mixtures thereof.
- Copolymers of urethane/carbonate include polycarbonates that are diol terminated which are then reacted with a diisocyanate such as methylene bisphenyl diisocyanate to provide for the urethane/carbonate copolymers.
- a diisocyanate such as methylene bisphenyl diisocyanate
- non-degradable polymers suitable for the binding component include poly(ethylene-co-vinyl acetate) ("EVA") copolymers, non-degradable polyesters, such as poly(ethylene terephthalate), silicone rubber, acrylic polymers (polyacrylate, polyacrylic acid, polymethylacrylic acid, polymethylmethacrylate, poly(butyl methacrylate)), poly(alkylcynoacrylate) (e.g., poly(ethylcyanoacrylate), poly(butylcyanoacrylate), poly(hexylcyanoacrylate), and poly(octylcyanoacrylate)), acrylic resin, polyethylene, polypropylene, polyamides (e.g., nylon 6 and nylon 6,6), polyurethanes (e.g., Chronoflex AR, Chronoflex AL, Bionate, and Pellethane), poly(ester urethanes), poly(ether urethanes), poly(ester-urea), cellulose
- EVA ethylene
- Anionic polymers such as alginate, carrageenan, carboxymethyl cellulose, poly(acrylamido-2-methyl propane sulfonic acid), poly(methacrylic acid) and poly(acrylic acid), and cationic polymers such as chitosan, poly-L-lysine, polyethylenimine, and poly(allyl amine), as well as blends and copolymers thereof, are also suitable for use in the binding component.
- the binding component may comprise polymeric carriers which are temperature sensitive. See, for example, Hoffman, "Thermally Reversible Hydrogels Containing Biologically Active Species,” in Migliaresi et al. (eds.), Polymers in Medicine III, Elsevier Science Publishers B. V., Amsterdam, 1988, pp. 161-167, and Hoffman, "Applications of Thermally Reversible Polymers and Hydrogels in Therapeutics and Diagnostics,” in Third International Symposium on Recent Advances in Drug Delivery Systems, Salt Lake City, Utah, Feb. 24-27,1987, pp. 297-305.
- the binding component may comprise, for example, a plurality of polymers that form a hydrogel upon mixing.
- Copolymers, blends, mixtures, and composites of any of the aforementioned polymers and their constitutional monomer units are also suitable for the binding components of the compositions disclosed herein.
- the binding component may comprise a variety of materials including organic salts, inorganic salts, ceramics, hydroxyapatite, tricalciumphosphate, solgels, organosilanes, sea coral, demineralized bone, glass, metal oxides (i.e. TiO 2 ), metals, lipids, polysaccharides, gold, silver, titanium, talc, Teflon, e-PTFE, Dacron, carbon, hydrogels, elastomers, plastics, metal alloys, cellulose, oxidized cellulose, polymers of drugs, silicone, antibodies or their analogs, or combinations and derivatives of thereof.
- materials including organic salts, inorganic salts, ceramics, hydroxyapatite, tricalciumphosphate, solgels, organosilanes, sea coral, demineralized bone, glass, metal oxides (i.e. TiO 2 ), metals, lipids, polysaccharides, gold, silver, titanium, talc, Teflon, e-
- the binding component can be prepared with a non-polymeric agent.
- non-polymeric carriers can include sucrose derivatives (e.g., sucrose acetate isobutyrate, sucrose oleate), sterols such as cholesterol, stigmasterol, ⁇ -sitosterol, and estradiol; cholesteryl esters such as cholesteryl stearate; Ci 2 -C 24 fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, and lignoceric acid; C 18 -C36 mono-, di- and triacylglycerides such as glyceryl monooleate, glyceryl monolinoleate, glyceryl monolaurate, glyceryl monodocosanoate, glyceryl monomyristate, glyceryl monodicenoate, glyceryl dipalmitate,
- sucrose derivatives e.
- non-polymeric additives may be part of the binding component per se, or they may be a part of the binding composition in general (e.g., as transport agents, delivery vehicles, etc.).
- Representative examples of patents relating to non-polymeric delivery systems and their preparation include U.S. Pat. Nos. 5,736,152; 5,888,533; 6,120,789; 5,968,542; and 5,747,058.
- binding components for use in the compositions disclosed herein will be selected based on a number of factors, including the identity and nature of the chemical target. Binding moieties for the chemical targets described herein are well-known in the art. For example, for chemical targets such as calcium or magnesium ions (e.g., Ca +2 or Mg +2 ), the binding component may contain binding moieties such as carboxylate ions and the like. [00074]
- the binding component for a composition according to the disclosure may have a single type of binding moiety or a plurality of binding moieties. Each binding moiety is capable of binding one or more chemical targets. These binding associations are equilibrium reactions. The binding moiety will uptake the target when the concentration of the target in the physiological fluid or ecosystem exceeds an equilibrium concentration.
- the binding moiety will release the target when the concentration of the target in the physiological fluid or ecosystem falls below the equilibrium concentration.
- the equilibrium concentration is determined by the binding constant (discussed hereinbelow), which is an equilibrium constant that measures the strength with which a binding moiety binds to a particular chemical target.
- the binding component may be prepared by standard organic synthetic techniques.
- the binding component may also be prepared by, for example, molecular imprinting, template polymerization, genetic engineering, or may be selected from synthetic combinatorial libraries.
- Other components may be prepared by, for example, molecular imprinting, template polymerization, genetic engineering, or may be selected from synthetic combinatorial libraries.
- compositions disclosed herein may also contain various additives such as pharmaceutically acceptable carriers, transport agents, excipients, solubilizing agents, colorants, and visualization aids.
- Pharmaceutically acceptable carriers are materials such as binders, lubricants, disintegrants, fillers, stabilizers, surfactants, coloring agents, and the like. Binders are used to impart cohesive qualities, and thus ensure that the composition remains intact (e.g., as an implant).
- Suitable binder materials include, but are not limited to, polymer matrices, hydrogels, starch (including corn starch and pregelatinized starch), gelatin, sugars (including sucrose, glucose, dextrose, and lactose), polyethylene glycol, waxes, and natural and synthetic gums, e.g., acacia sodium alginate, polyvinylpyrrolidone, cellulosic polymers (including hydroxypropyl cellulose, hydroxypropyl methylcellulose, methyl cellulose, microcrystalline cellulose, ethyl cellulose, hydroxyethyl cellulose, and the like), and Veegum.
- Lubricants are used to facilitate manufacture, promoting powder flow and preventing particle capping (i.e., particle breakage) when pressure is relieved.
- Useful lubricants are magnesium stearate, calcium stearate, and stearic acid.
- Disintegrants are used to facilitate disintegration of the composition, and are generally starches, clays, celluloses, algins, gums, or crosslinked polymers. Fillers include, for example, materials such as silicon dioxide, titanium dioxide, alumina, talc, kaolin, powdered cellulose, and microcrystalline cellulose, as well as soluble materials such as mannitol, urea, sucrose, lactose, dextrose, sodium chloride, and sorbitol.
- Stabilizers are used to inhibit or retard decomposition reactions that include, by way of example, oxidative reactions.
- the components of a composition may be distributed homogeneously throughout the pharmaceutically acceptable carrier, or localized regions of concentrations gradients may exist.
- components of a composition such as the binding moieties, may be covalently or otherwise attached to the pharmaceutically acceptable carrier.
- compositions disclosed herein may contain a contrast agent such as a biocompatible (non-toxic) radiopaque material.
- a contrast agent such as a biocompatible (non-toxic) radiopaque material.
- a material may be capable, for example, of being monitored by radiography during injection into a mammalian subject.
- the contrast agent can be either water soluble or water insoluble. Examples of water soluble contrast agents include metrizamide, iopamidol, iothalamate sodium, iodomide sodium, and meglumine.
- Water insoluble contrast agents may have a water solubility of less than 0.01 milligrams per milliliter at 20 0 C, and include tantalum, tantalum oxide and barium sulfate, each of which is commercially available in a form suitable for in vivo use and preferably having a particle size of 10 micrometers or less.
- Other water insoluble contrast agents include gold, tungsten and platinum powders.
- compositions described herein comprise pharmaceutical agents, growth factors, proteins, and other physiological fluid components. These components may be released into the physiological fluid due to resorption of the composition. Such compositions may exhibit beneficial tissue healing and tissue regeneration effects.
- the composition can also comprise radio-opaque, echogenic materials and magnetic resonance imaging (MRI) responsive materials (i.e., MRI contrast agents) to aid in visualization of the composition under ultrasound, fluoroscopy and/or MRI.
- MRI magnetic resonance imaging
- the composition may be made in the form of a device containing or coated with a composition which is echogenic or radiopaque (e.g., made with echogenic or radiopaque with materials such as powdered tantalum, tungsten, barium carbonate, bismuth oxide, barium sulfate, metrazimide, iopamidol, iohexol, iopromide, iobitridol, iomeprol, iopentol, ioversol, ioxilan, iodixanol, iotrolan, acetrizoic acid derivatives, diatrizoic acid derivatives, iothalamic acid derivatives, ioxithalamic acid derivatives, metrizoic acid derivatives, iodamide, lypophylic agents, iodipamide and ioglycamic acid or, by the addition of microspheres or bubbles which present an acoustic interface).
- Echogenic coatings are described in, e.g., US Patents Nos. 6,106,473 and 6,610,016.
- contrast agents e.g., gadolinium (III) chelates or iron oxide compounds
- a medical device may include radio-opaque or MRI visible markers (e.g., bands) that may be used to orient and guide the device during the implantation procedure.
- compositions described herein may, alternatively or in addition, be visualized under visible light, using fluorescence, or by other spectroscopic means.
