Negative charge biased active epoxy zwitterionic copolymer as well as preparation method and application thereof

Abstract

The invention provides a negative charge biased active epoxy zwitterionic copolymer as well as a preparation method and application thereof, which can simultaneously realize excellent non-specific protein adsorption resistance of a modified surface and an instant effect of the copolymer. The non-specific protein adsorption resistance of the modified surface refers to below 20% of the adsorption capacity of the aminated polyurethane sheet, the instant dissolving refers to that the dissolving time is less than or equal to 600s, the minimum dissolving time is only 20s, and when the aminated polyurethane sheet is applied to the pelvic and abdominal cavity operation, the reaction activity is high, the aminated polyurethane sheet can quickly react with the inner membrane of the pelvic and abdominal cavity for covalent binding, and the non-specific protein adsorption resistance of the modified surface can be greatly improved. According to the intraperitoneal anti-adhesion device, the whole cavity can be comprehensively and integrally covered, an isolation barrier can be rapidly formed, the whole intraperitoneal anti-adhesion effect can be achieved only through one-step intraperitoneal irrigation, the liquid residual quantity is low, the metabolic pressure is small, and the intraperitoneal anti-adhesion device is widely suitable for various operation types, special crowds with sugar intolerance and the like.

Description

Technical Field

[0001] The present invention relates to the field of polymers, and in particular to a negatively charged active epoxy zwitterionic copolymer and a preparation method and application thereof. Background Art

[0002] Clinically, postoperative adhesions are primarily iatrogenic complications, often related to surgically induced sharp, mechanical, or thermal injury, infection, thermal radiation, local ischemia, dehydration, and foreign body reactions. Postoperative adhesions generally refer to the peritoneum and are divided into local adhesions and distal adhesions. Local adhesions occur near the wound surface or wound opening, forming an adhesion band between the wound surfaces. Distal adhesions are adhesions caused by inflammation or foreign body reactions, resulting in stress-induced fibrin precipitation and deposition in the peritoneal cavity or peritoneum (non-invasive adhesions). In other words, these adhesions are not directly caused by the wound surface or wound opening. Distal adhesions occur at sites far from the wound surface or wound opening, and may even occur in organs other than the wound. For example, if the wound surface is on the cecum, distal adhesions may occur in the small intestine. (Acta Biomaterialia 116(2020)84–104). Therefore, correspondingly, in vivo adhesion prevention is divided into three prevention and treatment methods: local adhesion prevention, distal adhesion prevention, and whole abdominal cavity adhesion prevention. The local adhesion prevention refers to preventing the local adhesion, the distal adhesion prevention refers to preventing the distal adhesion, and the whole abdominal cavity adhesion prevention refers to preventing local adhesion and distal adhesion at the same time in the cavity. Only when local adhesion and / or distal adhesion do not occur can it be called whole abdominal cavity adhesion prevention. Whole abdominal cavity adhesion prevention can be evaluated by laparotomy observation.

[0003] It is well known to those skilled in the art that the prior art refers to local anti-adhesion as anti-adhesion, and if the anti-adhesion of distal anti-adhesion is not clearly mentioned, the anti-adhesion refers to local anti-adhesion. Postoperative adhesion in vivo refers to the occurrence of local adhesion and / or distal adhesion, and then causes direct complications including female infertility, adhesive intestinal obstruction, chronic pelvic and abdominal pain, etc., and after any adhesion of local adhesion or distal adhesion occurs, the patient will face the increased difficulty of secondary surgery and serious economic burden (Chin J Min Inv Surg 2020,20 (6): 481-488). Therefore, in recent years, the country continues to launch and update corresponding clinical guidelines to avoid the problems such as waste of medical resources, strained medical relationship caused by postoperative adhesion in vivo.

