CN114452436B

CN114452436B - Collagen-based injectable self-repairing hydrogel and preparation method thereof

Info

Publication number: CN114452436B
Application number: CN202210006961.8A
Authority: CN
Inventors: 魏清荣; 顾浩杰
Original assignee: Sichuan University
Current assignee: Sichuan University
Priority date: 2022-03-15
Filing date: 2022-03-15
Publication date: 2022-08-23
Anticipated expiration: 2042-03-15
Also published as: CN115887742B; CN115887742A; CN114452436A

Abstract

The invention provides collagen-based injectable self-repairing hydrogel and a preparation method thereof, which are applicable to healing of complex or chronic wound surfaces; the collagen-based injectable self-repairing hydrogel is prepared by crosslinking through a dynamic Schiff base bond between oxidized konjac glucomannan and collagen and adding chitosan on the basis of the crosslinking to prevent collagen molecules from self-assembling, so that the collagen-based injectable self-repairing hydrogel with excellent self-repairing performance is prepared; the preparation method discovers that the pH adjustment before gelation is a key influence factor through a gradient experiment, and finally prepares the collagen-based hydrogel product with excellent injectability and self-repairing performance.

Description

Collagen-based injectable self-repairing hydrogel and preparation method thereof

Technical Field

The invention relates to the technical field of collagen-based biomedical materials, in particular to collagen-based injectable self-repairing hydrogel and a preparation method thereof, which can be used as a functional dressing and is suitable for complex or chronic wound healing.

Background

The phenomena of complicated wounds, large tissue necrosis and defects caused by aging of population, burns, scalds, diseases, operations and the like, chronic wounds caused by diabetic foot ulcers and the like are on the increasing trend. Functional dressing materials for promoting and assisting the gradual healing and rehabilitation of complex chronic wounds and wound surfaces which are large in area and difficult to heal are one of the biomedical materials with the largest clinical demand.

At present, more and more researches show that injectable and self-repairing hydrogels show outstanding advantages in clinical application. On one hand, the injection can be conveniently used, not only can be used on the body surface, but also can be used in the body in a minimally invasive way; self-healing type materials, on the other hand, can match irregular defect shapes and maintain the continuity and integrity of the material. The injectable self-repairing hydrogel is particularly suitable for long-term nursing rehabilitation of complex or chronic wounds with large irregular wound surfaces, ulcers and the like. Because the dressing on the wound needs to be replaced every few days during the slow healing process, it is required that the old dressing is easy to remove and cannot adhere tightly to the newly healed wound to cause secondary trauma; meanwhile, the dressing is required to be replaced and operated simply and conveniently, and can be quickly coated on the whole wound surface, particularly the wound surface with a large area and an irregular shape. The injectability of the gel determines its ease of coating; the self-repairing property of the gel determines that after the gel is coated on a wound surface or a wound, gaps can be repaired to finally form a continuous and complete gel layer, so that the wound surface is protected and a moist microenvironment which is beneficial to healing is maintained. The gel dressing material can be automatically replaced at home without the help of professional medical staff. On one hand, the burden of the patient is reduced in economy, time and nursing manpower; on the other hand, public medical resources are saved to a certain extent, and the workload of medical staff is reduced.

Based on the applicability advantage that the injectable self-repairing hydrogel has the effect of assisting the continuous rehabilitation and healing of complex chronic wounds or wounds, the trend of functional dressing development at present is to select proper natural biological macromolecules to combine and design the injectable self-repairing hydrogel dressing material from the aspects of excellent biocompatibility and biodegradability. While satisfying good biocompatibility, easy biodegradation is also required, since faster biodegradability facilitates easy and convenient replacement and removal of old dressings, avoiding secondary trauma.

However, the injectable self-repairing hydrogels do not have a collagen component or a collagen-like component, and thus have the following disadvantages that, since the hydrogels are mainly composed of non-collagenous synthetic polymers or natural polysaccharide polymers, or a complex of the two, the affinity of cells to these gel materials is much lower, i.e., the biocompatibility of cells is not good; secondly, even if gelatin, which is a denatured product of collagen, has a molecular structure that does not have the native triple-helical conformation of collagen molecules, the native triple-helical conformation of collagen molecules expresses its unique biological activity, and thus gelatin does not have the biological activity of collagen molecules. The results of a number of studies show that collagen molecules with specific biological activity exhibit better regenerative modification function for wound healing compared to gelatin.

Therefore, based on the above-mentioned drawbacks, there have been proposed studies on collagen-based hydrogels. Collagen (Collagen) is a major component of the extracellular matrix of animals, accounts for about 25-30% of the total amount of proteins in the animal body, is widely present in bones, tendons, cartilage and skin and other connective tissues, and is the fibrous structural protein with the largest content in the animal body. As a natural biological macromolecule, the unique triple helix structure of the collagen molecule endows the collagen molecule with excellent biological properties such as biocompatibility, biodegradability, low antigenicity, cell adaptability, cell proliferation and the like, and specific gel forming property and mechanical property. At present, collagen is widely applied to the fields of biomedical materials, health care, cosmetics, food and the like.

The evaluation research result of the collagen material shows that the collagen is not only beneficial to the healing of the natural wound surface, but also has better local treatment effect on chronic wounds, wound surfaces, bedsores and the like caused by clinical ulcer lesions; meanwhile, the intensive research on the wound healing mechanism discovers that a moist microenvironment is more suitable for self-repair and regeneration of wound tissues, so that ideal regenerative repair is favorably realized, and scar repair is reduced or even avoided. The hydrogel has a three-dimensional network bionic structure constructed by hydrophilic macromolecules, has good water retention and porosity, and can form and maintain a proper moist microenvironment, so that the hydrogel is an ideal material for promoting wound treatment and repair. In addition, the hydrogel is also an excellent carrier for storing and delivering the drugs and the functional nanoparticles, and the diversification of the gel function can be realized at the same time.

On the other hand, the specific triple helix structure of collagen endows collagen macromolecules with the ability of spontaneously arranging and assembling into a three-dimensional through fiber network hydrogel under in vitro physiological conditions. Based on such properties, collagen-based biomaterials are usually obtained by compounding collagen macromolecules with natural polysaccharide macromolecules, such as chitosan, sodium alginate, sodium hyaluronate, or synthetic macromolecules, such as polylactic acid, polyethylene glycol, or polyvinyl alcohol, by physical blending or chemical crosslinking to obtain collagen-polysaccharide or collagen-synthetic macromolecule composite hydrogels.