- Visualization agents that can be included for this purpose include dyes, pigments, and other colored agents.
- the composition may further include a colorant to improve visualization in an ecosystem, in vivo, and/or ex vivo. Frequently, for example, implants can be difficult to visualize upon insertion, especially at the margins of the implant.
- a coloring agent can be incorporated into an implant comprising a composition of the invention to reduce or eliminate the incidence or severity of this problem. The coloring agent provides a unique color, increased contrast, or unique fluorescence characteristics to the device.
- a solid implant in one aspect, includes a colorant such that it is readily visible (under visible light or using a fluorescence technique) and easily differentiated from its implant site.
- a colorant can be included in a liquid or semi-solid composition.
- a single component of a two component mixture may be colored, such that when combined ex-vivo or in-vivo, the mixture is sufficiently colored.
- the coloring agent may be, for example, an endogenous compound (e.g., an amino acid or vitamin) or a nutrient or food material and may be a hydrophobic or a hydrophilic compound.
- the colorant has a very low or no toxicity at the concentration used.
- colorants that are safe and normally enter the body through absorption such as ⁇ -carotene.
- Representative examples of colored nutrients include fat soluble vitamins such as Vitamin A (yellow); water soluble vitamins such as Vitamin B 12 (pink-red) and folic acid (yellow-orange); carotenoids such as ⁇ - carotene (yellow-purple) and lycopene (red).
- coloring agents include natural product (berry and fruit) extracts such as anthrocyanin (purple) and saffron extract (dark red).
- the coloring agent may be a fluorescent or phosphorescent compound such as ⁇ - tocopherolquinol (a Vitamin E derivative) or L-tryptophan. Derivatives, analogs, and isomers of any of the above colored compound may also be used.
- the method for incorporating a colorant into an implant or therapeutic composition may be varied depending on the properties of and the desired location for the colorant. For example, a hydrophobic colorant may be selected for hydrophobic matrices.
- the colorant may be incorporated into a carrier matrix, such as micelles. Further, the pH of the environment may be controlled to further control the color and intensity.
- the composition of the present invention include one or more coloring agents, also referred to as dyestuffs, which will be present in an effective amount to impart observable coloration to the composition, e.g., the gel.
- coloring agents include dyes suitable for food such as those known as F.D. & C. dyes and natural coloring agents such as grape skin extract, beet red powder, beta carotene, annato, carmine, turmeric, paprika, and so forth. Derivatives, analogs, and isomers of any of the above colored compound may also be used.
- the method for incorporating a colorant into an implant or therapeutic composition may be varied depending on the properties of and the desired location for the colorant. For example, a hydrophobic colorant may be selected for hydrophobic matrices.
- the colorant may be incorporated into a carrier matrix, such as micelles. Further, the pH of the environment may be controlled to further control the color and intensity.
- the binding compositions disclosed herein comprises magnetic components such as magnetite, stabilized magnetic ferro-colloids, or magnetic fluids.
- magnetic field-responsive materials can aid in concentration and removal of the compositions disclosed herein from the organism or ecosystem.
- gold particles and colloids can be used as a part of the compositions disclosed herein.
- commercially available gold particles ranging in size between 1 nm and 1000 nm can be coated with the binding component.
- Gold particles provide high total surface area for quick binding or release of the chemical target.
- an implant may be prepared using a gold particle suspension with a glucose-binding component, and the composition can be placed in an immunoisolation-like device used to cultivate transplanted islet cells in vivo. The immunoisolation device protects the gold particles and glucose binding surfaces from direct contact with cells, particularly macrophages, thus increasing the functional longevity of the implant.
- compositions of the present invention include one or more preservatives or bacteriostatic agents, present in an effective amount to preserve the composition and/or inhibit bacterial growth in the composition, for example, bismuth tribromophenate, methyl hydroxybenzoate, bacitracin, ethyl hydroxybenzoate, propyl hydroxybenzoate, erythromycin, 5-fluorouracil, methotrexate, doxorubicin, mitoxantrone, rifamycin, chlorocresol, benzalkonium chlorides, and the like.
- preservatives or bacteriostatic agents present in an effective amount to preserve the composition and/or inhibit bacterial growth in the composition, for example, bismuth tribromophenate, methyl hydroxybenzoate, bacitracin, ethyl hydroxybenzoate, propyl hydroxybenzoate, erythromycin, 5-fluorouracil, methotrexate, doxorubicin, mitoxantrone,
- compositions of the present invention include one or more bactericidal (also known as bacteriacidal) agents.
- bactericidal agents also known as bacteriacidal agents.
- the compositions of the present invention include one or more antioxidants, present in an effective amount. Examples of the antioxidant include sulfites, alpha-tocopherol and ascorbic acid.
- compositions disclosed herein or the precursors thereof may further contain porosifying agents that achieve greater surface area of, for example, an implanted metabolite-binding composition and faster diffusion and chemical target equilibrium between the metabolite-binding composition and the living body or ecosystem.
- porosifying agents include inorganic salts, sucrose, surfactants, small molecular weight polymers, fast degrading polymers, thermoreversible polymer precipitates, gas bubbles, and cavitation bubbles.
- compositions may also comprise additional ingredients such as surfactants (e.g., PLURONICSTM, such as F-127, L- 122, L-IOl, L-92, L-81, and L-61), anti-inflammatory agents (e.g., dexamethasone or aspirin), anti-thrombotic agents (e.g., heparin, high activity heparin, heparin, and quaternary amine complexes such as heparin benzalkonium chloride complex), anti-infective agents (e.g., 5-fluorouracil, triclosan, rifamycim, and silver compounds), preservatives, anti-oxidants and/or anti-platelet agents.
- surfactants e.g., PLURONICSTM, such as F-127, L- 122, L-IOl, L-92, L-81, and L-61
- anti-inflammatory agents e.g., dexamethasone or aspirin
- compositions disclosed herein include: hydroxypropyl cyclodextrin, liposomes, liposome/gel, nanocapsules, micelles, implants, nanoparticles, nanoparticles having modified surface, micelle (surfactant), synthetic phospholipid compounds, gas borne dispersion, liquid emulsions, foam, spray, gel, lotion, cream, ointment, dispersed vesicles, particles or droplets solid- or liquid-aerosols, microemulsions, polymeric shell (nano- and micro- capsule), emulsion, nanospheres and implants.
- surfactant surfactant
- synthetic phospholipid compounds gas borne dispersion
- liquid emulsions foam, spray, gel, lotion, cream, ointment, dispersed vesicles, particles or droplets solid- or liquid-aerosols
- microemulsions polymeric shell (nano- and micro- capsule), emulsion, nanospheres and implants.
- any suitable solvent may be used to prepare and/or deliver the compositions described herein to an organism or ecosystem; such solvents are well known in the art, and the choice of solvent will be apparent to those skilled in the art.
- Suitable biocompatible solvents that can be used to deliver non- water soluble binding compositions into the body or ecosystem include, by way of example, dimethylsulfoxide, analogs/homologues of dimethylsulfoxide, ethanol, ethyl lactate, acetone, and the like.
- Aqueous mixtures with the biocompatible solvent can also be employed provided that the amount of water employed is sufficiently small that the dissolved metabolite-binding composition precipitates upon injection into a human body.
- the biocompatible solvent is ethyl lactate or dimethylsulfoxide .
- the binding composition comprises a drug or other entity used to alter a biological process locally or systemically.
- drug or entity may be covalently attached to the binding component, entrapped within the binding component by polymer or retained with the binding component by charge, hydrophobic or other molecular interactions.
- drug or entity can have anti-infective, anti-inflammatory, anti-proliferative, anti-scarring, anti-adhesive, antineoplastic, immuno-modulating, analgesic, scar-forming, tissue-regenerative and tissue-repair promoting effects.
- compositions described herein may be incorporated into any appropriate dosage form for delivery to an organism or to an ecosystem, such dosage forms being well known in the art.
- dosage forms that have no defined structure, such as a solution
- the compositions may be formed into a variety of different structures or devices.
- a range of polymeric and non-polymeric materials can be used to incorporate the binding composition onto or into a dosage form or device.
- the binding composition can be incorporated into or onto the device in a variety of ways.
- the binding composition may be coated onto the entire device or a portion of the device using a method, such as by dipping, spraying, painting or vacuum deposition that is appropriate for the particular type of device.
- the device can be a device that has not been modified as well as a device that has been further modified by coating with a polymer (e.g., parylene), surface treated by plasma treatment, flame treatment, corona treatment, surface oxidation or reduction, surface etching, mechanical smoothing or roughening, or grafting prior to the coating process.
- a polymer e.g., parylene
- compositions intended to be used in vivo may include a fibrosis-inhibiting agent and an anti-thrombotic agent and/or antiplatelet agent and/or a thrombolytic agent, which reduces the likelihood of thrombotic events upon implantation of a medical implant.
- a device is coated on one aspect with a composition which inhibits fibrosis (and/or restenosis), as well as being coated with a composition or compound which prevents thrombosis on another aspect of the device.
- anti-thrombotic and/or antiplatelet and/or thrombolytic agents include heparin, heparin fragments, organic salts of heparin, heparin complexes (e.g., benzalkonium heparinate, tridodecylammonium heparinate), dextran, sulfonated carbohydrates such as dextran sulphate, Coumadin, coumarin, heparinoid, danaparoid, argatroban chitosan sulfate, chondroitin sulfate, danaparoid, lepirudin, hirudin, AMP, adenosine, 2-chloroadenosine, acetylsalicylic acid, phenylbutazone, indomethacin, meclofenamate, hydrochloroquine, dipyridamole, iloprost, streptokinase, factor Xa inhibitors, such as DXa inhibitor
- Further examples include plasminogen, lys-plasminogen, alpha-2-antiplasmin, urokinase, aminocaproic acid, ticlopidine, clopidogrel, trapidil (triazolopyrimidine), naftidrofuryl, auriritricarboxylic acid and glycoprotein Ilb/IIIa inhibitors such as abcixamab, eptifibatide, and tirogiban.
