CN110384831B

CN110384831B - Preparation method of zwitterionic hydrogel for postoperative adhesion prevention, cross-linking agent and polymer

Info

Publication number: CN110384831B
Application number: CN201910581677.1A
Authority: CN
Inventors: 李俊杰; 姚芳莲; 郭�旗; 孙红
Original assignee: Tianjin University
Current assignee: Tianjin University
Priority date: 2019-06-30
Filing date: 2019-06-30
Publication date: 2021-10-08
Anticipated expiration: 2039-06-30
Also published as: CN110384831A

Abstract

The invention relates to a zwitterionic cross-linking agent for preventing adhesion, a zwitterionic polymer, a zwitterionic injectable hydrogel and a preparation method thereof. N-methyldiethanolamine is subjected to acylation and ring-opening addition to synthesize a zwitterionic crosslinking agent with double bonds at two ends; carrying out free radical polymerization and disulfide bond reduction on a zwitterionic compound monomer and a disulfide bond monomer to prepare a zwitterionic polymer with side chain belt sulfydryl; then, the two solutions are respectively dissolved in phosphate buffer solution, and the zwitterionic injectable hydrogel is prepared through the mercapto-alkene addition reaction. The prepared zwitterionic cross-linking agent and the zwitterionic polymer have excellent protein resistance, and the corresponding zwitterionic injectable hydrogel formed by the zwitterionic cross-linking agent and the zwitterionic polymer has better biocompatibility and cell adhesion resistance, and can be used as an anti-adhesion material to prevent postoperative adhesion.

Description

Preparation method of zwitterionic hydrogel for postoperative adhesion prevention, cross-linking agent and polymer

Technical Field

The invention relates to a preparation method of a zwitterionic hydrogel for postoperative adhesion prevention, a cross-linking agent and a polymer, and belongs to the field of biomedical materials.

Background

Postoperative adhesion has become a common medical problem, the incidence rate is as high as 93%, and even if patients after the adhesion are subjected to adhesion release surgery, the incidence rate of the adhesion is more than 50%. Postoperative adhesions can cause serious complications such as intestinal obstruction, female infertility, long-term intolerable pain, etc. Adhesion not only increases the economic and mental burden on the patient, but also the re-operation on the adhesion site prolongs the time for anesthesia, operation and recovery, and causes additional risks to the patient, such as blood loss, visceral injury, and even intestinal tract resection.

Currently, in order to slow down the occurrence of adhesion, many methods such as improvement of surgical operation, use of drugs and solid films and synergistic use of physical release agents and drugs have been put into use. Minimizing trauma and surgical time during surgery is considered a major measure of reducing adhesions, but has limited effectiveness. When antibiotics, anti-inflammatory drugs, anticoagulants and other drugs are applied in the abdominal cavity, the drugs are quickly removed due to the existence of abdominal cavity fluid, and the drugs cannot exert the effects. Although the liquid anti-adhesion material can completely cover irregular wound surfaces, the fluidity of the liquid anti-adhesion material prevents the liquid anti-adhesion material from being maintained on the wound surfaces for a long time and is difficult to play a physical barrier effect for a long time, so that the anti-adhesion effect of the liquid anti-adhesion material is limited. Although the application of the solid film after the abdominal cavity operation can play a role in physical isolation, the solid film is formed, so that irregular wound surfaces cannot be completely covered, and minimally invasive surgery cannot be performed, so that the effect on clinical application is poor. The injectable hydrogel is convenient to operate, is free-flowing liquid before injection, and is formed in situ by temperature or chemical reaction when injected to a wound, so that the injectable hydrogel not only can completely cover wound tissues, but also can play a physical isolation role for a long time, and the injectable in-situ hydrogel has wide research in the field of postoperative adhesion prevention due to the advantage. However, most injectable in-situ hydrogels can not prevent adhesion well and have no anti-adhesion effect in clinical use. Therefore, there is a need to develop a new injectable in situ hydrogel with unique resistance to post-operative adhesions.

The molecules of the zwitterionic polymer material are simultaneously provided with anionic and cationic charges, which endow the zwitterionic material with an electrically neutral property, so that a hydration layer is formed around the zwitterionic material. Therefore, the zwitterionic material has super-strong hydrophilicity and can well resist the adsorption of nonspecific protein. Due to its excellent protein resistance, zwitterionic materials have been extensively studied in the biomedical field. The crosslinking agent such as commonly used N, N methylene bisacrylamide has no protein resistance, so that the application of the crosslinking agent in the field of biological materials is limited. Based on the method, N-methyldiethanolamine is subjected to acylation and ring-opening addition to synthesize the zwitterionic crosslinking agent with double bonds at two ends. The zwitterionic polymer with sulfydryl is generally prepared by activity-controllable polymerization, the reaction process is harsh, the yield is low, and large-scale synthesis and preparation cannot be realized. The zwitterionic polymer with the side chain having the mercapto group is prepared by free radical polymerization and disulfide bond reduction reaction of the zwitterionic compound monomer and the disulfide bond monomer, the reaction process is simple, and the yield is high. Finally, the zwitterionic crosslinking agent and the zwitterionic polymer with sulfydryl on the side chain are subjected to 'sulfydryl-alkene' addition reaction to prepare the in-situ injectable zwitterionic hydrogel. The prepared hydrogel has good biocompatibility and unique protein resistance, and can well prevent postoperative adhesion.

Disclosure of Invention

The invention aims to overcome the defects of inconvenient clinical operability, poor anti-adhesion effect, potential biological safety hazards and the like of the conventional anti-adhesion material, provides a preparation method of a novel zwitter-ion hydrogel, a cross-linking agent and a polymer, and uses the novel zwitter-ion hydrogel as the anti-adhesion material in the field of postoperative adhesion prevention. The zwitterionic cross-linking agent with acryloyl groups at two ends and the zwitterionic polymer with sulfydryl on the side chain, which are prepared by the invention, have simple synthesis methods and excellent protein resistance. The zwitterion injectable hydrogel is prepared by taking a zwitterion compound monomer with good biocompatibility and protein adsorption resistance as a raw material through a sulfydryl-alkene Michael addition reaction and is used as an anti-adhesion material to prevent postoperative adhesion. The anti-adhesion material prepared by the invention has excellent biocompatibility and anti-adhesion effect.

The technical scheme of the invention is as follows:

a zwitterionic hydrogel for preventing adhesion, which has the following structure:

the preparation method of the zwitterionic hydrogel for preventing adhesion comprises the following steps:

1. preparing a zwitterionic crosslinking agent (the structure of which is shown in the specification) with acryloyl groups at two ends by performing acylation reaction on an N-methyldiethanolamine monomer and acryloyl chloride or methacryloyl chloride or acrylic acid and performing ring-opening addition reaction on 1, 3-propane sultone or 1, 4-butane sultone or beta-propane lactone;

2. carrying out free radical polymerization on a zwitterionic compound monomer and a disulfide bond monomer to obtain a zwitterionic polymer with a disulfide bond on a side chain, dissolving the polymer in a sodium chloride solution, and reducing the disulfide bond into a sulfydryl group by using 1, 4-dithiothreitol to prepare the zwitterionic polymer with the sulfydryl group on the side chain;

3. then, the two solutions are respectively dissolved in phosphate buffer solution, and the zwitterionic injectable hydrogel is prepared through the mercapto-alkene addition reaction.

