Zwitterionic nanogel as well as preparation method and application thereof

Abstract

The invention relates to the field of postoperative adhesion medicines, in particular to zwitter-ion nanogel, a preparation method thereof and application of the zwitter-ion nanogel in preparation of postoperative adhesion medicines and secondary adhesion medicines. The preparation method of the zwitterionic nanogel comprises the following steps: preparing a polymer which is a zwitterionic monomer; a nano silicate; the crosslinking agent is ethylene glycol dimethacrylate, the catalyst is tetramethylethylenediamine, and the photoinitiator is 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy) phenyl]-1-acetone. According to the preparation method of the zwitterionic nanogel, synthesis is simple, and the nanogel prepared through the method has excellent biological activity and mechanical performance and has excellent anti-adhesion capacity. Compared with commercial anti-adhesion hydrogel, the zwitterionic nanogel prepared by the invention can safely and reliably prevent postoperative adhesion and secondary adhesion, and has great clinical potential.

Description

Technical Field

[0001] The present invention relates to the field of drugs for postoperative adhesions, and particularly to an amphoteric ion nanogel, a preparation method thereof, and an application thereof in the preparation of drugs for treating postoperative adhesions and secondary adhesions. Background Art

[0002] Abdominal adhesion (PA) is a common and serious complication after abdominal and pelvic surgeries. To reduce or prevent abdominal adhesions, a series of methods including surgery, drugs, and barrier materials have been adopted. Traditional enterolysis for adhesions can cause new traumas due to primary or secondary adhesions, and the chance of re-adhesion is still very high even after adhesions are released. The complexity of surgery and some uncontrollable factors make the development of drugs and barrier materials crucial. However, the efficacy of drugs acting on adhesion-related factors is still limited and has serious side effects. Therefore, as a new type of highly biocompatible physical barrier, the effect of hydrogels in treating postoperative adhesions has attracted much attention. But there are still many factors that greatly reduce the therapeutic effect of hydrogels on adhesions. Moreover, most hydrogels need careful hemostasis and effective suturing to be fixed on the surface of injured tissues to play an anti-adhesion role. If the postoperative wound is infected, the residence time of the hydrogel on the wound will be shortened again, resulting in the recurrence of postoperative adhesions. Therefore, the purpose of this study is to prepare an amphoteric ion nanogel with good anti-adhesion performance, improved biological activity, and effective prevention of abdominal adhesions and secondary adhesions, to meet the market demand. Summary of the Invention

[0003] The purpose of the present invention is to provide an amphoteric ion nanogel, a preparation method thereof, and an application thereof in the preparation of drugs for treating postoperative adhesions and secondary adhesions.

[0004] The preparation method of an amphoteric ion nanogel provided by the present invention is simple in synthesis. The nanogel prepared by this method has excellent biological activity and mechanical properties, and has excellent anti-adhesion ability. It can be used as an effective material for physical barrier to achieve postoperative adhesions and secondary adhesions. The present invention solves its technical problems by adopting the following technical solutions. The present invention proposes a preparation method of an amphoteric ion nanogel, which includes: first, dissolve nanosilicates (laponites) in water to prepare solution A, and dissolve amphoteric ion 3-[2-(methacryloyloxy)ethyl](dimethyl)ammonio]-1-propanesulfonate (SBMA, 98%) in solution A to obtain a mixed solution B; ultrasonic degas the solution B, and add a crosslinking agent, an initiator, and a catalyst to obtain a clear and transparent mixed liquid; irradiate the mixed liquid under the condition of 365 nm ultraviolet light to obtain an amphoteric ion nanogel.

[0005] A preparation method of an amphoteric ion nanogel includes the following steps:

[0006] S1. First, dissolve nano-silicate (laponites) in water to prepare solution A;

[0007] S2. Dissolve zwitterionic ions in solution A to obtain a mixed solution B;

[0008] S3. Remove air bubbles from solution B by ultrasonic treatment, and add a crosslinking agent, an initiator, and a catalyst to obtain a clear and transparent mixed liquid;

[0009] S4. Irradiate the mixed liquid under 365 nm ultraviolet light to obtain zwitterionic nano-gel.

[0010] In step S1, the mass concentration of nano-silicate (laponites) in solution A is 0.5% - 2%.

