CN106832060A - Shitosan, its preparation method and injectable anti-bacterial hydrogel that arginine is modified - Google Patents

Abstract

Shitosan, its preparation method and injectable anti-bacterial hydrogel the invention provides a kind of modification of arginine, the shitosan and crosslinking agent that the injectable anti-bacterial hydrogel is modified by the arginine with formula (I) structure carry out self-crosslinking reaction and obtain in a solvent；The crosslinking agent is the polyethylene glycol of terminal aldehyde group.Compared with prior art, the injectable anti-bacterial hydrogel that the present invention is provided itself has anti-microbial property, and with good biocompatibility, can be formed in situ in vivo, is conducive to directly acting on diseased region and more permanent performance drug effect；And the polyethylene glycol of terminal aldehyde group has aldehyde radical structure, conventional formaldehyde, glutaraldehyde etc. can be replaced to poison larger crosslinking agent to human body；Meanwhile, the injectable anti-bacterial hydrogel also has good biological degradability, can degradation in vivo, and catabolite is amino acid, polysaccharide, polyethylene glycol, can directly be excluded by kidney it is external, it is harmless.

Description

Arginine-modified chitosan, its preparation method and injectable antibacterial hydrogel

technical field

The invention relates to the technical field of polysaccharide polymer materials, in particular to arginine-modified chitosan, a preparation method thereof and an injectable antibacterial hydrogel.

Background technique

Antibacterial materials are a class of substances that have excellent bactericidal or antimicrobial functions (such as some organic compounds with specific groups, some inorganic metal materials and their compounds, some minerals and natural substances) or substances that contain antibacterial properties. (such as antibiotics and other antibacterial agents) and a new class of functional materials that have the ability to kill or inhibit bacteria has become a research hotspot in the field of biomedical polymer materials.

Injectable hydrogel is a three-dimensional network structure formed by physical or chemical crosslinking. Hydrophilic residues combine with water molecules to connect water molecules inside the network, while hydrophobic residues swell with water. polymer. Injectable hydrogels have the advantages of high water content, strong water retention capacity, softness, certain viscoelasticity and shape, and good biocompatibility. In addition, it exists in a solution state and can be mixed with antibacterial agents; when it is implanted in a solution state by injection, it can rapidly undergo a sol-gel phase transition and form a gel in situ; at the same time, the antibacterial agent is embedded In the interior of the hydrogel, it is slowly released through diffusion or hydrogel self-degradation, so as to achieve the purpose of long-term sustained release; moreover, it also has the advantages of easy use, minimal surgical trauma, and the ability to fill any shape defect. Therefore, injectable hydrogel can be used as an antibacterial drug carrier and become a good antibacterial material, which has attracted extensive attention in the field of anti-infection. In addition, the hydrogel with its own antibacterial properties has unique physical and chemical properties, which can dissolve cell walls, prevent the formation of bacterial biofilm barriers, and affect the metabolism of bacteria to achieve bacteriostatic or bactericidal effects. Poison safety, non-irritating and other advantages. In recent years, injectable antibacterial hydrogels have been widely studied and applied in the fields of wound dressings and fillers, burn infections, prosthetic implants, and tissue engineering.

The research on injectable antibacterial hydrogel has attracted great interest and attention from many researchers, and it is also the key to its practical application. Among them, bacteria-responsive gel-loaded antibiotics (Adv. Mater., 2012, 24, 6175–6180) are effective means for treating bacterial infections, but they face the serious problem of producing drug-resistant strains, and their antibacterial function depends on antibiotics. of seepage. With the deepening of scientific research, researchers have prepared antibacterial hydrogels loaded with gold or silver antibacterial agents (ACS NANO, 2014, 8:2900–2907; Adv.Funct.Mater.2014,24,3933–3943 ), resulting in good antibacterial properties, but when the concentration of these heavy metal ions is too low, the sterilization speed is slow and the antibacterial effect is difficult to ideal; when the concentration is too high, it may endanger human health. At present, although some cationic polymer-based hydrogels with antibacterial properties have been continuously developed, many of these gels are not ideal in biocompatibility, and have the ability to trigger immune reactions or inflammation or even hinder antibacterial functional groups. The potential risk of failure limits the further application of this type of antibacterial hydrogel to a certain extent.

Contents of the invention

In view of this, the object of the present invention is to provide a kind of arginine-modified chitosan, its preparation method and injectable antibacterial hydrogel, the injectable antibacterial hydrogel provided by the present invention has antibacterial property itself, and has good biocompatibility and biodegradability.

The invention provides a kind of chitosan modified by arginine, which has structure shown in formula (I):

Among them, n is the degree of polymerization, 10≤n≤3200;

The substitution degree of arginine in the arginine-modified chitosan is 0.1%-80%.

The present invention also provides a kind of preparation method of the chitosan of arginine modification, comprises the following steps:

a) mixing chitosan, arginine derivatives and an activator for amidation reaction to obtain a compound shown in formula (II);

The arginine derivative has a structure shown in formula (III):

b) deprotecting the compound shown in formula (II) to obtain arginine-modified chitosan;

The chitosan modified by described arginine has structure shown in formula (I):

Among them, n is the degree of polymerization, 10≤n≤3200;

The substitution degree of arginine in the arginine-modified chitosan is 0.1%-80%.

Preferably, the activator in step a) is selected from 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, N-hydroxysuccinimide, N,N-di One or more of isopropylcarbodiimide, N,N'-dicyclohexylcarbodiimide and N-hydroxysulfosuccinimide.

Preferably, the mass ratio of chitosan, arginine derivative and activator in step a) is 1:(0.1-0.8):(0.15-1.2).

Preferably, the process of mixing chitosan, arginine derivatives and activator described in step a) is specifically:

a1) mixing chitosan with an acid solution to obtain a first mixed solution;

a2) mixing an arginine derivative, an activator and an organic solvent to obtain a second mixed solution;

a3) adding the second mixed solution to the first mixed solution to obtain a mixed solution of chitosan, arginine derivative and activator;

Steps a1) and a2) are not limited in order.

Preferably, the temperature of the amidation reaction in step a) is 20°C-40°C, and the time is 24h-72h.

Preferably, the temperature of the deprotection reaction in step b) is 20°C-45°C, and the time is 2h-8h.

The present invention also provides an injectable antibacterial hydrogel, the arginine-modified chitosan obtained by the arginine-modified chitosan described in the technical scheme or the preparation method described in the above-mentioned technical scheme and cross-linked The linking agent is obtained by self-crosslinking reaction in a solvent;

The cross-linking agent is polyethylene glycol with terminal aldehylation.