- agents capable of affecting the rate of clotting include glycosaminoglycans, danaparoid, 4- hydroxycourmarin, warfarin sodium, dicumarol, phenprocoumon, indan-l,3-dione, acenocoumarol, anisindione, and rodenticides including bromadiolone, brodifacoum, diphenadione, chlorophacinone, and pidnone.
- the thrombogenicity of a binding composition may be reduced by coating the implant with a polymeric formulation that has anti-thrombogenic properties.
- a medical device may be coated with a metabolite-binding hydrophilic polymer gel.
- the polymer gel can comprise a hydrophilic, biodegradable polymer that is physically removed from the surface of the device over time, thus reducing adhesion of platelets to the device surface.
- the gel composition can include a polymer or a blend of polymers.
- Representative examples include alginates, chitosan and chitosan sulfate, hyaluronic acid, dextran sulfate, PLURONICTM polymers (e.g., F-127 or F87), chain extended PLURONICTM polymers, various polyester-polyether block copolymers of various configurations (e.g., AB, ABA, or BAB, where A is a polyester such as PLA, PGA, PLGA, PCL or the like), examples of which include MePEG-PLA, PLA-PEG-PLA, and the like).
- PLURONICTM polymers e.g., F-127 or F87
- chain extended PLURONICTM polymers e.g., various polyester-polyether block copolymers of various configurations (e.g., AB, ABA, or BAB, where A is a polyester such as PLA, PGA, PLGA, PCL or the like), examples of which include MePEG-PLA, PLA-P
- the anti-thrombotic composition can include a crosslinked gel formed from a combination of molecules (e.g., PEG) having two or more terminal electrophilic groups and two or more nucleophilic groups.
- PEG molecules having two or more terminal electrophilic groups and two or more nucleophilic groups.
- Other examples of implantable biomaterials that can be used to prepare binding compositions in this invention include sprayable collagen-containing formulations such as VitaGel (from Orthovita, Inc.
- sprayable PEG-containing formulations such as CoSeal (Baxter Healthcare Corporation, Deerfield, IL), SprayGel or DuraSeal (both from Confluent Surgical, Inc., Boston, Mass.), FocalSeal (Genzyme Corporation, Cambridge, Mass.), fibrin-containing formulations such as FloSeal or Tisseel (both from Baxter Healthcare Corporation, Deerfield, IL), hyaluronic acid-containing formulations such as Restylane or Perlane (both from Q-Med AB, Sweden), Hylaform (Inamed Corporation (Santa Barbara, Calif.)), Synvisc (Biomatrix, Inc., Ridgefield, N.J.), Seprafilm or Sepracoat (both from Genzyme Corporation, Cambridge, Mass.), Intergel (Lifecore Biomedical), polymeric gels for surgical implantation such as Repel (Life Medical Sciences, Inc., Princeton, NJ.) or Flogel (Baxter Healthcare Corporation), orthopedic "cements" used to hold prosthese
- compositions described herein may incorporate an angiogenic layer to promote vascularization.
- an implant/tissue interface must be created which provides quick diffusion equilibrium between the chemical target in the peripheral blood and the binding composition.
- the achievement of rapid equilibrium for the binding composition in the living body or in the ecosystem is particularly important for vital chemical targets such as glucose or certain drugs and toxic chemical targets such as toxins.
- the proximity of blood capillaries to the surface of the metabolite-binding composition is essential for achieving rapid equilibrium between the binding composition and the blood circulation. The development of such blood/implant interfaces in other contexts has been reported.
- a binding composition can comprise or be coated with a material causing microvascular ingrowth in vivo.
- a material causing microvascular ingrowth in vivo is e-PTFE material or porous polyvinylpyrrolidone.
- the outermost layer of a binding composition such as an implant includes an angiogenic material.
- the angiogenic layer of the compositions of the present invention may be constructed of membrane materials such as hydrophilic polyvinylidene fluoride (e.g., Durapore.RTM.; Millipore Bedford, Mass.), mixed cellulose esters (e.g., MF; Millipore Bedford, Mass.), polyvinyl chloride (e.g., PVC; Millipore Bedford, Mass.), and other polymers including, but not limited to, polypropylene, polysulfone, and polymethylmethacrylate.
- the thickness of the angiogenic layer is about 10 micrometers to about 50 micrometers.
- the angiogenic layer comprises pores sizes of about 0.5 micrometers to about 20 micrometers, for example about 1.0 micrometers to about 10 micrometers, sizes that allow most substances to pass through, including, e.g., macrophages.
- One specific example material is expanded PTFE of a thickness of about 15 micrometers and pore sizes of about 5 micrometers to about 10 micrometers.
- an additional outermost layer of material comprised of a thin low-density non-woven polyester (e.g., manufactured by Reemay, Inc.) can be laminated over the angiogenic layer (e.g., PTFE) described above.
- the thickness of this layer is about 120 micrometers.
- This additional thin layer of material does not interfere with angiogenesis and enhances the manufacturability of the angiogenic layer. Examples of such angiogenic and protective layer materials are described in US Patents Nos. 5,741,330, 5,782,912, 5,800,529, 5,882,354 5,964,804 and Published US Patent Application No. 2005/0177036, and hereby are incorporated by reference.
- compositions described herein may contain a bioprotective material such as a bioprotective membrane.
- a bioprotective material such as a bioprotective membrane.
- Example bioprotective materials include polyurethane, polytetrafluoroethylene, polypropylene, polyethylene, and polysulfone.
- the inflammatory response that initiates and sustains a foreign body response is associated with both advantages and disadvantages. Some inflammatory response may be beneficial to create a new capillary bed in close proximity to the surface of the binding composition. On the other hand, inflammation is associated with invasion of tissue macrophages that have the ability to biodegrade many artificial biomaterials (some of which were, until recently, considered nonbiodegradable).
- hypochlorite When activated by a foreign body, tissue macrophages degranulate, releasing from their cytoplasmic myeloperoxidase system hypochlorite (bleach), H 2 O 2 and other oxidant species. Both hypochlorite and H 2 O 2 are known to break down a variety of polymers, including polyurethane, by a phenomenon referred to as environmental stress cracking.
- the present invention contemplates the use of a bioprotective membrane that allows transport of a chemical target but prevents the entry of inflammatory cells such as macrophages and foreign body giant cells.
- the bioprotective membrane is placed proximal to the angiogenic membrane, when one is present. It may be simply placed adjacent to the angiogenic layer without adhering, or it may be attached with an adhesive material to the angiogenic layer, or it may be cast in place upon the angiogenic layer.
- the devices of the present invention are not limited by the nature of the bioprotective layer.
- the bioprotective membrane and the angiogenic layer when both are present, may be combined into a single bilayer membrane as described by way of example in published US Patent Application No. 2005/0124873 and incorporated herein by reference.
- the active angiogenic function of the combined membrane is based on the presentation of the e-PTFE side of the membrane to the reactive cells of the foreign body capsule and further to the response of the tissue to the microstructure of the e-PTFE.
- the physical structure of the e-PTFE represents one embodiment, many other combinations of materials that provide the same function.
- the e-PTFE could be replaced by other fine fibrous materials.
- polymers such as spun polyolefin or non-organic materials such as mineral or glass fibers may be useful.
- compositions described herein may further be contained within a container.
- a container may have, for example a semi-permeable or permeable boundary layer that prevents the composition from losing cohesiveness, but does not prevent transport of the chemical target (or other components of the environment or composition) into or out of the composition. Therefore, the pore sizes in the boundary layer will be selected to ensure such transport.
- Semi-permeable and permeable membranes with varying pore sizes are well known in the art.
- the boundary layer may be impermeable. In such a case, the container will preferentially be configured such that the boundary layer is breached and the binding composition is released (either wholly or in portions) from the container once the container is placed in the ecosystem or in contact with the physiological fluid.
- Activated PEG implants and particles may be prepared in various ways.
- a commercially available PEG polymer having a pentaerythritol (2,2- bis(hydroxymethyl)-l,3-propanediol) core and molecular weight of approximately 10,000 Da can be crosslinked into a three-dimensional polymer by reaction with glutaryl dichloride in the presence of pyridine as a base.
- the crosslinked PEG can be formed into an implant of a desired shape or into particles of different sizes by mechanical grinding after the crosslinking step or by conducting the crosslinking process in a micellar system where a prepolymer is crosslinked in micelles of the desired size.
- the crosslinking process conditions can be optimized such that the formed particles contain carboxyl groups in the form of glutaryl groups.
- additional carboxyl groups can be readily prepared by conversion of the exposed, unreacted hydroxyl groups to carboxylic acid groups using a reaction with an anhydride in the presence of a nitrogenous base.
- the carboxyl groups on the particles can be activated by esterification with N-hydroxysuccinimide, N- hydroxysulfosuccinimide, or the like, to prepare polyfunctionally activated PEG implants or particles.
- Yet other forms of activated particles are functionally activated PEG glycidyl ether particles, PEG-isocyanate particles, and PEG-vinylsulfone particles.
- binding compositions described herein may be prepared in the form of an implant.
- Binding compositions of the present invention may also be prepared in a variety of "paste" or gel forms.