[0011] In step S2, the zwitterionic ions are 3-[2-(methacryloyloxy)ethyl](dimethyl)ammonio]-1-propanesulfonate (SBMA), 3-[[2-(methacryloyloxy)ethyl]dimethylammonio]propionate (CBMA), and the concentration is 2 - 4 M.

[0012] In step S3, the crosslinking agent is ethylene glycol dimethacrylate;

[0013] The initiator is 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]-1-propanone;

[0014] The catalyst is N,N,N',N'-tetramethylethylenediamine.

[0015] The concentration of ethylene glycol dimethacrylate is 0.5 - 5% (based on the amount of monomer SBMA);

[0016] The concentration of nano-silicate (lap) is 0.5 - 2%.

[0017] The concentration of the crosslinking agent is 0.5 - 5% (based on the amount of monomer SBMA); the concentration of the initiator is 0.5 - 1% (based on the amount of monomer SBMA); the catalyst is 0.5 - 1 μ / mL (volume ratio of the solvent water).

[0018] Due to the nano-silicate presenting a nano-disk structure, its surface shows a positive charge and its side shows a negative charge, endowing it with good electrostatic repulsion. The hydrophilic SBMA is an amphoteric ion with positive and negative charges in its structure, resulting in the ability to react with laponite through electrostatic interaction. Based on this, the gelation mechanism of the entire nano-gel is interpreted as follows: In the system of the entire hydrogel preparation process, due to the presence of the initiator, the crosslinking agent (ethylene glycol dimethacrylate) is activated to break its carbon-carbon double bond. Under ultraviolet conditions, it undergoes chemical crosslinking with the internal carbon-carbon double bond of SBMA to form the first network of the hydrogel. At the same time, laponite and SBMA are crosslinked through electrostatic interaction to synthesize the second network of the hydrogel. The catalyst does not participate in the reaction but accelerates the reaction rate between the key groups. The nano-gel prepared by this mechanism has more excellent protein adsorption resistance compared with other conventional physical gels, minimizing the foreign body reaction and being able to provide the rigidity required for gel-like drugs to adapt to postoperative adhesions. In addition, the addition of laponite results in the nano-gel showing enhanced biological activity.

[0019] In step S4, the ultraviolet irradiation time is 30 min - 1 h.

[0020] The application of the amphoteric ion nano-gel in the treatment of postoperative adhesions and secondary adhesions. The application of the amphoteric ion nano-gel in the preparation of drugs for treating postoperative adhesions and secondary adhesions, such as drugs for treating peritoneal adhesions.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] The beneficial effect of the preparation method of a novel amphoteric ion nano-gel according to the embodiment of the present invention is that: The amphoteric ion nano-gel constructed by the present invention combines the nano-silicate laponites with anisotropic charges and the amphoteric ion SBMA. The unique charge structure of laponites helps to enhance the mechanical properties of the hydrogel, enabling it to adapt to the dynamic environment in the body and preventing the direct contact between the damaged part of the cecum and the abdominal wall tissue; at the same time, SBMA endows the hydrogel with excellent biocompatibility and the ability of non-specific protein adsorption resistance (nonfouling property). Secondly, compared with the commercial hydrogels on the market, such as those with unsatisfactory application processes, poor mechanical properties, unstable nonfouling properties or easy to induce immune reactions, etc. The present invention patent has better performance in preventing peritoneal adhesions and secondary adhesions and has great potential in the clinical treatment of peritoneal adhesions. Description of the Drawings

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the embodiments. It should be understood that the following drawings only show certain embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other relevant drawings can also be obtained based on these drawings.

[0024] Figure 1 This is the microscopic image of Example 8, Example 4, Example 3, and Example 1 of the present invention. A scanning electron microscope can display the microscopic structure of a sample. The microscopic images of Example 8, Example 4, Example 3, and Example 1 of the present invention are as Figure 1 shown, and all the embodiments exhibit a porous structure.

[0025] Figure 2 This is the fibrin adsorption rate of Example 8, Example 4, Example 3, and Example 1 of the invention. By evaluating the fibrinogen residue on the surface of the embodiments, the anti-adhesion ability of the hydrogel is evaluated. The quantitative evaluation of the surface fibrinogen of Example 8, Example 4, Example 3, and Example 1 of the present invention is as Figure 2 shown, and the fibrinogen residue of all the embodiments is lower than 25%, indicating that the excellent anti-adhesion characteristics of our hydrogel are attributed to zwitterions.