Preferably, the mass ratio of the arginine-modified chitosan to the cross-linking agent is 1: (0.1-20).

Preferably, the solvent is water, physiological saline, buffer solution, tissue culture fluid or body fluid.

The present invention provides a kind of arginine-modified chitosan, its preparation method and injectable antibacterial hydrogel, and described injectable antibacterial hydrogel is made of arginine-modified chitosan having the structure of formula (I) and a cross-linking agent in a solvent for self-cross-linking reaction; Compared with the prior art, the arginine-modified chitosan provided by the invention not only improves the water solubility of the chitosan but also improves its biocompatibility by introducing arginine. The injectable antibacterial hydrogel provided by the present invention itself has antibacterial properties, and has good biocompatibility, can be formed in situ in the body, and is conducive to directly acting on the lesion and exerting the drug effect for a long time; and the terminal aldehyde group The modified polyethylene glycol has an aldehyde structure, which can replace the commonly used formaldehyde, glutaraldehyde and other cross-linking agents that are more toxic to the human body; at the same time, the injectable antibacterial hydrogel also has good biodegradability and can It degrades in the body, and the degradation products are amino acids, polysaccharides, and polyethylene glycol, which can be directly excreted through the kidneys and are harmless to the human body. Experimental results show that the injectable antibacterial hydrogel provided by the present invention has significant antibacterial effect on Gram-positive bacteria and Gram-negative bacteria, and is a new type of injectable antibacterial hydrogel with medical potential.

In addition, the injectable antibacterial hydrogel provided by the present invention has a relatively high adjustable space, and can adjust the molecular weight of chitosan, the degree of substitution of arginine on the side chain of chitosan, the degree of substitution of arginine on the side chain of chitosan, and the degree of polyformylation at the end. The molecular weight of ethylene glycol, the type of polyethylene glycol, etc., so that various hydrogel materials with different physical and chemical properties can be prepared.

In addition, the preparation method of the arginine-modified chitosan provided by the present invention has simple and easy-to-obtain raw materials and low cost; at the same time, it has simple operation, mild reaction conditions, stable preparation process, is easy to realize industrial production, and has good application prospects.

Description of drawings

Fig. 1 is the solid powder proton nuclear magnetic resonance spectrogram that the embodiment of the present invention 1 obtains;

Fig. 2 is the solid powder proton nuclear magnetic resonance spectrogram that the embodiment of the present invention 4 obtains;

Fig. 3 is the cell survival rate of the polyethylene glycol solution of the end-formylation of different concentrations described in Example 33 of the present invention within the corresponding time;

Fig. 4 is the cell survival rate of the chitosan solution modified by arginine of different concentrations obtained in Example 34 of the present invention in corresponding time;

Fig. 5 is the cell survival rate of the gel extract solution of different concentrations obtained in Example 35 of the present invention;

Fig. 6 is the cell survival rate of the gel extract solution of different concentrations obtained in Example 36 of the present invention;

Fig. 7 shows the injectable antibacterial hydrogel obtained by self-crosslinking of terminal aldylated polyethylene glycol and arginine-modified chitosan with different degrees of substitution (component ratio 1:1) obtained in Example 37 of the present invention. The antibacterial effect of glue on Escherichia coli (E.coil);

Fig. 8 shows the injectable antibacterial hydrogel obtained by self-crosslinking of terminal aldehydeylated polyethylene glycol and arginine-modified chitosan with different degrees of substitution (component ratio 1:1) obtained in Example 38 of the present invention. The antibacterial effect of glue on Staphylococcus aureus (S.aureus);

Fig. 9 shows the injectable antibacterial hydrogel obtained by self-crosslinking of terminal aldehydeylated polyethylene glycol and arginine-modified chitosan with different degrees of substitution (component ratio 1:4) obtained in Example 39 of the present invention. The antibacterial effect of glue on Escherichia coli (E.coil);

Fig. 10 shows the injectable antibacterial hydrogel obtained by self-crosslinking of terminal formhylated polyethylene glycol and arginine-modified chitosan with different degrees of substitution (component ratio 1:4) obtained in Example 40 of the present invention. Antibacterial effect of gum against Staphylococcus aureus (S. aureus).

detailed description

The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

The invention provides a kind of chitosan modified by arginine, which has structure shown in formula (I):

Among them, n is the degree of polymerization, 10≤n≤3200;

The substitution degree of arginine in the arginine-modified chitosan is 0.1%-80%.

In the present invention, the arginine-modified chitosan having the structure of formula (I) not only improves the water solubility of chitosan, but also improves its biocompatibility by introducing arginine. In addition, the arginine-modified chitosan provided by the invention is non-toxic to organisms, and is beneficial to wide application in the field of biomedical materials.

In the present invention, said n is the degree of polymerization, 10≤n≤3200. In the present invention, the substitution degree of arginine in the arginine-modified chitosan is 0.1%-80%, preferably 1%-40%, more preferably 3%-23%. In the present invention, the arginine-modified chitosan can adjust the molecular weight of chitosan and the degree of substitution of arginine on the chitosan side chain according to different needs, so that it can be used for various physical and chemical properties. Preparation of hydrogel materials.

The present invention also provides a kind of preparation method of the chitosan of arginine modification, comprises the following steps:

a) mixing chitosan, arginine derivatives and an activator for amidation reaction to obtain a compound shown in formula (II);

The arginine derivative has a structure shown in formula (III):

b) deprotecting the compound shown in formula (II) to obtain arginine-modified chitosan;

The chitosan modified by described arginine has structure shown in formula (I):

Among them, n is the degree of polymerization, 10≤n≤3200;

The substitution degree of arginine in the arginine-modified chitosan is 0.1%-80%.

In the present invention, chitosan, arginine derivatives and activators are firstly mixed for amidation reaction to obtain the compound represented by the formula (II). In the present invention, described chitosan has structure shown in formula (IV):

In the present invention, the molecular weight of the chitosan is preferably 2000Da to 500000Da, more preferably 8000Da to 300000Da, more preferably 10000Da to 200000Da; Commercially available products well known to those skilled in the art will suffice.

In the present invention, the arginine derivative has the structure shown in formula (III):

In the present invention, there is no special limitation on the source of the arginine derivative, and commercially available products well known to those skilled in the art can be used.

In the present invention, the activator is preferably selected from 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC), N-hydroxysuccinimide (NHS), One of N,N-diisopropylcarbodiimide (DIC), N,N'-dicyclohexylcarbodiimide (DCC) and N-hydroxysulfosuccinimide (sulfo-NHS) or more, more preferably 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS). In the present invention, the activator can activate the carboxyl group of the arginine derivative; the present invention has no special limitation on the source of the activator, and the above-mentioned 1-(3-dimethyl Aminopropyl)-3-ethylcarbodiimide hydrochloride (EDC), N-hydroxysuccinimide (NHS), N,N-diisopropylcarbodiimide (DIC), N,N Commercially available products of '-dicyclohexylcarbodiimide (DCC) and N-hydroxysulfosuccinimide (sulfo-NHS) may be used.

