CN116370697A

CN116370697A - Gel sponge material and preparation method and application method thereof

Info

Publication number: CN116370697A
Application number: CN202310588314.7A
Authority: CN
Inventors: 吕建华; 吴攀; 赵岩; 雷凯君
Original assignee: Ji Hua Laboratory
Current assignee: Ji Hua Laboratory
Priority date: 2023-05-24
Filing date: 2023-05-24
Publication date: 2023-07-04

Abstract

The invention discloses a gel sponge material, a preparation method and a use method thereof, and belongs to the field of medical materials. In the invention, solute is concentrated and crosslinked at the grain boundary to form a macroporous structure in freezing, and then the formation of an ion crosslinked network is completed in the macroporous structure, after the ion crosslinked network is formed, holes are smaller, and a tertiary butanol solution with a certain concentration is used as a freezing solvent in the freeze drying process, so that the size of ice crystals is reduced, the unique microstructure of sponge is reserved, and the problems of poor mechanical property and low liquid absorption rate of the conventional carboxymethyl chitosan mixed anion polyelectrolyte sponge are solved.

Description

Gel sponge material and preparation method and application method thereof

Technical Field

The invention relates to a gel sponge material, a preparation method and a use method thereof, and belongs to the field of medical materials.

Background

Uncontrolled bleeding from wounds can lead to various complications such as reduced blood pressure, hypothermia, bacterial infection, and even shock. Common hemostatic materials are typically bandages and gauze dressings, which provide hemostasis by direct compression. Bandages and gauze dressings are susceptible to bacterial infection after absorption of blood or interstitial fluid, are detrimental to wound healing, and are unable to accommodate irregular wounds and deep and narrow wounds. Therefore, there is an urgent need to develop a material that is suitable for different hemostatic environments (various wounds) and is beneficial to wound repair.

In recent years, sponge materials have been designed for hemostatic treatment of various types of major bleeding. The sponge material has extremely high porosity and is favorable for quickly absorbing blood oozing from a wound. The sponge material also has a very large specific surface area, is favorable for adsorbing and gathering blood cells in blood, and promotes blood coagulation. Moreover, the unique shape recovery properties of the sponge material provide advantages for treating certain abnormal wounds, such as irregular and incompressible wounds that are applied in a compressed state, allowing them to expand rapidly and fully contact the irregular bleeding wound. Based on the characteristics, the sponge has wide prospect in rapid hemostasis.

The hydrogel material has good biocompatibility and flexibility, can provide a moist environment which is beneficial to tissue regeneration for wounds as a wound repair material, and can prevent invasion of external microorganisms. The characteristic of the hydrogel sliding bullet is beneficial to solving the problem of wound crusting and avoiding secondary damage of the wound.

The natural high molecular polymer has good biocompatibility, liquid absorption and environmental sensitivity due to the existence of a large number of active functional groups such as amino, carboxyl, hydroxyl and the like on the sugar chain. The chitosan is the only positively charged natural polysaccharide in nature, has wide sources and low price, and has good antibacterial performance and hemostatic performance due to the existence of a large number of active amino groups and hydroxyl groups. Carboxymethyl chitosan, which is a water-soluble derivative of chitosan, is commonly used to form a polyelectrolyte material with negatively charged natural polysaccharide through electrostatic interaction, and the polyelectrolyte material has good antibacterial property, biocompatibility and excellent blood cell adhesion property, and is commonly used for hemostasis treatment and subsequent wound repair.

The conventional preparation method of the chitosan-based sponge comprises the following steps: by adjusting the pH of the precursor solution, the positively charged polycation electrolyte and the negatively charged anionic polyelectrolyte form an electrostatic interaction, thereby forming a hydrogel with an ionic cross-linked network, and the formed hydrogel is subsequently freeze-dried to remove solvent components, thereby forming a sponge with a porous structure. In the step of freeze-drying the chitosan-based material, the solvent water can form a larger ice crystal structure, so that the ionic crosslinking network in the hydrogel is damaged to a certain extent, the mechanical property of the freeze-dried sponge is reduced, and the shape recovery property is poor. To suppress these problems, it is common practice to increase the concentration of the polycation electrolyte and the anionic polyelectrolyte in the precursor solution, thereby increasing the solid content of the chitosan-based sponge, but this results in a slow imbibition rate, low imbibition rate, and poor blood cell adhesion properties of the chitosan-based sponge. This greatly limits the application of chitosan-based materials in hemostasis.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides a gel sponge material, a preparation method and a use method thereof, so that the chitosan-based sponge has low solid content and good shape recovery capability.