In The physical blending method, collagen is usually used as The main basic component, other macromolecules are used as The minor components, or The two are half, and The self-assembly behavior of neutral collagen molecules responding to heat is used as The driving force to realize The co-growth of fibers, so as to obtain The collagen-chitosan composite fiber hydrogel (Xiaooling Wang, Lin Sangg, Dongmei Luo, Xudong Li. from collagen-chitosan blends to be a three-dimensional scaffold: The inflammation of collagen on collagen not fibrous structure and mechanical property [ J ]. Colloids and Surfaces B: Biointerfaces 82(2011) 233-.

Collagen-based composite hydrogels have also been prepared by a cyclic freeze-thaw process, such as collagen-chitosan-polyvinyl alcohol composite hydrogel and collagen-chitosan-fucoidan composite hydrogel (YanTing, Meng snow-duch, Liwenong, Tonke courage, a new collagen/chitosan/polyvinyl alcohol composite hydrogel dressing, 2016, the eleventh national leather chemistry Commission and Chinese leather Association technical Commission, Abstract of the 21 st year; Eco-friendly gels from mineral hydrogels, products and uses therof, International Patent, PCT/IB/2020/056341). The method utilizes multiple orientations among macromolecules such as collagen and the like to form a micro-crystalline region, thereby realizing physical crosslinking of several macromolecules.

Also, a collagen-based composite hydrogel (Lisheng, Wanghai, He Lang, Zhang Jun, a collagen-chitosan hydrogel and a preparation method thereof, CN202010202330.4) was prepared by an electrochemical method. Inserting a cathode and an anode which are connected with an electrochemical workstation into the mixed solution of the collagen and the chitosan, and then carrying out electrodeposition by controlling the electrifying mode through the electrochemical workstation to obtain the collagen-chitosan hydrogel.

In the above physical methods or preparation techniques, although the collagen molecules and non-collagen molecules such as chitosan are co-assembled or co-deposited by non-covalent bonds such as molecular chain entanglement, hydrogen bonds or hydrophobic bonds to form composite fiber hydrogels, the three-dimensional network of these hydrogels is a unidirectional irreversible fixed network, and cannot reversibly return to an injectable fluid state under the condition of applying shear force, such as injection or extrusion; and cannot repair the fracture itself and regain a gel of integrity after being damaged.

Therefore, the existing collagen-based hydrogel has no injectability and self-repairing property, so that the convenient application of the collagen-based hydrogel material in the fields of biomedical treatment and medical cosmetology is still limited to a certain extent.

In view of excellent biocompatibility and specific bioactivity of the collagen, the collagen-based hydrogel which takes the collagen as a main component and has self-repairing property and injectability is prepared by integrating and utilizing the advantageous properties of the collagen, and has great biomedical application value.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides collagen-based injectable self-repairing hydrogel and a preparation method thereof, the collagen-based injectable self-repairing hydrogel is crosslinked by adopting a dynamic Schiff base bond between oxidized konjac glucomannan and collagen, and chitosan is added to block collagen molecules from self-assembling on the basis, so that the collagen-based injectable self-repairing hydrogel with excellent self-repairing performance is prepared; the preparation method discovers that the pH adjustment before gelation is a key influence factor through a gradient experiment, and finally prepares the collagen-based hydrogel product with excellent injectability and self-repairing performance.

In order to achieve the purpose, the invention adopts the technical scheme formed by the following technical measures.

The collagen-based injectable self-repairing hydrogel mainly comprises the following raw materials in parts by weight:

100 parts of collagen;

100-200 parts of chitosan;

20-30 parts of oxidized konjac glucomannan;

wherein the oxidized konjac glucomannan is obtained by selectively oxidizing konjac glucomannan, the oxidation degree is 30-70%, and the weight average molecular weight is 3-20 ten thousand.

Wherein the collagen and chitosan have different solution concentrations according to the purpose and performance of preparing the gel. In order to facilitate the Schiff base dynamic crosslinking reaction of the collagen and the chitosan with the oxidized konjac glucomannan, a person skilled in the art can select a proper concentration of the oxidized konjac glucomannan solution according to the specific use condition, and select a proper concentration of the collagen and the chitosan solution when the selected collagen and the chitosan are non-solid so as to facilitate the normal running of the dynamic Schiff base crosslinking reaction. In addition, the weight parts of collagen, chitosan and oxidized konjac glucomannan in the raw materials refer to dry weight.

Generally, the oxidized konjac glucomannan is obtained by selectively oxidizing konjac glucomannan, the oxidation degree of the oxidized konjac glucomannan is 30-70%, the weight average molecular weight of the oxidized konjac glucomannan is 3-20 ten thousand, and on the premise that the oxidation degree and the weight average molecular weight are met, a person skilled in the art can select a proper selective oxidation technical mode according to the prior art. The principle of selective oxidation is based on the formation of an aldehyde substituent by breaking the bond with a hydroxyl group at both the 2 and 3 carbons of the saccharide ring. In order to better illustrate the present invention and provide a preferred technical solution, the oxidized konjac glucomannan is obtained by dissolving konjac glucomannan and then selectively oxidizing with sodium periodate.

Further, the preparation method of the oxidized konjac glucomannan specifically comprises the following steps:

preparing 0.5-3% konjac glucomannan solution, adding sodium periodate solution into the konjac glucomannan solution to enable the final concentration of the sodium periodate in the solution to be 5-20 mM, enabling the reaction temperature to be 25-40 ℃, and stirring and reacting for 6-12 hours under the condition of keeping out of the sun; after the reaction time is up, adding an ethylene glycol solution, and stirring for 15-30 minutes to terminate the reaction; dialyzing the obtained solution in pure water for 12-48 hours, and freeze-drying to obtain the oxidized konjac glucomannan product.

The reaction principle of the oxidation of the konjac glucomannan by the sodium periodate is shown as follows:

the degree of oxidation can be measured by the hydroxylamine hydrochloride method, and those skilled in the art can select an appropriate measurement method according to actual conditions and production scale. For a better illustration of the invention, under laboratory conditions, reference may be made to the following specific assay formats:

1.74g of hydroxylamine hydrochloride is weighed into a 100mL volumetric flask containing 80mL of deionized water, 1mL of 0.05% methyl orange solution is added, and the volume is determined by using deionized water. 0.1g of the lyophilized oxidized konjac glucomannan powder was dissolved in 25mL of the above solution and incubated at 40 ℃ for 4 h. Further, NaOH solution (0.1 mol/L) was added dropwise, and the volume of the NaOH solution consumed when the solution changed from red to yellowish brown was recorded, and then the degree of oxidation OD (equation 1) was calculated as follows.