The preparation method of the zwitterionic crosslinking agent comprises the following steps:

(1) dissolving N-methyldiethanolamine and anhydrous triethylamine in a molar ratio of 1: 2-1: 4 in anhydrous dichloromethane, stirring uniformly in an ice-water bath, and then dropwise adding acryloyl chloride or methacryloyl chloride or acrylic acid dissolved in dichloromethane into a reaction container, wherein the molar ratio of N-methyldiethanolamine to acryloyl chloride or methacryloyl chloride or acrylic acid is 1: 2-1: 4; continuously stirring the solution in an ice-water bath for 0.5 to 3 hours, and then transferring the solution to room temperature for reaction for 6 to 48 hours; filtering and rotary steaming the mixed product to obtain a crude product, and then washing the crude product with acid, alkali and water in sequence to finally obtain yellow liquid;

(2) dissolving the monomer obtained in the step (1) in acetone, stirring uniformly in an ice-water bath, dropwise adding an acetone solution containing 1, 3-propane sultone or 1, 4-butane sultone or beta-propiolactone, wherein the molar ratio of the 1, 3-propane sultone or 1, 4-butane sultone or beta-propiolactone to the monomer obtained in the step (1) is 1: 1-1: 2, stirring uniformly in the ice-water bath, transferring to a water bath kettle at 40-70 ℃ and continuing to react for 12-60 hours. The white product was filtered and washed with acetone to remove unreacted monomer, and then dried under vacuum to give white zwitterionic crosslinker monomer.

Wherein: the preparation method of the zwitterionic polymer is as follows:

(1) dissolving a disulfide bond monomer and a zwitterionic monomer (the structures of the zwitterionic compound monomer and the disulfide bond monomer are shown as follows) in dimethyl sulfoxide according to a molar ratio of 1: 1-1: 100, heating to 50-100 ℃, and filling argon to remove O in the solution₂Adding an initiator azobisisobutyronitrile in an amount of 0.1-5 mol% of the sum of the molar amounts of the disulfide bond monomer and the zwitterionic monomer, and stopping the reaction after polymerizing for 12-48 hours;

(2) dropwise precipitating the polymer solution obtained in the step (1) in anhydrous methanol to remove unreacted disulfide bond monomers and zwitterionic monomers, obtaining precipitates through vacuum filtration, dissolving the precipitates in a sodium chloride solution again, and then dropwise precipitating again to remove redundant 1, 4-dithiothreitol, and finally obtaining white zwitterionic polymer solid with disulfide bonds on side chains;

(3) dissolving the polymer obtained in the step (2) in a sodium chloride solution, bubbling argon for 0.5-3 hours, adding 1, 4-dithiothreitol with the molar weight 5-20 times that of a disulfide bond monomer added during polymerization, reacting for 12-48 hours, and dialyzing the product with deionized water; and (4) freeze-drying to obtain white zwitterionic polymer solid with sulfydryl on the side chain.

The preparation of the zwitterionic injectable hydrogel is: dissolving a zwitterionic crosslinking agent and the obtained zwitterionic polymer in a phosphate buffer solution at a double bond and sulfydryl molar ratio of 5: 1-1: 5, respectively preparing solutions with mass fractions of 5-30 wt%, fully mixing the two solutions, and then placing the mixture at 37 ℃ for gelation to finally obtain the zwitterionic injectable hydrogel. The prepared hydrogel has good biocompatibility and cell adhesion resistance, and can be used as an anti-adhesion material to prevent postoperative adhesion.

Compared with the prior art, the invention has the following advantages: the zwitterionic cross-linking agent, the zwitterionic polymer and the zwitterionic injectable hydrogel anti-adhesion material prepared by the invention have excellent protein resistance, and the preparation method is simple and convenient to operate. The zwitterionic injectable gel does not participate in light or a catalyst and the like in the preparation process, and has excellent biocompatibility; as shown in FIG. 1, the viability of the gel extract prepared in example 38 was as high as 95% or more compared to the cells cultured in the normal medium (control group), which demonstrates that the gel extract has almost no influence on the activity of the cells. Due to the super-hydrophilic property of the zwitter-ion material, the gel has good anti-adhesion property to fibroblasts; as shown in FIG. 2, the number of cells seeded on the cell culture plate (FIG. 2A) was large and in the form of spindle, while the number of cells seeded on the zwitterionic hydrogel (FIG. 2B) prepared in example 38 of the present invention was small and in the form of circle, indicating that the cells on the gel did not adhere well thereto and that the gel had good anti-adhesion to fibroblasts; the prepared zwitterionic hydrogel is prepared through a sulfydryl-alkene reaction, and can be durably maintained on a wound surface and keep better integrity after being injected to the wound surface in situ to form hydrogel, so that an excellent postoperative anti-adhesion effect is exerted; as shown in FIG. 3, the gel can be formed in situ by mixing the zwitterionic crosslinker with the precursor solution of the zwitterionic polymer. Fig. 4 shows the procedure of using the zwitterionic injectable hydrogel prepared in example 38 in the adhesion model of abdominal wall-cecal injury in SD rats: normal abdominal wall-cecum (fig. 4A) pictures (fig. 4C, fig. 4D) of zwitterionic hydrogel injected at the wound site after trauma (fig. 4B). FIG. 5 shows that no adhesion occurred in abdominal wall and cecum of SD rats 14 days after surgery (FIG. 5B) compared to the saline control group (FIG. 5A). Due to the in-situ injectability of the gel, the convenience of operation is improved, and the gel has good clinical application prospect in the field of postoperative adhesion prevention.

Drawings

FIG. 1 is a graph showing the effect of the zwitterionic hydrogel leaching solution prepared in example 38 of the present invention on the cell activity of L929 fibroblasts.

FIG. 2 is a graph showing the anti-adhesion of the zwitterionic hydrogel prepared in example 38 of the present invention to fibroblasts. A: fibroblasts seeded on a cell culture plate; b: fibroblasts seeded on the gel.

Figure 3 is a graph showing injectability of the zwitterionic hydrogel prepared in example 38 of the present invention.

Fig. 4 is a photograph of the zwitterionic injectable hydrogel prepared in example 38 of the present invention when used in adhesion model of abdominal wall-cecal injury in SD rats. A: normal abdominal wall and cecum; b: rat abdominal wall-cecum injury adhesion model; c: the injection process of the post-operative anti-adhesion material of zwitterionic hydrogel prepared in example 38 of the present invention; d: the invention also discloses the application of the post-operative anti-adhesion material of the zwitterionic hydrogel prepared in the embodiment 38.

FIG. 5 is a photograph showing the effect of preventing adhesion of the zwitterionic hydrogel prepared in example 38 of the present invention in an adhesion model of abdominal wall-cecum injury in SD rats after a surgery for 14 days. A: adhesion occurred between the injured cecum and abdominal wall in the control group using physiological saline; b: animals using the zwitterionic hydrogel anti-adhesion material did not adhere.

Detailed Description

The technical solutions of the present invention are further described below with reference to the examples and the drawings, but the present invention is not limited to the following examples, and modifications or equivalent substitutions may be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Example 1: preparation of zwitterionic crosslinkers

(1) Dissolving N-methyldiethanolamine and anhydrous triethylamine in a molar ratio of 1:2 in anhydrous dichloromethane, uniformly stirring in ice-water bath, and then dropwise adding acryloyl chloride dissolved in dichloromethane into a reaction vessel, wherein the molar ratio of N-methyldiethanolamine to acryloyl chloride is 1:2. The solution was stirred for 0.5 hour under ice-water bath and then transferred to room temperature for reaction for 6 hours. Filtering and rotary steaming the mixed product to obtain a crude product, and then washing the crude product with acid, alkali and water in sequence to finally obtain yellow liquid.