- therapeutic compositions are provided which are liquid at one temperature (e.g., temperature greater than 37 0 C, such as 40 0 C, 45 0 C, 50 0 C, 55 0 C or 60 0 C), and solid or semi-solid at another temperature (e.g., ambient body temperature, or any temperature lower than 37 0 C).
- temperature e.g., temperature greater than 37 0 C, such as 40 0 C, 45 0 C, 50 0 C, 55 0 C or 60 0 C
- solid or semi-solid e.g., ambient body temperature, or any temperature lower than 37 0 C.
- Such "thermopastes” may be readily made utilizing a variety of techniques (see, e.g., PCT Publication WO 98/24427).
- Other pastes may be applied as a liquid, which solidify in vivo due to dissolution of a water-soluble component of the paste
- the binding compositions of the present invention may be formed as a film or tube.
- These films or tubes can be porous or non- porous.
- films or tubes are generally less than 5, 4, 3, 2, or 1 mm thick, more preferably less than 0.75 mm, 0.5 mm, 0.25 mm, or, 0.10 mm thick.
- Films or tubes can also be generated of thicknesses less than 50 micrometers, 25 micrometers or 10 micrometers.
- Such films are preferably flexible with a good tensile strength (e.g., greater than 50, preferably greater than 100, and more preferably greater than 150 or 200 N/cm 2 ), good adhesive properties (i.e., adheres to moist or wet surfaces), and have controlled permeability.
- the binding compositions described herein can be formulated to be biodegradable with a half-degradation time ranging from 1 day to 12 months. The rate of biodegradation can be modulated by incorporating into the composition hydrolysable or biodegradable chemical bonds and biodegradable segments mention herein and well known in the art.
- hydrogel materials containing up to 30% of water by weight are biodegraded more rapidly than elastomeric materials containing less then 50% of water by weight.
- Longer lasting elastomeric materials such as cellular perfluoroelastomers from CuMedica, Ltd. UK or a non-degradable material, EnteryxTM, from Boston Scientific are examples of longer lasting biomaterial implants potentially suitable for the binding compositions.
- the binding composition can be associated with a medical device or other device or dosage form suitable for administration to an organism or ecosystem using the polymeric carriers or coatings described herein.
- a medical device or other device or dosage form suitable for administration to an organism or ecosystem using the polymeric carriers or coatings described herein.
- the binding compositions disclosed herein are suitable for use as physiological and/or environmental buffer compositions.
- a physiological buffer the binding composition is useful in regulating the concentration of a chemical target in a physiological fluid.
- Pharmaceutical compositions as disclosed herein are generally administered in a pharmaceutically acceptable dosage form.
- an environmental buffer the binding composition may be introduced into an ecosystem in order to regulate the concentration of a chemical target therein.
- Environmental formulations comprising the binding composition are generally introduced in a form that is environmentally compatible and appropriate for achieving this goal. In many instances, such as tablets, hydrogels, solutions, particles, and beads, an environmental formulation may be very similar to a pharmaceutical dosage form. Differences, such as tablet size, carrier matrix, solvent composition, and appropriate additives, will be apparent to one of skill in the art.
- Regulation of the concentration of a chemical target may involve increasing or decreasing the concentration from an relatively low or relatively high initial value. Regulation may also involve maintaining the concentration substantially within some predetermined and desirable range of concentrations.
- a pharmaceutical composition may be a solid, semi-solid, or liquid, such as, for example, a tablet, a capsule, caplets, a liquid solution, a suspension, an emulsion, a gel, a suppository, granules, particles, pellets, beads, a powder, or the like, preferably in unit dosage form suitable for single administration of a precise dosage.
- Suitable pharmaceutical compositions and dosage forms may be prepared using conventional methods known to those in the field of pharmaceutical formulation and described in the pertinent texts and literature. See, e.g., Remington: The Science and Practice of Pharmacy, 19th Ed. (Easton, Pa.: Mack Publishing Co., 1995).
- the compositions may be in the form of a hydrogel, hydrogel particles, hydrogel beads, or a hydrogel paste.
- the compositions may be in the form of a bolus, either for implantation or injection.
- compositions disclosed herein may be suitable for administration to a patient parenterally, orally, rectally, vaginally, sublingually, nasally, topically, or transdermally.
- the composition may also be suitable to be implanted into a patient.
- Such implantation procedures may involve implantation into, for example, muscle tissue, subcutaneous tissue, bone, liver tissue, the peritoneal cavity, the thoracic cavity, a blood vessel, lung tissue, brain tissue, the cerebrospinal canal, eye tissue, kidney tissue, spleen tissue, fatty tissue, or bladder tissue
- compositions useful as environmental buffers may be introduced to the ecosystem in the form of a solid, semi-solid, or liquid, such as, for example, a tablet, a capsule, caplets, a liquid, a suspension, an emulsion, a gel, granules, particles, pellets, beads, a powder, or the like.
- polymers carrying a binding component can be formulated as aqueous solutions for delivery into the body or ecosystem.
- the binding component can be incorporated directly into the solution to provide a homogeneous solution or dispersion.
- the solution is an aqueous solution.
- the aqueous solution may further include buffer salts, as well as viscosity modifying agents (e.g., hyaluronic acid, alginates, carboxymethylcelluloe (CMC), and the like).
- the solution can include a biocompatible solvent, such as ethanol, DMSO, glycerol, PEG-200, PEG-300 or NMP.
- the binding compositions described herein may also be formulated as particles.
- Particles can be prepared by covalently crosslinking monomers or prepolymers, by condensation from reactive prepolymers, by charge interaction, by hydrophobic interaction, by physical crosslinking, by temperature precipitation, by solvent precipitation, by co- precipitation with other component, by drying, by freeze-drying, by phase separation, by emulsif ⁇ cation, by sonication, by extrusion, by spray-drying, by denaturation and by many other methods known in the art.
- compositions and devices described herein should preferably have a stable shelf-life for several months and capable of being produced and maintained under sterile conditions.
- Many pharmaceuticals are manufactured to be sterile and this criterion is defined by the USP XXII ⁇ 1211>.
- USP refers to U.S. Pharmacopeia (see www.usp.org, Rockville, Md.).
- Sterilization may be accomplished by a number of means accepted in the industry and listed in the USP XXII ⁇ 1211>, including gas sterilization, ionizing radiation or, when appropriate, filtration. Sterilization may be maintained by what is termed aseptic processing, defined also in USP XXII ⁇ 121 1>.
- Acceptable gases used for gas sterilization include ethylene oxide.
- Acceptable radiation types used for ionizing radiation methods include gamma, for instance from Cobalt 60 source and electron beam. A typical dose of gamma radiation is 2.5 MRad. Filtration may be accomplished using a filter with suitable pore size, for example 0.22 micrometers and of a suitable material, for instance polytetrafluoroethylene (e.g., Teflon from EJ. DuPont De Nemours and Company, Wilmington, Del.).
- the binding compositions and devices of the present invention are contained in a container that allows them to be used for their intended purpose, e.g., as a pharmaceutical composition or in a device for regulating environmental variables.
- Properties of the container that are important are a volume of empty space to allow for the addition of a constitution medium, such as water or other aqueous medium, e.g., saline, acceptable light transmission characteristics in order to prevent light energy from damaging the composition in the container (refer to USP XXII ⁇ 661>), an acceptable limit of extractables within the container material (refer to USP XXII), and an acceptable barrier capacity for moisture (refer to USP XXII ⁇ 671>) or oxygen.
- a constitution medium such as water or other aqueous medium, e.g., saline
- Typical materials used to make containers for pharmaceuticals include USP Type I through II and Type NP glass (refer to USP XXII ⁇ 661>), polyethylene, TEFLON, silicone, and gray-butyl rubber.
- the product containers can be thermoformed plastics.
- a secondary package can be used for the product.
- the product can be in a sterile container that is placed in a box that is labeled to describe the contents of the box.
- the binding compositions are used in vivo for regulation of a component of a physiological fluid, and any component of the binding compositions can be formed in-situ.
- a polymeric binding component may form in situ, and the precursors can be monomers or macromers that contain unsaturated groups that can be polymerized and/or cross-linked.
- the monomers or macromers can then, for example, be injected into the treatment area or onto the surface of the treatment area and polymerized in situ using a radiation source (e.g., visible or UV light) or a free radical system (e.g., potassium persulfate and ascorbic acid or iron and hydrogen peroxide).
- a radiation source e.g., visible or UV light
- a free radical system e.g., potassium persulfate and ascorbic acid or iron and hydrogen peroxide
- the polymerization step can be performed immediately prior to, simultaneously to or post injection of the reagents into the treatment site.
- Materials that undergo polymerization e.g., free radical polymerization
- the metabolite-binding composition may be formed from reagents that can undergo an electrophilic-nucleophilic reaction to produce a crosslinked matrix.
- a 4-armed thiol derivatized polyethylene glycol can be reacted with a 4 armed NHS-derivatized polyethylene glycol under basic conditions (pH> about 8).
- pH> about 8 Representative examples of compositions that undergo electrophilic-nucleophilic crosslinking reactions are described in U.S. Pat. Nos.
- the binding composition delivered into the body or ecosystem is composed of two reactive polymers able to form a hydrogel or elastomer within 1 sec to 20 min.
- the two reactive polymers are mixed during delivery of the binding composition.
- a Y-shaped connector and mixer may be used, wherein soluble reactive reagents are placed into syringes connected to the Y-connector having a mixing chamber.
- the reagents are mixed with each other as the mixture is delivered onto the target tissue site.