In the formula:

c: the concentration of NaOH used during titration, mol/L;

v: the volume of NaOH used during titration, L;

m: weighing the mass of the oxidation product, g;

360: the molecular mass of the oxidized konjac glucomannan repeating unit is g/mol.

Wherein the collagen is of animal origin, and usually, those skilled in the art can select a suitable collagen source according to the actual application. Preferably, the collagen is type I collagen extracted from pig skin or cow leather or fish skin or bovine achilles tendon.

The technical principle of the invention is as follows:

first, the irreversibility and non-self-repairing property of collagen-based hydrogels in the prior art are determined by the formation mechanism of such collagen-based hydrogels, and the chemical crosslinking of collagen is to form a relatively stable network structure by generating covalent crosslinking bonds between active groups in or among collagen molecules, for example, carbodiimide or glutaraldehyde is commonly used for chemical crosslinking. Although the mechanical property, stability and the like of the hydrogel network are improved, the mobility of molecular chains is restricted, so that the injectability is lost, and once the network is damaged and cracks appear, the network cannot repair itself, so that the integrity of the hydrogel structure is lost.

Therefore, in order to achieve reversibility and self-repairing property of the collagen-based hydrogel, reversibility of chemical bond crosslinking of the hydrogel needs to be achieved.

The invention adopts a crosslinking mode of dynamic Schiff base bonds, and the dynamic Schiff base bonds are dynamically reversible, so that the self-repairing performance can be generated, and the free movement of collagen molecules can be further limited to weaken the self-assembling capability of the collagen molecules, so that irreversible collagen fibers cannot be smoothly formed. Through contrast experiments, the oxidized konjac glucomannan with good biocompatibility, low cost and rich sources is selected as the flexible macromolecular cross-linking agent. In addition, the oxidized konjac glucomannan has better effect when being used as a cross-linking agent in dressing, in the traditional Chinese medicine book, konjac is often used for treating burn and skin diseases, and konjac glucomannan is a main polysaccharide component of konjac.

In order to realize the crosslinking mode of the dynamic Schiff base bond, the konjac glucomannan molecules are selectively oxidized, and one hydroxyl group on the C-2 and 3 positions of the sugar ring on the molecular chain is oxidized into an aldehyde group, so that the oxidized konjac glucomannan molecular chain has a certain number of aldehyde groups and can form the Schiff base bond with amino. Under the condition that the pH value is 5.0-6.5, the formed Schiff base bond is a dynamic covalent cross-linking bond, and a typical shear thinning effect, namely injectability (see the attached figure 1 of the specification) and a self-repairing effect (see the attached figure 2 of the specification) can be realized on rheological properties; furthermore, experiments prove that in one preferable technical scheme, for konjac glucomannan with different concentrations, as long as the oxidation conditions of sodium periodate are the same, the physicochemical properties (aldehyde group content, weight average molecular weight range and the like) of the oxidation products are similar, so that the repeatability is better; in addition, the konjac glucomannan molecular chain is a flexible macromolecule with a certain branching degree, has a good synergistic composite effect with collagen, can increase the toughness of rigid molecular systems such as collagen and the like, and is favorable for an application mode that the collagen-based hydrogel is suitable for multiple scenes.

However, it is important to point out that, although the reversible chemical bond crosslinking of the collagen-based hydrogel is realized through the schiff base bond, and the prepared collagen-based hydrogel has injectability and self-repairing property, the inventor of the present invention finds that the self-repairing time of the self-repairing hydrogel prepared only through the schiff base bond crosslinking between collagen and oxidized konjac glucomannan is as long as 1-2 h, and the practical application effect and feasibility thereof are severely restricted.

Further analysis speculates that this may be due to the fact that collagen is a natural protein with a certain number of amino groups in its molecular chain; the unique triple helix structure of the collagen molecule endows the collagen molecule with specific gel forming performance: in vitro, collagen molecules can rapidly undergo self-assembly of oriented arrangement as long as physiological pH and room temperature to physiological temperature conditions are reached, thereby forming a three-dimensional fibrous network from the self-assembly of individual molecules. The lower concentration limit that triggers this self-assembly behavior of collagen molecules is 0.1% (wt/wt). That is, collagen molecules readily self-assemble into fibers as long as environmental conditions are appropriate, but the hydrogel formed by such fibers is irreversible, i.e., the gel has no self-healing ability after breaking. Therefore, hydrogels formed based on the self-assembly property of collagen molecules are not self-repairing hydrogels, but are only irreversible hydrogels, including hydrogels containing collagen components prepared by various conventional methods described in the background art, all belonging to non-self-repairing hydrogels.

Therefore, although the reversible chemical bond crosslinking of the collagen-based hydrogel is realized through the Schiff base bond, the self-repairing property and the injectability of the collagen-based hydrogel still have obvious defects due to the characteristics of collagen molecules, so that the technical products still remain in a laboratory stage and cannot be converted into practical and feasible industrial products.

The inventors of the present invention have found that if a certain amount of other macromolecules are inserted between collagen molecules, the orientation of the collagen molecules is influenced or even prevented, and the self-assembly into fibers does not occur smoothly, which is presumed to be advantageous for preparing collagen into hydrogel having self-repairing properties. The invention selects chitosan molecules with good biocompatibility to be compounded with collagen molecules so as to prevent the collagen molecules from self-assembling. It is important to point out that this is quite different from the cross-linking complexation of collagen macromolecules with natural polysaccharide macromolecules mentioned in the background art. In the technical scheme of the invention, the association between the chitosan and the collagen is that under the acidic condition of low pH, the collagen molecules and the chitosan molecules are both cation polyelectrolyte with net positive electricity, and when the proportion of the chitosan reaches a specific proportion range value, the effect of obviously hindering the self-assembly of the collagen molecules is achieved, so that the dynamic cross-linking bond formation of the collagen molecules and the macromolecule cross-linking agent oxidized konjac glucomannan molecules is facilitated, the excellent self-repairability and injectability are realized, and the irreversible gel mentioned in the background technology due to the irreversible self-assembly among the collagen molecules is avoided.