[0004] The Expert Consensus on Prevention and Diagnosis of Pelvic and Abdominal Adhesions after Gynecological Surgery (hereinafter referred to as the “Consensus”) points out that the probability of postoperative adhesions occurring after all pelvic and abdominal surgeries is as high as 60-80%, and requires treatment with adhesion lysis in subsequent surgeries (PLoS ONE, 2018, 13(8):e0202418). The Scottish Surgical and Clinical Adhesion Research Group, in a comprehensive analysis of gynecological patient surgical records and postoperative complications, observed that 34.5% of patients undergoing open abdominal or pelvic surgery had at least two complications clearly related to adhesions within 10 years after surgery; and the readmission rate after the initial surgery was as high as 64%. In a clinical study of 29,790 cases, it was shown that 22% of patients undergoing open abdominal surgery were readmitted for adhesions within just one year after the initial surgery (Lancet, 1999, 353(9163):1476-1480; BJOG, 2000, 107(7):855-862; Hum Reprod Update, 2017, 23(3):276-288). Among the complications caused by postoperative adhesions, the high incidence of female infertility will further aggravate the social problem of negative population growth. Epidemiological statistics show that 23% of patients with a history of abdominal surgery received treatment for infertility, and the full-term pregnancy rate was negatively correlated with the adhesion score at the time of surgery. Adhesive intestinal obstruction is the core component of clinical intestinal obstruction patients, accounting for 74% of all causes of intestinal obstruction, with an overall incidence of 2.4%, a readmission rate of 4.5%, and a mortality risk of up to 10%.

[0005] Although clinical medicine has recognized the serious risks associated with postoperative adhesions and has issued a series of consensus documents in recent years emphasizing the importance of preventing and treating these conditions, the strategies emphasized in these consensus documents still prioritize delicate and gentle surgical techniques and minimally invasive surgery, maximizing surgical skill, minimizing peritoneal injury, and avoiding foreign bodies in the abdominal cavity. Anti-adhesion medical devices and related drug treatments are categorized as "other measures." The development of anti-adhesion products in the treatment process is primarily limited by the following fundamental principles: 1. They must not interfere with the normal healing process of the peritoneum or affect local immune function; and 2. They must reduce the excessive health and economic burden based on patient medical insurance and financial resources.

[0006] Currently, commercially available products for postoperative adhesion prevention can be divided into local adhesion prevention and whole-abdominal adhesion prevention based on the intended goals. The ideal postoperative adhesion prevention is to achieve whole-abdominal adhesion prevention. Among them, gel / solid membrane is the core product type of local adhesion prevention, which is mainly used to isolate the local wound generated during the operation, limit the migration and leakage of cells in the wound bed area, and thus avoid the occurrence of postoperative adhesion. Gel-type local adhesion prevention materials can absorb, expand and compress bleeding points to reduce bleeding and exudation. The main materials are hyaluronic acid and carboxymethyl chitin. Hyaluronic acid is a non-immunogenic material that will not trigger the recognition and adhesion of macrophages, nor will it cause abnormal repair caused by increased levels of inflammation in the abdominal cavity. Therefore, it complies with the first principle of adhesion prevention and treatment, that is, it does not interfere with the normal healing of the peritoneum and does not affect the local immune function. However, hyaluronic acid metabolizes quickly and has a short retention time at the site of action. It is often completely metabolized within 48 hours of administration, which is a time difference from the 3-5 days after surgery when adhesions mainly develop. Therefore, it is currently mainly used for patients with clinical evaluations of being prone to severe adhesions, reducing the early fibrin precipitation caused by peritoneal inflammation, thereby alleviating the severity of adhesions, but its preventive and therapeutic effect on the adhesion development stage is relatively weak. Carboxymethyl chitin products have a longer metabolic cycle and can form a stable barrier during the adhesion development stage, but they are immunogenic and activate the peritoneal immune system as a foreign body, causing strong inflammation and aggravating fibrin precipitation, which violates the principle of not affecting local immune function. Therefore, the level of evidence in clinical studies is not as good as that of hyaluronic acid (Eur J Obstet Gynecol Reprod Biol, 2020, 244: 1-4; Fertil Steril, 2003, 80 (3): 631-636; Chin J Min Inv Surg 2020, 20 (6): 481-488). Compared with gel products, solid membranes can better cover the wound area and have a longer stability period. They can continuously isolate the wound surface during the critical period of postoperative adhesion formation and mesothelial repair (3-5 days) (Chin J Min Inv Surg 2020, 20(6): 481-488). The main products of solid membranes include hyaluronic acid-carboxymethyl cellulose composite membrane (Seprafilm), oxidized regenerated cellulose membrane (Interceed), and expanded polytetrafluoroethylene (Gore-Tex). Among them, Interceed and Gore-Tex have the defects of incomplete absorption, side effects, or the need for invasive operation to remove them (Chin J Min Inv Surg 2020, 20(6): 481-488). Seprafilm can be completely removed within 4 weeks, but it is prone to fragmentation and has poor operability, so it cannot be used in laparoscopic surgery (Chin J Min Inv Surg 2020, 20(6): 481-488).While localized gel and solid film anti-adhesion products have been clinically accepted, they cannot fundamentally address the root cause of peritoneal adhesions. Furthermore, during our survey of clinicians, we received feedback from patients that using gel or solid film products resulted in the re-exposure of wound surfaces due to the sliding or squeezing of intra-abdominal organs, further demonstrating the urgent clinical need for full peritoneal anti-adhesion products.