In the present invention, the mass ratio of the chitosan, the arginine derivative and the activator is preferably 1:(0.1-0.8):(0.15-1.2). In a preferred embodiment of the present invention, the activator is selected from EDC and NHS; the mass ratio of chitosan, arginine derivatives, EDC and NHS is preferably 1:0.1:0.1:0.05. In another preferred embodiment of the present invention, the activator is selected from EDC and NHS; the mass ratio of chitosan, arginine derivatives, EDC and NHS is preferably 1:0.2:0.2:0.1. In another preferred embodiment of the present invention, the activator is selected from EDC and NHS; the mass ratio of chitosan, arginine derivatives, EDC and NHS is preferably 1:0.4:0.4:0.2. In another preferred embodiment of the present invention, the activator is selected from EDC and NHS; the mass ratio of chitosan, arginine derivatives, EDC and NHS is preferably 1:0.8:0.8:0.4.

In the present invention, the process of mixing chitosan, arginine derivatives and activators is preferably specifically:

a1) mixing chitosan with an acid solution to obtain a first mixed solution;

a2) mixing an arginine derivative, an activator and an organic solvent to obtain a second mixed solution;

a3) adding the second mixed solution to the first mixed solution to obtain a mixed solution of chitosan, arginine derivative and activator;

Steps a1) and a2) are not limited in order.

The invention mixes the chitosan with the acid solution to obtain the first mixed solution. In the present invention, the acid solution is preferably hydrochloric acid solution and/or acetic acid solution, more preferably hydrochloric acid solution. In the present invention, the function of the acid solution is to promote the dissolution of chitosan, which is not particularly limited in the present invention. In the present invention, the dosage ratio of the chitosan to the acid solution is preferably 1g:(25mL-200mL), more preferably 1g:(50mL-150mL), more preferably 1g:100mL.

At the same time, the present invention mixes the arginine derivative, the activator and the organic solvent to obtain the second mixed solution. In the present invention, the organic solvent is preferably one or more of N,N-dimethylformamide (DMF), dimethylsulfoxide (DMSO), tetrahydrofuran (THF) and acetonitrile, more preferably N,N-Dimethylformamide (DMF). The present invention is not particularly limited to the source of the organic solvent, and the above-mentioned N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), tetrahydrofuran (THF) and acetonitrile known to those skilled in the art are used. Commercially available items will do. In the present invention, the ratio of the arginine derivative to the organic solvent is preferably 1 g: (10 mL-150 mL), more preferably 1 g: (12.5 mL-100 mL).

After obtaining the first mixed solution and the second mixed solution respectively, the present invention adds the second mixed solution into the first mixed solution to obtain a mixed solution of chitosan, arginine derivative and activator, and completes the mixing process . Then, the present invention directly performs amidation reaction to obtain the compound represented by formula (II). In the present invention, the amidation reaction is preferably carried out under stirring conditions, and the present invention has no special limitation on this. In the present invention, the amidation reaction temperature is preferably 20°C-40°C, more preferably 30°C; the amidation reaction time is preferably 24h-72h, more preferably 48h.

After the amidation reaction is completed, the present invention preferably further includes purifying the reaction product to obtain a solid powder. In the present invention, since the final product of the reaction is chitosan modified by arginine, and polysaccharide NMR is difficult to analyze, the displacement of hydrogen on arginine is similar to the displacement of hydrogen in polysaccharides, so it is difficult to calculate the degree of substitution, and the formula ( The structure of the benzene ring in the compound shown in II) is easy to carry out nuclear magnetic analysis and calculation of the degree of substitution, so the present invention analyzes and characterizes it.

After obtaining the compound represented by formula (II), the present invention deprotects the compound represented by formula (II) to obtain arginine-modified chitosan. In the present invention, the process of the deprotection reaction is preferably specifically:

Dispersing the compound represented by formula (II) in the reaction medium, carrying out deprotection reaction in the presence of hydrogen bromide solution, and purifying to obtain arginine-modified chitosan. In the present invention, the reaction medium is preferably trifluoroacetic acid. In the present invention, the amount of the reaction medium is preferably 50mL-200mL, more preferably 80mL-150mL; the amount of the hydrogen bromide solution is preferably 2mL-25mL, more preferably 4mL-20mL.

In the present invention, the temperature of the deprotection reaction is preferably 20°C-45°C, more preferably 30°C; the time of the deprotection reaction is preferably 2h-8h, more preferably 6h.

The present invention also provides an injectable antibacterial hydrogel, the arginine-modified chitosan obtained by the arginine-modified chitosan described in the technical scheme or the preparation method described in the above-mentioned technical scheme and cross-linked The linking agent is obtained by self-crosslinking reaction in a solvent;

The cross-linking agent is polyethylene glycol with terminal formhylation.

In the present invention, the cross-linking agent is polyethylene glycol with terminal aldehylation. In the present invention, there is no special limitation on the structure of the polyethylene glycol with terminal aldehylation, and a linear structure or a branched structure well known to those skilled in the art can be adopted. In the present invention, the polyethylene glycol with terminal aldehydes has an aldehyde structure, which can replace the commonly used formaldehyde, glutaraldehyde and other cross-linking agents that are more harmful to the human body; The source of polyethylene glycol is not particularly limited, and the self-made product obtained by the following preparation method can be used.

In the present invention, the preparation method of the poly(ethylene glycol) with terminal formhylation is preferably specifically as follows:

Polyethylene glycol, p-aldehyde benzoic acid, EDC·HCl, and DMAP are subjected to esterification reaction in a solvent, followed by suction filtration, dialysis and freeze-drying in sequence to obtain aldehyde-terminated polyethylene glycol.

In the present invention, the polyethylene glycol is preferably one or more of linear polyethylene glycol, branched four-arm polyethylene glycol and branched eight-arm polyethylene glycol; The source of polyethylene glycol is not particularly limited, and the above-mentioned linear polyethylene glycol, branched four-arm polyethylene glycol and branched eight-arm polyethylene glycol known to those skilled in the art are commercially available. In the present invention, the molecular weight of the polyethylene glycol is preferably 400Da-100000Da, more preferably 2000Da-10000Da.

In the present invention, the molar ratio of polyethylene glycol, p-aldehyde benzoic acid, EDC·HCl and DMAP is preferably 1: (1.5-2.4): (2.5-3.5): (2.5-3.5), more preferably It is 1:2:3:3.