- An optional gas source nitrogen, carbon dioxide, compressed air
- the reaction conditions can be set to allow immediate (less then 10 sec) polymerization or gelation or slow (up to 20 min or longer) polymerization or gelation of the binding composition.
- the reactive reagents can be premixed immediately prior to application of the admixture to the tissue site or ecosystem.
- the reactive agents may be premixed and delivered in a suitable body cavity in the form of a single reagent.
- the reaction conditions can be set to allow the admixture to remain liquid and extrudable for several minutes, which, typically, is sufficient for completing the delivery of the admixed material into the body or ecosystem.
- one or more reactive reagents are also reactive with nucleophilic groups on the tissue surface (e.g., amino and sulfhydril groups of proteins on the cell surface and extracellular matrix).
- nucleophilic groups on the tissue surface e.g., amino and sulfhydril groups of proteins on the cell surface and extracellular matrix.
- the admixed reactive reagents react with each other and form the binding biomaterial implant.
- Some of the electrophilic groups react with nucleophilic groups on the tissue surface forming covalent chemical links between the metabolite-binding implant and the tissue surface.
- the implanted metabolite-binding composition can covalently link to the peritoneal tissue surface.
- Implantable sealants and adhesives such as CoSeal® , DuraSealTM and BioGlueTM, are based on crosslinking chemistries that also allow the covalent linking of the implant with the tissue surface.
- binding compositions can be prepared to contain reactive groups, or groups that can be further modified or activated to render said groups reactive.
- groups are carboxylic acid groups. Since a carboxylic acid group per se may not be susceptible to reaction with a nucleophilic amine or a sulfhydryl, components containing carboxylic acid groups must be activated so as to be amine-, or sulfhydryl-reactive.
- a carboxylic acid can be reacted with an alkoxy-substituted N-hydroxy-succinimide or N-hydroxysulfosuccinimide in the presence of DCC to form the reactive electrophilic groups N-hydroxysuccinimide ester and N-hydroxysulfosuccinimide ester, respectively.
- Carboxylic acids may also be activated by reaction with an acyl halide such as acyl chloride (e.g., acetyl chloride), to provide a reactive anhydride group.
- acyl chloride e.g., acetyl chloride
- a carboxylic acid may be converted to an acid chloride group using a thionyl chloride or an acyl chloride capable of an exchange reaction.
- the activated electrophilic groups can react with the nucleophilic groups on the tissue surface or nucleophilic groups present on the tissue surface.
- the reactive electrophilic groups include those that form thioester linkages upon reaction with the sulfhydryl group.
- Such sulfhydryl reactive groups include, but are not limited to: mixed anhydrides; ester derivatives of phosphorus; ester derivatives of p- nitrophenol, p-nitrothiophenol and pentafluorophenol; esters of substituted hydroxylamines, including N-hydroxyphthalimide esters, N-hydroxysuccinimide esters, N- hydroxysulfosuccinimide esters, and N-hydroxyglutarimide esters; esters of 1- hydroxybenzotriazole; 3-hydroxy-3,4-dihydro-benzotriazin-4-one; 3-hydroxy-3,4-dihydro- quinazoline-4-one; carbonylimidazole derivatives; acid chlorides; ketenes; and isocyanates.
- auxiliary reagents can also be used to facilitate bond formation, for example l-ethyl-3-[3-dimethylaminopropyl]carbodiimide can be used to facilitate the coupling of sulfhydryl groups to carboxyl-containing groups.
- various other sulfhydryl reactive functionalities can be utilized to form other types of linkages. For example, compounds that contain methyl imidate derivatives form imido-thioester linkages with sulfhydryl groups.
- sulfhydryl reactive groups are those forming thioether bonds with sulfhydryl groups.
- groups include, inter alia, maleimido, substituted maleimido, haloalkyl, epoxy, imino, and aziridino, as well as olefins (including conjugated olefins) such as ethenesulfonyl, etheneimino, acrylate, methacrylate, and alpha-, beta- unsaturated aldehydes and ketones.
- This class of sulfhydryl reactive groups is particularly useful because the thioether bonds may provide faster crosslinking and longer in vivo stability.
- sulfhydryl reactive groups can be employed to form disulfide bonds with sulfhydryl groups, such as ortho pyridyl disulfide, 3-nitro-2- pyridenesulfenyl, 2-nitro-5-thiocyanobenzoic acid, 5,5'-dithio-bis(2-nitrobenzoic acid), derivatives of methane-thiosulfate, and 2,4-dinitrophenyl cysteinyl disulfides.
- auxiliary reagents such as hydrogen peroxide or the di-tert-butyl ester of azodicarboxylic acid can be used to facilitate disulfide bond formation.
- sulfhydryl reactive groups form thioether bonds with sulfhydryl groups.
- groups include, inter alia, iodoacetamide, N-ethylmaleimide and other maleimides, including dextran maleimides, mono-bromo-bimane and related compounds, vinylsulfones, epoxides, derivatives of O-methyl-isourea, ethyleneimines, and aziridines.
- linking groups used in preparation of binding compositions For example, if higher molecular weight components are to be used, it is preferred that they have biodegradable linkages as described above, so that fragments larger than 15,000 Daltons are not generated during resorption in the body. In addition, to promote water miscibility and/or solubility, it may be desired to add sufficient electric charge or hydrophilicity. Hydrophilic groups can be easily introduced using known chemical synthesis, as long as they do not give rise to unwanted swelling or an undesirable decrease in compressive strength. In particular, polyalkoxy segments may weaken gel strength.
- the binding component may be linked to the polymer by covalent bonds formed between reactive moieties present on chemical target binding moieties and reactive groups on the polymer, or by occlusion in the matrices of the polymer, or encapsulated in polymeric microcapsules.
- therapeutic compositions are provided in non-capsular formulations such as microspheres (ranging from nanometers to micrometers in size), pastes, threads of various size, films, or sprays.
- an anti-scarring agent may be incorporated into biodegradable magnetic nanospheres.
- the nanospheres may be used, for example, to replenish target-binding moieties into an implanted intravascular device, such as a stent containing a weak magnetic alloy (see, e.g., Z. Forbes, B. B. Yellen, G. Friedman, K. Barbee. "An approach to targeted drug delivery based on uniform magnetic fields," IEEE Trans. Magn. 39(5): 3372-3377 (2003)).
- therapeutic compositions may be fashioned in the form of microspheres, microparticles and/or nanoparticles having any size ranging from about 30 nm to 500 micrometers, depending upon the particular use.
- compositions can be formed by spray-drying methods, milling methods, coacervation methods, W/O emulsion methods, W/O/W emulsion methods, and solvent evaporation methods.
- these compositions can include microemulsions, emulsions, liposomes and micelles.
- such compositions may also be readily applied as a "spray", which solidifies into a film or coating for use as a device/implant surface coating or to line the tissues of the implantation site.
- the binding composition described herein and for which the chemical target is a drug may also be used to prolong drug release of the drug.
- the drug typically is injected or introduced into the body by known techniques such as intra- venous, intraperitoneal, intra-muscular, sub-cutaneous, orally, by inhalation or otherwise.
- Drug is bound by the binding composition while it is present in the body at a high concentration following the bolus injection or intake of the drug.
- the drug is released by dissociation from the bound form when free drug concentration in the body is lower than the peak concentration or after bolus injection or intake of the drug.
- the binding composition is an implant, for example, the drug may be injected or introduced into the body at a location that is either relatively distant or relatively near to the location of the binding composition implant. This method may also be used, for example, to regulate the concentration of the chemical target in the body.
- the binding composition uptakes (i.e., binds) the chemical target when the target is present in the body at a concentration that is higher than the equilibrium concentration for the implant. Conversely, the binding composition releases the chemical target when the target is present in the body at a concentration that is lower than the equilibrium concentration for the implant.
- the equilibriurii concentration and reservoir capacity for the chemical target in the binding composition must be appropriately chosen for the particular application intended. Factors that affect the equilibrium concentration and reservoir capacity are well known and well characterized in the art, and include binding constants and the quantity of binding sites in the composition.
- drugs, biopharmaceuticals, or any other physiological process modifying agents are concentrated at the local tissue after the drug is introduced into the body. Such increase in local concentration of the drug or agent in the proximity of the drug-binding implant occurs due to the reversible binding of the drug with the drug-binding implant.
- the biomaterial delivered drug, biopharmaceuticals, therapeutic agents or physiological process modifying agents can be anti-infective, anti-inflammatory, antiproliferative, anti-angiogenic, anti-neoplastic, anti-searing, scar-inducing, tissue-regenerative, anesthetic, analgesic, immuno-modulating agents and neuro-modulating. Further examples of drugs include those described in U.S.
- Patent 6,759,431, and U.S. Patent Applications 20040219214, 20050177225 which are thereby incorporated by the reference.
- important factors for consideration include the binding constant(s) of the binding moieties and the quantity of the binding moieties in the composition.
- the binding constant relates to the equilibrium concentration of the chemical target, and is therefore important in determining the concentration at which there will be no further net uptake or release of the chemical target into or out of the composition (and, conversely, no further net outflow or inflow of the chemical target from or into the physiological fluid or ecosystem).
- the quantity of binding moieties in a composition may be influenced by a number of factors, such as volume, mass, density, surface area, porosity, and the number of binding moieties per molecule of the binding component.
- the compositions disclosed herein are useful in maintaining the concentration of a chemical target in a physiological fluid or ecosystem substantially within a beneficial range of concentrations.
- beneficial ranges of concentrations corresponding to physiologically acceptable levels are known in the art.
- beneficial ranges of concentrations are dete ⁇ nined by the recommended dosage for the individual drug.
- beneficial ranges will typically be maximum concentrations wherein the health of the resident organisms are not adversely affected by the toxin.