[0026] Figure 3 This is the bovine serum albumin adsorption rate of Example 8, Example 4, Example 3, and Example 1 of the invention. By evaluating the bovine serum albumin residue on the surface of the embodiments, the anti-adhesion ability of the hydrogel is evaluated. The quantitative evaluation of the surface protein of Example 8, Example 4, Example 3, and Example 1 of the present invention is as Figure 3 shown, and the protein residue of all the embodiments is lower than 20%, indicating that the excellent anti-adhesion characteristics of our hydrogel are attributed to zwitterions.

[0027] Figure 4 This is the plasma adsorption rate provided by Example 8, Example 4, Example 3, and Example 1 of the present invention. By evaluating the plasma residue on the surface of the embodiments, the anti-adhesion ability of the hydrogel is evaluated. The quantitative evaluation of the surface plasma of Example 8, Example 4, Example 3, and Example 1 of the present invention is as Figure 4 shown, and the plasma residue of all the embodiments is lower than 20%, indicating that the excellent anti-adhesion characteristics of our hydrogel are attributed to zwitterions.

[0028] Figure 5Hemolysis rates provided by Examples 8, 4, 3, and 1 of the present invention. The hemolysis rate of a biomaterial is one of the important indicators for evaluating its blood compatibility. The hemolysis rate reflects the degree of damage of the biomaterial to red blood cells and is usually determined through a hemolysis experiment. The hemolysis rates of Examples 8, 4, 3, and 1 of the present invention are as Figure 5 shown. The hemolysis rates of all examples are less than 5%, indicating that the examples are non-toxic to blood.

[0029] Figure 6 Gram-negative bacteria adsorption rates of Examples 8, 4, 3, and 1 of the present invention. OD600 is one of the indicators for evaluating bacterial activity. By evaluating the residue of Escherichia coli on the surface of the examples, the anti-adhesion ability of the hydrogel is evaluated. The evaluation of Escherichia coli on the surface of Examples 8, 4, 3, and 1 of the present invention is as Figure 6 shown. The OD600 of all examples is lower than 0.05, indicating that our examples have excellent anti-adhesion characteristics against gram-negative bacteria (Escherichia coli).

[0030] Figure 7 Gram-positive bacteria adsorption rates of Examples 8, 4, 3, and 1 of the present invention. OD600 is one of the indicators for evaluating bacterial activity. By evaluating the residue of Staphylococcus aureus on the surface of the examples, the anti-adhesion ability of the hydrogel is evaluated. The evaluation of Escherichia coli on the surface of Examples 8, 4, 3, and 1 of the present invention is as Figure 7 shown. The OD600 of all examples is lower than 0.05, indicating that our examples have excellent anti-adhesion characteristics against gram-positive bacteria (Staphylococcus aureus).

[0031] Figure 8 Viscosity evaluation of Examples 8, 4, 3, and 1 of the present invention. As Figure 8 shown, Example 1 has the best viscosity, specifically manifested as the strongest cross-linking degree and the strongest mechanical properties.

[0032] Figure 9 Tensile stress statistics of Examples 8, 4, 3, and 1 of the present invention. The results are as Figure 9 shown. By evaluating the mechanical properties of different examples, it is found that the higher the concentration of nano-silicate, the stronger the mechanical properties of the examples it represents.

[0033] Figure 10 Therapeutic repair diagram of rat abdominal wall and cecal defects in Application Example 1 of the present invention.

[0034] Figure 11 Therapeutic scoring diagram of rat abdominal wall and cecal defects in Application Example 1 of the present invention.

[0035] Figure 12 Schematic diagram of the secondary injury model of the abdominal wall and cecum defects in rats in Application Example 2 of the present invention.

[0036] Figure 13 Schematic diagram of the treatment and repair of the secondary injury model of the abdominal wall and cecum defects in rats in Application Example 2 of the present invention.

[0037] Figure 14 Schematic flow diagram of the method of the present invention. Detailed implementation manners

[0038] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. The reagents or instruments used without indicating the manufacturer can be obtained as conventional products through commercial purchase. The preparation method of the novel drug carrier in the embodiments of the present invention will be specifically described below.