[0007] Products used for whole-abdominal adhesion prevention need to have good fluidity and fully infiltrate the complex surface environment of the abdominal cavity, so the product must be in liquid form. Current products are mainly achieved through peritoneal perfusion, which refers to the injection of a large dose of solution into the abdominal cavity to form a "peritoneal bath", thereby forming a peritoneal surface barrier throughout the entire abdominal cavity. Such products are mainly polysaccharides, including 32% dextran 70 or low-concentration sodium hyaluronate solution or 4% icodextrin, etc. (Human Reproduction, 2000, 15(8):1764-1772; Chin J Min Inv Surg 2020, 20(6):481-488). However, the clinical evidence of the above-mentioned carbohydrate peritoneal perfusion products is still insufficient to support their use as an effective treatment for pelvic and abdominal adhesion prevention. For example, low-concentration sodium hyaluronate has only been shown to have limited preventive and therapeutic effects on distal adhesions; the application of icodextrin to patients with carbohydrate intolerance is severely limited. Since pelvic and abdominal perfusion is not a necessary part of abdominal surgery and there is insufficient clinical evidence for related anti-adhesion products, it is still used as a "preventive" treatment method. As a result, such products are still not included in the medical insurance system, and patients need to pay for the drugs out of their own pockets. This poses a challenge to the second principle of adhesion prevention and treatment, which is to reduce the excessive health and economic burden.

[0008] Compared to peritoneal perfusion, which is only performed on patients with high risk or a history of adhesions, peritoneal lavage is a necessary step for every patient after pelvic and abdominal surgery. Its main purpose is to clean the abdominal cavity, thereby avoiding the induction of a foreign body reaction after surgery. In this step, the clinician injects normal saline or Ringer's solution (i.e., compound sodium chloride solution) into the abdominal cavity, and after sufficient shaking, it is pumped out to achieve the effect of peritoneal cleaning. Currently, only Ringer's solution has been clearly used to treat adhesions caused by peritoneal dryness caused by CO2 pneumoperitoneum after laparoscopic surgery (J Am Assoc Gynecol Laparosc, 2002, 9(4):447-452; Fertil Steril, 2007, 88(5):1413-1426). Compared with peritoneal perfusion, the use of anti-adhesion products during peritoneal lavage can not only avoid additional surgical procedures and prolonged surgery, but also significantly reduce the amount of anti-adhesion products that need to be absorbed by the peritoneum in the abdominal cavity, reducing the peritoneal inflammation that may be caused by metabolic pressure, and thus further reducing the possibility of pelvic and abdominal adhesions, which is particularly important for patients at high risk of adhesions. However, peritoneal lavage has a short duration and higher requirements for fluidity and infiltration, which makes it impossible for even products that have been proven to be effective in peritoneal perfusion to function properly. Taking icodextrin as an example, studies have shown that 4% icodextrin can reduce the adhesion score from 25 to 5.5 when used alone for peritoneal perfusion, while the adhesion score only decreased from 25 to 16.8 after changing the use of icodextrin from peritoneal perfusion to peritoneal lavage (Human Reproduction, 2000, 15(8):1764-1772). Therefore, developing a product that can achieve truly effective full-abdominal adhesion prevention during peritoneal lavage is an important breakthrough point for transforming pelvic and abdominal adhesion prevention from a "preventive measure" to a "therapeutic measure."