(2) Dissolving the monomer obtained in the step (1) in acetone, stirring uniformly in an ice-water bath, dropwise adding an acetone solution containing 1, 3-propane sultone, wherein the molar ratio of the 1, 3-propane sultone to the monomer obtained in the step (1) is 1:1, stirring uniformly in the ice-water bath, and then transferring to a water bath kettle at 40 ℃ for continuous reaction for 12 hours. The white product was filtered and washed with acetone to remove unreacted monomer, and then dried under vacuum to give white zwitterionic crosslinker monomer.

Example 2: preparation of zwitterionic crosslinkers

(1) Dissolving N-methyldiethanolamine and anhydrous triethylamine in a molar ratio of 1:2.4 in anhydrous dichloromethane, uniformly stirring in ice-water bath, and then dropwise adding acryloyl chloride dissolved in dichloromethane into a three-necked bottle, wherein the molar ratio of the N-methyldiethanolamine to the acryloyl chloride is 1: 2.4. The solution was stirred for 2 hours under ice water bath and then transferred to room temperature for reaction for 24 hours. Filtering and rotary steaming the mixed product to obtain a crude product, and then washing the crude product with acid, alkali and water in sequence to finally obtain yellow liquid.

(2) Dissolving the monomer obtained in the step (1) in acetone, stirring uniformly in an ice-water bath, and then dropwise adding an acetone solution containing 1, 3-propane sultone, wherein the molar ratio of the 1, 3-propane sultone to the monomer obtained in the step (1) is 1: 1.2. Stirring the mixture evenly in an ice water bath, transferring the mixture to a water bath kettle at the temperature of 55 ℃ and continuing to react for 48 hours. The white product was filtered and washed with acetone to remove unreacted monomer, and then dried under vacuum to give white zwitterionic crosslinker monomer.

Example 3: preparation of zwitterionic crosslinkers

(1) Dissolving N-methyldiethanolamine and anhydrous triethylamine in a molar ratio of 1:4 in anhydrous dichloromethane, uniformly stirring in ice-water bath, and then dropwise adding acryloyl chloride dissolved in dichloromethane into a three-necked bottle, wherein the molar ratio of N-methyldiethanolamine to acryloyl chloride is 1: 4. The solution was stirred well in an ice water bath and then transferred to room temperature for reaction for 48 hours. Filtering and rotary steaming the mixed product to obtain a crude product, and then washing the crude product with acid, alkali and water in sequence to finally obtain yellow liquid.

(2) Dissolving the monomer obtained in the step (1) in acetone, stirring uniformly in an ice-water bath, and then dropwise adding an acetone solution containing 1, 3-propane sultone, wherein the molar ratio of the 1, 3-propane sultone to the monomer obtained in the step (1) is 1:2. Stirring the mixture evenly in an ice water bath, transferring the mixture to a water bath kettle at 70 ℃ and continuing to react for 60 hours. The white product was filtered and washed with acetone to remove unreacted monomer, and then dried under vacuum to give white zwitterionic crosslinker monomer.

Example 4: preparation of zwitterionic crosslinkers

(1) Dissolving N-methyldiethanolamine and anhydrous triethylamine in a molar ratio of 1:2 in anhydrous dichloromethane, uniformly stirring in ice-water bath, and then dropwise adding methacryloyl chloride dissolved in dichloromethane into a reaction vessel, wherein the molar ratio of the N-methyldiethanolamine to the methacryloyl chloride is 1:2. The solution was stirred for 0.5 hour under ice-water bath and then transferred to room temperature for reaction for 6 hours. Filtering and rotary steaming the mixed product to obtain a crude product, and then washing the crude product with acid, alkali and water in sequence to finally obtain yellow liquid.

(2) Dissolving the monomer obtained in the step (1) in acetone, stirring uniformly in an ice-water bath, dropwise adding an acetone solution containing 1, 3-propane sultone, wherein the molar ratio of the 1, 3-propane sultone to the N-methyl-diethanolamine dimethacrylate monomer is 1:1, stirring uniformly in the ice-water bath, transferring to a 40 ℃ water bath, and continuing to react for 12 hours. The white product was filtered and washed with acetone to remove unreacted monomer, and then dried under vacuum to give white zwitterionic crosslinker monomer.

Example 5: preparation of zwitterionic crosslinkers

(1) Dissolving N-methyldiethanolamine and anhydrous triethylamine in a molar ratio of 1:2.4 in anhydrous dichloromethane, uniformly stirring in ice-water bath, and then dropwise adding methacryloyl chloride dissolved in dichloromethane into a three-necked bottle, wherein the molar ratio of the N-methyldiethanolamine to the methacryloyl chloride is 1: 2.4. The solution was stirred for 2 hours under ice water bath and then transferred to room temperature for reaction for 24 hours. Filtering and rotary steaming the mixed product to obtain a crude product, and then washing the crude product with acid, alkali and water in sequence to finally obtain yellow liquid.

(2) Dissolving the monomer obtained in the step (1) in acetone, stirring uniformly in an ice-water bath, and then dropwise adding an acetone solution containing 1, 3-propane sultone, wherein the molar ratio of the 1, 3-propane sultone to the N-methyl-diethanolamine dimethacrylate monomer is 1: 1.2. Stirring the mixture evenly in an ice water bath, transferring the mixture to a water bath kettle at the temperature of 55 ℃ and continuing to react for 48 hours. The white product was filtered and washed with acetone to remove unreacted monomer, and then dried under vacuum to give white zwitterionic crosslinker monomer.

Example 6: preparation of zwitterionic crosslinkers

(1) Dissolving N-methyldiethanolamine and anhydrous triethylamine in a molar ratio of 1:4 in anhydrous dichloromethane, uniformly stirring in ice-water bath, and then dropwise adding methacryloyl chloride dissolved in dichloromethane into a three-necked bottle, wherein the molar ratio of the N-methyldiethanolamine to the methacryloyl chloride is 1: 4. The solution was stirred well in an ice water bath and then transferred to room temperature for reaction for 48 hours. Filtering and rotary steaming the mixed product to obtain a crude product, and then washing the crude product with acid, alkali and water in sequence to finally obtain yellow liquid.

(2) Dissolving the monomer obtained in the step (1) in acetone, stirring uniformly in an ice-water bath, and then dropwise adding an acetone solution containing 1, 3-propane sultone, wherein the molar ratio of the 1, 3-propane sultone to the N-methyl-diethanolamine dimethacrylate monomer is 1:2. Stirring the mixture evenly in an ice water bath, transferring the mixture to a water bath kettle at 70 ℃ and continuing to react for 60 hours. The white product was filtered and washed with acetone to remove unreacted monomer, and then dried under vacuum to give white zwitterionic crosslinker monomer.

Example 7: preparation of zwitterionic crosslinkers

(1) Dissolving N-methyldiethanolamine and anhydrous triethylamine in a molar ratio of 1:2 in anhydrous dichloromethane, stirring uniformly in ice-water bath, and then dropwise adding acrylic acid dissolved in dichloromethane into a reaction container, wherein the molar ratio of N-methyldiethanolamine to acrylic acid is 1:2. The solution was stirred for 0.5 hour under ice-water bath and then transferred to room temperature for reaction for 6 hours. Filtering and rotary steaming the mixed product to obtain a crude product, and then washing the crude product with acid, alkali and water in sequence to finally obtain yellow liquid.