[0039] A preparation method of a novel zwitterionic nanogel provided by the present invention includes: A preparation method of a zwitterionic nanogel is proposed, which includes: First, dissolve nanosilicates (laponites) in water to prepare solution A. In a preferred embodiment of the present invention, the concentration of laponites is preferably 2%.

[0040] Dissolve the zwitterion in solution A to obtain a mixed solution B; In a preferred embodiment of the present invention, the zwitterion is preferably 3-[2-(methacryloyloxy)ethyl](dimethyl)ammonio]-1-propanesulfonate (SBMA, 98%), and the concentration of SBMA is preferably 4M.

[0041] Remove the bubbles from solution B by ultrasonic treatment, and add a crosslinking agent, an initiator and a catalyst to obtain a clear and transparent mixed liquid. In a preferred embodiment of the present invention, the concentration of the crosslinking agent is preferably 5% (accounting for the amount of the monomer SBMA), the initiator is 1% (accounting for the amount of the monomer SBMA), and the catalyst is 1 μ / mL.

[0042] Irradiate the mixed liquid under the condition of 365 nm ultraviolet light to obtain the zwitterionic nanogel. In a preferred embodiment of the present invention, the ultraviolet light irradiation time is preferably 1 h.

[0043] The beneficial effects of the preparation method of a novel zwitterionic nanogel provided by the present invention are as follows: The unique charge structure of laponites helps to enhance the mechanical properties of the hydrogel, enabling it to adapt to the dynamic environment in the body and preventing direct contact between the damaged cecal site and abdominal wall tissue. At the same time, SBMA endows the hydrogel with excellent biocompatibility and anti-protein non-specific adsorption ability (nonfouling property). Secondly, compared with commercial hydrogels on the market, such as those with unsatisfactory application processes, poor mechanical properties, unstable nonfouling properties, or prone to inducing immune reactions. This invention patent has better performance in preventing abdominal adhesions and secondary adhesions and has great potential in the clinical treatment of abdominal adhesions.

[0044] The features and properties of the present invention will be further described in detail with reference to the following examples.

[0045] Example 1

[0046] The present invention provides a preparation method of a novel zwitterionic nanogel, which includes: First, dissolve nano-silicate (laponites) in water to prepare solution A with a 2% concentration of laponites. Dissolve the zwitterion - 3-[2-(methacryloyloxy)ethyl](dimethyl)ammonio]-1-propanesulfonate (SBMA) in solution A to obtain a mixed solution B, where the SBMA concentration is 4M. Ultrasonically remove the bubbles from solution B, and add 5% crosslinking agent ethylene glycol dimethacrylate (proportion of the amount of monomer SBMA), 1% initiator 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]-1-propanone (proportion of the amount of monomer SBMA), and 1 μ / mL catalyst tetramethylethylenediamine (volume ratio of the solvent water). Irradiate the mixed liquid under 365 nm ultraviolet light for 1 h to obtain the zwitterionic nanogel.

[0047] Example 2

[0048] The present invention provides a preparation method of a novel zwitterionic nanogel, which includes: First, dissolve nano-silicate (laponites) in water to prepare solution A with a 2% concentration of laponites. Dissolve the zwitterion - 3-[[2-(methacryloyloxy)ethyl]dimethylammonio]propionate (CBMA) in solution A to obtain a mixed solution B, where the CBMA concentration is 4M. Ultrasonically remove the bubbles from solution B, and add 5% crosslinking agent ethylene glycol dimethacrylate (proportion of the amount of monomer SBMA), 1% initiator 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]-1-propanone (proportion of the amount of monomer SBMA), and 1 μ / mL catalyst tetramethylethylenediamine (volume ratio of the solvent water). Irradiate the mixed liquid under 365 nm ultraviolet light for 1 h to obtain the zwitterionic nanogel.

[0049] Example 3

[0050] The present invention provides a method for preparing a novel zwitterionic nanogel, which includes: first dissolving nanosilicates (laponites) in water to prepare solution A with a concentration of 1% laponites. Dissolving the zwitterion - 3-[2-(methacryloyloxy)ethyl](dimethyl)ammonio]-1-propanesulfonate (SBMA) in solution A to obtain a mixed solution B, where the concentration of SBMA is 4M. Bubbles in solution B are removed by ultrasonic treatment, and 5% crosslinking agent ethylene glycol dimethacrylate (proportion of the amount of monomer SBMA), 1% initiator 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]-1-propanone (proportion of the amount of monomer SBMA), and 1 μ / mL catalyst tetramethylethylenediamine (volume ratio of the solvent water) are added. The mixed liquid is irradiated under 365 nm ultraviolet light for 1 h to obtain the zwitterionic nanogel.

