CN101574539A - Gelatin sponge and preparation method thereof - Google Patents

Abstract

The invention provides gelatin sponge, gelatin aqueous solution is irradiated to crosslink to form gelatin hydrogel, and then the gelatin hydrogel is swollen, frozen and dried to obtain the gelatin sponge. The invention also provides a preparation method of the gelatin sponge by an irradiation crosslinking way, the whole process flow is finished in a pure water system, the irradiation and crosslinking processes have sterilizing function and good controllability, the obtained product has better structural uniformity compared with a chemical crosslinking method, and the gelatin sponge has unique advantages as biomedical materials.

Description

A kind of gelatin sponge and preparation method thereof

technical field

The invention relates to a gelatin sponge and a preparation method thereof, in particular to a gelatin sponge prepared by a radiation crosslinking method.

Background technique

Gelatin has good biological activity and has a very wide range of uses in the field of biomedicine. Gelatin sponge has a strong hemostatic effect, can quickly absorb a large amount of water and exudate, and can be used as a dressing for surgical incisions, various wounds, and embolisms for various interventional treatments. Modified gelatin sponge with chitosan can further improve the hemostatic speed of the sponge, the ability to absorb exudate, and improve the flexibility of the sponge.

The traditional gelatin sponge or gelatin-chitosan sponge mostly dissolves chitosan with hydrochloric acid and acetic acid, cross-links the gelatin or gelatin/chitosan mixture with formaldehyde, glutaraldehyde and other cross-linking agents, and finally uses freeze-drying method Dehydration, sterilization to obtain a sponge product. However, a large number of cytotoxic substances are used in these processes, such as hydrochloric acid, acetic acid, formaldehyde, glutaraldehyde, etc. Most of the sterilization processes use ethylene oxide fumigation, and the residual toxicity of these chemical agents will seriously affect cell growth and tissue Regeneration, thereby affecting the healing effect.

Chinese invention patent CN1097980A provides a preparation method of chitosan-gelatin sponge, which is aimed at making band-aids and hemostatic patches. In the invention, gelatin, chitosan, hydrochloric acid, sodium hydroxide, formaldehyde and distilled water are formulated into a solution, which is then foamed, frozen, dried and sterilized to make a porous sponge. However, this process uses formaldehyde, hydrochloric acid, sodium hydroxide and other highly cytotoxic chemical reagents, and the sterilization process uses ethylene oxide fumigation. These processes have been gradually restricted or prohibited by relevant regulations. They are used as band-aids and hemostatic patches. biosecurity is poor.

Chinese invention patent CN1775302A provides a preparation method of chitosan-gelatin sponge wound dressing. The invention dissolves chitosan with dilute hydrochloric acid, acetic acid and formic acid solution, dissolves gelatin in water, adds cross-linking agents such as formaldehyde or glyoxal, plasticizers such as glycerin, pearl powder and other substances, mixes these components, and freezes them. The dry method yields a spongy wound dressing 1-2 mm thick. However, this process also uses biotoxic chemical reagents such as formaldehyde, glyoxal, hydrochloric acid, acetic acid, and formic acid, and non-biodegradable pearl powder, whose particles may remain in the wound tissue and become foreign bodies in the body.

Chinese invention patent CN101161298A provides a process for preparing gelatin sponge particle embolism using gelatin as raw material. In the invention, gelatin aqueous solution and formaldehyde solution are mixed, frozen and cross-linked to obtain a porous sponge sample. The sponge samples were thawed, washed and dried to obtain gelatin sponge. The gelatin sponge is frozen, pulverized and sieved to obtain the gelatin sponge particle embolism. This invention uses formaldehyde as a cross-linking agent. Although there are washing steps, the reagents in the porous material are difficult to remove through simple washing, and the residual formaldehyde will inevitably affect the histocompatibility of the final product.

The invention aims to adopt a green synthesis process to obtain a gelatin sponge with better biocompatibility and better structural uniformity.

Contents of the invention

The invention aims at abandoning the traditional technique of using a large amount of toxic chemical agents, and provides a gelatin sponge obtained by a radiation cross-linking method, which has good biocompatibility and good structural uniformity.

Another object of the present invention is to provide a preparation method of gelatin sponge, which adopts radiation crosslinking and radiation sterilization to be carried out simultaneously, so that gelatin sponge with better biocompatibility and better structural uniformity can be obtained.

The purpose of the present invention and the solution to its technical problems are achieved by adopting the following technical solutions.

The gelatin sponge of the present invention is formed by radiation-crosslinking a gelatin aqueous solution to form a gelatin hydrogel, and then swelling and freeze-drying.

The radiation cross-linking is carried out by cobalt-60 gamma rays or electron beams, and the radiation dose is 1-50 kGy, preferably 10-30 kGy.

The weight percent concentration of the gelatin aqueous solution is 3-50%, preferably 10-30%.

The aqueous gelatin solution may also contain water-soluble natural polysaccharides. The ratio of gelatin to water-soluble natural polysaccharide is 10:0-1:9, preferably 4:6-8:2.