The technical scheme adopted for solving the technical problems is as follows:

in a first aspect, the present application provides a method for preparing a gel sponge material, comprising the steps of:

dissolving carboxymethyl chitosan, anionic polyelectrolyte and double bond material in water to form precursor solution;

adding an initiator and a cross-linking agent into the precursor solution, and placing the mixture in a low-temperature environment to be coagulated into ice cubes;

thawing the ice cubes to room temperature to obtain a solid-liquid mixture;

fumigating the solid-liquid mixture with acetic acid to obtain a first gel;

replacing water in the first gel with tertiary butanol to obtain a second gel;

and freeze-drying the second gel to obtain the gel sponge material.

According to the preparation method of the gel sponge material, the precursor solution is placed below the crystallization point temperature of solvent water, the solvent water can crystallize, solute is separated out and enriched at the crystal boundary of the solvent, and a cross-linked network can be formed when the concentration of raw materials is low, so that the double-bond material is cross-linked in a freezing environment to form a covalent cross-linked network with a macroporous structure. Under the condition that the solid content of the precursor solution is the same, the mechanical property of the material formed by the method is better than that of a covalent cross-linked network directly reacted in the solution. In the thawing process, the anionic polyelectrolyte and the carboxymethyl chitosan at the grain boundary are dissolved in the gaps of the covalent cross-linking network, acetic acid is used for fumigation after complete thawing, and the space for forming the ionic cross-linking network by the anionic polyelectrolyte and the carboxymethyl chitosan is the macropores of the covalent cross-linking network, so that the size of the ionic cross-linking network is limited, and the gaps in the first gel are smaller than the gaps of the covalent cross-linking network after the ionic cross-linking network is formed. And finally, replacing part or all of solvent water by tertiary butanol, so that the second gel can still keep small gaps after freeze drying, and a unique microstructure is kept, and the obtained gel sponge material has stronger liquid absorption capacity and better shape recovery capacity than the common gel sponge material.

Further, the anionic polyelectrolyte is selected from one of alginate, sodium hyaluronate, carrageenan, sodium carboxymethyl cellulose, sodium carboxymethyl starch, carboxymethyl curdlan and carboxymethyl pachyman, and has good biocompatibility.

Still further, the double bond material is the anionic polyelectrolyte modified with methacrylic anhydride.

If double bond monomers are additionally added, the artificially synthesized monomers cannot be completely polymerized after the polymerization reaction, and small molecule residues exist, so that cytotoxicity exists. In addition, the main purpose of the invention is to form gel sponge with good shape recovery capability by using precursor solution with low solid content, wherein the gel is formed by forming an ionic cross-linked network by anionic polyelectrolyte and carboxymethyl chitosan, and the solid content is increased by adding double bond monomer additionally. Double bond modification is carried out on the cationic polyelectrolyte or the anionic polyelectrolyte, so that the precursor solution has the capability of covalent crosslinking in a freezing environment, does not increase the solid content additionally, and has good biocompatibility. While chitosan as a cationic polyelectrolyte has been carboxymethyl-modified to accommodate water solubility, it is difficult to further graft-modify double bonds, and modification of an anionic polyelectrolyte (hereinafter sometimes referred to as modified anionic polyelectrolyte) with methacrylic anhydride is easier to carry out, and does not affect the water solubility of the system.

Still further, the double bond material is used in the precursor solution in an amount by mass of: 0.2-2 parts of the double bond material is added per 100 parts of water.

The modified anion polyelectrolyte with such low concentration (for example, 0.2%) cannot be solidified at room temperature, but the modified anion polyelectrolyte is enriched at the grain boundary in the freezing environment, so that a covalent cross-linked network with better mechanical property can be constructed with lower concentration, and the gel sponge can be finally prepared from precursor solution with low solid content. Moreover, since such low concentrations of modified anionic polyelectrolytes cannot be cured in advance at room temperature, the macropores of the covalent cross-linked network are related to the ice crystal size, i.e., the size of the space for supplying the anionic polyelectrolyte and carboxymethyl chitosan to form the ionic cross-linked network is easily controlled.

Further, in the precursor solution, the sum of the amounts of the double bond material and the anionic polyelectrolyte is equal to the amount of the carboxymethyl chitosan by mass. The modified and unmodified anionic polyelectrolytes are fully interacted with carboxymethyl chitosan to form a first gel through static electricity, and the gel sponge material is formed by using a precursor solution with the lowest solid content.