Example 8: preparation of zwitterionic crosslinkers

(1) Dissolving N-methyldiethanolamine and anhydrous triethylamine in a molar ratio of 1:2.4 in anhydrous dichloromethane, uniformly stirring in ice-water bath, and then dropwise adding acrylic acid dissolved in dichloromethane into a three-necked bottle, wherein the molar ratio of the N-methyldiethanolamine to the acrylic acid is 1: 2.4. The solution was stirred for 2 hours under ice water bath and then transferred to room temperature for reaction for 24 hours. Filtering and rotary steaming the mixed product to obtain a crude product, and then washing the crude product with acid, alkali and water in sequence to finally obtain yellow liquid.

Example 9: preparation of zwitterionic crosslinkers

(1) Dissolving N-methyldiethanolamine and anhydrous triethylamine in a molar ratio of 1:4 in anhydrous dichloromethane, uniformly stirring in ice-water bath, and then dropwise adding acrylic acid dissolved in dichloromethane into a three-necked bottle, wherein the molar ratio of the N-methyldiethanolamine to the acrylic acid is 1: 4. The solution was stirred well in an ice water bath and then transferred to room temperature for reaction for 48 hours. Filtering and rotary steaming the mixed product to obtain a crude product, and then washing the crude product with acid, alkali and water in sequence to finally obtain yellow liquid.

Example 10: preparation of zwitterionic crosslinkers

(2) Dissolving the monomer obtained in the step (1) in acetone, stirring uniformly in an ice-water bath, dropwise adding an acetone solution containing 1, 4-butane sultone, wherein the molar ratio of the 1, 4-butane sultone to the monomer obtained in the step (1) is 1:1, stirring uniformly in the ice-water bath, and then transferring to a water bath kettle at 40 ℃ for continuous reaction for 12 hours. The white product was filtered and washed with acetone to remove unreacted monomer, and then dried under vacuum to give white zwitterionic crosslinker monomer.

Example 11: preparation of zwitterionic crosslinkers

(2) Dissolving the monomer obtained in the step (1) in acetone, stirring uniformly in an ice-water bath, and then dropwise adding an acetone solution containing 1, 4-butane sultone, wherein the molar ratio of the 1, 4-butane sultone to the monomer obtained in the step (1) is 1: 1.2. Stirring the mixture evenly in an ice water bath, transferring the mixture to a water bath kettle at the temperature of 55 ℃ and continuing to react for 48 hours. The white product was filtered and washed with acetone to remove unreacted monomer, and then dried under vacuum to give white zwitterionic crosslinker monomer.

Example 12: preparation of zwitterionic crosslinkers

(2) Dissolving the monomer obtained in the step (1) in acetone, stirring uniformly in an ice-water bath, and then dropwise adding an acetone solution containing 1, 4-butane sultone, wherein the molar ratio of the 1, 4-butane sultone to the monomer obtained in the step (1) is 1:2. Stirring the mixture evenly in an ice water bath, transferring the mixture to a water bath kettle at 70 ℃ and continuing to react for 60 hours. The white product was filtered and washed with acetone to remove unreacted monomer, and then dried under vacuum to give white zwitterionic crosslinker monomer.

Example 13: preparation of zwitterionic crosslinkers

Example 14: preparation of zwitterionic crosslinkers

Example 15: preparation of zwitterionic crosslinkers

Example 16: preparation of zwitterionic crosslinkers

(2) Dissolving the monomer obtained in the step (1) in acetone, stirring uniformly in an ice-water bath, dropwise adding an acetone solution containing 1, 4-butane sultone, wherein the molar ratio of the 1, 4-butane sultone to the monomer obtained in the step (1) is 1:1, stirring uniformly in the ice-water bath, and then transferring to a water bath kettle at 40 ℃ for continuous reaction for 12 hours. The white product was filtered, washed three times with acetone, and then dried under vacuum to give a white zwitterionic crosslinker monomer.

Example 17: preparation of zwitterionic crosslinkers

Example 18: preparation of zwitterionic crosslinkers

Example 19: preparation of zwitterionic crosslinkers

(2) Dissolving the monomer obtained in the step (1) in acetone, stirring uniformly in an ice-water bath, dropwise adding an acetone solution containing beta-propiolactone, wherein the molar ratio of the beta-propiolactone to the monomer obtained in the step (1) is 1:1, stirring uniformly in the ice-water bath, transferring to a water bath kettle at 40 ℃ and continuing to react for 12 hours. The white product was filtered and washed with acetone to remove unreacted monomer, and then dried under vacuum to give white zwitterionic crosslinker monomer.

Example 20: preparation of zwitterionic crosslinkers

(2) Dissolving the monomer obtained in the step (1) in acetone, stirring uniformly in an ice-water bath, and then dropwise adding an acetone solution containing beta-propiolactone, wherein the molar ratio of the beta-propiolactone to the monomer obtained in the step (1) is 1: 1.2. Stirring the mixture evenly in an ice water bath, transferring the mixture to a water bath kettle at the temperature of 55 ℃ and continuing to react for 48 hours. The white product was filtered and washed with acetone to remove unreacted monomer, and then dried under vacuum to give white zwitterionic crosslinker monomer.

Example 21: preparation of zwitterionic crosslinkers

(2) Dissolving the monomer obtained in the step (1) in acetone, stirring uniformly in an ice-water bath, and then dropwise adding an acetone solution containing beta-propiolactone, wherein the molar ratio of the beta-propiolactone to the monomer obtained in the step (1) is 1:2. Stirring the mixture evenly in an ice water bath, transferring the mixture to a water bath kettle at 70 ℃ and continuing to react for 60 hours. The white product was filtered and washed with acetone to remove unreacted monomer, and then dried under vacuum to give white zwitterionic crosslinker monomer.

Example 22: preparation of zwitterionic crosslinkers

(2) Dissolving the monomer obtained in the step (1) in acetone, stirring uniformly in an ice-water bath, dropwise adding an acetone solution containing beta-propiolactone, wherein the molar ratio of the beta-propiolactone to the N-methyl-diethanolamine dimethacrylate monomer is 1:1, stirring uniformly in the ice-water bath, transferring to a 40 ℃ water bath, and continuing to react for 12 hours. The white product was filtered and washed with acetone to remove unreacted monomer, and then dried under vacuum to give white zwitterionic crosslinker monomer.

Example 23: preparation of zwitterionic crosslinkers

(2) Dissolving the monomer obtained in the step (1) in acetone, stirring uniformly in an ice-water bath, and then dropwise adding an acetone solution containing beta-propiolactone, wherein the molar ratio of the beta-propiolactone to the N-methyl-diethanolamine dimethacrylate monomer is 1: 1.2. Stirring the mixture evenly in an ice water bath, transferring the mixture to a water bath kettle at the temperature of 55 ℃ and continuing to react for 48 hours. The white product was filtered and washed with acetone to remove unreacted monomer, and then dried under vacuum to give white zwitterionic crosslinker monomer.

Example 24: preparation of zwitterionic crosslinkers

(2) Dissolving the monomer obtained in the step (1) in acetone, stirring uniformly in an ice-water bath, and then dropwise adding an acetone solution containing beta-propiolactone, wherein the molar ratio of the beta-propiolactone to the N-methyl-diethanolamine dimethacrylate monomer is 1:2. Stirring the mixture evenly in an ice water bath, transferring the mixture to a water bath kettle at 70 ℃ and continuing to react for 60 hours. The white product was filtered and washed with acetone to remove unreacted monomer, and then dried under vacuum to give white zwitterionic crosslinker monomer.