In addition, gradient experiments also show that the dosage of chitosan is required in order to block the action of collagen molecules. If the consumption of the chitosan is less, the self-assembly of collagen molecules cannot be hindered; if the consumption of the chitosan is larger, the advantages of the collagen can not be reflected due to the obvious reduction of the proportion of the collagen, the adding significance of the collagen-based hydrogel is lost, and the adding significance is verified in the results of cell experiments (see the attached figure 3 in the specification).

And because the addition of the chitosan can also influence the Schiff base bond crosslinking relationship between the oxidized konjac glucomannan and the collagen, the proper dosage proportion among the collagen, the oxidized konjac glucomannan and the chitosan is the most important and critical. Moreover, because the degree of Schiff base bond reaction is not 100%, the substitution of konjac glucomannan into other Schiff base bond components can also cause influence, and similarly, whether the macromolecular components of other non-chitosan components can play the same purpose and effect under the equivalent proportion is unknown. Only the content based on experimental verification is protected based on the invention.

Through a large number of experiments, the inventor finally finds that when the proportion of the collagen, the oxidized konjac glucomannan and the chitosan meets the range defined by the invention, the self-repairing property and the injectability of the prepared collagen-based hydrogel achieve better effects, and the excellent characteristics of the collagen are retained because the proportion of the collagen is larger.

It is important to point out that after the adding proportion of the collagen and the oxidized konjac glucomannan is determined, through a further gradient experiment, the inventor of the invention finds that the adding amount of the chitosan greatly influences the self-repairing performance of the prepared collagen-based hydrogel, particularly the time required by the self-repairing.

When the amount of the chitosan is 100-125 parts, the self-repairing time of the collagen-based hydrogel is about 8 minutes on average.

When the chitosan accounts for 125-150 parts, the self-repairing time of the collagen-based hydrogel is about 6 minutes on average.

When the amount of the chitosan is 150-175 parts, the self-repairing time of the collagen-based hydrogel is about 4 minutes on average.

When the amount of the chitosan is 175-200 parts, the self-repairing time of the collagen-based hydrogel is about 2 minutes on average.

It is worth explaining that the time required for determining the self-repairing of the hydrogel is to inject 2ml of collagen-chitosan-oxidized konjac glucomannan composite liquid into a cylindrical mold for molding, then cut the cylindrical hydrogel into two independent equal parts, stack the two hydrogels together, and determine the time for fusing the two hydrogels into a whole by using a stopwatch, wherein the time takes the self weight of the whole hydrogel after the gel edge is clamped by a pair of tweezers and suspended in the air to bear the repairing as the repairing end point.

Obviously, the higher the adding proportion of the chitosan is, the stronger the capability of the chitosan for hindering collagen self-assembly is, and the higher the self-repairing performance of the prepared hydrogel is, but the adding proportion of the collagen is certainly influenced along with the increasing of the adding proportion of the chitosan, so that the dominant performance brought by the collagen in the collagen-based hydrogel is reduced. Through the above practical experiments, it is also outlined that the time required for self-repairing can greatly influence the practicability of the product in practical use (especially when the product is used as a dressing). However, the time required for self-repairing is not measured in the existing research reports, and the laboratory products only stay on the level of describing the self-repairing property, which may also be one reason why the products cannot be converted into practical industrial products.

Generally, the raw material components of the collagen-based injectable self-repairing photothermal hydrogel of the invention may further comprise a functional auxiliary agent, thereby endowing the hydrogel with more functionality. The functional additives, which are conventionally used in the art, including pharmaceutically active molecules such as artemisinin, curcumin and the like, and functional nanoparticles such as silver nanoparticles, gold nanoparticles, superparamagnetic iron oxide nanoparticles, fluorescent small molecules and the like, can be added by those skilled in the art according to the required addition ratio of the functional additives. It is noted that it is generally recommended to choose functional aids with lower addition rates, so as to preserve the procollagen proportion to the maximum, thus ensuring that the product has more of the beneficial properties of collagen.

In order to better illustrate the invention and to provide a preferred solution:

further, in order to be suitable for applying the collagen-based injectable self-repairing photo-thermal hydrogel to the field of medical dressings, the raw material components of the collagen-based injectable self-repairing photo-thermal hydrogel further comprise 1-10 parts of silver nanoparticles, so that the collagen-based injectable self-repairing photo-thermal hydrogel is endowed with antibacterial performance and photo-thermal performance.

Typically, the silver nanoparticle source is a commercially available functional aid or is self-prepared according to the prior art. To better illustrate the present invention, and to provide a reference method for self-made silver nanoparticles prepared by in-situ reduction of plant polyphenols. The method comprises the following specific steps: mixing the saturated tannin, or gallic acid, or procyanidin, or catechin solution with silver nitrate water solution under vigorous stirring; and then adjusting the pH value to be alkaline by using a sodium hydroxide solution, stirring the mixed solution for 30-120 min in a dark place, cooling the solution to room temperature, purifying by using a dialysis bag, and freeze-drying to obtain the silver nanoparticles.

It is noted that, because the principle that chitosan hinders collagen molecules from self-assembling is utilized in the components of the invention, the pH value in the preparation method based on the components greatly influences the self-repairing performance and the mechanical performance of the prepared product. The actual gradient experiment shows that the pH adjustment before gelation is a key factor, if the pH adjustment is too low (lower than 4.5), the mechanical performance of the product is greatly influenced, and if the pH adjustment is too high (higher than 6.5), the self-repairing performance of the product is greatly influenced.

Thus, to better illustrate the invention, and to provide a matched preparation method:

the preparation method of the collagen-based injectable self-repairing photo-thermal hydrogel comprises the following steps:

(1) stock preparation

Preparing the following raw materials in parts by weight:

100 parts of collagen;

100-200 parts of chitosan;

20-30 parts of oxidized konjac glucomannan;

wherein the oxidized konjac glucomannan is obtained by selectively oxidizing konjac glucomannan, the oxidation degree is 30-70%, and the weight average molecular weight is 3-20 ten thousand;

(2) dynamic chemical crosslinking

Respectively dissolving the collagen, the chitosan and the oxidized konjac glucomannan prepared in the step (1) in a solvent, then uniformly mixing the collagen solution and the chitosan solution, then adding the oxidized konjac glucomannan solution, stirring and mixing for 10-30 minutes, and finally adjusting the pH value of the mixed system to 5.0-6.5 for gelation to obtain the collagen-based injectable self-repairing photothermal hydrogel.