[0051] Example 4

[0052] The present invention provides a method for preparing a novel zwitterionic nanogel, which includes: first dissolving nanosilicates (laponites) in water to prepare solution A with a concentration of 0.5% laponites. Dissolving the zwitterion - 3-[2-(methacryloyloxy)ethyl](dimethyl)ammonio]-1-propanesulfonate (SBMA) in solution A to obtain a mixed solution B, where the concentration of SBMA is 4M. Bubbles in solution B are removed by ultrasonic treatment, and 5% crosslinking agent ethylene glycol dimethacrylate (proportion of the amount of monomer SBMA), 1% initiator 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]-1-propanone (proportion of the amount of monomer SBMA), and 1 μ / mL catalyst tetramethylethylenediamine (volume ratio of the solvent water) are added. The mixed liquid is irradiated under 365 nm ultraviolet light for 1 h to obtain the zwitterionic nanogel.

[0053] Example 5

[0054] The present invention provides a method for preparing a novel zwitterionic nanogel, which includes: first, dissolving nanosilicate (laponites) in water to prepare solution A with a 2% concentration of laponites. Dissolving the zwitterion - 3 - [2 - (methacryloyloxy)ethyl](dimethyl)ammonio]-1 - propanesulfonate (SBMA) in solution A to obtain a mixed solution B, where the concentration of SBMA is 4M. Bubbles in solution B are removed by ultrasonic treatment, and 1% cross - linker ethylene glycol dimethacrylate (by the amount of monomer SBMA), 1% initiator 2 - hydroxy - 2 - methyl - 1 - [4 - (2 - hydroxyethoxy)phenyl]-1 - propanone (by the amount of monomer SBMA), and 1 μ / mL catalyst tetramethylethylenediamine (volume ratio of the solvent water) are added. The mixed liquid is irradiated under 365 nm ultraviolet light for 1 h to obtain the zwitterionic nanogel.

[0055] Example 6

[0056] The present invention provides a method for preparing a novel zwitterionic nanogel, which includes: first, dissolving nanosilicate (laponites) in water to prepare solution A with a 2% concentration of laponites. Dissolving the zwitterion - 3 - [2 - (methacryloyloxy)ethyl](dimethyl)ammonio]-1 - propanesulfonate (SBMA) in solution A to obtain a mixed solution B, where the concentration of SBMA is 4M. Bubbles in solution B are removed by ultrasonic treatment, and 0.5% cross - linker ethylene glycol dimethacrylate (by the amount of monomer SBMA), 1% initiator 2 - hydroxy - 2 - methyl - 1 - [4 - (2 - hydroxyethoxy)phenyl]-1 - propanone (by the amount of monomer SBMA), and 1 μ / mL catalyst tetramethylethylenediamine (volume ratio of the solvent water) are added. The mixed liquid is irradiated under 365 nm ultraviolet light for 1 h to obtain the zwitterionic nanogel.

[0057] Example 7

[0058] The present invention provides a method for preparing a novel zwitterionic nanogel, which includes: first, dissolving nanosilicate (laponites) in water to prepare solution A with a 2% concentration of laponites. Dissolving the zwitterion - 3 - [2 - (methacryloyloxy)ethyl](dimethyl)ammonio]-1 - propanesulfonate (SBMA) in solution A to obtain a mixed solution B, where the concentration of SBMA is 4M. Bubbles in solution B are removed by ultrasonic treatment, and 5% cross - linker ethylene glycol dimethacrylate (by the amount of monomer SBMA), 1% initiator 2 - hydroxy - 2 - methyl - 1 - [4 - (2 - hydroxyethoxy)phenyl]-1 - propanone (by the amount of monomer SBMA), and 1 μ / mL catalyst tetramethylethylenediamine (volume ratio of the solvent water) are added. The mixed liquid is irradiated under 365 nm ultraviolet light for 30 min to obtain the zwitterionic nanogel.

