MX2008006402A - Use of a composition for preserving organs and members - Google Patents

Abstract

The invention relates to the use of a composition for preserving organs and members which contains at least one type of semi-fluorinated alkane compound, at least one type of liquid siloxane and whose density ranges from 0,8 to 1,5 g/cm3.

Description

USE OF A COMPOSITION TO PRESERVE ORGANS AND TIPS DESCRIPTION OF THE INVENTION The invention relates to the use of a composition for preserving organs and extremities. When the organs or limbs are removed for a transplant, they have to be stored until they are used in such a way that they suffer as little damage and deterioration as possible. The limbs that were disengaged and that are going to be stitched again should be stored in a protected condition until they are integrated into the blood circulation again. The organs or limbs have to be protected from mechanical damage but also from the detrimental effects that occur by virtue of the fthat they are not integrated into the blood circulation. To retard the degradation process or the onset of decomposition that occurs as soon as the organs or limbs are separated from the circulatory system, several methods have been developed. A possible option involves the storage of organs or limbs in liquid perfluorocarbons. The liquid perfluorocarbons have the advantage that they are inert, that is to say that they do not rewith the tissue of the organ. Perfluorocarbons also have the advantage that they have a high oxygen absorption capacity so that when Ref. 192568 they are stored in perfluorocarbons, the organs or limbs can be supplied with oxygen. This prolongs the survival time of the organ or limbs. The use of perfluorocarbons was an important advance in transplant medicine. A disadvantage when using perfluorocarbons, however, is that they are of a very high density that is well above the density of the organs or limbs. For this reason, the organs or limbs float in the liquid instead of being submerged in it. To provide that the organ is enclosed by the perfluorocarburos it is necessary to apply a force to counterthe flotation. In general this is done by keeping the organs or limbs below the surface of the perfluorocarbons with clamping devices. Only when this has been assured, they are adequately supplied with oxygen and do not come into contwith the environment that is detrimental to the organs or extremities. However, the capillary systems in the tissue can be mechanically damaged by the fastening devices. The damage to the structures can thus be so extensive that a transplant or new sewing is no longer a possibility. A further disadvantage of perfluorocarbons is their low dissolution power towards other compounds. Therefore it is not possible to add a preservative solution of perfluorocarbons, ve substances that can perform a function that is useful in terms of the preservation of the organs and extremities. This is already known for the organs that are going to be stored at very low temperatures, that is to say to effect the cryopreservation. It will be noted, however, that for this purpose, the water has to be removed first from the tissue so that the cells do not burst during the freezing process. The storage is carried out in the case of cryopreservation at temperatures in the range of -100 SC to -180 SC. Cryopreservation is suitable for cells that are not very sensitive to mechanical stress, but which lead to major problems in relation to sensitive organs and tissues. The demands of a composition to conserve organs or limbs are thus many and very variable. Therefore, the object of the invention is to provide a composition with which the organs and limbs can be stored and conserved in a careful way in such a way that they suffer as little damage as possible. A further object is to provide a sterile composition that is immediately ready for use, that does not require the dehydration of the tissue and that can be adapted to the prevailing conditions in a simple way. A further object of the invention is to provide a composition that makes it possible to dissolve substances to stabilize the organs and extremities in order to avoid harmful influences. This object is achieved by the use of a composition as defined in claim 1. It was surprisingly found that a composition containing at least one semifluorinated alkane compound which is liquid at room temperature and which may be a semifluorinated alkane and / or a hydrofluoroether, and at least one siloxane that is liquid at room temperature, produces a possible way to carefully store organs and limbs, where they can be supplied with oxygen at the same time as semifluorinated alkane compounds and liquid siloxanes, produces a Good gas solvent power. In addition, the composition according to the invention provides the possibility of adding substances that further provide for the preservation of the organs and extremities. Furthermore, the composition according to the invention offers the advantage that it forms a barrier layer around the organ or limbs that are to be conserved, and that it prevents contamination of the organs or limbs that are to be stored. The composition itself is hostile to germs and can be well sterilized. The compositions according to the invention are inert chemically, physically and physiologically and are non-toxic. The subject matter of the invention is therefore the use of a composition containing at least one liquid semifluorinated alkane compound, at least one liquid siloxane or a combination of at least one semifluorinated liquid alkane compound and at