In the present invention, the temperature of the esterification reaction is preferably 15°C-50°C, more preferably 20°C-40°C; the time of the esterification reaction is preferably 48h-96h, more preferably 72h.

In the present invention, the injectable antibacterial hydrogel is obtained by self-crosslinking reaction of arginine-modified chitosan and a crosslinking agent in a solvent. In the present invention, the mass ratio of the arginine-modified chitosan to the cross-linking agent is preferably 1:(0.1-20), more preferably 1:(0.25-4).

The present invention has no special limitation on the preparation method of the injectable antibacterial hydrogel, and adopts the Schiff base reaction well known to those skilled in the art. In the present invention, the preparation method of the injectable antibacterial hydrogel is preferably specifically:

The cross-linking agent and the arginine-modified chitosan are respectively mixed with a solvent, and then blended to obtain an injectable antibacterial hydrogel by self-cross-linking. In the present invention, the solvent is preferably water, physiological saline, buffer solution, tissue culture fluid or body fluid, more preferably buffer solution. In a preferred embodiment of the present invention, the solvent is a buffer solution of phosphoric acid.

In the present invention, the mass concentration of the crosslinking agent in the solution obtained by mixing the crosslinking agent with the solvent is preferably 2%-30%, more preferably 4%-20%, and even more preferably 5%-15%. In the present invention, the mass concentration of the arginine-modified chitosan in the solution obtained by mixing the arginine-modified chitosan with the solvent is preferably 2% to 30%, more preferably 4% to 20%, more preferably Preferably it is 5% to 15%.

In the present invention, the self-crosslinking temperature is preferably 10°C to 50°C, more preferably 15°C to 45°C, even more preferably 20°C to 40°C.

The present invention provides a kind of arginine-modified chitosan, its preparation method and injectable antibacterial hydrogel, and described injectable antibacterial hydrogel is made of arginine-modified chitosan having the structure of formula (I) and a cross-linking agent in a solvent for self-cross-linking reaction; Compared with the prior art, the arginine-modified chitosan provided by the invention not only improves the water solubility of the chitosan but also improves its biocompatibility by introducing arginine. The injectable antibacterial hydrogel provided by the present invention itself has antibacterial properties, and has good biocompatibility, can be formed in situ in the body, and is conducive to directly acting on the lesion and exerting the drug effect for a long time; and the terminal aldehyde group The modified polyethylene glycol has an aldehyde structure, which can replace the commonly used formaldehyde, glutaraldehyde and other cross-linking agents that are more toxic to the human body; at the same time, the injectable antibacterial hydrogel also has good biodegradability and can It degrades in the body, and the degradation products are amino acids, polysaccharides, and polyethylene glycol, which can be directly excreted through the kidneys and are harmless to the human body. Experimental results show that the injectable antibacterial hydrogel provided by the present invention has significant antibacterial effect on Gram-positive bacteria and Gram-negative bacteria, and is a new type of injectable antibacterial hydrogel with medical potential.

In addition, the injectable antibacterial hydrogel provided by the present invention has a relatively high adjustable space, and can adjust the molecular weight of chitosan, the degree of substitution of arginine on the side chain of chitosan, the degree of substitution of arginine on the side chain of chitosan, and the degree of polyformylation at the end. The molecular weight of ethylene glycol, the type of polyethylene glycol, etc., so that various hydrogel materials with different physical and chemical properties can be prepared.

In addition, the preparation method of the arginine-modified chitosan provided by the present invention has simple and easy-to-obtain raw materials and low cost; at the same time, it has simple operation, mild reaction conditions, stable preparation process, is easy to realize industrial production, and has good application prospects.

In order to further illustrate the present invention, the arginine-modified chitosan provided by the present invention, its preparation method and injectable antibacterial hydrogel are described in detail below in conjunction with the examples. The raw materials used in the following examples of the present invention are all commercially available, wherein the arginine derivative is BOC-Arg(Z)-OH provided by Shanghai Gil Biochemical Co., Ltd., and its structural formula is:

Example 1

(1) Weigh 2g chitosan and mix it with 200mL hydrochloric acid solution to obtain the first mixed solution; then weigh 0.2g arginine derivative, 0.2g EDC, 0.1g NHS in a round bottom flask, add 20mL DMF to dissolve it , to obtain a second mixed solution; adding the second mixed solution to the first mixed solution, stirring and reacting at 30° C. for 48 hours, and purifying to obtain a solid powder;

(2) The solid powder obtained in step (1) is dispersed as the reaction medium with 100mL trifluoroacetic acid, 15mL of hydrogen bromide solution is added, reacted for 6h at 30°C, and purified to obtain arginine-modified chitosan, the yield is 80%.

Carry out nuclear magnetic resonance analysis to the solid powder that step (1) obtains, as shown in Figure 1. The results showed that arginine was successfully attached to chitosan, and the substitution degree of arginine was 3%.

Example 2

(1) Mix 2g chitosan with 200mL hydrochloric acid solution to obtain the first mixed solution; then weigh 0.4g arginine derivative, 0.4g EDC, 0.2g NHS in a round bottom flask, add 20mL DMF to dissolve it , to obtain a second mixed solution; adding the second mixed solution to the first mixed solution, stirring and reacting at 30° C. for 48 hours, and purifying to obtain a solid powder;

(2) The solid powder obtained in step (1) is dispersed as the reaction medium with 100mL trifluoroacetic acid, 15mL of hydrogen bromide solution is added, reacted for 6h at 30°C, and purified to obtain arginine-modified chitosan, the yield is 85%.

The solid powder obtained in step (1) was subjected to nuclear magnetic resonance analysis, and the results showed that arginine was successfully connected to chitosan, and the substitution degree of arginine was 6%.

Example 3

(1) Mix 2g chitosan with 200mL hydrochloric acid solution to obtain the first mixed solution; then weigh 0.8g arginine derivative, 0.8g EDC, 0.4g NHS in a round bottom flask, add 20mL DMF to dissolve it , to obtain a second mixed solution; adding the second mixed solution to the first mixed solution, stirring and reacting at 30° C. for 48 hours, and purifying to obtain a solid powder;

(2) The solid powder obtained in step (1) is dispersed as the reaction medium with 100mL trifluoroacetic acid, 15mL of hydrogen bromide solution is added, reacted for 6h at 30°C, and purified to obtain arginine-modified chitosan, the yield is 83%.

The solid powder obtained in step (1) was subjected to nuclear magnetic resonance analysis, and the results showed that arginine was successfully connected to chitosan, and the substitution degree of arginine was 10%.