Described water-soluble natural polysaccharide is selected from aloe polysaccharide, carboxymethyl chitosan, hydroxypropyl chitosan, sodium alginate, propylene glycol alginate, sodium carboxymethyl cellulose, hydroxypropyl methyl cellulose , one or more of carboxymethyl hydroxypropyl cellulose.

The swelling of the gelatin hydrogel is carried out by soaking in sterile water, growth factor aqueous solution or auxiliary treatment drug aqueous solution. The swelling time is 2 to 72 hours, preferably 6 to 24 hours. The swelling process is carried out in a sterile room.

The growth factor aqueous solution can be selected from those commonly used by those skilled in the art, such as fibroblast growth factor or human epidermal growth factor, which can promote the regeneration and repair of skin tissue.

For the aqueous drug solution, the aqueous drug solutions such as disinfectants, antibiotics, burn and scald drugs, and antithrombotic drugs commonly used in the art can be selected to have corresponding adjuvant therapeutic effects, and the dosage can adopt the conventional dosage in the art.

The cross-linking degree of the gelatin hydrogel prepared by the invention is in the range of 70-99%, and the water absorption rate can be adjusted in the range of 5-500 times.

In the preparation method of the gelatin sponge of the present invention, the gelatin aqueous solution is irradiated and cross-linked to form a gelatin hydrogel, and then swollen and freeze-dried.

The freeze-drying temperature is -10 to -80°C, preferably -20 to -60°C.

The porous gelatin sponge with excellent properties can be obtained by adopting the radiation crosslinking method of the present invention. The pore diameter is in the range of 5-100 microns, and has excellent ability to absorb tissue fluid and stop bleeding, preferably in the range of 20-70 microns.

If necessary, the porous gelatin sponge can be frozen, crushed, and sieved to obtain granular gelatin sponges of different particle sizes.

The gelatin sponge obtained by the present invention can be used as a hemostatic dressing, burn wound dressing, ulcer dressing, etc.; the gelatin sponge particles can be used as an embolism for various interventional treatments, such as uterine fibroids, hemangiomas, arteriovenous malformations, and malignant tumors. And arterial embolization of various hemorrhages.

The gelatin sponge obtained by the method provided by the invention has no chemical agent residue and has better biocompatibility and structural uniformity. Fibroblasts grow well on the gelatin/carboxymethyl chitosan hydrogel of the present invention, and the proliferation rate is greater than 100% in 5 days; while culturing fibroblasts on the hydrogel prepared by dissolving chitosan with acetic acid, 7 The daily proliferation rate is between 82% and 97%. There is no cell culture data of formaldehyde cross-linked gelatin and/or chitosan gel materials, but formaldehyde is more toxic than acetic acid, and its cell proliferation rate is expected to be lower.

The gelatin sponge of the present invention and its radiation preparation method have at least the following advantages and beneficial effects:

(1) The present invention adopts water-soluble natural polysaccharide to replace chitosan, so the solvent has replaced acetic acid, formic acid and other skin-irritating substances by water.

(2) Compared with chitosan, water-soluble natural polysaccharide has better ability to promote tissue growth.

(3) The water-soluble natural polysaccharide modified gelatin can increase the water solubility and flexibility of gelatin, and can promote the growth of granulation, which is very important for its application as a dressing.

(4) Using radiation cross-linking technology to replace formaldehyde, glutaraldehyde and other cross-linking technologies can avoid the chemical residual toxicity of the product, and at the same time play a role in sterilization.

(5) The porous material obtained by radiation cross-linking technology has better structural uniformity, which is beneficial to the adhesion of skin tissue cells and the regeneration of skin tissue.

(6) The controllability of the process is very good, and the structural uniformity of the obtained product is also better than that of the chemical cross-linking method, which has unique advantages as a biomedical material.

Detailed ways

The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

Example 1

Dissolve 30 grams of gelatin in 70 grams of water, heat to 80° C., and stir evenly to obtain a 30% gelatin aqueous solution. Pour the gelatin aqueous solution into a plate, and irradiate 20 kGy with cobalt-60 gamma rays to obtain a gelatin hydrogel with a crosslinking degree of 99%. The hydrogel was soaked in sterile water for 24 hours until the swelling equilibrium, and a water-containing porous material with a water absorption rate of 10 times was obtained. Freeze-dry the aqueous porous material at -80°C, pulverize, sieve and classify with a universal pulverizer at -20°C to obtain a gelatin sponge embolism with uniform pore size and particle size (the average pore size is 15 microns) and soft texture.

Example 2

Dissolve 12 grams of gelatin and 3 grams of carboxymethyl chitosan in 85 grams of water, heat to 60° C., and stir evenly with a defoaming mixer to obtain an aqueous solution with a solid content of 15%. Pour the aqueous solution into a plate, and irradiate 30 kGy with cobalt-60 gamma rays to obtain a gelatin/carboxymethyl chitosan hydrogel with a crosslinking degree of 82%. Soak the hydrogel in the aqueous solution containing the growth factor for 72 hours until the swelling equilibrium, and obtain a water-containing porous material with a water absorption rate of 20 times. The water-containing porous material is freeze-dried at -40° C. to obtain a gelatin/carboxymethyl chitosan sponge dressing with uniform pore size (the average pore size is 50 microns) and soft texture.