[0009] Although both have been confirmed to be non-immunogenic materials, the non-immunogenicity of hyaluronic acid comes from the fact that it is a product of human life activities, while the non-immunogenicity of zwitterionic polymers comes from their unique structure in which each side chain unit contains equal amounts of cationic and anionic functional groups (Sci.Adv.2021;7:eabc5442). This unique side chain structure can form a tight and firm hydration layer in aqueous solution, effectively resisting the nonspecific adsorption of proteins even in plasma, thereby avoiding being recognized as a foreign body by immune cells. It is a "stealth" material in the physiological environment. Also benefiting from the resistance to nonspecific binding of proteins, the surface of materials composed of zwitterionic polymers has been proven to have excellent resistance to biofouling in the past two decades, even in the harsh marine ecological environment. Therefore, using zwitterionic polymers as pelvic and abdominal anti-adhesion materials can not only form a long-term and effective isolation barrier, but also avoid inflammation caused by the foreign body response caused by the material itself, making it an ideal material for pelvic and abdominal anti-adhesion work. However, at present, zwitterionic polymers can only be used in a high-concentration, viscous form to prevent adhesion of local wounds. For example, in animal experiments, using viscous zwitterionic polymer gel to cover pelvic and abdominal postoperative wounds can effectively avoid the occurrence of local adhesions (PNAS 2020, 117 (50): 32046-32055). However, on the one hand, since zwitterionic polymers lack autonomous metabolic capacity, they need to be degraded by activating the immune system. This means that zwitterionic polymers used for pelvic and abdominal adhesion prevention must have a very low retention rate. When high-concentration, viscous zwitterionic polymers are used for local wound adhesion prevention, the retention rate is high, which will significantly increase the metabolic burden on patients. On the other hand, high-concentration, viscous zwitterionic polymers cannot be used for peritoneal lavage, which means that they cannot achieve full peritoneal adhesion prevention. This is because existing zwitterionic polymers have poor solubility and low reactivity, and require a long time to react with the peritoneum. In addition, the fluidity of peritoneal lavage fluid is similar to that of saline or Ringer's solution. The zwitterionic polymer concentration is low, and it cannot firmly bind to the peritoneum to form an isolation barrier and achieve tissue isolation in the extremely short time of rapid lavage. Therefore, it cannot achieve the full peritoneal adhesion prevention effect of preventing both local and distal adhesions. Summary of the Invention

[0010] In response to the above technical problems, the present invention provides for the first time a negatively charged active epoxy zwitterionic copolymer and its preparation method and application. The negatively charged active epoxy zwitterionic copolymer is composed of a gradient hydrophilic ternary component of "hydrophobic-hydrophilic-strongly hydrophilic", and unexpectedly achieves comprehensive and overall coverage of the entire cavity in the form of a low-concentration, highly fluid peritoneal lavage fluid. It can quickly and firmly combine with the peritoneum to form an isolation barrier and achieve tissue isolation, achieving the effect of achieving full abdominal cavity anti-adhesion through only one-step peritoneal lavage, solving the technical problem in the prior art that zwitterionic polymers can only be applied to local wounds in a high-concentration, viscous form for local anti-adhesion. Specifically, the present invention utilizes the gradually increasing hydrophilicity and like-charge repulsion of the ternary components (hydrophobic unit A, hydrophilic unit B, and superhydrophilic unit C) to synergistically achieve structural stretching of the ternary copolymer in aqueous solution and high binding activity with the peritoneum. As a result, the active epoxy zwitterionic copolymer of the present invention can achieve the prevention and treatment of whole-abdominal adhesions through pelvic and abdominal lavage at low concentrations. It is widely applicable to various surgeries and exhibits significant reductions in adhesion scores and adhesion incidence compared to Ringer's solution and saline solutions currently used for abdominal lavage. Furthermore, the negatively charged active epoxy zwitterionic copolymer of the present invention has a low concentration and fast lavage rate during abdominal lavage, resulting in a low retention rate in the cavity, which does not significantly increase the patient's metabolic burden.