Example 4

(1) Mix 2g chitosan with 200mL hydrochloric acid solution to obtain the first mixed solution; then weigh 1.6g arginine derivatives, 1.6g EDC, 0.8g NHS in a round bottom flask, add 20mL DMF to dissolve it , to obtain a second mixed solution; adding the second mixed solution to the first mixed solution, stirring and reacting at 30° C. for 48 hours, and purifying to obtain a solid powder;

(2) The solid powder obtained in step (1) is dispersed as the reaction medium with 100mL trifluoroacetic acid, 15mL of hydrogen bromide solution is added, reacted for 6h at 30°C, and purified to obtain arginine-modified chitosan, the yield is 81%.

Carry out nuclear magnetic resonance analysis to the solid powder that step (1) obtains, as shown in Figure 2. The results showed that arginine was successfully attached to chitosan, and the substitution degree of arginine was 23%.

Example 5

Dissolve linear polyethylene glycol (M _w =2000), p-aldehyde benzoic acid, EDC·HCl, and DMAP in dichloromethane solvent, wherein the hydroxyl group in polyethylene glycol and p-aldehyde benzoic acid, EDC·HCl 1. The substance ratio of DMAP was 1:2:3:3, and reacted at room temperature for 3 days; the solvent dichloromethane was removed, dialyzed in primary water for 3 days, and freeze-dried to obtain the product with a yield of 85%.

The obtained product was analyzed by nuclear magnetic resonance, and the results showed that p-aldehyde benzoic acid was successfully connected to linear polyethylene glycol (M _w =2000), and each polyethylene glycol was connected with 2 p-aldehyde benzene formic acid.

Example 6

Dissolve linear polyethylene glycol (M _w =5000), p-aldehyde benzoic acid, EDC·HCl, and DMAP in dichloromethane solvent, wherein the hydroxyl group in polyethylene glycol and p-aldehyde benzoic acid, EDC·HCl 1. The substance ratio of DMAP was 1:2:3:3, and reacted at room temperature for 3 days; the solvent dichloromethane was removed, dialyzed in primary water for 3 days, and freeze-dried to obtain the product with a yield of 88%.

The obtained product was analyzed by nuclear magnetic resonance, and the results showed that p-aldehyde benzoic acid was successfully connected to linear polyethylene glycol (M _w =5000), and each polyethylene glycol was connected with 2 p-aldehyde benzene formic acid.

Example 7

Dissolve branched four-arm polyethylene glycol (M _w =10000), p-aldehyde benzoic acid, EDC·HCl, and DMAP in dichloromethane solvent, wherein the hydroxyl group in polyethylene glycol and p-aldehyde benzoic acid , EDC·HCl, and DMAP in a ratio of 1:2:3:3, reacted at room temperature for 3 days; removed the solvent dichloromethane, dialyzed in primary water for 3 days, and freeze-dried to obtain the product with a yield of 91 %.

The obtained product was analyzed by nuclear magnetic resonance, and the results showed that p-aldehyde benzoic acid was successfully connected to branched four-armed polyethylene glycol (M _w =10000), and each polyethylene glycol was connected with four p-Aldehydobenzoic acid.

Example 8

Dissolve branched eight-armed polyethylene glycol (M _w =10000), p-aldehyde benzoic acid, EDC·HCl, and DMAP in dichloromethane solvent, wherein the hydroxyl group in polyethylene glycol and p-aldehyde benzoic acid , EDC·HCl, and DMAP in a ratio of 1:2:3:3, reacted at room temperature for 3 days; removed the solvent dichloromethane, dialyzed in primary water for 3 days, and freeze-dried to obtain the product with a yield of 89 %.

The obtained product was analyzed by nuclear magnetic resonance, and the results showed that p-aldehyde benzoic acid was successfully connected to branched eight-armed polyethylene glycol (M _w =10000), and each polyethylene glycol was connected with 8 p-Aldehydobenzoic acid.

Example 9

The polyoxyethylene glycol that obtains in embodiment 5 and the arginine-modified chitosan that obtains in embodiment 1 are formulated respectively into the phosphate buffer solution that mass concentration is 6%, and the two prepared The two solutions were blended at a volume ratio of 1:1, and the viscosity change at 37 ° C was observed by the small tube inversion method. When the small tube was inverted, no flow occurred within 30 seconds. glue.

Example 10

The polyoxyethylene glycol of the end formylation obtained in embodiment 5 and the chitosan modified by arginine obtained in embodiment 2 are formulated respectively into a phosphate buffer solution with a mass concentration of 6%, and the prepared two The two solutions were blended at a volume ratio of 1:1, and the viscosity change at 37 ° C was observed by the small tube inversion method. When the small tube was inverted, no flow occurred within 30 seconds. glue.

Example 11

The polyoxyethylene glycol that obtains in embodiment 5 and the arginine-modified chitosan that obtains in embodiment 3 are formulated respectively into the phosphate buffer solution that mass concentration is 6%, and the two prepared The two solutions were blended at a volume ratio of 1:1, and the viscosity change at 37 ° C was observed by the small tube inversion method. When the small tube was inverted, no flow occurred within 30 seconds. glue.

Example 12

The polyoxyethylene glycol that obtains in embodiment 5 and the arginine-modified chitosan that obtains in embodiment 4 are formulated respectively into the phosphate buffer solution that mass concentration is 6%, and the two prepared The two solutions were blended at a volume ratio of 1:1, and the viscosity change at 37 ° C was observed by the small tube inversion method. When the small tube was inverted, no flow occurred within 30 seconds. glue.

Example 13

The polyoxyethylene glycol that obtains in embodiment 6 and the arginine-modified chitosan that obtains in embodiment 1 are prepared respectively into the phosphate buffer solution that mass concentration is 6%, the two prepared two The two solutions were blended at a volume ratio of 1:1, and the viscosity change at 37 ° C was observed by the small tube inversion method. When the small tube was inverted, no flow occurred within 30 seconds. glue.

Example 14

The polyoxyethylene glycol that obtains in embodiment 6 and the arginine-modified chitosan that obtains in embodiment 2 are formulated respectively into the phosphate buffer solution that mass concentration is 6%, and the two prepared The two solutions were blended at a volume ratio of 1:1, and the viscosity change at 37 ° C was observed by the small tube inversion method. When the small tube was inverted, no flow occurred within 30 seconds. glue.

Example 15

The polyoxyethylene glycol that obtains in embodiment 6 and the arginine-modified chitosan that obtains in embodiment 3 are formulated respectively into the phosphate buffer solution that mass concentration is 6%, and the two prepared The two solutions were blended at a volume ratio of 1:1, and the viscosity change at 37 ° C was observed by the small tube inversion method. When the small tube was inverted, no flow occurred within 30 seconds. glue.