In the step (2), a skilled person in the art can select a proper solvent and concentration by referring to the existing collagen-based hydrogel preparation process according to different requirements of the collagen-based injectable self-repairing photo-thermal hydrogel on rheological property, appearance morphology, biocompatibility and the like.

In order to better illustrate the invention and provide a preferred solution:

preferably, in order to obtain the collagen-based injectable self-repairing photothermal hydrogel with good biocompatibility, the collagen is dissolved in any one of citric acid solution, malic acid solution, lactic acid solution, hydrochloric acid solution and phosphoric acid solution with the pH value of 2.5-3.0. Wherein the mass concentration of the collagen is 0.5 to 2 wt%, and more preferably 1 wt%.

The solvent of the chitosan can be selected to be the same as that used for the collagen, wherein the mass concentration of the chitosan is 0.5-2 wt%, and the preferable mass concentration is 2 wt%.

Preferably, in order to make the number of the dynamic schiff base cross-links between the oxidized konjac glucomannan and the collagen and chitosan more compact, the oxidized konjac glucomannan is dissolved in neutral pure water and is configured into a neutral oxidized konjac glucomannan solution, wherein the mass concentration of the oxidized konjac glucomannan solution is 1-3 wt%, and is further preferably 2.4 wt%.

Through the preparation steps, the finally prepared collagen-based hydrogel has good injectability and self-repairing performance, in-vitro cell biocompatibility and in-vivo biocompatibility.

Tests prove that under the guidance of one preferred technical scheme, the collagen-based injectable self-repairing photothermal hydrogel is prepared, strain amplitude scanning shows that the hydrogel generates sol-gel transformation when the strain reaches 197 percent, and the hydrogel generates sol-gel transformation at high shear rate (100 s) ^-1 ) The following shows excellent shear thinning properties. The self-repair time measurement shows that the hydrogel can be rapidly self-repaired into a whole within 90 seconds at most. In the preferable technical scheme of adding the silver nanoparticles, the hydrogel is heated to 21.5 ℃ under the irradiation of near infrared light within ten minutes (see figure 4 in the specification), and the photothermal conversion efficiency reaches 27.5%; the photothermal synergistic antibacterial effect enables the killing effect of the hydrogel on staphylococcus aureus and escherichia coli to be as high as 99% (see the attached figure 5 in the specification). Meanwhile, animal experiments show that the wound surface can be effectively repaired in the face of a wound infected by staphylococcus aureus, the wound surface can be repaired within 14 days by 96.7%, and the mild heat treatment performance improves the blood circulation of the whole wound surface area, promotes the complex or chronic wound surface to realize regenerative repair and avoids scar repair (see the attached figure 6, figure 7 and figure 8 of the specification).

Compared with the traditional collagen hydrogel and collagen-based hydrogel, the collagen hydrogel keeps the excellent bioactivity and biocompatibility of collagen molecules, and on the basis, the collagen-based hydrogel with the collagen ratio of more than one third is simultaneously provided with injectability and self-repairing performance on the premise of solving the problems of excellent biocompatibility and easy degradability by adjusting the mass ratio of collagen, oxidized konjac glucomannan and chitosan in a specific ratio range, so that the collagen-based hydrogel is suitable for large wounds with irregular shapes and coating and attaching of wound surfaces, thereby rapidly achieving complete coverage and protection; meanwhile, in a preferred technical scheme, silver nanoparticles are embedded into the collagen-based hydrogel to endow the hydrogel with better antibacterial property and mild photo-thermal efficiency, so that the photo-thermal antibacterial property and the photo-thermal physical therapy property of the injectable self-repairing collagen-based hydrogel are realized.

Drawings

Fig. 1 is a rheological representation diagram and a physical injection photograph of the collagen-based injectable self-repairing photothermal hydrogel prepared in example 1 of the present invention. Wherein, the graph (a) is a rheological characterization graph of the collagen-based injectable self-repairing photo-thermal hydrogel: the hydrogel viscosity is in a relation with the change of the shearing force, and the shearing force and the viscosity are in an inverse relation, so that the hydrogel is proved to have excellent injectability; FIG. b is a photograph of the site where the hydrogel was injected with a 26G syringe.

Fig. 2 is a rheological representation diagram and a self-repairing demonstration photograph of the collagen-based injectable self-repairing photo-thermal hydrogel prepared in example 1 of the present invention. Figure (a) is a rheological characterization of collagen-based injectable self-repairing photothermal hydrogel: the hydrogel is subjected to periodic step strain scanning, the hydrogel is subjected to corresponding sol-gel transition along with the strain action under the repeated period, and excellent self-repairability is shown; and (b) the figure shows that two independent hydrogels are repaired and fused into a whole after being contacted, and the excellent self-repairing performance of the hydrogel is proved.

FIG. 3 is a comparative photograph of cell culture experiment of collagen-based injectable self-repairing photo-thermal hydrogel prepared in example 1 of the present invention and collagen-free chitosan-oxidized konjac glucomannan hydrogel prepared in comparative example 2. The figure (a) shows that when cell culture is carried out on the surface of chitosan-oxidized konjac glucomannan hydrogel without collagen, the gel can be disintegrated into fragments in a culture medium solution, so that necessary mechanical support cannot be provided, and the cells cannot find a landing point which can adhere to the wall, namely a material substrate; and (b) the collagen-based injectable self-repairing photo-thermal hydrogel can provide a scaffold substrate necessary for cell growth, and the gel can support normal adherent cell growth.

FIG. 4 is a thermal infrared contrast image generated by the collagen-based injectable self-repairing hydrogel containing silver nanoparticles with different concentrations, which is prepared in embodiments 1, 5 to 8 of the present invention, under 808nm near-infrared irradiation.

Fig. 5 is a comparative photograph of in vitro antibacterial test of the collagen-based injectable self-repairing photo-thermal hydrogel prepared in example 1 of the present invention. Wherein the upper and lower pictures (I) are photographs of the collagen-based injectable self-repairing photo-thermal hydrogel which is respectively incubated with escherichia coli and staphylococcus aureus together and the bacteria are proliferated for 24 hours; the upper and lower graphs (II) are photographs of the collagen-based injectable self-repairing photo-thermal hydrogel incubated with escherichia coli and staphylococcus aureus respectively, and after bacteria proliferate for 24 hours in an experimental group under the near-infrared irradiation condition.