least one liquid siloxane and It has a density in the range of 0.8 to 1.5 g / cm3, to preserve the organs and extremities. Semi-fluorinated alkane compounds are amphiphilic compounds with lipophobic RF segments and lipophilic RH segments. Both semifluorinated alkanes and also hydrofluoroethers are understood as semifluorinated alkane compounds according to the invention. The compounds are made of perfluorinated alkane (RF) blocks and non-fluorinated alkane (RH) blocks. The perfluorinated and non-fluorinated blocks can be linked either by a bond (semifluorinated alkane) or by means of an oxygen atom (hydrofluoroethers). According to the invention both compounds in which the fluorinated and non-fluorinated blocks are alternated and also the compounds in which a fluorinated block is attached to a non-fluorinated block, are considered. In particular, semifluorinated alkanes as described in WO 97/12858 are suitable. It is possible to use both the RF-A-RH diblock compounds and the triblock compounds of RFA-RHA-RF, where A independently means a bond or oxygen. Preferably, diblock compounds are used. In this case, the blocks may have respectively both straight and branched components. The unbranched and semifluorinated alkane compounds are of the formulas: F (CF2) nA (CH2) mH F (CF2) nA (CH2) mA (CF2) nF with n = 1-20 m = 3-20 where A is a bond or oxygen. The branched semifluorinated alkane compounds may also have within the perfluoroalkyl groups the FCH units with X = CF3, C2F5, C3F7 or C4F9 and also within the HCY units of the alkyl groups with Y = CH3, C2H5 C3H7, or C4H9. A group of -CX2 may also be contained within a perfluoroalkyl chain and a -CY2 group may also be contained within an alkyl chain. Instead of the perfluoroalkyl group F3C- a group FCX2- or F2CX with X = C2F5, C3H7 or C4F9, an HCY2 or H2CY group with Y = C2H5, C3H7 can also be bound in the molecule at the end and also instead of the H3C alkyl group. or C4H9 can also be bound in the molecule at the end. Nevertheless, in the case of all the specified isomers, ie straight or branched semifluorinated alkanes, the total number of carbon atoms in the perfluoroalkyl portion always remains as previously established within the limits of n = 1-20, the number of carbon atoms in the alkyl part also remain within the predetermined limits of m = 3-20. In a preferred embodiment semifluorinated alkanes are used, in which n is from 3 to 10 and m is a value of 3. to 12. The semifluorinated alkanes used according to the invention are liquid at room temperature. Very short chain compounds that are gaseous at room temperature can not be considered for use for a composition according to the invention. Preferably, semifluorinated alkanes are used, whose melting temperature is higher than -50 ° C. In a preferred embodiment, semifluorinated alkane compounds are used in a highly purified form. For this purpose it is possible to use the process described in WO 93/16974 whereby the semifluorinated alkane compounds are first treated with an acid permanganate solution and after that autoclaved or heated under reflux with a mixture of a hydroxide solution of aqueous potassium (4-8 n), CaO or BaO and a nucleophilic agent (for example a secondary amine) at 150 to 180 ° C over a prolonged period. The reaction product is then separated from the alkaline aqueous phase which possibly still contains alcohol and the amine phase, treated several times in succession with a dilute mineral acid, a solution of NaHCO 3, distilled water, Na 2 SO 4 free of water and free CaCl 2. water and subjected to fractional distillation on a Powerful column. Semi-fluorinated alkanes treated in this manner, according to IR spectroscopy, 1 H-NMR, 19 F-NMR and GC / MS, are free of groups which with elimination of intramolecular HF can lead to the formation of toxic olefinic by-products. The process described in WO 93/16974 can be used for the quantitative determination of the groups that can lead to the separation of intramolecular HF or the exchange of a fluorine atom attached to the carbon by means of a nucleophilic agent, with which the fluoride The ionisable process is detected in the reaction of the sample material with hexamethylene diamine in an unborn or decane by heating for several hours at 120 to 150 ° C, where any fluoride released is detected by means of an ion-sensitive electrode. After the purification process, the fluoride ions must be detectable at the highest level up to a ratio of 40 ppm, where the detection limit for the fluoride concentration is less than or equal to 10 ~ 5 mol l "1. As stated above according to the invention, both semifluorinated alkanes and also hydrofluoroethers as well as a combination of both can be used as semifluorinated alkane compounds.The appropriate compounds or combinations, respectively, can be selected by the person skilled in the art. Thus, it is possible to use a semifluorinated alkane compound or a combination of two or more semifluorinated alkane compounds, wherein both combinations of several semifluorinated alkanes and also the combination of various hydrofluoroethers as well as combinations of at least one semifluorinated alkane and at least one hydrofluoroether is suitable, as semifl alkane compounds When they have a high dissolution power of the gas, this class of compounds can be used alone to preserve the tissue but only on the condition that their density is in the claimed range. Semi-fluorinated alkane compounds whose density is outside the claimed range will be used, a preferred embodiment involves the use of a combination with at least one liquid siloxane.