[0059] Example 8

[0060] The present invention provides a method for preparing an amphoteric ion hydrogel, which includes: dissolving an amphoteric ion, 3-[2-(methacryloyloxy)ethyl](dimethyl)ammonio]-1-propanesulfonate (SBMA), in solution A to obtain a mixed solution B, where the concentration of SBMA is 4M. The solution B is degassed by ultrasonic treatment, and 5% cross-linking agent ethylene glycol dimethacrylate (by the amount of monomer SBMA), 1% initiator 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]-1-propanone (by the amount of monomer SBMA), and 1 μ / mL catalyst tetramethylethylenediamine (volume ratio of the solvent water) are added. The mixed liquid is irradiated under 365 nm ultraviolet light for 1 h to obtain an amphoteric ion nanogel.

[0061] Example 9

[0062] The present invention provides a method for preparing a novel amphoteric ion nanogel, which includes: first dissolving nanosilicates (laponites) in water to prepare solution A with a concentration of 2% laponites. Dissolving an amphoteric ion, 3-[2-(methacryloyloxy)ethyl](dimethyl)ammonio]-1-propanesulfonate (SBMA), in solution A to obtain a mixed solution B, where the concentration of SBMA is 2M. The solution B is degassed by ultrasonic treatment, and 5% cross-linking agent ethylene glycol dimethacrylate (by the amount of monomer SBMA), 1% initiator 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]-1-propanone (by the amount of monomer SBMA), and 0.5 μ / mL catalyst tetramethylethylenediamine (volume ratio of the solvent water) are added. The mixed liquid is irradiated under 365 nm ultraviolet light for 1 h to obtain an amphoteric ion nanogel.

[0063] Example 10

[0064] The present invention provides a method for preparing a novel amphoteric ion nanogel, which includes: first dissolving nanosilicates (laponites) in water to prepare solution A with a concentration of 2% laponites. Dissolving an amphoteric ion, 3-[2-(methacryloyloxy)ethyl](dimethyl)ammonio]-1-propanesulfonate (SBMA), in solution A to obtain a mixed solution B, where the concentration of SBMA is 4M. The solution B is degassed by ultrasonic treatment, and 5% cross-linking agent ethylene glycol dimethacrylate (by the amount of monomer SBMA), 1% initiator 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]-1-propanone (by the amount of monomer SBMA), and 0.5 μ / mL catalyst tetramethylethylenediamine (volume ratio of the solvent water) are added. The mixed liquid is irradiated under 365 nm ultraviolet light for 1 h to obtain an amphoteric ion nanogel.

[0065] Example 11

[0066] The present invention provides a method for preparing a novel zwitterionic nanogel, which includes: first dissolving nanosilicates (laponites) in water to prepare solution A with a 2% concentration of laponites. Dissolve the zwitterion 3-[2-(methacryloyloxy)ethyl](dimethyl)ammonio]-1-propanesulfonate (SBMA) in solution A to obtain a mixed solution B, where the concentration of SBMA is 3M. Bubble-remove the mixed solution B by ultrasonic treatment, and add 5% crosslinking agent ethylene glycol dimethacrylate (by the amount of monomer SBMA), 1% initiator 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]-1-propanone (by the amount of monomer SBMA), and 1 μ / mL catalyst tetramethylethylenediamine (by the volume ratio of solvent water). Irradiate the mixed liquid under 365 nm ultraviolet light for 1 h to obtain the zwitterionic nanogel.

[0067] The microscopic images of Example 8, Example 4, Example 3, and Example 1 of the present invention are as Figure 1 shown, and the scanning electron microscope can display the microscopic structure of the sample. The microscopic images of Example 8, Example 4, Example 3, and Example 1 of the present invention are as Figure 1 shown, and all examples exhibit a porous structure.

[0068] The fibrin adsorption rates of Example 8, Example 4, Example 3, and Example 1 of the present invention are as Figure 2 shown. By evaluating the fibrinogen residue on the surface of the examples, the anti-adhesion ability of the hydrogel is evaluated. The quantitative evaluation of the surface fibrinogen of Example 8, Example 4, Example 3, and Example 1 of the present invention is as Figure 2 shown, and the fibrinogen residue of all examples is lower than 25%, indicating that the excellent anti-adhesion characteristics of our hydrogel are attributed to the zwitterion.