Fig. 6 is a comparative healing photograph of collagen-based injectable self-repairing photo-thermal hydrogel prepared in example 1 of the present invention and collagen-free chitosan-oxidized konjac glucomannan hydrogel prepared in comparative example 2 after different treatment times of staphylococcus aureus infected wounds in animal experiments. Wherein, the diagram (I) is a blank group; FIG. II shows a collagen-free chitosan-oxidized konjac glucomannan hydrogel composition irradiated with near infrared light; FIG. III shows a collagen-based injectable self-repairing photothermal hydrogel group; and (IV) is a collagen-based injectable self-repairing photo-thermal hydrogel group irradiated by near infrared light.

Fig. 7 is a thermal infrared contrast image of a collagen-based injectable self-repairing photothermal hydrogel prepared in example 1 of the present invention after being applied to the body surface of a mouse and before and after the mouse is irradiated with near infrared light. It is evident that the temperature rise at the application site is evident upon irradiation with infrared light.

Fig. 8 is a bar graph comparing the collagen deposition amount, the epidermal thickness and the vascular density at the wound on the 14 th day in an animal experiment of the collagen-based injectable self-repairing photo-thermal hydrogel prepared in example 1 of the present invention and the collagen-free chitosan-konjac glucomannan hydrogel prepared in comparative example 2. Column (I) is blank; the column (II) is a chitosan-oxidized konjac glucomannan hydrogel group which is irradiated by near infrared light and does not contain collagen; the column (III) is a collagen-based injectable self-repairing photo-thermal hydrogel group; the column (IV) is a collagen-based injectable self-repairing photo-thermal hydrogel group irradiated by near infrared light.

Detailed Description

The invention is further illustrated by the following examples in conjunction with the accompanying drawings. It should be noted that the examples given are not to be construed as limiting the scope of the invention, and that those skilled in the art, on the basis of the teachings of the present invention, will be able to make numerous insubstantial modifications and adaptations of the invention without departing from its scope.

Experimental reagent: highly purified collagen (type I) extracted from calfskin. Chitosan (CS, Mw: 310-. KGM powder (purity is more than or equal to 90 percent and 200 meshes) is purchased from a Chengdu synergetic konjak scientific planting and processing garden. Sodium periodate (NaIO) ₄ 99.5% or more) were purchased from alading, shanghai, china. Chloral hydrate and Fluorescein Diacetate (FDA) were purchased from Sigma-Aldrich (St.Louis, Mo., USA). Phosphate Buffered Saline (PBS) and sterile consumables used in the cell experiments were purchased from Corning, USA, and the CCK-8 kit was supplied by Beyotime. Bovine Serum Albumin (BSA) and 4% paraformaldehyde solution were supplied by Solarbio (beijing, china). Ultrapure water from Millipore systems (Millipore, Billerica, MA, USA).

The main apparatus is as follows: lyophilizer (FD-1A-50) was purchased from Beijing Bo Yi kang; fourier infrared spectrometer (NEXUS670) from Thermo Electron; scanning electron microscope (S-4800) from Hitachi; transmission electron microscopy (Tecnai G2F 20S-TWIN) was purchased from FEI; rheometer (MCR102) from Anton Paar; a nanosize and Zeta potential analyzer (Zetasizer Nano ZS) from Malvern; infrared thermal imaging camera (T530) was purchased from FILR.

Testing the in vitro photothermal performance:

1.5 ml of each of the hydrogels with different silver contents are injected into a bottle, and the 808nm near-infrared laser is used for irradiating for 10 minutes, wherein the power density is 2.0W cm ^-2 . Containing 200. mu.g/mL of a surfactant ^-1 Heating the Ag hydrogel by 3 times of laser irradiation (808nm,2W cm) ^-2 10min) and natural cooling cycles to evaluate the photothermal stability of the hydrogels. During the irradiation process, the temperature was recorded with an infrared thermal imaging camera at 0.5min intervals.

Rheological testing:

at 37 deg.C, using a moduleThe storage modulus (G '), loss modulus (G') at different oscillation, strain or shear rates were evaluated by a rheometer (MCR102, Anton Paar, Germany). The breaking strain of the hydrogel was evaluated at a frequency of 1Hz in the strain range of 0.1-1000%. In the step strain test, the strains of 1% and 500% are repeated 3 times at a constant frequency of 1.0rad/s for 120 s. In the range of 0.1-300s ^-1 The effect of high shear rate on gel viscosity was determined over the range of shear rates.

In vitro antibacterial testing:

the antibacterial performance of the hydrogel on staphylococcus aureus and escherichia coli is analyzed by adopting a diffusion plate method. First, 100. mu.l of a bacterial solution (108 CFU. mL) was added ^-1 ) The resulting solution was added dropwise to 100. mu.l of PBS as a blank sample. Meanwhile, the bacteria are dripped on the surface of COL-CS-OKGM hydrogel containing or not containing silver to be used as a control group. The experimental group adopts GA-Ag-containing hydrogel and 808nm laser (2w cm) ^-2 10 minutes) irradiation. After incubation of each group of bacterial suspensions with the culture medium for 1 hour, the cells were washed with 900. mu.l of PBS and 100. mu.l of bacterial suspension was spread on a petri dish (petri dish). After 24 hours of bacterial culture, the number of bacterial CFUs was counted on agar plates. In addition, an inhibition zone experiment is also carried out, and the persistence of the hydrogel inhibition is further evaluated. 200. mu.l of Staphylococcus aureus and Escherichia coli (10) were added, respectively ⁶ CFU·mL ^-1 ) Spread evenly on LB agar plates, and then place the silver-free and silver-containing hydrogels on the agar plates, respectively. Wherein a hydrogel containing silver nanoparticles is prepared by using 808nm laser (2w cm) ^-2 10 minutes) irradiation, the other was not treated. And (5) placing the bacteria in a bacteria incubator for 24 hours, and measuring the diameter of the inhibition zone.