- beneficial ranges will typically be minimum concentrations below which resident organisms are not able to find sufficient nourishment.
- Beneficial ranges of concentrations for each of these situations, as well as others, are known in the art.
- the beneficial range of concentrations that is determined for any particular situation is useful for determining the preferred binding constant of the binding moieties. Selection of appropriate binding moieties is therefore based on known or determined binding constants for a particular moiety with a particular chemical target.
- the binding constant of a suitable binding moiety will preferentially be complementary to the beneficial range of concentrations for the chemical target in the environment in which it is to be regulated. That is, a complementary binding constant is such that, in the binding composition, the equilibrium concentration of the chemical target is within the beneficial range of concentrations.
- the binding composition is thereby suitable for maintaining the concentration of the chemical target substantially within the beneficial range of concentrations.
- the beneficial concentration of Ca +2 in blood plasma of an average human is 2.5 mM.
- a complementary binding constant for the binding moieties of a suitable Ca +2 -binding composition would be one in which the Ca +2 -binding composition is at equilibrium with a physiological fluid containing Ca +2 in a concentration of 2.5 mM. That is, the binding composition has no net uptake or release of Ca +2 when the surrounding environment contains a Ca +2 concentration of 2.5 mM.
- compositions disclosed herein may be capable of regulating the concentration of a chemical target in a physiological fluid or ecosystem for a predetermined period of time. The period of time may be, for example, less than about 10 minutes.
- the period of time may be about 30 minutes, about 1 hour, about 2 hours, about 6 hours, about 12 hours, about 24 hours, about 3 days, about 1 week, about 4 weeks, about 1 year, or more.
- the period of time is not limited to the values recited herein, but may be any period of time that is deemed suitable for a particular application.
- the compositions disclosed herein may be capable of regulating or maintaining the concentration of a chemical target in a physiological fluid or ecosystem substantially within a predetermined range.
- the predetermined range as described above, is generally the beneficial range of concentrations.
- the predetermined range may include values that are 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, or 99% of the minimum value of the beneficial range of concentrations.
- the predetermined range may also include values that are 101%, 105%, 110%, 120%, 130%, 140%, 150%, 200%, 250%, 300%, 400%, or 500% of the maximum value of the beneficial range of concentrations.
- the chemical target may be, for example, a metabolite which has a nominal concentration in the physiological fluid of an organism.
- the nominal concentration may be a range or a specific value.
- the concentration of a metabolite in a human patient's blood prior to administration of a pharmaceutical composition according to the current disclosure may be between about 0.1 and about 100 times, or about 0.2 and about 10 times, or between about 0.5 and about 5 times, or between about 0.8 and about 3 times, or between about 0.9 and about 2 times, or between about 0.95 and about 1.5 times the nominal concentration in the blood for that patient.
- the concentration of the metabolite in the pharmaceutical composition may also be within these limits.
- the binding constant of the binding moieties in the composition will be complementary with the nominal concentration of the metabolite for the patient. Such a binding constant will allow the pharmaceutical composition to modify (i.e., increase or decrease) the concentration of the metabolite in the patients' blood until the concentration reaches the nominal level.
- the concentration of a chemical target in a physiological fluid of a patient is regulated.
- the method comprises contacting the physiological fluid with the composition of the invention.
- the contacting may occur within the body (in vivo), such as for an injectable or implantable composition, or outside the body (ex vivo), such as in a dialysis procedure.
- the concentration of glucose in a patients' blood may be regulated using the compositions disclosed herein.
- the patient may be suffering from diabetes, for example.
- Such treatment may be effective in reducing glycemic variations and/or oxidative stress in the patient.
- the concentration of the chemical target may be regulated in either the tissue that is local to the implant, if an implant is used, or the concentration may be regulated systemically.
- the composition to be administered to the patient may or may not contain the chemical target.
- the chemical target may be administered separately to the patient, such as by injection. Further details of an example - i.e., a method for regulating glucose concentrations - are provided below.
- the compositions described herein may be used to aid the normal functioning of a liver in an organism such as a human.
- the liver is able to remove toxins from the blood, although the rate of toxin removal is limited. In some cases, a toxin damages or kills an organism simply because the liver is not able to lower the concentration of a toxin in the blood quickly enough to prevent such damage.
- the compositions described herein may be useful as a supplemental reservoir for toxins in the blood.
- the composition binds with the toxin to lower the concentration of the toxin in the blood below toxic levels. As the liver removes unbound toxin from the blood, the composition continually releases bound toxin. The concentration of the toxin is maintained below toxic levels, and the liver is given sufficient time to process all of the toxin from the blood. This method may be useful, for example, in mitigating the risk to humans of certain fish and meat toxins.
- the concentration of a chemical target in an aqueous environment of an ecosystem is regulated.
- the method comprises contacting the aqueous solution found in the ecosystem with the composition of the invention.
- the contacting may or may not occur within the aqueous environment itself.
- the composition may be added to the lake, or the water may be removed from the lake, contacted with the composition, and returned to the lake.
- the composition to be administered to the ecosystem may or may not contain the chemical target.
- the chemical target may be administered separately to the ecosystem.
- the glucose-binding composition comprises a plurality of glucose binding moieties.
- the binding constant of the glucose binding moieties preferentially has a glucose- binding constant value complementary with the range of glucose concentration variations in a living body or ecosystem.
- the glucose-binding composition therefore binds glucose when glucose is elevated and dissociates glucose when glucose levels subside below normal levels.
- said implant reduces glycemic variations and the magnitude and duration of hyper- and hypo-glycemic events associated with diabetes.
- glucose binding moieties capable of reversibly binding glucose in vivo.
- the glucose-binding composition is capable of such reversible binding where the glucose concentrations in the physiological fluid (e.g., blood) is between 0.1 mM and 50 mM.
- the binding constant of the binding moieties allows the binding moieties to be in equilibrium with the physiological fluid when the concentration of glucose in the physiological fluid is in the range of about 0.1 mM to about 50 mM.
- glucose-binding moieties include boron-containing moieties such as boronic acid and boronate ion, arsenious acid, arsenite ion, telluric acid, tellurate ion, germanic acid, germanate ion, glucoseoxidase and glucose-binding moieties prepared by template or molecular-imprint polymerization.
- boron-containing moieties such as boronic acid and boronate ion, arsenious acid, arsenite ion, telluric acid, tellurate ion, germanic acid, germanate ion, glucoseoxidase and glucose-binding moieties prepared by template or molecular-imprint polymerization.
- Each type of glucose-binding moiety has an associated binding constant.
- the overall binding capacity and equilibrium concentration of the composition may be varied.
- a glucose-binding composition can be formulated in the form of small hydrogel particles allowing for rapid glucose diffusion and binding.
- Such implanted glucose binding composition serves as a "glucose buffer". It binds glucose during hypoglycemic events and releases free glucose later as levels subside to normal or below normal. Since a certain amount of glucose is bound to the glucose-binding composition at normal glucose levels, the composition serves as a glucose source during hypoglycemic events by dissociating bound glucose at lower than normal levels.
- the amount of glucose bound to the composition at normal glucose levels and, respectively, its capacity to serve as a source of glucose in hypoglycemic events can be optimized by designing the glucose-binding composition with a higher or lower glucose binding constant.
- the glucose-binding composition comprises glucose-binding moieties linked to a polymeric matrix forming a hydrogel.
- a hydrogel Such hydrogel material is formed into particles ranging in diameter from 0.1 micrometers to 3 mm.
- the hydrogel matrix is biocompatible, non-immunogenic and optionally bioresorbable.
- suitable hydrogel material include polyethyleneglycol hydrogels, hyaluronic acid hydrogels and hydroxyethylmethacrylate hydrogels.
- the particles of hydrogel can be coated or covalently modified to reduce cell adhesion and provide a molecular weight cut-off function for diffusion into the hydrogel particles.
- One example of such a coating is the layer-by-layer polyelectrolyte method well described in literature (H.
- Polymer pairs that can be used for layer-by-layer coating of glucose binding compositions include sodium cellulose and polydiallyldimethylammonium chloride; polylysine and alginate; dextran sulfate and protamine; polystyrene sulfate and polydiallyldimethylammonium chloride.
- a glucose binding composition is a biodegradable composition with a half-degradation time of a few days to several weeks or months.
- the breakdown products are biocompatible, non-immunogenic, non-toxic or have acceptable toxicity, are smaller then 20 kDa in molecular weight and are preferentially excreted via kidneys.
- a glucose binding composition is used to modulate glucose concentration at the implant tissue site.
- the binding constant of the implant for glucose is adjusted such that at equilibrium the concentration of free glucose in proximity to the implant or inside of the implant is higher than the glucose concentration at the tissue site without implant.
- Such locally elevated glucose concentration can be beneficial for tissue regeneration and wound healing.
- the glucose-binding composition can be placed into a wound, laceration, surgical wound, ulcer, or any other site undergoing repair and healing to promote, accelerate or enhance biological processes associated with tissue healing and regeneration. It has been shown in vitro studies that elevated extracellular glucose increased migration, adhesion and proliferation of human corneal epithelial (HCE) cells.
- HCE human corneal epithelial
- the glucose-binding composition can be used to treat diabetes. Functioning, in a sense, as an "artificial pancreas," the composition may be formulated and introduced into the body (e.g., in the form of an implant or solution) such that the composition regulates the concentration of glucose in the blood of a diabetic patient.
- the equilibrium glucose concentration of the composition is chosen to approximate the "normal" equilibrium concentration in the blood of the patient.
- Hypoglycemia and hyperglycemia are regulated by the release and/or uptake of glucose by the glucose-binding composition.