Further, in the precursor solution, the carboxymethyl chitosan is used in an amount of: 0.5-4 parts of the carboxymethyl chitosan is added to 100 parts of water.

Further, the initiator is selected from ammonium persulfate, potassium persulfate or calcium persulfate; in the step of adding the initiator and the cross-linking agent to the precursor solution, N, N, N ', N' -tetramethyl ethylenediamine is also added at the same time.

The ammonium persulfate, the potassium persulfate and the calcium persulfate are difficult to generate free radicals in a freezing environment, and the addition of the N, N, N ', N' -tetramethyl ethylenediamine is helpful for the polymerization and the crosslinking of double bond materials in the freezing environment.

Further, maintaining the ice in the low temperature environment for 12-72 hours prior to the step of thawing the ice to room temperature. The freezing is to enrich solute in the grain boundary, so that solute with low concentration is enriched in the grain boundary, and the freezing for 12h-72 is favorable for forming a covalent cross-linked network frame with good mechanical property.

In a second aspect, the present application provides a gel sponge material made by the method of making a gel sponge material according to the first aspect. Has higher imbibition rate and faster imbibition rate, is obviously superior to cotton gauze, gelatin sponge and conventional chitosan-based sponge, and can be matched with medicament for tissue repair after hemostasis. The mechanical property and the shape recovery capability of the gel sponge material are obviously stronger than those of the sponge formed by mixing the conventional carboxymethyl chitosan with the anionic polyelectrolyte.

In a third aspect, the present application provides a method of using the gel sponge of the second aspect to apply the gel sponge to a wound or to fill, inject the gel sponge into a wound. Besides reducing blood loss, the wound can be supported, so that secondary injury in the compression hemostasis treatment process is avoided, and the subsequent treatment and recovery of the affected part are facilitated.

The beneficial effects of the invention are as follows: in the invention, under the freezing environment, solute is concentrated and crosslinked at the grain boundary to form a macroporous structure, and then the crosslinking of the anionic polyelectrolyte and the carboxymethyl chitosan is completed in the macroporous structure, so that the size of an ionic crosslinked network is limited, after the ionic crosslinked network is formed, the gap in the first gel is smaller than the gap of a covalent crosslinked network, and a tertiary butanol solution with a certain concentration is used as a freezing solvent in the freeze drying process, so that the size of ice crystals is reduced, the unique microstructure of sponge is reserved, and the problems of poor mechanical property and low liquid absorption rate of the conventional carboxymethyl chitosan mixed anionic polyelectrolyte sponge are solved.

Additional features and advantages of the application will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the application. The objects and other advantages of the present application may be realized and attained by the structure particularly pointed out in the written description and drawings.

Drawings

FIG. 1 is a scanning electron micrograph of the gel sponges obtained in comparative example 2, example 6, example 5, example 7 and example 2.

FIG. 2 is a scanning electron micrograph of the gel sponges obtained in comparative example 1 and examples 1 to 4.

FIG. 3 is a graph showing the results of the liquid absorbing and retaining ability test of the gel sponges obtained in comparative example 1 and examples 1 to 4.

FIG. 4 is a graph showing the results of the coagulation index test of the gel sponges obtained in comparative example 1 and examples 1 to 4.

Fig. 5 is a graph showing the results of the test of the gel sponges obtained in comparative example 1, example 2 and example 4 for hemostasis by visceral perforation in rats.

Fig. 6 is a flowchart of a preparation method and a usage method of a gel sponge material according to an embodiment of the present application.

Detailed Description

In the prior art, in order to enhance the mechanical property of the gel sponge, covalent and ionic double-crosslinking researches are also adopted, but the solid content is higher, for the hemostatic sponge, the volume change after imbibition is small, the density (solid content) is smaller, the more and the faster the absorbed blood is, and the better the hemostatic effect is. When the conventional polysaccharide material sponge is prepared, hydrogel is formed at room temperature and then freeze-dried into the sponge, the mechanical properties of the sponge depend on the amount of solid content to a great extent, and the higher the solid content, the better the mechanical properties. If the solid content is high, besides slow imbibition rate and low imbibition rate, the solid content is difficult to apply to a wound by injection and can only be applied to the wound. In the prior art, the ionic crosslinking is firstly studied, and then the in-situ covalent crosslinking is induced after the ionic crosslinking is injected into a wound, however, after the ionic crosslinking is injected into the wound, ultraviolet light is difficult to irradiate deep, in-situ free radical polymerization is difficult to induce, in-vivo free radical polymerization is easy to cause inflammation, the in-situ crosslinking degree is difficult to control, and unlike the conventional gel sponge, the soft and hard degree is defined and the in-situ covalent crosslinking is injected into human tissues.