Evaluation of cytotoxicity:

the cytotoxicity of the hydrogel was evaluated by NIH-3T3 cells and HUVEC cells. Hydrogels (0. mu.g. mL) containing different concentrations of silver nanoparticles ^-1 、50μg·mL ^-1 、100μg·mL ^-1 、150μg·mL ^-1 、200μg·mL ^-1 ) Placed at the bottom of a 24-well plate, and the hydrogel surface was inoculated with NIH-3T3 cells and HUVEC cells (1X 10) ⁵ ). These cell-containing hydrogels were then cultured for 1 day, 3 days, and 5 days, respectivelyAnd (4) day. The cell image of the hydrogel surface was obtained by confocal laser microscopy and quantified using cck-8. Untreated cells were used as Positive Control (PC) and blank wells of untreated cells were used as Negative Control (NC). The relative cell viability was calculated as follows:

cell survival rate ═ OD _Sample(s) -OD _NC )/(OD _PC -OD _NC )*100％

To further evaluate the biocompatibility of the hydrogel, NIH-3T3 cells were mixed with hydrogel precursors to form hydrogels. Then, the NIH-3T3 cell hydrogel was cultured in DMEM medium for 5 days. Three-dimensional culture images were obtained with a confocal laser scanning microscope (Zeiss Ism710, germany) using Fluorescein Diacetate (FDA) and Propidium Iodide (PI) as the vital stain.

The preparation method of the oxidized konjac glucomannan specifically comprises the following steps:

preparing 1% konjac glucomannan solution by mass concentration, adding sodium periodate solution into the konjac glucomannan solution to ensure that the final concentration of the sodium periodate in the solution is 20mM, the reaction temperature is 25 ℃, and stirring and reacting for 12 hours under the condition of keeping out of the sun; after the reaction time is up, adding glycol solution and stirring for 15 minutes to terminate the reaction; dialyzing the obtained solution in pure water for 48 hours, and freeze-drying to obtain the oxidized konjac glucomannan product, wherein the oxidation degree is 70%, and the weight average molecular weight is 7.3 ten thousand.

Example 1

(1) stock preparation

Preparing the following raw materials in parts by weight:

(2) dynamic chemical crosslinking

Respectively dissolving the collagen, the chitosan and the oxidized konjac glucomannan prepared in the step (1) in a solvent, preparing silver nanoparticles into a suspension, uniformly mixing the collagen solution and the chitosan solution, adding the silver nanoparticle suspension and the oxidized konjac glucomannan solution, stirring and mixing for 20 minutes, and finally adjusting the pH value of the mixed system to 6.0 for gelation to obtain the collagen-based injectable self-repairing photothermal hydrogel.

Tests prove that the collagen-based injectable self-repairing photo-thermal hydrogel prepared by the method can quickly form gel at a pH value of faintly acid of 5-6. The strain amplitude scan showed that the hydrogel underwent sol-gel transition at a strain of 197% and at high shear rate (100 s) ^-1 ) The following shows excellent shear thinning properties. The self-repairing time measurement shows that the hydrogel can be rapidly self-repaired into a whole within 2 minutes. The hydrogel was heated to 21.5 ℃ under irradiation with near infrared light for ten minutes (see fig. 4), and the photothermal conversion efficiency reached 27.5%. The photothermal synergistic antibacterial effect enables the killing effect of the hydrogel on staphylococcus aureus and escherichia coli to be as high as 99% (see the attached figure 5 in the specification). Meanwhile, animal experiments show that the wound surface can be effectively repaired in the face of a wound infected by staphylococcus aureus, the wound surface can be repaired within 14 days by 96.7%, and the mild heat treatment performance improves the blood circulation of the whole wound surface area, promotes the complex or chronic wound surface to realize regenerative repair and avoids scar repair (see the attached figure 6, the figure 7 and the figure 8 of the specification).

Example 2

The embodiment of the invention provides a preparation method of a collagen-based injectable self-repairing photo-thermal hydrogel, which comprises the following steps:

(1) stock preparation

Preparing the following raw materials in parts by weight:

(2) dynamic chemical crosslinking

Through testing, the self-repairing time measurement shows that the hydrogel can be rapidly self-repaired into a whole within 4 minutes at most.

Example 3

(1) stock preparation

Preparing the following raw materials in parts by weight:

(2) dynamic chemical crosslinking

Through testing, the self-repairing time measurement shows that the hydrogel can be rapidly self-repaired into a whole within 6 minutes at most.

Example 4

(1) stock preparation

Preparing the following raw materials in parts by weight:

(2) dynamic chemical crosslinking

Through testing, the self-repairing time measurement shows that the hydrogel can be rapidly self-repaired into a whole within 8 minutes at most.

Example 5

The preparation method of the collagen-based injectable self-repairing hydrogel comprises the following steps:

(1) stock preparation

Preparing the following raw materials in parts by weight:

100 parts of collagen;

175 parts of chitosan;

oxidized konjac glucomannan 20 parts;

(2) dynamic chemical crosslinking

Respectively dissolving the collagen, the chitosan and the oxidized konjac glucomannan prepared in the step (1) in a solvent, then uniformly mixing the collagen solution and the chitosan solution, then adding the oxidized konjac glucomannan solution, stirring and mixing for 20 minutes, and finally adjusting the pH value of the mixed system to 6.0 for gelation to obtain the collagen-based injectable self-repairing hydrogel.

Example 6

(1) stock preparation

Preparing the following raw materials in parts by weight:

(2) dynamic chemical crosslinking

Example 7

(1) stock preparation

Preparing the following raw materials in parts by weight:

(2) dynamic chemical crosslinking

Example 8

(1) stock preparation

Preparing the following raw materials in parts by weight:

100 parts of collagen;

150 parts of chitosan;

30 parts of oxidized konjac glucomannan;

(2) dynamic chemical crosslinking

Respectively dissolving the collagen, the chitosan and the oxidized konjac glucomannan prepared in the step (1) in a solvent, then uniformly mixing the collagen solution and the chitosan solution, then adding the oxidized konjac glucomannan solution, stirring and mixing for 15 minutes, and finally adjusting the pH value of the mixed system to 5.5 for gelation to obtain the collagen-based injectable self-repairing hydrogel.

Example 9

(1) stock preparation

Preparing the following raw materials in parts by weight:

wherein, the oxidized konjac glucomannan is obtained from the market, and the oxidation degree is 60%.

(2) Dynamic chemical crosslinking

Respectively dissolving the collagen, the chitosan and the oxidized konjac glucomannan prepared in the step (1) in a solvent, preparing silver nanoparticles into a suspension, uniformly mixing the collagen solution and the chitosan solution, adding the silver nanoparticle suspension and the oxidized konjac glucomannan solution, stirring and mixing for 25 minutes, and finally adjusting the pH value of the mixed system to 5.0 for gelation to obtain the collagen-based injectable self-repairing photothermal hydrogel.

Example 10

(1) stock preparation

Preparing the following raw materials in parts by weight:

wherein, the oxidized konjac glucomannan is obtained from the market, and the oxidation degree is 40%.