Example 16

The polyoxyethylene glycol that obtains in embodiment 6 and the arginine-modified chitosan that obtains in embodiment 4 are formulated respectively into the phosphate buffer solution that mass concentration is 6%, and the two prepared The two solutions were blended at a volume ratio of 1:1, and the viscosity change at 37 ° C was observed by the small tube inversion method. When the small tube was inverted, no flow occurred within 30 seconds. glue.

Example 17

The polyoxyethylene glycol of the end formylation that obtains in embodiment 7 and the chitosan that the arginine modification that obtains in embodiment 1 are formulated into the phosphate buffer solution that mass concentration is 6% respectively, and the two prepared The two solutions were blended at a volume ratio of 1:1, and the viscosity change at 37 ° C was observed by the small tube inversion method. When the small tube was inverted, no flow occurred within 30 seconds. glue.

Example 18

The polyoxyethylene glycol of the end formylation that obtains in embodiment 7 and the chitosan that the arginine modification that obtains in embodiment 1 are formulated into the phosphate buffer solution that mass concentration is 6% respectively, and the two prepared The two solutions were blended at a volume ratio of 1:4, and the viscosity change at 37 ° C was observed by the small tube inversion method. When the small tube was inverted, no flow occurred within 30 seconds. glue.

Example 19

The polyoxyethylene glycol of the end formylation that obtains in embodiment 7 and the chitosan that the arginine modification that obtains in embodiment 1 are formulated into the phosphate buffer solution that mass concentration is 6% respectively, and the two prepared The two solutions were blended at a volume ratio of 4:1, and the viscosity change at 37 ° C was observed by the small tube inversion method. When the small tube was inverted, no flow occurred within 30 seconds. glue.

Example 20

The polyoxyethylene glycol that obtains in embodiment 7 and the arginine-modified chitosan that obtains in embodiment 2 are formulated respectively into the phosphate buffer solution that mass concentration is 6%, and the two prepared The two solutions were blended at a volume ratio of 1:1, and the viscosity change at 37 ° C was observed by the small tube inversion method. When the small tube was inverted, no flow occurred within 30 seconds. glue.

Example 21

The polyoxyethylene glycol that obtains in embodiment 7 and the arginine-modified chitosan that obtains in embodiment 2 are formulated respectively into the phosphate buffer solution that mass concentration is 6%, and the two prepared The two solutions were blended at a volume ratio of 1:4, and the viscosity change at 37 ° C was observed by the small tube inversion method. When the small tube was inverted, no flow occurred within 30 seconds. glue.

Example 22

The polyoxyethylene glycol that obtains in embodiment 7 and the arginine-modified chitosan that obtains in embodiment 2 are formulated respectively into the phosphate buffer solution that mass concentration is 6%, and the two prepared The two solutions were blended at a volume ratio of 4:1, and the viscosity change at 37 ° C was observed by the small tube inversion method. When the small tube was inverted, no flow occurred within 30 seconds. glue.

Example 23

The polyoxyethylene glycol of terminal aldehylation obtained in embodiment 7 and the chitosan modified by arginine obtained in embodiment 3 are formulated into respectively a phosphate buffer solution with a mass concentration of 6%, and the prepared two The two solutions were blended at a volume ratio of 1:1, and the viscosity change at 37 ° C was observed by the small tube inversion method. When the small tube was inverted, no flow occurred within 30 seconds. glue.

Example 24

The polyoxyethylene glycol of terminal aldehylation obtained in embodiment 7 and the chitosan modified by arginine obtained in embodiment 3 are formulated into respectively a phosphate buffer solution with a mass concentration of 6%, and the prepared two The two solutions were blended at a volume ratio of 1:4, and the viscosity change at 37 ° C was observed by the small tube inversion method. When the small tube was inverted, no flow occurred within 30 seconds. glue.

Example 25

The polyoxyethylene glycol of terminal aldehylation obtained in embodiment 7 and the chitosan modified by arginine obtained in embodiment 3 are formulated into respectively a phosphate buffer solution with a mass concentration of 6%, and the prepared two The two solutions were blended at a volume ratio of 4:1, and the viscosity change at 37 ° C was observed by the small tube inversion method. When the small tube was inverted, no flow occurred within 30 seconds. glue.

Example 26

The polyoxyethylene glycol that obtains in embodiment 7 and the arginine-modified chitosan that obtains in embodiment 4 are formulated respectively into the phosphate buffer solution that mass concentration is 6%, and the two prepared The two solutions were blended at a volume ratio of 1:1, and the viscosity change at 37 ° C was observed by the small tube inversion method. When the small tube was inverted, no flow occurred within 30 seconds. glue.

Example 27

The polyoxyethylene glycol that obtains in embodiment 7 and the arginine-modified chitosan that obtains in embodiment 4 are formulated respectively into the phosphate buffer solution that mass concentration is 6%, and the two prepared The two solutions were blended at a volume ratio of 1:4, and the viscosity change at 37 ° C was observed by the small tube inversion method. When the small tube was inverted, no flow occurred within 30 seconds. glue.

Example 28

The polyoxyethylene glycol that obtains in embodiment 7 and the arginine-modified chitosan that obtains in embodiment 4 are formulated respectively into the phosphate buffer solution that mass concentration is 6%, and the two prepared The two solutions were blended at a volume ratio of 4:1, and the viscosity change at 37 ° C was observed by the small tube inversion method. When the small tube was inverted, no flow occurred within 30 seconds. glue.

Example 29

The polyoxyethylene glycol of end formylation obtained in embodiment 8 and the chitosan modified by arginine obtained in embodiment 1 are formulated into respectively a phosphate buffer solution with a mass concentration of 6%, and the prepared two The two solutions were blended at a volume ratio of 1:1, and the viscosity change at 37 ° C was observed by the small tube inversion method. When the small tube was inverted, no flow occurred within 30 seconds. glue.

Example 30

The polyoxyethylene glycol that obtains in embodiment 8 and the arginine-modified chitosan that obtains in embodiment 2 are formulated respectively into the phosphate buffer solution that mass concentration is 6%, and the two prepared The two solutions were blended at a volume ratio of 1:1, and the viscosity change at 37 ° C was observed by the small tube inversion method. When the small tube was inverted, no flow occurred within 30 seconds. glue.

Example 31

The polyoxyethylene glycol of end formylation obtained in embodiment 8 and the chitosan modified by arginine obtained in embodiment 3 are respectively formulated into a phosphate buffer solution with a mass concentration of 6%, and the prepared two The two solutions were blended at a volume ratio of 1:1, and the viscosity change at 37 ° C was observed by the small tube inversion method. When the small tube was inverted, no flow occurred within 30 seconds. glue.