Example 25: preparation of zwitterionic crosslinkers

Example 26: preparation of zwitterionic crosslinkers

Example 27: preparation of zwitterionic crosslinkers

Example 28: preparation of zwitterionic polymers with pendant thiol groups

(1) Dissolving disulfide bond monomer and zwitterionic monomer sulfobetaine in a molar ratio of 1:1 in dimethyl sulfoxide, heating to 50 deg.C, and introducing argon to remove O in the solution₂The amount of azobisisobutyronitrile added as an initiator was 0.1 mol% of the sum of the molar amounts of the disulfide bond monomer and the zwitterionic monomer, and the reaction was stopped after 12 hours of polymerization.

(2) And (2) dropwise precipitating the polymer solution obtained in the step (1) in anhydrous methanol to remove unreacted disulfide bond monomers and zwitterionic monomers, carrying out vacuum filtration on the precipitate, dissolving the precipitate in a sodium chloride solution again, and then dropwise precipitating again to remove redundant 1, 4-dithiothreitol to finally obtain white sulfobetaine polymer solid with disulfide bonds on side chains.

(3) Dissolving the polymer obtained in the step (2) in a sodium chloride solution, bubbling argon for 0.5 hour, adding 1, 4-dithiothreitol with the molar weight 5 times that of the disulfide bond monomer added during polymerization, and dialyzing the product by using deionized water after reacting for 12 hours. And (5) freeze-drying to obtain white sulfobetaine polymer solid with a sulfydryl side chain.

Example 29: preparation of zwitterionic polymers with pendant thiol groups

(1) Dissolving disulfide bond monomer and zwitterionic monomer sulfobetaine in a molar ratio of 1:2 in dimethyl sulfoxide, heating to 70 deg.C, and introducing argon to remove O in the solution₂The amount of azobisisobutyronitrile added as an initiator was 3 mol% of the sum of the molar amounts of the disulfide bond monomer and the zwitterionic monomer, and the reaction was stopped after 24 hours of polymerization.

(3) And (3) dissolving the polymer obtained in the step (2) in a sodium chloride solution, bubbling argon for 1 hour, adding 1, 4-dithiothreitol, wherein the molar weight of the 1, 4-dithiothreitol is 10 times that of a disulfide bond monomer added during polymerization, and dialyzing a product by using deionized water after reacting for 24 hours. And (5) freeze-drying to obtain white sulfobetaine polymer solid with a sulfydryl side chain.

Example 30: preparation of zwitterionic polymers with pendant thiol groups

(1) Dissolving disulfide bond monomer and zwitterionic monomer sulfobetaine in a molar ratio of 1:100 in dimethyl sulfoxide, heating to 100 ℃, and introducing argon to remove O in the solution₂The amount of azobisisobutyronitrile added as an initiator was 5 mol% of the sum of the molar amounts of the disulfide bond monomer and the zwitterionic monomer, and the reaction was stopped after 48 hours of polymerization.

(3) And (3) dissolving the polymer obtained in the step (2) in a sodium chloride solution, bubbling argon for 3 hours, adding 1, 4-dithiothreitol, wherein the molar weight of the 1, 4-dithiothreitol is 20 times that of a disulfide bond monomer added during polymerization, and dialyzing a product by using deionized water after reacting for 48 hours. And (5) freeze-drying to obtain white sulfobetaine polymer solid with a sulfydryl side chain.

Example 31: preparation of zwitterionic polymers with pendant thiol groups

(1) Dissolving disulfide bond monomer and zwitterionic compound monomer carboxylic acid betaine in a molar ratio of 1:1 in dimethyl sulfoxide, heating to 50 deg.C, and introducing argon to remove O in the solution₂The amount of azobisisobutyronitrile added as an initiator was 0.1 mol% of the sum of the molar amounts of the disulfide bond monomer and the zwitterionic monomer, and the reaction was stopped after 12 hours of polymerization.

(2) And (2) dropwise precipitating the polymer solution obtained in the step (1) in anhydrous methanol to remove unreacted disulfide bond monomers and zwitterionic monomers, carrying out vacuum filtration on the precipitate, dissolving the precipitate in a sodium chloride solution again, and then dropwise precipitating again to remove redundant 1, 4-dithiothreitol to finally obtain white carboxylic betaine polymer solid with disulfide bonds on side chains.

(3) Dissolving the polymer obtained in the step (2) in a sodium chloride solution, bubbling argon for 0.5 hour, adding 1, 4-dithiothreitol with the molar weight 5 times that of the disulfide bond monomer added during polymerization, and dialyzing the product by using deionized water after reacting for 12 hours. And (5) freeze-drying to obtain white carboxylic betaine polymer solid with sulfhydryl side chains.

Example 32: preparation of zwitterionic polymers with pendant thiol groups

(1) Dissolving disulfide bond monomer and zwitterionic compound monomer carboxylic acid betaine in a molar ratio of 1:2 in dimethyl sulfoxide, heating to 70 deg.C, and introducing argon to remove O in the solution₂The amount of azobisisobutyronitrile added as an initiator was 3 mol% of the sum of the molar amounts of the disulfide bond monomer and the zwitterionic monomer, and the reaction was stopped after 24 hours of polymerization.

(3) And (3) dissolving the polymer obtained in the step (2) in a sodium chloride solution, bubbling argon for 1 hour, adding 1, 4-dithiothreitol, wherein the molar weight of the 1, 4-dithiothreitol is 10 times that of a disulfide bond monomer added during polymerization, and dialyzing a product by using deionized water after reacting for 24 hours. And (5) freeze-drying to obtain white carboxylic betaine polymer solid with sulfhydryl side chains.

Example 33: preparation of zwitterionic polymers with pendant thiol groups

(1) Dissolving disulfide bond monomer and zwitterionic compound monomer carboxylic betaine in dimethyl according to a molar ratio of 1:100In sulfoxide, the temperature was raised to 100 ℃ and argon was introduced to remove O from the solution₂The amount of azobisisobutyronitrile added as an initiator was 5 mol% of the sum of the molar amounts of the disulfide bond monomer and the zwitterionic monomer, and the reaction was stopped after 48 hours of polymerization.

(3) And (3) dissolving the polymer obtained in the step (2) in a sodium chloride solution, bubbling argon for 3 hours, adding 1, 4-dithiothreitol, wherein the molar weight of the 1, 4-dithiothreitol is 20 times that of a disulfide bond monomer added during polymerization, and dialyzing a product by using deionized water after reacting for 48 hours. And (5) freeze-drying to obtain white carboxylic betaine polymer solid with sulfhydryl side chains.

Example 34: preparation of zwitterionic polymers with pendant thiol groups

(1) Dissolving disulfide bond monomer and zwitterionic compound monomer phosphorylcholine in dimethyl sulfoxide at a molar ratio of 1:1, heating to 50 deg.C, and introducing argon to remove O in the solution₂The amount of azobisisobutyronitrile added as an initiator was 0.1 mol% of the sum of the molar amounts of the disulfide bond monomer and the zwitterionic monomer, and the reaction was stopped after 12 hours of polymerization.

(2) And (2) dropwise precipitating the polymer solution obtained in the step (1) in anhydrous methanol to remove unreacted disulfide bond monomers and zwitter ion monomers, obtaining precipitates through vacuum filtration, dissolving the precipitates in a sodium chloride solution again, and then dropwise precipitating again to remove redundant 1, 4-dithiothreitol to finally obtain white phosphorylcholine polymer solid with disulfide bonds on side chains.

(3) Dissolving the polymer obtained in the step (2) in a sodium chloride solution, bubbling argon for 0.5 hour, adding 1, 4-dithiothreitol with the molar weight 5 times that of the disulfide bond monomer added during polymerization, and dialyzing the product by using deionized water after reacting for 12 hours. And (4) freeze-drying to obtain white phosphorylcholine polymer solid with a sulfydryl side chain.