(2) Dynamic chemical crosslinking

Respectively dissolving the collagen, the chitosan and the oxidized konjac glucomannan prepared in the step (1) in a solvent, preparing silver nanoparticles into a suspension, uniformly mixing the collagen solution and the chitosan solution, adding the silver nanoparticle suspension and the oxidized konjac glucomannan solution, stirring and mixing for 30 minutes, and finally adjusting the pH value of the mixed system to 6.5 for gelation to obtain the collagen-based injectable self-repairing photothermal hydrogel.

Comparative example 1

The preparation method of the collagen-based hydrogel according to the comparative example includes the following steps:

(1) stock preparation

Preparing the following raw materials in parts by weight:

100 parts of collagen;

oxidized konjac glucomannan 20 parts;

2 parts of silver nanoparticles;

(2) dynamic chemical crosslinking

Respectively dissolving the collagen and the oxidized konjac glucomannan prepared in the step (1) in a solvent, preparing silver nanoparticles into a suspension, stirring and mixing the collagen solution, the silver nanoparticle suspension and the oxidized konjac glucomannan solution for 20 minutes, and finally adjusting the pH value of the mixed system to 6.0 for gelation, wherein the result shows that the final product is in a solution state with certain viscosity and can not completely form gel.

Comparative example 2

The preparation method of the chitosan-based hydrogel without collagen comprises the following steps:

(1) stock preparation

Preparing the following raw materials in parts by weight:

175 parts of chitosan;

oxidized konjac glucomannan 20 parts;

2 parts of silver nanoparticles;

(2) dynamic chemical crosslinking

Respectively dissolving the chitosan and the oxidized konjac glucomannan prepared in the step (1) in a solvent, preparing silver nanoparticles into a suspension, stirring and mixing the chitosan solution, the silver nanoparticle suspension and the oxidized konjac glucomannan solution for 20 minutes, and finally adjusting the pH value of the mixed system to 6.0 for gelation, thereby obtaining the collagen-free chitosan-oxidized konjac glucomannan hydrogel. The final product still has certain self-repairing performance after being tested, however, compared with the example 1, the excellent biocompatibility of the collagen is lost, the adherence time of the cells on the material is prolonged, the affinity to the material is reduced, and the inherent biological advantage of the core component of the collagen is lost.

Comparative example 3

(1) stock preparation

Preparing the following raw materials in parts by weight:

(2) dynamic chemical crosslinking

Respectively dissolving the collagen, the chitosan and the oxidized konjac glucomannan prepared in the step (1) in a solvent, preparing the silver nanoparticles into a suspension, uniformly mixing the collagen solution and the chitosan solution, adding the silver nanoparticle suspension and the oxidized konjac glucomannan solution, stirring and mixing for 20 minutes, and finally adjusting the pH value of the mixed system to 4.5 for gelation, wherein the final product is in a solution state and can not be gelatinized.

Comparative example 4

(1) stock preparation

Preparing the following raw materials in parts by weight:

(2) dynamic chemical crosslinking

Respectively dissolving the collagen, the chitosan and the oxidized konjac glucomannan prepared in the step (1) in a solvent, preparing silver nanoparticles into a suspension, uniformly mixing the collagen solution and the chitosan solution, adding the silver nanoparticle suspension and the oxidized konjac glucomannan solution, stirring and mixing for 20 minutes, and finally adjusting the pH value of the mixed system to 7 for gelation to obtain a final product, namely irreversible hydrogel with certain mechanical properties, which does not have injectability and self-repairing properties.

Comparative example 5

(1) stock preparation

Preparing the following raw materials in parts by weight:

100 parts of collagen;

oxidized konjac glucomannan 100 parts;

(2) dynamic chemical crosslinking

Respectively dissolving the collagen and the oxidized konjac glucomannan prepared in the step (1) in a solvent, then stirring and mixing the collagen solution and the oxidized konjac glucomannan solution for 20 minutes, and finally adjusting the pH value of the mixed system to 6.0 for gelation to obtain the collagen-based hydrogel.

Through tests, the self-repairing time measurement shows that the average time required by the hydrogel to be self-repaired into a whole is about 1 hour, and the data of the time required by the hydrogel to be self-repaired into the whole under multiple tests are distributed in the range of 0.8-1.2 hours.

Claims

1. A preparation method of collagen-based injectable self-repairing hydrogel is characterized by comprising the following steps:

(1) stock preparation

Preparing the following raw materials in parts by weight:

100 parts of collagen;

100-200 parts of chitosan;

20-30 parts of oxidized konjac glucomannan;

the oxidized konjac glucomannan is obtained by selectively oxidizing konjac glucomannan, an aldehyde substituent is formed by breaking bonds with hydroxyl groups on 2-and 3-position carbons of a sugar ring, the oxidation degree is 30-70%, and the weight average molecular weight is 3-20 ten thousand;

(2) dynamic chemical crosslinking

2. The method according to claim 1, wherein the method for preparing the oxidized konjac glucomannan comprises the steps of:

3. The method of claim 1, wherein: the collagen is I type collagen extracted from pig skin, cow skin, fish skin or bovine achilles tendon.

4. The method of claim 1, wherein: 150-200 parts of chitosan.

5. The method of claim 1, wherein: 150-175 parts of chitosan.

6. The method of claim 1, wherein: the raw material components of the collagen-based injectable self-repairing photothermal hydrogel also comprise functional auxiliary agents.

7. The production method according to claim 1 or 6, characterized in that: the raw material components of the collagen-based injectable self-repairing photo-thermal hydrogel further comprise 1-10 parts of silver nanoparticles.

8. The method of claim 1, wherein: dissolving the collagen in any one of a citric acid solution, a malic acid solution, a lactic acid solution, a hydrochloric acid solution and a phosphoric acid solution with the pH value of 2.5-3.0; wherein the mass concentration of the collagen is 0.5-2 wt%;

the solvent of the chitosan is selected to be consistent with that of the collagen, wherein the mass concentration of the chitosan is 0.5-2 wt%.

9. The method of claim 1, wherein: the oxidized konjac glucomannan is dissolved in neutral pure water and prepared into a neutral oxidized konjac glucomannan solution, wherein the mass concentration of the oxidized konjac glucomannan solution is 1-3 wt%.

10. The collagen-based injectable self-repairing hydrogel prepared by the preparation method of the collagen-based injectable self-repairing hydrogel according to claim 1.