CN1593385A - Gel capable of injecting temperature sensitive complex and its preparation method - Google Patents

Abstract

The invention provides an injectable thermosensitive complex gel and a preparation method thereof. Its components and contents are as follows by weight percentage: chitosan 1.0-2.0, glycerophosphate 1.9-4.5, disodium hydrogen phosphate: 0-0.5, gelatin: 0-1.25, 0.1mol/l HCl solution or acetic acid solution: 86.4-89.0, distilled water: 8.1-10. Prepare a chitosan solution with a solid content of 1.1-2.2%; then prepare a complex salt solution; under continuous stirring, carefully add 1 part of the complex salt solution to 9 parts of the chitosan filtrate, and the final solution The pH value is 6.0-8.0, and the overall gel is formed at and above the gelation temperature. The prepared complex salt, by adjusting the formula, greatly reduces the salt content in the gel scaffold, and is used to wrap some drugs and cells with poor salt tolerance, broadening the scope of application.

Description

Injectable thermosensitive complex gel and preparation method thereof

Technical field

The invention belongs to the technical field of material science, and in particular relates to an injectable temperature-sensitive complex gel and a preparation method thereof.

Background technique

Injectable gel scaffold material is a kind of biological material, which is liquid at room temperature and can wrap active cells and therapeutic drugs. A phase transition occurs at the injection site to form a gel scaffold. Injectable gel scaffolds have the advantages of easy operation, convenient shaping, reduced surgical difficulty, and reduced surgical trauma. They can be used in drug delivery, tissue repair, and cell culture. They have high medical value and broad application prospects.

Chitosan is a copolymer of glucosamine and acetylglucosamine, which can be prepared by deacetylation of chitin under alkaline conditions. It is a natural cationic polysaccharide with good biocompatibility and biodegradability. The properties of pure polysaccharide gels and their complex gels formed with other polymers have been extensively studied. In recent years, people began to study chitosan as an injectable gel scaffold material. In the literature report of Chenite A, Chaput C, Wang D. Novel injectable neutral solutions of chitosan form biodegradable gels in situ, Biomaterials, 2000, 21: 2155-2161, Chenite et al first used chitosan/β-sodium glycerophosphate to prepare An injectable neutral chitosan gel system, which is liquid at room temperature and gels at 37°C, has been successfully applied to deliver biologically active growth factors in organisms, and is also used to encapsulate active Various factors must be considered in the preparation of an injectable gel from the matrix of chondrocytes. In addition to having good rheological properties to facilitate injection, it should also have fast response and certain gel strength. Long or poor gel strength, which will lead to undesired flow or rupture after injection. However, to make this chitosan gel solution gel at body temperature, the concentration of the salt used must reach more than 4.0% w/w, if it can be gelled at lower temperatures, it will be more effective at body temperature. Short gel time and greater gel strength also need to further increase the salt content of the system, which is unfavorable for encapsulating some drugs and cells with poor salt tolerance. In addition, relevant biocompatibility experiments showed that injection of this chitosan gel solution into the hind paws of mice would cause acute inflammation, and the severity of the inflammation was related to the degree of deacetylation of chitosan. The chitosan system produced a more severe inflammatory reaction than the one with a higher degree of deacetylation. Therefore, for chitosan-based injectable gel solutions, in addition to choosing chitosan with a relatively high degree of deacetylation, it is also necessary to try to replace chitosan with some other biocompatible biomaterials to reduce the system The content of chitosan in the middle reduces the possibility of inflammatory reactions.

Contents of Invention

In order to solve the deficiencies in the prior art, the complex salt prepared by the present invention can adjust the composition and content of the complex salt without increasing the salt content in the gel support. Gel time and gel strength at initial gelation temperature and body temperature. Moreover, while maintaining the excellent performance of the gel scaffold, the salt content in the gel scaffold can be greatly reduced by adjusting the formula, which can be used to wrap some drugs and cells with poor salt tolerance, broadening its application range.

The invention provides an injectable thermosensitive complex gel, the components and content of which are as follows by weight percentage:

Chitosan: 1.0～2.0

Glycerophosphate: 1.9～4.5

Disodium hydrogen phosphate: 0～0.5

Gelatin: 0～1.25

0.1mol/l HCl solution or acetic acid solution: 86.4～89.0

Distilled water: 8.1～10

Among them: glycerophosphate includes sodium glycerophosphate, potassium glycerophosphate, calcium glycerophosphate;

Glycerophosphate is GP, a mixture of α-sodium glycerophosphate (α-GP) and β-sodium glycerophosphate (β-GP); the mixing ratio of α-GP in GP is 0-30%.