Example 32

The polyoxyethylene glycol that obtains in embodiment 8 and the arginine-modified chitosan that obtains in embodiment 4 are formulated respectively into the phosphate buffer solution that mass concentration is 6%, and the two prepared The two solutions were blended at a volume ratio of 1:1, and the viscosity change at 37 ° C was observed by the small tube inversion method. When the small tube was inverted, no flow occurred within 30 seconds. glue.

Example 33

The in vitro cytotoxicity test was performed on the terminal formhylated polyethylene glycol obtained in Example 7: the cells were planted in a 96-well plate at a cell density of 1×10 ⁴ cells/well at 37° C., 5% CO ₂ Culture in a sterile incubator for 24 hours; remove the medium, add different concentrations of doubling-diluted polyethylene glycol solutions (maximum concentration of 10mg/mL, 200μL/well), and continue to cultivate for different periods of time (24h , 48h), the MTT method was used to test after removing the culture medium.

See Figure 3 for the results. Figure 3 shows the cell viability of different concentrations of the aldehydated polyethylene glycol solutions described in Example 33 of the present invention within the corresponding time period. As can be seen from Figure 3, within the corresponding time period, the cell survival rates of different concentrations of solutions were all greater than 85%, indicating that the polyethylene glycol solution of the terminal aldehydes of the present invention has no obvious cytotoxicity, and the terminal aldehydes The aldehyde group contained in polyethylene glycol can be used as a macromolecular cross-linking agent, so it can be further applied in the field of biomedical materials.

Example 34

The arginine-modified chitosan described in Example 4 was subjected to an in vitro cytotoxicity test: the cells were planted in a 96-well plate at a cell density of 1×10 ⁴ cells/well at 37° C., 5% CO ₂ Cultivate in a sterile incubator for 24 hours; remove the medium, add polysaccharide derivative solutions with different concentrations and multiple dilutions (maximum concentration is 10mg/mL, 200μL/well), continue to cultivate for different times (24h, 48h), remove After the culture medium was tested by MTT method.

The results are shown in FIG. 4 , which shows the cell viability of different concentrations of arginine-modified chitosan solutions obtained in Example 34 of the present invention within a corresponding period of time. It can be seen from Fig. 4 that the cell survival rates of solutions with different concentrations are all greater than 85%, indicating that the arginine-modified chitosan solution has no obvious cytotoxicity, so it can be further applied in the field of biomedical materials.

Example 35

The injectable antibacterial hydrogel prepared in Example 17 was subjected to an in vitro cytotoxicity test: the injectable antibacterial hydrogel prepared in Example 17 was leached with DMEM to obtain a gel extract; the cells were planted in a 96-well plate In the medium, the cell density is 1×10 ⁴ cells/well, and cultured in a sterile incubator with 5% CO ₂ at 37°C for 24 hours; remove the medium, add different concentrations of doubly diluted gel extracts, and continue Cultivate for different times (24h, 48h), and use the MTT method to test after removing the culture medium.

See Figure 5 for the results. Figure 5 shows the cell viability of gel extracts with different concentrations obtained in Example 35 of the present invention. In FIG. 5 , the cell survival rates of different concentrations of gel extracts are all greater than 85%, indicating that the injectable antibacterial hydrogel has no obvious cytotoxicity. In addition, the mixed solution can form a hydrogel at 37°C, that is, a hydrogel can be formed at body temperature, so it can be further applied as an injectable hydrogel in the field of biomedical materials.

Example 36

The injectable antibacterial hydrogel prepared in Example 26 was subjected to an in vitro cytotoxicity test: the injectable antibacterial hydrogel prepared in Example 26 was leached with DMEM to obtain a gel extract; the cells were planted in a 96-well plate In the medium, the cell density is 1×10 ⁴ cells/well, and cultured in a sterile incubator with 5% CO ₂ at 37°C for 24 hours; remove the medium, add different concentrations of doubly diluted gel extracts, and continue Cultivate for different times (24h, 48h), and use the MTT method to test after removing the culture medium.

See Figure 6 for the results. Figure 6 shows the cell viability of gel extracts with different concentrations obtained in Example 36 of the present invention. In Fig. 6, the cell viability of gel extracts with different concentrations were all greater than 85%, indicating that the injectable hydrogel had no obvious cytotoxicity. In addition, the mixed solution can form a hydrogel at 37°C, that is, a hydrogel can be formed at body temperature, so it can be further applied as an injectable hydrogel in the field of biomedical materials.

Example 37

Prepare LB solid petri dishes, dig out cylindrical gels with a diameter of 2 cm in the middle of the solid petri dishes, start from the upper left corner of the LB solid petri dishes, and fill the hollow positions of the cylinders in a clockwise direction with Example 17 and Example 20 , Example 23, and the injectable antibacterial hydrogel provided in Example 26, coat Escherichia coli (E.coil) on the surface of the solid medium and above the gel, then place the culture dish in a 37°C incubator for 24 hours, and take out Then observe the antibacterial effect.

Refer to Fig. 7 for the results. Fig. 7 is the self-crosslinked polyoxyethylene glycol obtained in Example 37 of the present invention and arginine-modified chitosan with different degrees of substitution (component ratio 1:1). Antibacterial effect of injectable antibacterial hydrogel against Escherichia coli (E.coil). In Figure 7, no bacterial growth was observed on the injectable antibacterial hydrogel provided by the present invention, indicating that this injectable antibacterial hydrogel has significant antibacterial properties against Escherichia coli.

Example 38

Prepare LB solid petri dishes, dig out cylindrical gels with a diameter of 2 cm in the middle of the solid petri dishes, start from the upper left corner of the LB solid petri dishes, and fill the hollow positions of the cylinders in a clockwise direction with Example 17 and Example 20 , Example 23, and the injectable antibacterial hydrogel provided in Example 26, coat Staphylococcus aureus (S.aureus) on the surface of the solid medium and above the gel, and then place the culture dish in a 37°C incubator for 24h , Observe the antibacterial effect after taking it out.

Refer to Fig. 8 for the results. Fig. 8 is the self-crosslinked polyoxyethylene glycol obtained in Example 38 of the present invention and arginine-modified chitosan with different degrees of substitution (component ratio 1:1). Antimicrobial efficacy of injectable antimicrobial hydrogel against Staphylococcus aureus (S. aureus). In Figure 8, no bacterial growth was observed on the injectable antibacterial hydrogel provided by the present invention, indicating that this injectable antibacterial hydrogel has significant antibacterial properties against Staphylococcus aureus.