[0011] The performance indicators of the negatively charged active epoxy zwitterionic copolymer with a gradient hydrophilic composition described in the present invention can be evaluated by the resistance to nonspecific protein binding of the surface modified by the copolymer and the rapid dissolution effect in physiological saline. The resistance to nonspecific protein adsorption of the modified surface refers to less than 20% of the adsorption amount of the amino polyurethane sheet, which indicates that the terpolymer can form an effective non-immunogenic barrier in the peritoneum; the rapid dissolution refers to a dissolution time of ≤600s in physiological saline solution, with a minimum dissolution time of only 20s. This rapid dissolution property means that the terpolymer is subjected to the synergistic effect of the three functional groups of "hydrophobic-hydrophilic-superhydrophilic" in aqueous solution, exhibiting a stable and stretchable structure, which is conducive to the hydrophobic active functional groups used for binding to the peritoneum to form a strong bond within the short contact time of peritoneal lavage, meeting the requirements for use as a clinical peritoneal lavage product. The evaluation of postoperative pelvic and abdominal adhesions was conducted through animal experiments using a double-point anastomosis model of the cecum-abdominal wall wound. The copolymer described in the present invention can effectively prevent cells from adhering to the surface of the material and form adhesion bands. When used in pelvic and abdominal surgery, it can quickly react and covalently bind with the pelvic and abdominal lining, comprehensively cover the entire cavity and quickly form an isolation barrier, thereby achieving the prevention and treatment effect of full abdominal adhesion prevention through only one-step peritoneal lavage. The copolymer is widely applicable to various surgeries.

[0012] The technical solutions of the present invention are as follows:

[0013] The present invention provides a negatively charged active epoxy zwitterionic copolymer, the copolymer comprising unit A, ternary B and unit C, wherein the molar content of unit A is 1%-20%, the molar content of unit B is 0.1%-25%, and the molar content of unit C is not less than 70%. The copolymer has a structure shown in structural formula I:

[0014] -Ax-By-Cz-

[0015] (I)

[0016] Among them, Ax, By, and Cz are different and randomly arranged. <x,y,z≤1000,0<x / (x+y+z)≤0.2,0<y / (x+y+z)≤0.25;

[0017] The unit A contains an active functional group, and the side chain end of the unit A is an epoxy group; preferably, the unit A is Any one of, wherein R1=H or CH3, a=1, 2 or 3;

[0018] The unit B contains an anionic functional group, and the side chain end of the unit B is a sulfonic acid group; preferably, the unit B is One of the following, wherein R1=H or CH3, b=2 or 3;

[0019] The unit C contains a zwitterionic functional group, and the side chain end of the unit C is a terminal sulfonic acid group; the unit C is Any one of wherein R1=H or CH3;