Example 35: preparation of zwitterionic polymers with pendant thiol groups

(1) Dissolving disulfide bond monomer and zwitterionic compound monomer phosphorylcholine in dimethyl sulfoxide at a molar ratio of 1:2, heating to 70 deg.C, and introducing argon to remove O in the solution₂The amount of azobisisobutyronitrile added as an initiator was 3 mol% of the sum of the molar amounts of the disulfide bond monomer and the zwitterionic monomer, and the reaction was stopped after 24 hours of polymerization.

(3) And (3) dissolving the polymer obtained in the step (2) in a sodium chloride solution, bubbling argon for 1 hour, adding 1, 4-dithiothreitol, wherein the molar weight of the 1, 4-dithiothreitol is 10 times that of a disulfide bond monomer added during polymerization, and dialyzing a product by using deionized water after reacting for 24 hours. And (4) freeze-drying to obtain white phosphorylcholine polymer solid with a sulfydryl side chain.

Example 36: preparation of zwitterionic polymers with pendant thiol groups

(1) Dissolving disulfide bond monomer and zwitterionic compound monomer phosphorylcholine in dimethyl sulfoxide according to a molar ratio of 1:100, raising the temperature to 100 ℃, and filling argon to remove O in the solution₂The amount of azobisisobutyronitrile added as an initiator was 5 mol% of the sum of the molar amounts of the disulfide bond monomer and the zwitterionic monomer, and the reaction was stopped after 48 hours of polymerization.

(3) And (3) dissolving the polymer obtained in the step (2) in a sodium chloride solution, bubbling argon for 3 hours, adding 1, 4-dithiothreitol, wherein the molar weight of the 1, 4-dithiothreitol is 20 times that of a disulfide bond monomer added during polymerization, and dialyzing a product by using deionized water after reacting for 48 hours. And (4) freeze-drying to obtain white phosphorylcholine polymer solid with a sulfydryl side chain.

Example 37: preparation of zwitterionic injectable hydrogels

The zwitterionic crosslinking agent prepared in example 2 and the sulfobetaine polymer prepared in example 29 are dissolved in phosphate buffer solutions respectively at a molar ratio of double bonds to sulfydryl of 5:1 to prepare solutions with a mass fraction of 5 wt%, and the solutions are fully mixed and placed at 37 ℃ for gelation to finally obtain the zwitterionic injectable hydrogel anti-adhesion material.

Example 38: preparation of zwitterionic injectable hydrogels

(3) Dissolving the disulfide bond monomer and the zwitterionic compound monomer sulfobetaine in dimethyl sulfoxide according to a molar ratio of 1:2, raising the temperature to 70 ℃, andargon gas was introduced to remove O from the solution₂The amount of azobisisobutyronitrile added as an initiator was 3 mol% of the sum of the molar amounts of the disulfide bond monomer and the zwitterionic monomer, and the reaction was stopped after 24 hours of polymerization.

(4) And (3) dropwise precipitating the polymer solution obtained in the step (3) in anhydrous methanol to remove unreacted disulfide bond monomers and zwitterionic monomers, carrying out vacuum filtration on the precipitate, dissolving the precipitate in a sodium chloride solution again, and then dropwise precipitating again to remove redundant 1, 4-dithiothreitol to finally obtain white sulfobetaine polymer solid with disulfide bonds on side chains.

(5) And (3) dissolving the polymer obtained in the step (4) in a sodium chloride solution, bubbling argon for 1 hour, adding 1, 4-dithiothreitol, wherein the molar weight of the 1, 4-dithiothreitol is 10 times that of a disulfide bond monomer added during polymerization, and dialyzing a product by using deionized water after reacting for 24 hours. And (5) freeze-drying to obtain white sulfobetaine polymer solid with a sulfydryl side chain.

(6) Weighing the zwitterionic crosslinking agent prepared in the step (2) and the sulfobetaine polymer with the side chain containing sulfydryl prepared in the step (5) according to the molar ratio of double bonds to sulfydryl of 1:1, respectively dissolving the zwitterionic crosslinking agent and the sulfobetaine polymer in a phosphate buffer solution to prepare a solution with the mass fraction of 15 wt%, fully mixing the solution and the solution, and gelling at 37 ℃ to finally obtain the zwitterionic injectable hydrogel anti-adhesion material.

For the zwitterionic injectable hydrogel obtained in this example, the gel was biologically evaluated according to the experimental method described in GB/T16886, as shown in fig. 1, the viability of the gel extract at different concentrations was as high as more than 95% compared to the cells cultured in the normal medium (control group), which indicates that the gel extract had no effect on the activity of the fibroblasts. FIG. 2 shows that: the cells seeded on the cell culture plate (fig. 2A) were high in number and spindle-shaped, while the cells seeded on the zwitterionic hydrogel (fig. 2B) were low in number and round, indicating that the gel has an anti-adhesion effect on fibroblasts that are critical for adhesion. As shown in FIG. 3, the two precursors were mixed together and injection molded by syringe to the desired site, indicating the injectability of the gel.

Example 39: preparation of zwitterionic injectable hydrogels

The zwitterionic crosslinking agent prepared in example 8 and the sulfobetaine polymer prepared in example 29 were dissolved in phosphate buffer solutions at a molar ratio of double bonds to mercapto groups of 1:5, respectively, to prepare solutions with a mass fraction of 30 wt%, the two were mixed thoroughly and placed at 37 ℃ for gelation, and finally the zwitterionic injectable hydrogel anti-blocking material was obtained.

Example 40: preparation of zwitterionic injectable hydrogels

The zwitterionic crosslinking agent prepared in example 11 and the carboxylic acid betaine polymer prepared in example 29 were dissolved in phosphate buffer solutions at a molar ratio of double bonds to mercapto groups of 5:1, respectively, to prepare solutions with a mass fraction of 5 wt%, the two were mixed thoroughly and placed at 37 ℃ for gelation, and finally the zwitterionic injectable hydrogel anti-blocking material was obtained.

Example 41: preparation of zwitterionic injectable hydrogels

The zwitterionic crosslinking agent prepared in example 14 and the carboxylic acid betaine polymer prepared in example 29 were dissolved in phosphate buffer solutions at a molar ratio of double bonds to mercapto groups of 1:1, respectively, to prepare solutions with a mass fraction of 15 wt%, the two were mixed thoroughly and placed at 37 ℃ for gelation, and finally the zwitterionic injectable hydrogel anti-blocking material was obtained.

Example 42: preparation of zwitterionic injectable hydrogels

The zwitterionic crosslinking agent prepared in example 17 and the carboxylic acid betaine polymer prepared in example 29 were dissolved in phosphate buffer solutions at a molar ratio of double bonds to mercapto groups of 1:5, respectively, to prepare solutions with a mass fraction of 30 wt%, the two were mixed thoroughly and placed at 37 ℃ for gelation, and finally the zwitterionic injectable hydrogel anti-blocking material was obtained.

Example 43: preparation of zwitterionic injectable hydrogels

The zwitterionic crosslinking agent prepared in example 20 and the phosphorylcholine polymer prepared in example 29 were dissolved in phosphate buffer solutions at a molar ratio of double bonds to mercapto groups of 5:1, respectively, to prepare solutions with a mass fraction of 5 wt%, the two were mixed thoroughly and placed at 37 ℃ for gelation, and finally the zwitterionic injectable hydrogel anti-blocking material was obtained.

Example 44: preparation of zwitterionic injectable hydrogels

The zwitterionic crosslinking agent prepared in example 23 and the phosphorylcholine polymer prepared in example 29 were dissolved in phosphate buffer solutions at a molar ratio of double bonds to mercapto groups of 1:1, respectively, to prepare solutions with a mass fraction of 15 wt%, the two solutions were mixed thoroughly and placed at 37 ℃ for gelation, and finally, a zwitterionic injectable hydrogel anti-blocking material was obtained.