Referring to fig. 6, an embodiment of the present application provides a method for preparing a gel sponge material, including the following steps:

s1: carboxymethyl chitosan, anionic polyelectrolyte and double bond material are dissolved in water to form precursor solution.

S2: adding an initiator and a cross-linking agent into the precursor solution, and placing the mixture in a low-temperature environment (0 ℃ to-80 ℃) until the mixture is coagulated into ice cubes.

S3: thawing ice to room temperature to obtain solid-liquid mixture.

S4: fumigating the solid-liquid mixture with acetic acid to obtain a first gel.

S5: the water in the first gel was replaced with t-butanol to give a second gel.

S6: and freeze-drying the second gel to obtain the gel sponge material.

And S2, placing the precursor solution below the crystallization point temperature of solvent water, wherein the solvent water can crystallize, and solute is separated out and enriched at the crystal boundary of the solvent, and a cross-linked network can be formed when the concentration of raw materials is low, so that the double-bond material is cross-linked in a freezing environment to form a covalent cross-linked network with a macroporous structure. In the step S4, the anionic polyelectrolyte and the carboxymethyl chitosan at the grain boundary are dissolved in the gaps of the covalent cross-linking network, and after the covalent cross-linking network is completely thawed, acetic acid is used for fumigation, and the space for forming the ionic cross-linking network by the anionic polyelectrolyte and the carboxymethyl chitosan is the macropores of the covalent cross-linking network, so that the size of the ionic cross-linking network is limited, and after the ionic cross-linking network is formed, the gaps in the first gel are smaller than the gaps of the covalent cross-linking network. And S5, replacing part or all of solvent water by using a tertiary butanol aqueous solution, so that small gaps can still be reserved after the step S6, a unique microstructure is reserved, and the obtained gel sponge material has stronger liquid absorption capacity and better shape recovery capacity than a common gel sponge material.

The invention can reduce the solid content and increase the mechanical property, especially the shape recovery capability. In the step S1, water is used as a freezing solvent, crystals generated by water crystallization are large, double bond materials are crosslinked at crystal boundaries, a macroporous structure can be formed by thawing, and the formed frame has good mechanical properties due to small area of the crystal boundaries. In step S4, the anionic polyelectrolyte and carboxymethyl chitosan adhere to the original covalent cross-linked network frame and are filled in the above-mentioned macroporous structure, so as to form a microstructure (ionic cross-linked network) formed by smaller electrostatic interactions, and the solvent water is replaced by tertiary butanol, so that the size of ice crystals can be reduced, and the microstructure can be protected. If tertiary butanol is not used for replacement, the microstructure smaller than the macroporous structure generated by acetic acid fumigation is squeezed by ice crystals onto the inner wall of the original macroporous structure in step S6, and the microstructure cannot be maintained until sponge is formed.

Specifically, the precursor solution is poured in a plastic culture dish, and after the steps S2 and S3, the precursor solution is placed in a glass dryer with a baffle plate, the bottom of the dryer is filled with glacial acetic acid solution, acetic acid molecules at the bottom volatilize and fill the whole dryer at room temperature, and the acetic acid molecules penetrate through the surface of a material and enter the inside of the material to protonate amino groups on carboxymethyl chitosan molecules, so that the combination with the anionic polyelectrolyte is realized. Due to the existence of a large amount of protonated amino groups, the sponge has excellent blood cell adhesion performance and antibacterial performance, and can be used for healing wounds after rapid hemostasis.

The gel sponge material obtained by the invention can be applied to various hemostatic and wound healing scenes. For example:

(1) Can be matched with certain pressure to be used for the local external hemorrhage of the conventional superficial skin wound and the subsequent wound repair.

(2) Can be used as filling material for penetrating wound, and can reduce blood loss, absorb exudation tissue fluid, inhibit wound inflammation, and reduce infection probability.

(3) Arterial blood splatter in the subject can be reduced by injection of the syringe into the deeper wound arterial defect.