Example 39

Prepare LB solid petri dishes, dig out cylindrical gels with a diameter of 2 cm in the middle of the solid petri dishes, start from the upper left corner of the LB solid petri dishes, and fill the hollow cylindrical positions in the clockwise direction with Example 18 and Example 21 , Example 24, and the injectable antibacterial hydrogel provided in Example 27, coat Escherichia coli (E.coil) on the surface of the solid medium and above the gel, then place the culture dish in a 37°C incubator for 24 hours, and take out Then observe the antibacterial effect.

Refer to Fig. 9 for the results, Fig. 9 is the self-crosslinked polyoxyethylene glycol obtained in Example 39 of the present invention and arginine-modified chitosan with different degrees of substitution (component ratio 1:4) Antibacterial effect of injectable antibacterial hydrogel against Escherichia coli (E.coil). In Fig. 9, no bacterial growth was observed above the injectable antibacterial hydrogel provided by the present invention and obvious bacteriostatic rings appeared around the hydrogel, indicating that the injectable antibacterial hydrogel provided by the present invention has Excellent antibacterial performance, and increasing the composition ratio of arginine-modified chitosan is beneficial to improve its antibacterial effect.

Example 40

Prepare LB solid petri dishes, dig out cylindrical gels with a diameter of 2 cm in the middle of the solid petri dishes, start from the upper left corner of the LB solid petri dishes, and fill the hollow cylindrical positions in the clockwise direction with Example 18 and Example 21 , Example 24, the injectable antibacterial hydrogel provided by Example 27, coat Staphylococcus aureus (S.aureus) on the surface of the solid medium and above the gel, and then place the culture dish in a 37°C incubator for 24h , Observe the antibacterial effect after taking it out.

Refer to Fig. 10 for the results, Fig. 10 is obtained from self-crosslinking of polyoxyethylene glycol at the terminal formylation obtained in Example 40 of the present invention and arginine-modified chitosan with different degrees of substitution (component ratio 1:4) Antimicrobial efficacy of injectable antimicrobial hydrogel against Staphylococcus aureus (S. aureus). In Fig. 10, no bacterial growth is observed above the injectable antibacterial hydrogel provided by the present invention, and there are obvious antibacterial rings around the hydrogel, indicating that the injectable antibacterial hydrogel provided by the present invention is effective against Grape aureus. Coccus has excellent antibacterial properties, and increasing the composition ratio of arginine-modified chitosan is beneficial to improve its antibacterial effect.

As can be seen from the above examples, the injectable antibacterial hydrogel provided by the present invention has a relatively high adjustable space, and can adjust the degree of substitution of arginine on the side chain of chitosan, the polyethylene glycol with terminal formhylation according to different needs. The molecular weight of the alcohol, the type of polyethylene glycol, the composition ratio of the end-formylated polyethylene glycol and the arginine-modified chitosan, etc., so that various hydrogel materials with different physical and chemical properties can be prepared. Moreover, increasing the composition ratio of the arginine-modified chitosan is beneficial to improving the antibacterial performance of the injectable antibacterial hydrogel of the present invention. Furthermore, the injectable antibacterial hydrogel provided by the present invention exhibits significant antibacterial effects on both Escherichia coli and Staphylococcus aureus, and has the potential to be used as a broad-spectrum antibacterial material. In addition, the injectable antibacterial hydrogel provided by the present invention uses polyethylene glycol with terminal aldehydes to replace formaldehyde, glutaraldehyde and other cross-linking agents that are more toxic to the human body, and does not need to introduce additional chemical cross-linking agents, which is safe and non-toxic. Toxic, less environmental pollution. More importantly, the injectable antibacterial hydrogel provided by the present invention has high water content, and the cell survival rate of different concentrations of arginine-modified chitosan, end-formylated polyethylene glycol raw materials and gel extract The ratios are all greater than 85%, indicating that the injectable hydrogel of the present invention has no obvious cytotoxicity, good cytocompatibility, nontoxic to the human body, has the potential to be popularized and applied in the field of biomedicine, and can be applied to wound dressings or Used as a hemostatic material, etc., the market prospect is broad.

The above description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention will not be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. a kind of chitosan modified by arginine has structure shown in formula (I): Among them, n is the degree of polymerization, 10≤n≤3200; The substitution degree of arginine in the arginine-modified chitosan is 0.1%-80%. 2. a preparation method of arginine-modified chitosan, comprising the following steps: a) mixing chitosan, arginine derivatives and an activator for amidation reaction to obtain a compound shown in formula (II); The arginine derivative has a structure shown in formula (III): b) deprotecting the compound shown in formula (II) to obtain arginine-modified chitosan; The chitosan modified by described arginine has structure shown in formula (I): Among them, n is the degree of polymerization, 10≤n≤3200; The substitution degree of arginine in the arginine-modified chitosan is 0.1%-80%. 3. The preparation method according to claim 2, characterized in that, the activator described in step a) is selected from 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, One or more of N-hydroxysuccinimide, N,N-diisopropylcarbodiimide, N,N'-dicyclohexylcarbodiimide and N-hydroxysulfosuccinimide . 4. preparation method according to claim 2 is characterized in that, the mass ratio of chitosan, arginine derivative and activator described in step a) is 1: (0.1～0.8): (0.15～1.2 ). 5. preparation method according to claim 2, is characterized in that, described in step a) the process that chitosan, arginine derivative and activator are mixed is specifically: a1) mixing chitosan with an acid solution to obtain a first mixed solution; a2) mixing an arginine derivative, an activator and an organic solvent to obtain a second mixed solution; a3) adding the second mixed solution to the first mixed solution to obtain a mixed solution of chitosan, arginine derivative and activator; Steps a1) and a2) are not limited in order. 6 . The preparation method according to claim 2 , characterized in that, the temperature of the amidation reaction in step a) is 20° C. to 40° C. and the time is 24h to 72h. 7. The preparation method according to claim 2, characterized in that the temperature of the deprotection reaction in step b) is 20°C-45°C, and the time is 2h-8h. 8. An injectable antibacterial hydrogel, the arginine-modified chitosan obtained by the arginine-modified chitosan according to claim 1 or the preparation method described in any one of claims 2 to 7 It is obtained by self-crosslinking reaction with a crosslinking agent in a solvent; The cross-linking agent is polyethylene glycol with terminal aldehylation. 9. The injectable antibacterial hydrogel according to claim 8, characterized in that the mass ratio of the arginine-modified chitosan to the cross-linking agent is 1: (0.1-20). 10. The injectable antibacterial hydrogel according to claim 8, wherein the solvent is water, physiological saline, buffer solution, tissue culture fluid or body fluid.