[0069] The bovine serum albumin adsorption rates of Example 8, Example 4, Example 3, and Example 1 of the present invention are as Figure 3 shown. By evaluating the bovine serum albumin residue on the surface of the examples, the anti-adhesion ability of the hydrogel is evaluated. The quantitative evaluation of the surface protein of Example 8, Example 4, Example 3, and Example 1 of the present invention is as Figure 3 shown, and the protein residue of all examples is lower than 20%, indicating that the excellent anti-adhesion characteristics of our hydrogel are attributed to the zwitterion.

[0070] The plasma adsorption rates provided by Example 8, Example 4, Example 3, and Example 1 of the present invention are as Figure 4 shown. By evaluating the plasma residue on the surface of the examples, the anti-adhesion ability of the hydrogel is evaluated. The quantitative evaluation of the surface plasma of Example 8, Example 4, Example 3, and Example 1 of the present invention is asFigure 4 As shown, the plasma residues of all the examples are less than 20%, indicating that the excellent anti-adhesion property of our hydrogel is attributed to zwitterions.

[0071] The hemolysis rates provided by Example 8, Example 4, Example 3, and Example 1 of the present invention are as Figure 5 shown. The hemolysis rate of a biomaterial is one of the important indicators for evaluating its blood compatibility. The hemolysis rate reflects the degree of damage of the biomaterial to red blood cells and is usually determined by a hemolysis experiment. The hemolysis rates of Example 8, Example 4, Example 3, and Example 1 of the present invention are as Figure 5 shown. The hemolysis rates of all the examples are less than 5%, indicating that the examples are non-toxic to blood.

[0072] The Gram-negative bacteria adsorption rates of Example 8, Example 4, Example 3, and Example 1 of the present invention are as Figure 6 shown. OD600 is one of the indicators for evaluating bacterial activity. By evaluating the residues of Escherichia coli on the surface of the examples, the anti-adhesion ability of the hydrogel is evaluated. The evaluation of the surface Escherichia coli of Example 8, Example 4, Example 3, and Example 1 of the present invention is as Figure 6 shown. The OD600 of all the examples is less than 0.05, indicating that our examples have excellent anti-adhesion properties against Gram-negative bacteria (Escherichia coli).

[0073] The Gram-positive bacteria adsorption rates of Example 8, Example 4, Example 3, and Example 1 of the present invention are as Figure 7 shown. OD600 is one of the indicators for evaluating bacterial activity. By evaluating the residues of Staphylococcus aureus on the surface of the examples, the anti-adhesion ability of the hydrogel is evaluated. The evaluation of the surface Escherichia coli of Example 8, Example 4, Example 3, and Example 1 of the present invention is as Figure 7 shown. The OD600 of all the examples is less than 0.05, indicating that our examples have excellent anti-adhesion properties against Gram-positive bacteria (Staphylococcus aureus).

[0074] The viscosity evaluation of Example 8, Example 4, Example 3, and Example 1 of the present invention is as Figure 8 shown. Example 1 has the best viscosity, specifically manifested as the strongest cross-linking degree and the strongest mechanical properties.

[0075] The tensile stress statistical results of Example 8, Example 4, Example 3, and Example 1 of the present invention are as Figure 9 shown. By evaluating the mechanical properties of different examples, it is found that the higher the concentration of nano-silicate, the stronger the mechanical properties of the examples it represents.

[0076] Schematic diagram of the gelation mechanism of the nanogel prepared in Example 1 of the present invention. Specifically, due to the presence of the initiator, the crosslinking agent (ethylene glycol dimethacrylate) is activated to break its carbon-carbon double bond. Under ultraviolet conditions, it undergoes chemical crosslinking with the internal carbon-carbon double bond of SBMA to form the first network of the hydrogel. At the same time, lap and SBMA are crosslinked through electrostatic interaction to synthesize the second network of the hydrogel. The catalyst does not participate in the reaction but accelerates the reaction rate between the key groups. Compared with other conventional physical gels, the nanogel prepared by this mechanism has more excellent protein adsorption resistance, minimizes the foreign body reaction, and can provide the rigidity of the gel-like drug required to adapt to postoperative adhesions. In addition, the addition of lap results in the nanogel showing enhanced biological activity.