(4) The sponge material is injected into the internal viscera wound, which not only can quickly stop bleeding and reduce bleeding amount, but also can support the shape and structure of the viscera wound, thereby avoiding secondary injury in the treatment process and being convenient for subsequent treatment and recovery of the affected part. Has good performance in treating major bleeding caused by visceral incompressible wounds of a subject.

Comparative example 1

1 part of sodium alginate and 1 part of carboxymethyl chitosan are added into 100 parts of deionized water, and stirred until the sodium alginate and the carboxymethyl chitosan are fully dissolved. The solution was fumigated in acetic acid atmosphere for 4 hours. The gel sponge mixture is soaked in pure tertiary butanol for 2 hours, and then is taken out for freeze drying, so that the gel sponge CM1 is obtained.

Example 1

0.8 part of sodium alginate, 0.2 part of sodium alginate modified by methacrylic anhydride and 1 part of carboxymethyl chitosan are added into 100 parts of deionized water, and stirred until the sodium alginate, the sodium alginate and the carboxymethyl chitosan are fully dissolved. To the above solution, 0.04 parts of ammonium persulfate and 0.04 parts of N, N ' -methylenebisacrylamide as a crosslinking agent, and 0.05 parts of N, N, N ', N ' -tetramethylethylenediamine were added and stirred to form a uniform solution. Pouring the solution into a mould with a flat bottom, freezing in a refrigerator at-20 ℃ for 24 hours, then taking out, thawing at room temperature overnight, and finally fumigating in acetic acid atmosphere for 4 hours. The obtained first gel is placed in pure tertiary butanol for soaking for 2 hours, and then is taken out for freeze drying, so as to obtain the finished gel sponge CM2.

Example 2

0.5 part of sodium alginate, 0.5 part of sodium alginate modified by methacrylic anhydride and 1 part of carboxymethyl chitosan are added into 100 parts of deionized water, and stirred until the sodium alginate, the sodium alginate and the carboxymethyl chitosan are fully dissolved. To the above solution, 0.04 parts of ammonium persulfate and 0.04 parts of N, N ' -methylenebisacrylamide as a crosslinking agent, and 0.05 parts of N, N, N ', N ' -tetramethylethylenediamine were added and stirred to form a uniform solution. Pouring the solution into a mould with a flat bottom, freezing in a refrigerator at-20 ℃ for 24 hours, then taking out, thawing at room temperature overnight, and finally fumigating in acetic acid atmosphere for 4 hours. The obtained first gel is placed in pure tertiary butanol for soaking for 2 hours, and then is taken out for freeze drying, so as to obtain the finished gel sponge CM3.

Example 3

0.2 part of sodium alginate, 0.8 part of sodium alginate modified by methacrylic anhydride and 1 part of carboxymethyl chitosan are added into 100 parts of deionized water, and stirred until the sodium alginate, the sodium alginate and the carboxymethyl chitosan are fully dissolved. To the above solution, 0.04 parts of ammonium persulfate and 0.04 parts of N, N ' -methylenebisacrylamide as a crosslinking agent, and 0.05 parts of N, N, N ', N ' -tetramethylethylenediamine were added and stirred to form a uniform solution. Pouring the solution into a mould with a flat bottom, freezing in a refrigerator at-20 ℃ for 24 hours, then taking out, thawing at room temperature overnight, and finally fumigating in acetic acid atmosphere for 4 hours. The obtained first gel is placed in pure tertiary butanol for soaking for 2 hours, and then is taken out for freeze drying, so as to obtain the finished gel sponge CM4.

Example 4

1 part of sodium alginate modified by methacrylic anhydride and 1 part of carboxymethyl chitosan are added into 100 parts of deionized water, and stirred until the sodium alginate and the carboxymethyl chitosan are fully dissolved. To the above solution, 0.04 parts of ammonium persulfate and 0.04 parts of N, N ' -methylenebisacrylamide as a crosslinking agent, and 0.05 parts of N, N, N ', N ' -tetramethylethylenediamine were added and stirred to form a uniform solution. Pouring the solution into a mould with a flat bottom, freezing in a refrigerator at-20 ℃ for 24 hours, then taking out, thawing at room temperature overnight, and finally fumigating in acetic acid atmosphere for 4 hours. The obtained first gel is placed in pure tertiary butanol for soaking for 2 hours, and then is taken out for freeze drying, so as to obtain the finished gel sponge CM5.