- the glucose-binding composition can be used in conjunction with other therapies used treat diabetes, including various insulin therapies listed below: NovoLog (Novo Nordisk), Iletin I Regular (Lilly), Humulin R (Lilly), Novolin R (Novo Nordisk), Velosulin BR (Lilly), NPH Iletin II (Lilly), Humulin N (Lilly), Novolin N (Novo Nordisk), Lente Iletin II (Lilly), Humulin L (Lilly), Novolin L (Novo Nordisk), Humulin U Ultralente (Lilly), Humulin 70/30 (Lilly), Lantus (Aventis), Novolin 70/30 (Novo Nordisk), Humulin 50/50 (Lilly), Humalog Mix 75/25 (Lilly), NovoLog Mix 70/30, and oral pharmaceuticals including glyburide (Diabeta®, Micrometersase®, Glynase®), glipizide (Glucot)
- the glucose-binding implant has the capacity to bind glucose at hyperglycemic levels, thus normalizing glucose levels, insulin and other medications can be used less frequently. In cases of persistent hyperglycemia, the capacity of the glucose-binding implant may be exceeded. An injection of insulin or intake of oral diabetes drugs typically reduces the concentration of glucose in blood and this will cause dissociation of the bound glucose from the glucose-binding implant. Thus the capacity of glucose-binding implant can be "recycled". The glucose released from the glucose-binding implant after insulin injection may be beneficial in avoiding medication induced hypoglycemia.
- boron-containing compounds are used to prepare the glucose-binding component of the composition. It is known that boronic acids form cyclic esters with saccharides and the reaction occurs reversibly and rapidly at ambient temperature. It has been demonstrated that boronic acids serve as a useful interface to selectively recognize saccharides in water.
- boronate moieties and compounds suitable for reversible binding of glucose are phenylboronic acid, 2-carboxyethaneboronic acid, 1,2- dicarboxyethaneboronic acid, ⁇ , ⁇ '-dicarboxyethaneboronate, ⁇ , ⁇ -dicarboxypropaneboronate, 2-nitro- and 4-nitro-3-succinamidobenzene boronic acids, 3-nitro-4-(6-aminohexylamido)- phenyl boronic acid, ⁇ 4-[(hexamethylenetetramine)methyl]phenyl ⁇ boronic acid, 4-(N- methyl)carboxamidobenzene boronic acid, 2- ⁇ [(4-boronphenyl)methyl]-ethylammonio ⁇ ethyl and compounds containing 2- ⁇ [(4-boronphenyl)methyl]diethylammonio ⁇ ethyl groups, succinyl-3-amin
- the glucose-binding moieties of the invention may be immobilized in a saccharide-permeable biocompatible polymer matrix to form an implantable "glucose buffer".
- Suitable biocompatible polymer matrices used for medical implants are known in the art.
- the glucose-binding moieties can be covalently bound to the polymer matrix using techniques such as those described in U.S. Pat. No. 6,002,954, which is hereby incorporated by reference. Such methods generally involve adding a suitable tether to the molecule such that the tether can be used to covalently attach the compound to the matrix.
- the aryl boronic acid compounds of the present invention can also be reacted to form boronate esters with polymers having free alcohol or diol groups.
- Reactions for forming boronate ester bonds are well known in the art and include refluxing the boronic acid and diol in an appropriate solvent (e.g., alcohol, toluene, methylene chloride, tetrahydrofuran or dimethyl sulfoxide).
- an aryl boronic acid can be added to a polymer having free alcohol or diol groups by means of a transesterification reaction, as described in D. H. Kinder and M. M. Ames, Journal of Organic Chemistry 52:2452 (1987) and D. S. Matteson and R. Ray, Journal of American Chemical Society 102:7590 (1980), the entire teachings of which are incorporated herein by reference.
- the binding mechanism is believed to occur through bonding of adjacent hydroxyl groups on glucose to hydroxyl groups on a boronate moiety.
- Other references describing interaction of glucose with boronic acid and synthesis of boronate containing polymers include James et al.
- the present invention provides a way to preferentially bind glucose in a metabolic condition which may result in the presence of interfering compounds, such as alpha-hydroxy acids or beta-diketones.
- interfering compounds such as alpha-hydroxy acids or beta-diketones.
- Such potentially interfering compounds include lactate, acetoacetate, beta-hydroxy butyric acid, and the like.
- a glucose-binding composition is used which is capable of binding glucose from the physiological fluid, but which is less likely to bind interfering compounds in the physiological fluid.
- the glucose-binding composition has at least two recognition elements for glucose, oriented such that the interaction between the composition and glucose is more stable than the interaction between the composition and the interfering compounds. Increase in selectivity using two site recognition of glucose is described in Arimori S.
- Suitable recognition elements for multi-recognition include moieties which are capable of a preferably reversible interaction with glucose, especially with the diol groups present in glucose.
- recognition elements are known, and preferably include compounds containing boron such as boronic acid and boronate ion, arsenious acid, arsenite ion, telluric acid, tellurate ion, germanic acid, germanate ion, and the like.
- the recognition elements are spaced on the glucose binding composition a suitable distance from each other so as to allow at least two of the recognition elements to interact with a glucose molecule, resulting in increased specificity.
- the recognition elements may have a spacer of up to about 30 atoms between them.
- the recognition elements are oriented such that they are capable of being about 6 Angstroms apart when interacting with glucose.
- the glucose-binding formulation is placed into the peritoneal cavity in the form of particles, beads, sheets, strings, hydrogel, solution, bag, or capsules filled with glucose-binding compositions for a period of time ranging from 5min to 24 hours, or from 24 hours to several days, or from several days to several weeks, or from several weeks to several months, or from several months to several years, and thereafter removed surgically or via an access port by aspiration, morcelation, or other acceptable methods.
- the formulation may be prepared using a bioerodible composition, precluding the need to surgically remove the formulation. The formulation may bioerode over a period of hours, days, months, or years, as appropriate.
- a glucose-binding composition is implanted in peritoneal cavity in the amount sufficient to bind glucose several fold exceeding glucose amounts present in circulating blood. Elevated glucose levels are typically found in diabetic patients after ingestion of food and, if insulin therapy is not administered, can persist for several hours until excess of blood glucose is metabolized by the body.
- the peritoneal surface is known for rapid exchange of blood metabolites during peritoneal dialysis.
- a water soluble polymer having molecular weight 30,000-10,000,000 Da, or an extrudable hydrogel, or a crosslinked polymer with covalently bound glucose-binding moieties is used with a peritoneal glucose dialysis device to manage glucose levels in diabetic patients.
- examples of such polymers include hyaluronic acid, crosslinked hyaluronic acid (X. Shu, Y. Liu, Y. Luo, M. Roberts, G.
- polyethylenglycol hydrogels polyethylenglycol hydrogels, high molecular weight dextrans, high molecular weight extrudable crosslinked polyethylenglycol polymers, thermoreversible polymers all containing covalently bound glucose-binding moieties such as phenylboronic acid derivatives.
- This approach is particularly useful for managing glycemic levels in hospitalized patients with diabetes.
- the peritoneal glucose dialysis device in this embodiment may have only the dialysis part placed into the peritoneal cavity or the whole device may be implanted into the peritoneal cavity.
- the dialysis device is comprised of a reservoir for the glucose-binding polymer, a dialysis part comprised of a semi-permeable membrane with a molecular weight cut-off value sufficient to prevent the glucose-binding polymer from diffusing into the peritoneal cavity, a recirculation pump, and optionally a glucose sensor to monitor levels of glucose bound to the glucose-binding implant.
- the dialysis part of the device may have the shape of a tube and be inserted into the peritoneal cavity via throat or other surgical port. Similar to existing implantable insulin pumps, the reservoir may be accessed via an injection port to replace the glucose-binding polymer.
- the glucose dialysis device described above can be used as a part of an "artificial pancreas" unit comprising peripheral blood glucose sensor, insulin and/or other diabetes medication pump, glucose infusion pump, other medication delivery devices and a computer control unit.
- Hydrogel particles ranging in diameter between 100 and 200 micrometers are prepared by emulsion polymerization of or a 20% (w/w) aqueous solution at pH 8.0 of hydroxyethylmethacrylate-boronate (HEMA-boronate) and 4 armed PEG-acrylate having molecular weight between 8,000 and 10, 000 Da.
- HEMA-boronate hydroxyethylmethacrylate-boronate
- PEG-acrylate having molecular weight between 8,000 and 10, 000 Da.
- Toluene or another non-water miscible solvent that also does not dissolve the HEMA-boronate or PEG-acrylate is used to form the emulsion.
- TEMED and persulfate are used as reaction initiators.
- the HEMA-boronate reagent is synthesized by forming a covalent link between hydroxyl groups of HEMA and reactive groups on a phenylboronate moiety.
- Reactions for forming boronate ester bonds are well known in the art and include refluxing the boronic acid and diol in an appropriate solvent (e.g., alcohol, toluene, methylene chloride, tetrahydrofuran (THF) or dimethyl sulfoxide (DMSO)).
- an aryl boronic acid can be added to a polymer having free alcohol or diol groups by means of a transesterification reaction, as described (D. H. Kinder and M. M.
- the PEG- Acrylate reagent is prepared by reacting acryloyl-chloride with polyethylenglycol polymer having pentaerythritol (2,2-bis(hydroxymethyl)-l,3-propanediol) core and molecular weight of approximately 10,000 Da.
- the biodegradation rate of PEG/HEMA/Boronate particles can be modulated by introduction of thioester bonds in the structure of the particle polymer.