Example 45: preparation of zwitterionic injectable hydrogels

The zwitterionic crosslinking agent prepared in example 26 and the phosphorylcholine polymer prepared in example 29 were dissolved in phosphate buffer solutions at a molar ratio of double bonds to mercapto groups of 1:5, respectively, to prepare solutions with a mass fraction of 30 wt%, the two solutions were mixed thoroughly and placed at 37 ℃ for gelation, and finally, a zwitterionic injectable hydrogel anti-blocking material was obtained.

Example 46: preparation of zwitterionic injectable hydrogels

The zwitterionic crosslinking agent prepared in example 2 and the sulfobetaine polymer prepared in example 32 are dissolved in phosphate buffer solution respectively at a molar ratio of double bonds to sulfydryl of 5:1 to prepare a solution with a mass fraction of 5 wt%, and the solution are fully mixed and then placed at 37 ℃ for gelation to finally obtain the zwitterionic injectable hydrogel anti-adhesion material.

Example 47: preparation of zwitterionic injectable hydrogels

The zwitterionic crosslinking agent prepared in example 5 and the sulfobetaine polymer prepared in example 32 are dissolved in phosphate buffer solution respectively at a molar ratio of double bonds to sulfydryl of 1:1 to prepare a solution with a mass fraction of 15 wt%, and the solution are fully mixed and then placed at 37 ℃ for gelation to finally obtain the zwitterionic injectable hydrogel anti-adhesion material.

Example 48: preparation of zwitterionic injectable hydrogels

The zwitterionic crosslinking agent prepared in example 8 and the sulfobetaine polymer prepared in example 32 were dissolved in phosphate buffer solutions at a molar ratio of double bonds to mercapto groups of 1:5, respectively, to prepare solutions with a mass fraction of 30 wt%, the two were mixed thoroughly and placed at 37 ℃ for gelation, and finally the zwitterionic injectable hydrogel anti-blocking material was obtained.

Example 49: preparation of zwitterionic injectable hydrogels

The zwitterionic crosslinking agent prepared in example 11 and the carboxylic acid betaine polymer prepared in example 32 were dissolved in phosphate buffer solutions at a molar ratio of double bonds to mercapto groups of 5:1, respectively, to prepare solutions with a mass fraction of 5 wt%, the two were mixed thoroughly and placed at 37 ℃ for gelation, and finally the zwitterionic injectable hydrogel anti-blocking material was obtained.

Example 50: preparation of zwitterionic injectable hydrogels

The zwitterionic crosslinking agent prepared in example 14 and the carboxylic acid betaine polymer prepared in example 32 were dissolved in phosphate buffer solutions at a molar ratio of double bonds to mercapto groups of 1:1, respectively, to prepare solutions with a mass fraction of 15 wt%, the two were mixed thoroughly and placed at 37 ℃ for gelation, and finally the zwitterionic injectable hydrogel anti-blocking material was obtained.

Example 51: preparation of zwitterionic injectable hydrogels

The zwitterionic crosslinking agent prepared in example 17 and the carboxylic acid betaine polymer prepared in example 32 were dissolved in phosphate buffer solutions at a molar ratio of double bonds to mercapto groups of 1:5, respectively, to prepare solutions with a mass fraction of 30 wt%, the two were mixed thoroughly and placed at 37 ℃ for gelation, and finally the zwitterionic injectable hydrogel anti-blocking material was obtained.

Example 52: preparation of zwitterionic injectable hydrogels

The zwitterionic crosslinking agent prepared in example 20 and the phosphorylcholine polymer prepared in example 32 were dissolved in phosphate buffer solutions at a molar ratio of double bonds to mercapto groups of 5:1, respectively, to prepare solutions with a mass fraction of 5 wt%, the two solutions were mixed thoroughly and placed at 37 ℃ for gelation, and finally the zwitterionic injectable hydrogel anti-blocking material was obtained.

Example 53: preparation of zwitterionic injectable hydrogels

The zwitterionic crosslinking agent prepared in example 23 and the phosphorylcholine polymer prepared in example 32 were dissolved in phosphate buffer solutions at a molar ratio of double bonds to mercapto groups of 1:1, respectively, to prepare solutions with a mass fraction of 15 wt%, the two solutions were mixed thoroughly and placed at 37 ℃ for gelation, and finally, a zwitterionic injectable hydrogel anti-blocking material was obtained.

Example 54: preparation of zwitterionic injectable hydrogels

The zwitterionic crosslinking agent prepared in example 26 and the phosphorylcholine polymer prepared in example 32 were dissolved in phosphate buffer solutions at a molar ratio of double bonds to mercapto groups of 1:5, respectively, to prepare solutions with a mass fraction of 30 wt%, the two solutions were mixed thoroughly and placed at 37 ℃ for gelation, and finally, a zwitterionic injectable hydrogel anti-blocking material was obtained.

Example 55: preparation of zwitterionic injectable hydrogels

The zwitterionic crosslinking agent prepared in example 2 and the sulfobetaine polymer prepared in example 35 are dissolved in phosphate buffer solution respectively at a molar ratio of double bonds to sulfydryl of 5:1 to prepare a solution with a mass fraction of 5 wt%, and the solution are fully mixed and then placed at 37 ℃ for gelation to finally obtain the zwitterionic injectable hydrogel anti-adhesion material.

Example 56: preparation of zwitterionic injectable hydrogels

The zwitterionic crosslinking agent prepared in example 5 and the sulfobetaine polymer prepared in example 35 are dissolved in phosphate buffer solution respectively at a molar ratio of double bonds to sulfydryl of 1:1 to prepare a solution with a mass fraction of 15 wt%, and the solution are fully mixed and then placed at 37 ℃ for gelation to finally obtain the zwitterionic injectable hydrogel anti-adhesion material.

Example 57: preparation of zwitterionic injectable hydrogels

The zwitterionic crosslinking agent prepared in example 8 and the sulfobetaine polymer prepared in example 35 were dissolved in phosphate buffer solutions at a molar ratio of double bonds to mercapto groups of 1:5, respectively, to prepare solutions with a mass fraction of 30 wt%, the two were mixed thoroughly and placed at 37 ℃ for gelation, and finally the zwitterionic injectable hydrogel anti-blocking material was obtained.

Example 58: preparation of zwitterionic injectable hydrogels

The zwitterionic crosslinking agent prepared in example 11 and the carboxylic acid betaine polymer prepared in example 35 were dissolved in phosphate buffer solutions at a molar ratio of double bonds to mercapto groups of 5:1, respectively, to prepare solutions with a mass fraction of 5 wt%, the two were mixed thoroughly and placed at 37 ℃ for gelation, and finally the zwitterionic injectable hydrogel anti-blocking material was obtained.

Example 59: preparation of zwitterionic injectable hydrogels

The zwitterionic crosslinking agent prepared in example 14 and the carboxylic acid betaine polymer prepared in example 35 were dissolved in phosphate buffer solutions at a molar ratio of double bonds to mercapto groups of 1:1, respectively, to prepare solutions with a mass fraction of 15 wt%, the two were mixed thoroughly and placed at 37 ℃ for gelation, and finally the zwitterionic injectable hydrogel anti-blocking material was obtained.