Example 5

0.5 part of sodium alginate, 0.5 part of sodium alginate modified by methacrylic anhydride and 1 part of carboxymethyl chitosan are added into 100 parts of deionized water, and stirred until the sodium alginate, the sodium alginate and the carboxymethyl chitosan are fully dissolved. To the above solution, 0.04 parts of ammonium persulfate and 0.04 parts of N, N ' -methylenebisacrylamide as a crosslinking agent, and 0.05 parts of N, N, N ', N ' -tetramethylethylenediamine were added and stirred to form a uniform solution. Pouring the solution into a mould with a flat bottom, freezing in a refrigerator at-80 ℃ for 24 hours, then taking out, thawing at room temperature overnight, and finally fumigating in acetic acid atmosphere for 4 hours. The obtained first gel is placed in a tertiary butanol aqueous solution with the mass fraction of 10% for soaking for 2 hours, and then is taken out for freeze drying, so as to obtain the finished gel sponge CM6.

Comparative example 2

0.5 part of sodium alginate, 0.5 part of sodium alginate modified by methacrylic anhydride and 1 part of carboxymethyl chitosan are added into 100 parts of deionized water, and stirred until the sodium alginate, the sodium alginate and the carboxymethyl chitosan are fully dissolved. To the above solution, 0.04 parts of ammonium persulfate and 0.04 parts of N, N ' -methylenebisacrylamide as a crosslinking agent, and 0.05 parts of N, N, N ', N ' -tetramethylethylenediamine were added and stirred to form a uniform solution. Pouring the solution into a mould with a flat bottom, freezing in a refrigerator at-20 ℃ for 24 hours, taking out, thawing overnight at room temperature, fumigating in acetic acid atmosphere for 4 hours, taking out, and freeze-drying to obtain the gel sponge CM7.

Example 6

0.5 part of sodium alginate, 0.5 part of sodium alginate modified by methacrylic anhydride and 1 part of carboxymethyl chitosan are added into 100 parts of deionized water, and stirred until the sodium alginate, the sodium alginate and the carboxymethyl chitosan are fully dissolved. To the above solution, 0.04 parts of ammonium persulfate and 0.04 parts of N, N ' -methylenebisacrylamide as a crosslinking agent, and 0.05 parts of N, N, N ', N ' -tetramethylethylenediamine were added and stirred to form a uniform solution. Pouring the solution into a mould with a flat bottom, freezing in a refrigerator at-20 ℃ for 24 hours, then taking out, thawing at room temperature overnight, and finally fumigating in acetic acid atmosphere for 4 hours. The obtained first gel is placed in a tertiary butanol aqueous solution with the mass fraction of 2.5% for soaking for 2 hours, and then is taken out for freeze drying, so as to obtain the finished gel sponge CM8.

Example 7

0.5 part of sodium alginate, 0.5 part of sodium alginate modified by methacrylic anhydride and 1 part of carboxymethyl chitosan are added into 100 parts of deionized water, and stirred until the sodium alginate, the sodium alginate and the carboxymethyl chitosan are fully dissolved. To the above solution, 0.04 parts of ammonium persulfate and 0.04 parts of N, N ' -methylenebisacrylamide as a crosslinking agent, and 0.05 parts of N, N, N ', N ' -tetramethylethylenediamine were added and stirred to form a uniform solution. Pouring the solution into a mould with a flat bottom, freezing in a refrigerator at-20 ℃ for 24 hours, then taking out, thawing at room temperature overnight, and finally fumigating in acetic acid atmosphere for 4 hours. The obtained first gel is placed in a tertiary butanol aqueous solution with the mass fraction of 50% for soaking for 2 hours, and then is taken out for freeze drying, so as to obtain the finished gel sponge CM9.

Example 8

0.5 part of sodium hyaluronate, 0.5 part of double bond modified sodium hyaluronate and 1 part of carboxymethyl chitosan are added into 100 parts of deionized water, and stirred until fully dissolved. To the above solution, 0.04 parts of potassium persulfate and 0.04 parts of N, N ' -methylenebisacrylamide as a crosslinking agent, and 0.05 parts of N, N, N ', N ' -tetramethylethylenediamine were added and stirred to form a uniform solution. Pouring the solution into a mould with a flat bottom, freezing in a refrigerator at-20 ℃ for 12 hours, then taking out, thawing overnight at room temperature, and finally fumigating in acetic acid atmosphere for 8 hours. The obtained first gel is placed in pure tertiary butanol for soaking for 2 hours, and then is taken out for freeze drying, so as to obtain the finished gel sponge CM10.