[0077] Application Example 1

[0078] The present invention aims to prepare an amphoteric ion nanogel that not only has good anti-adhesion performance, improves biological activity, but also has excellent mechanical properties and can effectively prevent abdominal adhesions and secondary adhesions to meet clinical needs. Therefore, we believe that the prepared amphoteric ion nanogel has excellent anti-adhesion characteristics and can be used for the prevention of postoperative adhesions. Therefore, we established a stable rat abdominal wall and cecal defect model and applied the amphoteric ion nanogel prepared in Example 1 thereto. The commercial gel HA was used as a positive control, and the ability of the prepared material to treat postoperative adhesions was evaluated by assessing its healing ability in vivo at 7 days and 14 days. The results are as Figure 10 shown. The amphoteric ion nanogel prepared by us can perfectly treat postoperative adhesions at 7 days and 14 days after surgery. There is a significant variance compared with the model group and the positive HA group. This indicates that Example 1 of this project has better postoperative anti-adhesion ability. The anti-adhesion ability between different groups was evaluated by quantitatively scoring the adhesions of the tissues. The results are as Figure 11 shown. The results of Example 1 are lower than those of other groups and there is a significant variance compared with the model group and the HA group. This indicates that Example 1 of this project has significant anti-adhesion ability. The above results show that the amphoteric ion nanogel prepared by this invention patent can more effectively prevent postoperative adhesions.

[0079] Application Example 2

[0080] Blunt dissection is a commonly used method for treating adhesions clinically. However, this may cause secondary tissue damage, thus promoting the formation of more severe adhesions, which are more complex and difficult to treat than primary adhesions. For this reason, we established a recurrent adhesion model to evaluate the potential of the amphoteric ion nanogel for secondary adhesions. The results are as Figure 12 shown. Taking the re-injury as the initial day 0, the drug was given after the re-injury. The results are as Figure 13As shown, the final treatment outcome of Example 1 is better than that of the model group and the positive drug HA group. The nanogel treated in Example 1 has a better therapeutic effect on postoperative secondary adhesions. The above results show that the zwitterionic nanogel prepared by this invention patent can more effectively prevent secondary postoperative adhesions.

Claims

1. A preparation method of zwitterionic nanogel, characterized in that, It includes the following steps: S1. First, dissolve nano-silicate in water to prepare solution A; S2. Dissolve zwitterionic ions in solution A to obtain mixed solution B; S3. Remove air bubbles from mixed solution B by ultrasonic treatment, and add a crosslinking agent, an initiator, and a catalyst to obtain a clear and transparent mixed liquid; S4. Irradiate the mixed liquid under ultraviolet light conditions to obtain zwitterionic nano-gel.

2. The preparation method of the zwitterionic nanogel according to claim 1, characterized in that, In step S1, the mass concentration of nano-silicate in solution A is 0.5%-2%.

3. The preparation method of the zwitterionic nanogel according to claim 1, wherein In step S2, the zwitterionic ions are 3-[2-(methacryloyloxy)ethyl](dimethyl)ammonio]-1-propanesulfonate or 3-[[2-(methacryloyloxy)ethyl]dimethylammonio]propionate.

4. The preparation method of the zwitterionic nanogel according to claim 1, characterized in that, In step S2, the concentration of zwitterionic ions in the mixed solution B is 2-4 mol / L.

5. The preparation method of the zwitterionic nanogel according to claim 1, characterized in that, In step S3, the crosslinking agent is ethylene glycol dimethacrylate; The initiator is 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]-1-propanone; The catalyst is tetramethylethylenediamine.

6. The preparation method of the zwitterionic nanogel according to claim 1, characterized in that, In step S3, the dosage of the crosslinking agent is 0.5-5% of the mass of the zwitterionic ions; The dosage of the initiator is 0.5-1% of the mass of the zwitterionic ions; The volume ratio of the dosage of the catalyst to the solvent water in the mixed solution B is 0.5-1 μL:1 mL.

7. The preparation method of the zwitterionic nanogel according to claim 1, wherein In step S4, the wavelength of the ultraviolet light for irradiation under ultraviolet light conditions is 355-375 nm; The irradiation time under ultraviolet light conditions is 30 min-1 h.

8. Zwitterionic nano-gel prepared by the preparation method according to any one of claims 1-7.

9. Application of the zwitterionic nano-gel according to claim 8 in the preparation of drugs for treating postoperative adhesions and secondary adhesions.

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