According to the present invention, the term "liquid siloxanes" which can also be referred to as "silicone oils" is used to denote in particular those compounds which are made of dialkyl siloxane units and / or diarylsiloxane units and are capable of flowing at a temperature environment and body temperature. The alkyl residues are straight chain or branched and have up to six carbon atoms. The preferred alkyl residues are methyl residues. Preferably, the phenyl residues are used as the aryl residues. They are inert chemically, physically and physiologically, ie they do not react with the constituents of the tissue with which they come into contact, ie the proteins, lipids, etc., or with the additional constituents present in the composition , such as semifluorinated alkanes or additional additives. The siloxanes used are preferably those which are practically not crosslinked or which are only very slightly crosslinked. Siloxanes are commercially available in many different variants and the person skilled in the art can easily select those that are optimally suited for the respective purpose. Low viscosity mixtures of the siloxanes that are commercially available are particularly suitable. Preferably, the silanes used are those that are of a viscosity in the range of 0. 5 to 1000 mPas, preferably 0. 5 to 500 mPas, where the viscosity is measured respectively with a downward ball viscometer at room temperature. Preferably, a combination of at least one semifluorinated alkane compound and at least one siloxane are used for the composition according to the invention. In this case the components are mixed in such proportions that the density of the finished composition is in the desired range. The components - the semifluorinated alkane compound and the siloxane - are normally miscible with each other in any ratio at room temperature and any ratio of these components is therefore adequate. The composition according to the invention remains homogeneous for a period of at least one year, is sterile and physically-chemically stable and does not undergo separation of the mixture during storage at room temperature (20 to 25 ° C). The density of the composition can be adjusted by altering the proportions of the components and depends on the organ that is to be stored thereon or on the respective extremities. Preferably, the density is selected depending on the respective organ or the respective limbs that are to be conserved. If a higher level of oxygen demand is not desirable, then the proportion of semifluorinated alkane compounds is increased or only semifluorinated alkane compounds are used. If the oxygen demand may be lower or a density in the lower range is desirable, the proportion of siloxane is increased or pure siloxane is used. The density is preferably adjusted depending on the organ and is suitably in a range of 0.8 to 1.5, preferably 0.9 to 1.3 and particularly preferably 1.01 to 1.25 g / cm3. Preferably, the density of the composition is thus adjusted so that the organ or limbs are immersed in the medium without the use of a clamping device and are preferably fully submerged and in particular float preferably in a condition suspended in the medium without it going down and without floating on the top. The storage in a floating condition suspended in the composition is the storage that is the most careful for the fabric and avoids any mechanical damage. So that the composition according to the invention can act as a barrier layer, preferably the organ or limbs should be completely immersed.