Example 9

0.25 part of sodium carboxymethyl cellulose, 0.25 part of double bond modified sodium carboxymethyl cellulose and 0.5 part of carboxymethyl chitosan are added into 100 parts of deionized water, and stirred until fully dissolved. To the above solution, 0.04 parts of calcium persulfate and 0.04 parts of N, N ' -methylenebisacrylamide as a crosslinking agent, and 0.05 parts of N, N, N ', N ' -tetramethylethylenediamine were added and stirred to form a uniform solution. Pouring the solution into a mould with a flat bottom, freezing in a refrigerator at-20 ℃ for 72 hours, then taking out, thawing at room temperature overnight, and finally fumigating in acetic acid atmosphere for 2 hours. The obtained first gel is placed in a tertiary butanol aqueous solution with the mass fraction of 10% for soaking for 2 hours, and then is taken out for freeze drying, so as to obtain the finished gel sponge CM11.

Example 10

1 part of carrageenan, 1 part of double bond modified carrageenan and 2 parts of carboxymethyl chitosan are added into 100 parts of deionized water, and stirred until the carrageenan, the double bond modified carrageenan and the 2 parts of carboxymethyl chitosan are fully dissolved. To the above solution, 0.04 parts of potassium persulfate and 0.04 parts of N, N ' -methylenebisacrylamide as a crosslinking agent, and 0.05 parts of N, N, N ', N ' -tetramethylethylenediamine were added and stirred to form a uniform solution. Pouring the solution into a mould with a flat bottom, freezing in a refrigerator at-20 ℃ for 48 hours, then taking out, thawing at room temperature overnight, and finally fumigating in acetic acid atmosphere for 1 hour. The obtained first gel is placed in a tertiary butanol aqueous solution with the mass fraction of 10% for soaking for 2 hours, and then is taken out for freeze drying, so as to obtain the finished gel sponge CM12.

Example 11

2 parts of carboxymethyl curdlan, 2 parts of double bond modified carboxymethyl curdlan and 4 parts of carboxymethyl chitosan are added into 100 parts of deionized water, and stirred until the mixture is fully dissolved. To the above solution, 0.04 parts of calcium persulfate and 0.04 parts of N, N ' -methylenebisacrylamide as a crosslinking agent, and 0.05 parts of N, N, N ', N ' -tetramethylethylenediamine were added and stirred to form a uniform solution. Pouring the solution into a mould with a flat bottom, freezing in a refrigerator at-20 ℃ for 60 hours, then taking out, thawing at room temperature overnight, and finally fumigating in acetic acid atmosphere for 8 hours. The obtained first gel is placed in a tertiary butanol aqueous solution with the mass fraction of 10% for soaking for 2 hours, and then is taken out for freeze drying, so as to obtain the finished gel sponge CM13.

Fig. 1 is a scanning electron microscope picture of the gel sponges obtained in comparative example 2, example 6, example 5, example 7 and example 2, from which it can be seen that a macroporous sponge structure is formed when the solution is deionized water at the time of freeze-drying, and that the microstructure in the pores remains intact when the solution is t-butanol at the time of freeze-drying.

FIG. 2 is a scanning electron microscope image of the gel sponges obtained in comparative example 1 and examples 1 to 4. Examples 1 to 3 the microtopography of the cryogel sponge is a lamellar pore structure, which benefits from the fact that the ionic crosslinked network formed by electrostatic interactions is flooded with covalently crosslinked networks. Whereas the microstructure of the sponge of example 4 is a porous thick-walled structure, such structural differences may result from electrostatic interactions formed by carboxymethyl chitosan attaching to the modified anionic polyelectrolyte network.

The liquid absorption and retention capacities of the gel sponges obtained in comparative example 1 and examples 1 to 4 are shown in fig. 3, and fig. 3a shows the liquid absorption rate (in mass) of frozen gel versus time; FIG. 3b shows the imbibition rate of the gel sponge after two hours of equilibration in water and the imbibition rate remaining after continued centrifugation at 1500 rpm. As can be seen from fig. 3, the wicking rate of the sponge increases with increasing content of the modified anionic polyelectrolyte. The liquid absorption rate of the CM5 obtained in example 4 at 1 minute can reach about 40 times of the total mass of the sponge, which is mainly caused by capillary phenomenon caused by the macroporous structure in the sponge CM5. Whereas the liquid absorption rate of comparative example 1 sponge CM1 at 1 minute was about 20 times. In the case where the total mass of the anionic polyelectrolyte and the modified anionic polyelectrolyte is equal, the liquid retention capacity of the sponge decreases with increasing content of the modified anionic polyelectrolyte, which is related to the gel sponge structure transition of the material. The hemostatic sponge can form a gel sponge composite structure after absorbing blood, and the structure endows the hemostatic sponge with good liquid-retaining capacity, and effectively avoids exudation of blood in the hemostatic process.