- the polymer can be prepared to have a half-biodegradation time in vivo from a few days to several months. Washed and equilibrated in physiological solution, particles are introduced into the peritoneal cavity in the form of an injectable or flowable suspension. Since implanted particles typically are bioresorbed in several weeks, the foreign body reaction to the implant is minimal.
- the ongoing hydrolysis of polymer and boronate-containing groups from the surface of the particles prevents the fouling of the particle surface by glycoproteins. Resorbable glucose-modulating boronate implants are useful for managing glycemic variation in trauma patients, patients in hospital intensive care units, women with pregnancy- induced diabetes and in other conditions causing acute and transient dysglycemia.
- Polymethacrylic acid particles are prepared by emulsion polymerization to yield hydrogel particles with nominal size 200 micrometers.
- the particles are covalently modified with a phenylboronic acid derivative, and thereafter encapsulated into polyelectrolyte multilayers using layer-by-layer polymer adsorption as described in published US Patent Applications Nos. 2005/0196520, 2005/0191430, 2004/0063200.
- PEM polyelectrolyte multilayers
- the particles are further encapsulated in a double layered e-PTFE material (from WL Gore & Associates, Inc.).
- the first layer of this composite material is an e-PTFE layer with porosity of 5-20 micrometers
- the second layer is the bioisolation layer of with pore diameter of 1-2 micrometers.
- the angiogenic layer promotes ingrowth of microvasculature into the pores of e-PTFE.
- the new microvasculature is established inside the e-PTFE material within two to three weeks after implantation.
- the glucose-binding implant is expected to retain at least 80% of its functionality in vivo for several months.
- the synthesis of a GBI hydrogel containing 20% of PEG- boronate can be performed at a reasonably low temperature (+4°C) in aqueous system by using potassium persulfate and tetramethylenediamine as the redox system.
- Example 4 Determination of the required glucose-binding capacity, volume of the glucose-binding implant and toxicity of implant breakdown products.
- the GBI is a PEG hydrogel containing 20% of PEG-phenylboronate the volume of the GBI hydrogel that will be required for introduction into the human body will be approximately 615 ml. An implant of such volume is considered to be acceptable for the implantation into peritoneal cavity.
- the implant may be resorbed in several weeks or months after implantation.
- Chronic intravenous infusion of 90 mg/kg/day of PEG with molecular weight of 3,350 Da for 178 days showed no adverse effects in dogs (Working, P.K. et al. 1997).
- Experiments with chronic exposure to boric acid showed no observed adverse effect at 9-43 mg boron/kg/day (Hubbard, S.A. 1998).
Landscapes
- Health & Medical Sciences (AREA)
- Engineering & Computer Science (AREA)
- Bioinformatics & Cheminformatics (AREA)
- Animal Behavior & Ethology (AREA)
- Public Health (AREA)
- Pharmacology & Pharmacy (AREA)
- Epidemiology (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- General Health & Medical Sciences (AREA)
- Medicinal Chemistry (AREA)
- Veterinary Medicine (AREA)
- Biomedical Technology (AREA)
- Neurosurgery (AREA)
- Dermatology (AREA)
- Medicinal Preparation (AREA)
- Medicines That Contain Protein Lipid Enzymes And Other Medicines (AREA)
- Agricultural Chemicals And Associated Chemicals (AREA)
Abstract
La présente invention a trait à des compositions et des procédés pour la modulation et la régulation de la concentration d'une cible chimique dans un organisme ou dans un écosystème. Dans un mode de réalisation, la concentration est régulée de sorte qu'elle soit maintenue en-dessous ou au-dessus d'un certain seuil, permettant ainsi d'éviter des effets toxiques ou nuisibles de la cible chimique. Les compositions de l'invention peuvent, par exemple, être implantées dans un organisme humain ou disposées dans un écosystème. Les compositions comportent des groupes fonctionnels de liaison qui se lient de manière réversible à un cible chimique dans l'organisme ou l'écosystème. La capacité de liaison et les constantes de liaison pour une cible chimique sont conçues de sorte que la composition maintienne la concentration de la cible chimique sensiblement dans une plage de concentration bénéfique.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US12/047,076 US20080200434A1 (en) | 2006-09-14 | 2008-03-12 | Chemical Target-Binding Compositions |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US59630005P | 2005-09-14 | 2005-09-14 | |
| US60/596,300 | 2005-09-14 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| WO2007033353A2 true WO2007033353A2 (fr) | 2007-03-22 |
| WO2007033353A3 WO2007033353A3 (fr) | 2007-10-11 |
Family
ID=37865594
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/US2006/035968 Ceased WO2007033353A2 (fr) | 2005-09-14 | 2006-09-14 | Compositions de liaison a des cibles chimiques |
Country Status (1)
| Country | Link |
|---|---|
| WO (1) | WO2007033353A2 (fr) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115209954A (zh) * | 2020-03-09 | 2022-10-18 | 生物组织再生和修复公司 | 用于治疗呼吸系统病变的组合物 |
| WO2023003845A1 (fr) * | 2021-07-20 | 2023-01-26 | Ut-Battelle, Llc | Adhésif résistant à réticulation dynamique ayant une aptitude au recyclage |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6485703B1 (en) * | 1998-07-31 | 2002-11-26 | The Texas A&M University System | Compositions and methods for analyte detection |
| US6627177B2 (en) * | 2000-12-05 | 2003-09-30 | The Regents Of The University Of California | Polyhydroxyl-substituted organic molecule sensing optical in vivo method utilizing a boronic acid adduct and the device thereof |
| US6858148B2 (en) * | 2003-07-16 | 2005-02-22 | The Regents Of The University Of California | Method and apparatus for detecting chemical binding |
-
2006
- 2006-09-14 WO PCT/US2006/035968 patent/WO2007033353A2/fr not_active Ceased
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115209954A (zh) * | 2020-03-09 | 2022-10-18 | 生物组织再生和修复公司 | 用于治疗呼吸系统病变的组合物 |
| CN115209954B (zh) * | 2020-03-09 | 2024-04-30 | 生物组织再生和修复公司 | 用于治疗呼吸系统病变的组合物 |
| WO2023003845A1 (fr) * | 2021-07-20 | 2023-01-26 | Ut-Battelle, Llc | Adhésif résistant à réticulation dynamique ayant une aptitude au recyclage |
| EP4373655A4 (fr) * | 2021-07-20 | 2025-05-07 | UT-Battelle, LLC | Adhésif résistant à réticulation dynamique ayant une aptitude au recyclage |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2007033353A3 (fr) | 2007-10-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US20080200434A1 (en) | Chemical Target-Binding Compositions | |
| Rezk et al. | Drug release and kinetic models of anticancer drug (BTZ) from a pH-responsive alginate polydopamine hydrogel: Towards cancer chemotherapy | |
| JP6763988B2 (ja) | S−ニトロソ−n−アセチルペニシラミン(snap)をドープした安定性の向上した血栓形成抵抗性/殺菌性の酸化窒素放出性ポリマー | |
| Wang et al. | Metal ion coordination polymer-capped pH-triggered drug release system on titania nanotubes for enhancing self-antibacterial capability of Ti implants | |
| Chen et al. | Adaptive nanoparticle-mediated modulation of mitochondrial homeostasis and inflammation to enhance infected bone defect healing | |
| EP1131114B1 (fr) | Dispositif et procede permettant de controler les interactions tissu/implant | |
| US8263104B2 (en) | Polymer nanofilm coatings | |
| EP2211727B1 (fr) | Colles tissulaires à base de cyanoacrylate | |
| EP2919858B1 (fr) | Collagène réticulé comprenant un agent antimicrobien lié | |
| US10272098B2 (en) | Chelated drug delivery systems | |
| US20030099682A1 (en) | Apparatus and method for control of tissue/implant interactions | |
| EP2389925A2 (fr) | Implant d'hydrogel avec des degrés de réticulation divers | |
| EP2389896A2 (fr) | Implants d'hydrogel avec des degrés de réticulation divers | |
| EP2389895B1 (fr) | Implants d'hydrogel avec des degrés de réticulation divers | |
| Malone-Povolny et al. | Long-term accurate continuous glucose biosensors via extended nitric oxide release | |
| EP2389894A2 (fr) | Implants d'hydrogel avec des degrés de réticulation divers | |
| Qin et al. | Metal ion-containing hydrogels: synthesis, properties, and applications in bone tissue engineering | |
| EP2389926A2 (fr) | Implants d'hydrogel avec des degrés de réticulation divers | |
| Gültekin et al. | Advancements and applications of upconversion nanoparticles in wound dressings | |
| Soto et al. | Design considerations for silica-particle-doped nitric-oxide-releasing polyurethane glucose biosensor membranes | |
| Motealleh et al. | Stimuli-responsive local drug molecule delivery to adhered cells in a 3D nanocomposite scaffold | |
| WO2011052089A1 (fr) | Matériaux vecteurs permettant la libération prolongée in vivo d'un médicament et comprenant un hydrogel réticulé par rayonnement ionisant, et leur procédé de fabrication | |
| US20090028957A1 (en) | Implantable Tissue-Reactive Biomaterial Compositions and Systems, and Methods of Us Thereof | |
| Liu et al. | Multifunctional Janus membrane for diabetic wound healing and intelligent monitoring | |
| Jayant et al. | In vitro and in vivo evaluation of anti-inflammatory agents using nanoengineered alginate carriers: Towards localized implant inflammation suppression |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
| NENP | Non-entry into the national phase |
Ref country code: DE |
|
| 122 | Ep: pct application non-entry in european phase |
Ref document number: 06824967 Country of ref document: EP Kind code of ref document: A2 |