Example 60: preparation of zwitterionic injectable hydrogels

The zwitterionic crosslinking agent prepared in example 17 and the carboxylic acid betaine polymer prepared in example 35 were dissolved in phosphate buffer solutions at a molar ratio of double bonds to mercapto groups of 1:5, respectively, to prepare solutions with a mass fraction of 30 wt%, the two were mixed thoroughly and placed at 37 ℃ for gelation, and finally the zwitterionic injectable hydrogel anti-blocking material was obtained.

Example 61: preparation of zwitterionic injectable hydrogels

The zwitterionic crosslinking agent prepared in example 20 and the phosphorylcholine polymer prepared in example 35 were dissolved in phosphate buffer solutions at a molar ratio of double bonds to mercapto groups of 5:1, respectively, to prepare solutions with a mass fraction of 5 wt%, the two were mixed thoroughly and placed at 37 ℃ for gelation, and finally the zwitterionic injectable hydrogel anti-blocking material was obtained.

Example 62: preparation of zwitterionic injectable hydrogels

The zwitterionic crosslinking agent prepared in example 23 and the phosphorylcholine polymer prepared in example 35 were dissolved in phosphate buffer solutions at a molar ratio of double bonds to mercapto groups of 1:1, respectively, to prepare solutions with a mass fraction of 15 wt%, the two solutions were mixed thoroughly and placed at 37 ℃ for gelation, and finally, a zwitterionic injectable hydrogel anti-blocking material was obtained.

Example 63: preparation of zwitterionic injectable hydrogels

The zwitterionic crosslinking agent prepared in example 26 and the phosphorylcholine polymer prepared in example 35 were dissolved in phosphate buffer solutions at a molar ratio of double bonds to mercapto groups of 1:5, respectively, to prepare solutions with a mass fraction of 30 wt%, the two solutions were mixed thoroughly and placed at 37 ℃ for gelation, and finally, a zwitterionic injectable hydrogel anti-blocking material was obtained.

Example 64: application of gel in rat abdominal wall-cecum injury adhesion model and effect thereof

The example is to apply the zwitter-ion injectable hydrogel anti-adhesion material in an abdominal wall-cecum injury adhesion model of a rat and check the anti-adhesion effect.

The specific implementation method comprises the following steps: after the SD mice were anesthetized and sterilized with iodophor, the abdominal whiteline was found and the abdominal wall was cut along its position with a direct scissors incision of about 5cm along the abdominal midline. The abdominal wall was clamped with a pair of forceps, and the superficial muscles were dissected 1cm from the incision in the abdominal wall, and an area of about 1cm by 2cm was scribed. And rubbing the cecum at the position corresponding to the wound of the abdominal wall with sterile gauze until punctiform bleeding occurs, and then suturing and fixing the upper left corner of the wound surface of the abdominal wall and the mesentery of the cecum by using a 5-0 surgical suture line to ensure that the abdominal wall is fully contacted with the cecum.

Fig. 4 shows the use process of the zwitterionic injectable hydrogel in the abdominal wall-cecal injury adhesion model of SD rats: fig. 4A is a picture of normal abdominal wall and cecum, fig. 4B is a picture of abdominal wall and cecum after trauma, and fig. 4C and 4D are pictures of injection of zwitterionic hydrogel to the wound site. Fig. 5 shows that adhesion results were observed 14 days after surgery, compared to the saline control group (fig. 5A): animals using the prepared zwitterionic gel did not develop adhesions and the injured abdominal wall and cecum healed well (fig. 5B).

Claims

1. A zwitterionic hydrogel for preventing adhesion, which has the following structure:

Z:

2. the process for producing a zwitterionic hydrogel for preventing blocking according to claim 1, characterized by comprising the steps of:

1) preparing a zwitterionic crosslinking agent with acryloyl groups at two ends by carrying out acylation reaction on an N-methyldiethanolamine monomer and acryloyl chloride or methacryloyl chloride or acrylic acid and carrying out ring-opening addition reaction on 1, 3-propane sultone or 1, 4-butane sultone or beta-propiolactone, wherein the structure of the zwitterionic crosslinking agent is as follows;

2) carrying out free radical polymerization on a zwitterionic compound monomer and a disulfide bond monomer to obtain a zwitterionic polymer with a disulfide bond on a side chain, dissolving the polymer in a sodium chloride solution, and reducing the disulfide bond into a sulfydryl group by using 1, 4-dithiothreitol to prepare the zwitterionic polymer with the sulfydryl group on the side chain; the structures of the zwitterionic compound monomer and the disulfide bond monomer are as follows:

3) and then respectively dissolving the zwitterionic crosslinking agent prepared in the step 1) and the zwitterionic polymer with sulfydryl on the side chain prepared in the step 2) into phosphate buffer solutions, and preparing the zwitterionic injectable hydrogel through a sulfydryl-alkene addition reaction.

3. The method as set forth in claim 2, wherein the method for preparing the zwitterionic crosslinking agent in the step 1) comprises the steps of:

(2) dissolving the monomer obtained in the step (1) in acetone, stirring uniformly in an ice water bath, dropwise adding an acetone solution containing 1, 3-propane sultone or 1, 4-butane sultone or beta-propiolactone, wherein the molar ratio of the 1, 3-propane sultone or 1, 4-butane sultone or beta-propiolactone to the monomer obtained in the step (1) is 1: 1-1: 2, stirring uniformly in the ice water bath, transferring to a water bath kettle at the temperature of 40-70 ℃ and continuously reacting for 12-60 hours; the white product was filtered and washed with acetone to remove unreacted monomer and dried under vacuum to give white zwitterionic crosslinker monomer.

4. The method according to claim 2, wherein the zwitterionic polymer of step 2) is prepared as follows:

(1) the disulfide bond monomer and the zwitterionic compound monomer are mixed according to the moleDissolving the mixture in dimethyl sulfoxide at a molar ratio of 1: 1-1: 100, heating to 50-100 ℃, and introducing argon to remove O in the solution₂Adding an initiator azobisisobutyronitrile in an amount of 0.1-5 mol% of the sum of the molar amounts of the disulfide bond monomer and the zwitterionic compound monomer, and stopping the reaction after polymerizing for 12-48 hours;

(2) dropwise precipitating the polymer solution obtained in the step (1) in anhydrous methanol to remove unreacted disulfide bond monomers and zwitterionic compound monomers, obtaining precipitates through vacuum filtration, dissolving the precipitates in a sodium chloride solution again, and then dropwise precipitating again to finally obtain white zwitterionic polymer solids with disulfide bonds on side chains; the structures of the zwitterionic compound monomer and the disulfide bond monomer are as described in step 2) of claim 2;

(3) dissolving the polymer solid obtained in the step (2) in a sodium chloride solution, bubbling argon for 0.5-3 hours, adding 1, 4-dithiothreitol with the molar weight 5-20 times that of a disulfide bond monomer added during polymerization, reacting for 12-48 hours, and dialyzing the product with deionized water; and (4) freeze-drying to obtain white zwitterionic polymer solid with sulfydryl on the side chain.

5. The method according to claim 2, wherein the zwitterionic injectable hydrogel of step 3) is prepared by:

dissolving a zwitterionic crosslinking agent and the obtained zwitterionic polymer in a phosphate buffer solution at a double bond and sulfydryl molar ratio of 5: 1-1: 5 to prepare a solution with the mass fraction of 5-30 wt%, fully mixing the two solutions, and then placing the mixture at 37 ℃ for gelation to finally obtain the zwitterionic injectable hydrogel.

6. The method for preparing the zwitterionic hydrogel for preventing adhesion according to claim 2, wherein the postoperative adhesion-preventing material is used for preventing abdominal cavity adhesion, uterine horn adhesion and tendon adhesion caused after surgery.