A preparation method for preparing an injectable thermosensitive complex gel: comprising the following steps:

1) Prepare a chitosan solution with a solid content of 1.1-2.2%, the solvent is 0.1mol/l hydrochloric acid solution or acetic acid solution, and after dissolving at room temperature for 1-3 hours, filter out the insoluble matter.

2) Preparation of complex salt solution, solvent is distilled water, wherein the solid content of disodium hydrogen phosphate is 0-5%, glycerophosphate mixture (GP, α-sodium glycerophosphate (α-GP) and β-sodium glycerophosphate ( The mixture of β-GP)) has a solid content of 20-60%.

3) Under the condition of continuous stirring, carefully add 1 part of complex salt solution dropwise into 9 parts of chitosan filtrate to obtain a uniform and clear solution, and then continue stirring for 10-40 minutes to obtain chitosan complex solution. The pH value of the final solution is 6.0-8.0, and the solution is liquid at room temperature. After the temperature rises, the solution stops flowing at the initial gelation temperature (IGT) and exceeds this temperature, and forms an overall gel.

The present invention can also replace chitosan with gelatin part, and method is as follows:

Prepare a gelatin solution with a solid content of 1-2.5%, use distilled water as a solvent, and heat to dissolve. After cooling, filter out the insoluble matter; take 0-5 parts of gelatin solution and mix with 5 parts of chitosan complex solution prepared by the above method, stir evenly, and finally obtain a uniform and clear solution with a pH value of 6.0 to 8.0; The solution is liquid at room temperature, and at the initial gelation temperature and higher, the solution stops flowing and forms an overall gel.

The invention prepares an ideal reagent mixed with various phosphates in proportion. This reagent can endow the gel bracket with better performance without increasing the salt content of the system on the basis of maintaining the original excellent performance of the gel bracket. Excellent rheological properties, wider ability to adjust IGT, faster thermal response, and greater gel strength. Moreover, by adjusting the formula, the salt content of the system can be reduced while maintaining the excellent performance of the gel scaffold. The present invention selects gelatin as an ideal biological material partially replacing chitosan.

The innovation point of the present invention is:

1. Prepared a suitable reagent, which can adjust the composition and content of the complex salt arbitrarily on the basis of maintaining the original excellent performance of the gel scaffold, without increasing the salt content of the system. The initial gelation temperature of the biogel scaffold and the gel time and gel strength at body temperature.

2. A suitable reagent is prepared, which can reduce the salt content of the system on the basis of maintaining the excellent performance of the gel scaffold.

3. Gelatin is selected as an ideal base material to partially replace chitosan, which can maintain the original excellent performance of the gel scaffold while replacing a large amount of chitosan.

The present invention partially replaces chitosan with gelatin, reduces the amount of chitosan in the gel scaffold, further improves the biocompatibility of the gel scaffold, and greatly reduces the acute inflammatory response that may be caused by chitosan.

Detailed ways

Embodiment 1. prior art:

Accurately weigh 1.0 g of chitosan and add it to 45 ml of 0.1 mol/l HCl solution. After dissolving at room temperature for 2 hours, filter with a G3 glass sand core funnel to filter out insoluble substances and take 9 ml of chitosan filtrate. Weigh 420 mg of β-GP and dissolve it in 1 ml of distilled water, and carefully add it dropwise into the chitosan filtrate under continuous stirring to obtain a uniform and clear solution, and then continue to stir for about 20 min. The pH of the final solution was 7.0.

The prepared complex solution is in a liquid state at room temperature, and gels at a body temperature of 37°C. The gelation time at 37°C is about 10 minutes, and the gel strength is about 0.126KPa.

Example 2.

Accurately weigh 1.0 g of chitosan and add it to 45 ml of 0.1 mol/L HCl solution. After dissolving at room temperature for 2 hours, filter with a G3 glass sand core funnel to filter out insoluble substances, and take 9 ml of chitosan filtrate. The GP (the percentage content of α-GP in GP is 30%w/w) that takes by weighing 420mg is dissolved in 1ml distilled water, under the condition of continuous stirring, carefully drop in the chitosan filtrate, finally obtain uniform and clear solution, and continue to stir for about 20 min. The pH of the final solution was 7.15.

This complex solution, compared with the system using β-GP alone in Example 1, without increasing the salt content of the system, IGT decreased from 37°C to 29°C, and the gelation time at 37°C was shortened from 10min to 200s, and the gel strength increased about 4 times.

Example 3.

Accurately weigh 1.0 g of chitosan and add it to 45 ml of 0.1 mol/L HCl solution. After dissolving at room temperature for 2 hours, filter with a G3 glass sand core funnel to filter out insoluble substances, and take 9 ml of chitosan filtrate. Weigh 50mg of disodium hydrogen phosphate and 200mg of β-GP and dissolve them in 1.0ml of distilled water, and carefully drop them into the chitosan filtrate under continuous stirring to obtain a uniform and clear solution, and then continue to stir for about 20min. The pH of the final solution was 6.95.