Example 3

Dissolve 4 grams of gelatin and 6 grams of hydroxypropyl chitosan in 90 grams of water, heat to 60° C., and stir evenly with a defoaming mixer to obtain an aqueous solution with a solid content of 10%. Pour the aqueous solution into a petri dish, and irradiate 10 kGy with cobalt-60 gamma rays to obtain a gelatin/hydroxypropyl chitosan hydrogel with a crosslinking degree of 72%. The hydrogel was soaked in sterile water for 36 hours until the swelling equilibrium, and a water-containing porous material with a water absorption rate of 90 times was obtained. The water-containing porous material is freeze-dried at -40° C. to obtain a gelatin/hydroxypropyl chitosan sponge dressing with uniform pore size (the average pore size is 80 microns) and soft texture.

Example 4

Dissolve 8 grams of gelatin and 12 grams of propylene glycol alginate in 80 grams of water, heat to 60° C., and stir evenly with a defoaming mixer to obtain an aqueous solution with a solid content of 20%. The aqueous solution was poured into a plate, and 50 kGy of cobalt-60 gamma rays were irradiated to obtain a gelatin/propylene glycol alginate hydrogel with a crosslinking degree of 70%. Soak the hydrogel in sterile water containing 1 mg/L basic fibroblast growth factor for 48 hours until the swelling equilibrium, and obtain a water-containing porous material with a water absorption rate of 220 times. The water-containing porous material is freeze-dried at -80° C. to obtain a gelatin/propylene glycol alginate sponge dressing with uniform pore size (the average pore size is 30 microns) and soft texture.

Example 5

Dissolve 10 grams of gelatin in 90 grams of water, heat to 80° C., and stir evenly to obtain a 10% aqueous solution of gelatin. Pour the gelatin aqueous solution into a plate, and irradiate 5 kGy with cobalt-60 gamma rays to obtain a gelatin hydrogel with a cross-linking degree of 90%. The hydrogel is soaked in a sterile aqueous solution containing 10% mannitol antithrombotic agent for 6 hours until the swelling is balanced, and a water-containing porous material with a water absorption rate of 50 times is obtained. The aqueous porous material is freeze-dried at -60°C, pulverized and sieved with a universal pulverizer at a low temperature of -20°C to obtain a gelatin sponge embolism with uniform pore size (the average pore size is 40 microns), uniform particle size, and soft texture.

When using the gelatin sponge prepared by the method provided by the present invention as a dressing, the capacity and rate of absorbing tissue fluid and the hemostatic speed are better than the commercially available gelatin sponge control group; when used as a hemostatic sponge, the hemostasis time and total blood loss rate are better than the control group; when used as an embolic agent, its biocompatibility and immunogenicity were superior to those of the control group.

Although the present invention has been described in detail with general descriptions and specific embodiments above, it is obvious to those skilled in the art that some modifications or improvements can be made on the basis of the present invention. Therefore, the modifications or improvements made on the basis of not departing from the spirit of the present invention all belong to the protection scope of the present invention.

Claims (10)

1. a gelatin sponge, is characterized in that, it forms gelatin hydrogel by carrying out radiation cross-linking to gelatin aqueous solution earlier, then carries out swelling, freeze-drying and forms. 2 . The gelatin sponge according to claim 1 , wherein the radiation cross-linking is carried out by cobalt-60 gamma rays or electron beams, and the radiation dose is 1-50 kGy. 3. The gelatin sponge according to claim 1 or 2, characterized in that the degree of cross-linking of the gelatin hydrogel is in the range of 70% to 99%. 4. The gelatin sponge according to any one of claims 1-3, characterized in that the weight percent concentration of the aqueous gelatin solution is 3-50%, preferably 10-30%. 5. The gelatin sponge according to any one of claims 1-4, characterized in that, the aqueous gelatin solution also contains water-soluble natural polysaccharides. 6. gelatin sponge according to claim 5, is characterized in that, described natural polysaccharide is selected from aloe polysaccharide, carboxymethyl chitosan, hydroxypropyl chitosan, sodium alginate, propylene glycol alginate, One or more of sodium carboxymethylcellulose, hydroxypropylmethylcellulose, and carboxymethylhydroxypropylcellulose. 7. The gelatin sponge according to claim 5 or 6, characterized in that the ratio of the gelatin to the water-soluble natural polysaccharide is 10:0-1:9, preferably 4:6-8:2. 8. The gelatin sponge according to any one of claims 1-7, characterized in that the swelling of the gelatin hydrogel is carried out by soaking in sterile water, growth factor aqueous solution or adjuvant therapeutic drug aqueous solution. 9. The method for preparing the gelatin sponge according to any one of claims 1-8, characterized in that, the gelatin aqueous solution is first radiated and cross-linked to make a gelatin hydrogel, and then swollen and freeze-dried. 10. The preparation method of the gelatin sponge according to claim 9, characterized in that, the freeze-drying temperature is at -10 to -80°C, preferably -20 to -60°C.