The gel sponges obtained in comparative example 1 and examples 1 to 4 have the coagulation index shown in FIG. 4, in which the test material was used to absorb blood, and after a certain period of time, the gel sponges were rinsed with deionized water, and the absorbance of the rinsed deionized water was measured, so that the smaller the coagulation index was, the higher the coagulation ability was. As can be seen from fig. 4, the coagulation index of the gel sponge decreases sharply with increasing modified anionic polyelectrolyte ratio, wherein the coagulation index of example 4, example 5 is less than 2%, which is much less than 31.76% of cotton (Gauze). The extremely low coagulation index indicates that the gel sponge has good whole blood coagulation capability and can be used as an injectable sponge for hemostatic treatment of incompressible wounds.

Characterization of in vivo hemostatic effect of gel sponges using liver perforation model of female SD rats as shown in fig. 5, fig. 5a shows the amount of blood lost after hemostatic treatment, fig. 5b shows time to complete hemostasis after hemostatic treatment, and the model hemostatic time of experimental group for injectable sponge treatment is effectively shortened compared to Blank group Blank, from 62. 62 s of Blank group to 3 s, and the major bleeding of wound is effectively improved, from 701.4 mg of Blank group to 40 mg. Experiments show that the injectable hemostatic sponge has good in-vivo hemostatic performance.

The hemostatic sponge in the embodiment of the application has the advantages of high liquid absorption rate, high liquid absorption multiplying power and good liquid retention capacity, and the application range of the hemostatic sponge is far larger than that of cotton gauze, gelatin sponge and conventional chitosan-based sponge.

In the description of the present specification, the descriptions of the terms "one embodiment," "certain embodiments," "an exemplary embodiment," "an example," "a particular example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While the foregoing is directed to the preferred embodiments of the present invention, it will be appreciated by those skilled in the art that changes and modifications may be made without departing from the principles of the invention, such changes and modifications are also intended to be within the scope of the invention.

Claims

1. The preparation method of the gel sponge material is characterized by comprising the following steps:

thawing the ice cubes to room temperature to obtain a solid-liquid mixture;

fumigating the solid-liquid mixture with acetic acid to obtain a first gel;

replacing water in the first gel with tertiary butanol to obtain a second gel;

and freeze-drying the second gel to obtain the gel sponge material.

2. The method for preparing a gel sponge according to claim 1, wherein the anionic polyelectrolyte is selected from one of alginate, sodium hyaluronate, carrageenan, sodium carboxymethyl cellulose, sodium carboxymethyl starch, carboxymethyl curdlan and carboxymethyl pachymaran.

3. The method for preparing a gel sponge material as claimed in claim 2 wherein the double bond material is the anionic polyelectrolyte modified with methacrylic anhydride.

4. A method of preparing a gel sponge material as claimed in claim 3 wherein the amount of double bond material in the precursor solution is by mass: 0.2-2 parts of the double bond material is added per 100 parts of water.

5. A method of producing a gel sponge material as claimed in claim 3 wherein the sum of the amounts of the double bond material and the anionic polyelectrolyte in the precursor solution is equal to the amount of the carboxymethyl chitosan by mass.

6. The method for producing a gel sponge according to claim 1, wherein the carboxymethyl chitosan is used in the precursor solution in an amount of: 0.5-4 parts of the carboxymethyl chitosan is added to 100 parts of water.

7. The method for preparing a gel sponge material as claimed in claim 1 wherein the initiator is selected from ammonium persulfate, potassium persulfate or calcium persulfate; in the step of adding the initiator and the cross-linking agent to the precursor solution, N, N, N ', N' -tetramethyl ethylenediamine is also added at the same time.

8. The method of preparing a gel sponge of claim 1 wherein the ice is maintained in the low temperature environment for 12-72 hours prior to the step of thawing the ice to room temperature.

9. A gel sponge material prepared by the method of any one of claims 1 to 8.

10. A method of using the gel sponge of claim 9, wherein the gel sponge is applied to a wound or filled or injected into a wound.