The complex solution can gel at 37°C, and the gelation time and gel strength at 37°C are equivalent to those of the system using β-GP alone in Example 1, but the salt content in the system is changed from 4.0%w/ The w dropped to 2.4% w/w, a 40% drop in salt content.

Example 4.

Accurately weigh 1.0 g of chitosan and add it to 45 ml of 0.1 mol/L HCl solution. After dissolving at room temperature for 2 hours, filter with a G3 glass sand core funnel to filter out insoluble substances, and take 9 ml of chitosan filtrate. Weigh 50mg of disodium hydrogen phosphate and 200mg of β-GP and dissolve them in 1.0ml of distilled water, and carefully drop them into the chitosan filtrate under continuous stirring to obtain a uniform and clear solution, and then continue to stir for about 20min. The pH of the final solution was 7.0.

Accurately weigh 1.0g of gelatin and dissolve it in 50ml of distilled water, heat and dissolve in an oven at 50°C, filter with a G3 glass sand core funnel, and filter out the insoluble matter. After cooling, mix 10 g of gelatin solution with 10 g of chitosan complex solution, stir evenly, and finally obtain a uniform and clear solution. The pH of the final solution was 7.0.

The gel solution of this formula can gel at 37°C; compared with the system using β-GP alone in Example 1, its gelation time and gel strength at 37°C remain basically unchanged. However, the salt content of the system decreased from 4.0% w/w to 1.2% w/w, the salt content decreased by 70%, and the solid content of chitosan decreased from about 2.0% w/w to 1.0% w/w , chitosan content decreased by 50%.

The injectable temperature-sensitive complex gel and its preparation method disclosed and proposed by the present invention can be realized by those skilled in the art by referring to the content of this article and appropriately changing the raw materials, process parameters, structural design and other links. The products and methods of the present invention have been described through preferred implementation examples, and those skilled in the art can obviously make changes or appropriate changes and combinations to the methods and products described herein without departing from the content, spirit and scope of the present invention to realize The technology of the present invention. In particular, it should be pointed out that all similar substitutions and modifications will be obvious to those skilled in the art, and they are all considered to be included in the spirit, scope and content of the present invention.

Claims (3)

1. temperature sensitive coordination compound gel of injectable, its component and content are as follows by weight percentage:

Chitosan: 1.0～2.0

Glycerophosphate: 1.9～4.5

Sodium hydrogen phosphate: 0～0.5

Gelatin: 0～1.25

0.1mol/1 HCl solution or acetum: 86.4～89.0

Distilled water: 8.1～10

Wherein: glycerophosphate comprises sodium glycerophosphate, potassium glycerinophosphate, calcium glycerophosphate;

Glycerophosphate is GP, α-sodium glycerophosphate (α-GP) and sodium (mixture of β-GP); The mixed proportion of α-GP in GP is 0～30%.

2. the preparation method of the temperature sensitive coordination compound gel of injectable: may further comprise the steps:

1) the preparation solid content is the chitosan solution of 1.1-2.2%, and solvent is hydrochloric acid solution or the acetum of 0.1mol/l, and room temperature was dissolved after 1-3 hour, the elimination insoluble matter;

2) preparation complex salts solution, solvent is a distilled water, wherein the solid content of sodium hydrogen phosphate is 0-5%, the phosphoglycerol salt mixture (GP, (solid content of α-GP) and sodium (β-GP) mixture) is 20-60% to α-sodium glycerophosphate;

3) continuing under the stirring condition, with in 9 parts of chitosan filtrates of 1 part of complex salts drips of solution adding, obtaining homogeneous solution clearly carefully, continuing to stir 10～40min again; The pH value of final solution is 6.0～8.0, and this solution chamber's relaxing the bowels with purgatives of warm nature is in a liquid state, and after the intensification, locates and surpasses this temperature place at initial gelling temperature (IGT), and solution is no longer mobile, forms whole gel.

3. the preparation method of the temperature sensitive coordination compound gel of a kind of injectable as claimed in claim 2: further comprising the steps of:

The preparation solid content is the gelatin solution of 1-2.5%, and solvent is a distilled water, heating for dissolving; After the cooling, the elimination insoluble matter; Get 0-5 part gelatin solution and mix, stir, obtain homogeneous solution clearly at last, the pH value 6.0～8.0 of solution with the chitosan complex solution of 5 parts of claim 2 method preparations; This solution chamber's relaxing the bowels with purgatives of warm nature is in a liquid state, and at the temperature place of initial gelling temperature and Geng Gao, solution is no longer mobile, forms whole gel.