The composition used according to the invention is distinguished by its high power of dissolution of the gas and makes it possible to provide oxygen for the tissue to be stored or preserved. The proportion of the dissolved oxygen is preferably adjusted so as to ensure a sufficient supply of oxygen. The oxygen content is preferably adjusted depending on the organ, ie depending on the respective oxygen demand of the respective tissue to be conserved. In a preferred embodiment, the composition has 3-50% by volume, preferably 10-40% by volume of oxygen at room temperature and alternatively oxygen saturation. By virtue of its amphiphilic structure, the lipophilic and lipophobic components, it is possible to dissolve the substances that are insoluble in semifluorinated alkanes, in semifluorinated alkane compounds. This also produces the possibility of providing compounds dissolved in the composition that make it possible to improve the conservation of the tissue. Thus, for example, it is possible to add active substances such as antibiotics, steroids, anti-inflammatories, cytostatics or additives that protect and stabilize the composition such as antioxidants. The semifluorinated alkane compounds serve in this respect as the solution that helps substances that are not soluble in the siloxanes alone, can also be added in mixtures of semifluorinated alkane compounds and siloxanes. Examples that may be mentioned are 5-fluorouracil, daunomycin, ibuprofen, N-acetylcysteine, carotenoids, retinyl palmitate and α-tocopherol. Nutrients for organs and tissues can also be added to the composition used according to the invention to provide the optimal supply for the organ during transport. If the active substances and nutrients used do not dissolve in the composition according to the invention,. then it is possible in a further embodiment to use the co-solvents which dissolve the active substance or nutrient and are dissolved in the composition according to the invention of the semifluorinated alkane compound and the siloxane. Examples of suitable co-solvents are alcohols such as monovalent and polyvalent alcohols with 1 to 6 C atoms, for example ethanol, n-propyl alcohol, isopropyl alcohol, butanol, glycerin, sorbitol, etc. Additional selected compounds such as co-solvents are the ethers and esters. Water is not considered in relation to this, the composition used according to the invention is free of water. If a composition according to the invention is used, which either comprises a combination of the semifluorinated alkane compound and siloxane or the siloxane alone, it is recommended that the highly viscous adherent components of the preservation fluid be removed by washing the tissue prior to the additional use of it, that is, in the transplant or while they are sewn. For this purpose, the use of semifluorinated alkane compounds, preferably of high purity, is particularly advantageous by virtue of the compatibility thereof with the siloxanes. It is recommended that the absorbed or adsorbed components of the preservative liquid be removed by washing the respective tissue or eluates. Therefore, according to the invention, a composition is used which makes it possible for the tissue and in particular the organs or limbs, to be stored and conserved in a careful way without mechanical alteration while ensuring the supply of oxygen to the body. same. The use according to the invention can be carried out at room temperature and does not require neither dehydration of the organs or extremities nor storage at very low temperature. The composition according to the invention is biologically and physiologically compatible and maintains the quality and safeguards the life of the isolated organ or limbs. The composition used according to the invention is produced in a manner known per se by the respective proportions which are mixed together. Preferably, the individual components are mixed in the sterile form, and processed under sterile conditions. The resulting composition is homogeneous and physically-chemically stable at room temperature. The siloxanes have a good gas dissolving power even if it is somewhat lower than that of semifluorinated alkane compounds. Preferably, siloxanes of a density in the range of 0.75 to 0.98 g / cm 3 are used for the mixing operation. The composition according to the invention is produced by carefully storing the organs and tissue. When the composition is highly stable and can be stored for a prolonged period, for example during a period of at least one year at room temperature from 15 to 42 BC, it is very suitable to be kept ready for emergency situations. Thus, a composition according to the invention can be brought for example in ambulances to receive the limbs that have to be transported after an accident, without involving greater complication or cost. The examples which are proposed to further explain the subject matter of the present invention without limiting it by this, are described hereinafter.

Example 1 The silicone oil 1000 previously sterilized and the perfluorohexiloctane sterilized are mixed in a KGW Isotherm vessel with an IKA stirrer at room temperature under sterile conditions. The ratio of silicone oil 1000 to F6H8 is 69.5: 30.5 (w / w). The oxygen is then introduced into the solution at room temperature under sterile conditions at a flow rate of 2000 ml / min until a volume of oxygen of 30% by volume is reached. The density of the obtained solution is 1.05 g / cm3. If there is a desire to provide a composition of lower density, the proportion of silicone oil 1000 is increased. If the desire is to increase the density, the proportion of perfluorohexiloctane can be increased. Example 2 The previously sterilized silicone oil 50 is saturated with oxygen by oxygen which is introduced under sterile conditions at room temperature at a flow rate of about 5000 ml / min until full saturation of the oxygen is reached. The silicone oil 50 enriched with oxygen can then be used for tissue storage. Example 3 The previously sterilized silicone oil 100 and the perfluorohexiloctane previously sterilized are mixed in a KG Isotherm vessel with an IKA stirrer under sterile conditions at room temperature. The desired viscosity and / or density can be set by means of a mixing ratio of the silicone oil 100 with respect to F4H6. The oxygen enrichment of the solution (flow rate 3000 ml / min) up to 15% by volume is then carried out by the introduction of oxygen at room temperature under sterile conditions. Example 4 The perfluorohexiloctane previously sterilized and the cc-tocopherol previously sterilized are mixed in the KGW Isotherm vessel with an IKA stirrer under sterile conditions at room temperature. The ratio of F6H8 to a-tocopherol is 98: 2 (w / w). The oxygen is then introduced into the solution under sterile conditions at room temperature at a flow rate of 1000 ml / min until the solution has an oxygen content of 8% by volume. Example 5 The previously sterilized ethylnonafluorobutyl ether and the previously sterilized silicone oil 3 are mixed in the KGW Isotherm vessel with an IKA stirrer under sterile conditions at room temperature. The desired viscosity and / or density can be adjusted by means of the mixing ratio of the silicone oil 3 with respect to the ethylnonafluorobutyl ether. The oxygen is then introduced into the solution at room temperature under sterile conditions at a flow rate of 1500 ml / min of oxygen until an oxygen content of 25% by volume is reached. It is noted that in relation to this date the best method known by the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (1)

CLAIMS Having described the invention as above, the content of the following claims is claimed as property: 1. The use of a composition containing at least one semifluorinated alkane compound and at least one siloxane, wherein the composition is of a density in the range of 0.8 to 1.5 g / cm3, to preserve the organs or extremities. 2. The use of a composition comprising substantially: a) at least one semifluorinated alkane compound and b) at least one siloxane, wherein components a) and b) are mixed in proportions such that the density of the finished composition is in a range of 0.8 to 1.5 g / cm3, to preserve the organs or extremities. 3. The use according to claim 1 or claim 2, wherein at least one compound of the formula RFARH or a mixture of the compounds of this formula is used as the semifluorinated alkane, wherein RF is a perfluoroalkyl group straight or branched with 1-20 C atoms, RH is a straight or branched saturated alkyl group with 3-20 C atoms and A is a bond or oxygen. The use according to one of the preceding claims, wherein at least one semifluorinated alkane compound is a branched semifluorinated alkane which may have branched units within the perfluoroalkyl groups and / or within the alkyl groups. 5. The use according to claim 4, wherein the branched semifluorinated alkane compound may contain one or more side chains X with X = CF3, C2F5, C3F7 or C4F9 and / or the alkyl chain may have side chains Y with Y = CH3; C2H5, C3H7, or C4H9. The use according to one of the preceding claims, wherein the semifluorinated alkane used is a compound containing a perfluoroalkyl group with 3 to 10 carbon atoms and a saturated alkyl group with 3 to 12 carbon atoms. Use according to one of the preceding claims, wherein the composition is free of water. The use according to one of the preceding claims, wherein a semifluorinated alkane, a mixture of semifluorinated alkanes, a hydrofluoroether, a mixture of hydrofluoroethers or a combination of at least one semifluorinated alkane and at least one hydrofluoroether, is included as the semifluorinated alkane compound. The use according to one of the preceding claims, wherein a compound which is made of dialkylsiloxane units and / or diarylsiloxane units is included as the siloxane, wherein the alkyl residues may be straight or branched chain and they have 1-6 carbon atoms. 10. The use according to one of the preceding claims, wherein the siloxane is of a viscosity of 0.5 to 1000 mPas. 11. The use according to claim 10, wherein the siloxane is of a viscosity in the range of 0.5 to 500 mPas. The use according to one of the preceding claims, wherein the siloxane is a polydimethylsiloxane or a mixture of polydimethylsiloxanes. 13. Use in accordance with one. of the preceding claims, wherein the composition has an oxygen content corresponding to the oxygen demand of the organ or limbs to be conserved. The use according to one of the preceding claims, wherein the composition contains 10 to 40% by volume of oxygen, measured at room temperature. 15. The use according to one of the preceding claims, wherein the composition is saturated with oxygen at room temperature. The use according to one of the preceding claims, wherein the composition additionally includes one or more active substances and / or nutrients. 17. The use according to claim 13, wherein the composition contains one or more antibiotics, steroids, anti-inflammatories, cytostatic agents, virustatics and / or stabilizers. 18. The use of according to one of the preceding claims, wherein the composition contains additional active substances such as 5-fluoroacyl, daunomycin, acyclovir, ganciclovir, ibuprofen, N-acetylcysteine, carotenoids, retinol palmitate and / or c-tocopherol. 19. The use according to one of claims 1 to 17, wherein the composition additionally contains at least one antioxidant. 20. The use according to claim 18, wherein the composition contains α-tocopherol or retinyl palmitate. The use according to one of the preceding claims, wherein the composition contains vitamins, lipid-bearing substances and / or fats and / or oils that can be easily decomposed. 22. The use according to one of the preceding claims, wherein the composition additionally has a co-solvent for an active substance and / or nutrient. 23. The use according to one of the preceding claims, wherein the components (a) and (b) are included in such proportion that the density of the finished composition is in the range of 0.9 to 1.3 g / cm3. 24. The use according to one of the preceding claims, wherein the components (a) and (b) are included in such proportion that the density of the finished composition is in a range of 1.01 to 1.25 g / cm3. RKSUMEN OF THE INVENTION The invention relates to the use of a composition containing at least one semifluorinated alkane compound and at least one liquid siloxane, wherein the composition is of a density from 0.8 to

1.5 g / cm3, to preserve the organs or the extremities