[0020] Traditional zwitterionic polymers, especially when containing hydrophobic groups, are prone to structural curling, agglomeration and other conformations in aqueous solution, and have very poor covalent binding ability to the peritoneum. As a result, they can only be used in a high-concentration, viscous state for local anti-adhesion, and cannot be used for low-concentration, fast peritoneal lavage with good fluidity. The active negative charge biased epoxy zwitterionic copolymer described in the present invention breaks the structural limitations of conventional zwitterionic polymers. Unexpectedly, by constructing a gradient hydrophilic "hydrophobic-hydrophilic-superhydrophilic" structure, it achieves the goal of maintaining the stretch of the polymer structure and the activity of the hydrophobic active peritoneal fixation functional groups in aqueous solution. The negative charge bias refers to the presence of a specific anionic component in the zwitterionic copolymer of the present invention. The anti-nonspecific protein binding amount is below 20%, which can effectively prevent cells from adhering to the surface of the material and avoid the formation of adhesion bands. This performance depends primarily on whether the ratio of Unit C, the side chain component of the zwitterionic polymer, and the content of Unit A, the reactive side chain component, can anchor the copolymer to the inner membrane surface. This is because the copolymer comprises three units: Unit A containing an active epoxy functional group, Unit B containing an electronegative anionic functional group, and Unit C containing an electrically neutral zwitterionic functional group. The epoxy functional group of Unit A can undergo nucleophilic addition reactions with nucleophiles such as amino groups and sulfhydryl groups, rapidly forming a covalent bond to anchor the zwitterionic polymer of the present invention. Furthermore, it maintains long-term stability in environments other than protic solvents, making it the active reactive group of the zwitterionic polymer of the present invention. Furthermore, unreacted epoxy functional groups can spontaneously hydrolyze to diols in physiological environments, providing resistance to nonspecific protein binding. Unit B has a sulfonic acid anionic functional group. Due to the strong electronic attraction of the S atom, the lone pair of electrons on the attached O atom has a weak ability to delocalize and attack the electron-deficient epoxy functional group, allowing it to copolymerize with the epoxy functional group. In contrast, for another common carboxylic acid anion, the C atom is less electronically attractive than the O atom, so the oxygen atom of the carboxylic acid functional group has a stronger ability to attack with nucleophilicity, causing the epoxy functional group to open. Unit C is also a zwitterion with a sulfonic acid anionic functional group, chosen for the same reason as unit B. The diol structure formed after hydrolysis of unit A mimics the polysaccharide on the cell membrane surface, unit B mimics the negatively charged components on the cell membrane surface, and unit C mimics the zwitterionic phospholipid outer surface of the cell membrane. Therefore, the three-unit copolymer together forms a physical barrier on the pelvic and abdominal lining that mimics the cell membrane structure. The term "rapid dissolution" refers to a dissolution time of 600 seconds or less, with a minimum dissolution time of just 20 seconds. This rapid dissolution property indicates that the terpolymer exhibits a stable and stretchable structure in aqueous solution, thanks to the synergistic effects of its hydrophobic, hydrophilic, and super-hydrophilic functional groups. This facilitates the formation of a strong bond between the hydrophobic active functional groups and the peritoneum during the short contact time during peritoneal lavage, meeting the requirements for clinical peritoneal lavage products. These properties are determined by the composition and molecular weight distribution of the zwitterionic copolymer.When the copolymer lacks sufficient units B containing anionic side chain components, units A containing hydrophobic reactive side chain components and units C containing zwitterionic polymer side chain components cause the copolymer to easily form a core-shell structure in physiological solutions ( Figure 3 ), increasing the dissolution time and reducing the anchoring efficiency; when the molecular weight distribution of the copolymer is too wide, the large molecular weight components are difficult to dissolve, which also increases the dissolution time; the molecular weight distribution range of the negatively charged biased active epoxy zwitterionic copolymer described in the present invention is not higher than 4. Through the synergistic effect of the above multiple characteristics, excellent anti-nonspecific protein binding performance, instant solubility effect, and high reactivity can be achieved simultaneously.

[0021] Preferably, the molar content of unit A in the copolymer is 5% - 10%;

[0022] Preferably, the molar content of unit B in the copolymer is 0.1% - 20%;

[0023] Preferably, the molar content of unit C in the copolymer is not less than 90%.

[0024] Preferably, for a negatively charged biased active epoxy zwitterionic copolymer of the present invention, the copolymer has the structure shown in Structural Formula II:

[0025]

[0026] In Formula II, 0 < x, y, z ≤ 1000, 0 < x / (x + y + z) ≤ 0.2, 0 < y / (x + y + z) ≤ 0.25, b = 2 or 3, R1 = H or CH3, R2 = O or NH, m = 1 or 2, n = 3 or 4;

[0027] The present invention provides a method for preparing the negatively charged biased active epoxy zwitterionic copolymer. In a binary mixed solvent, an azo thermal initiator and an olefin monomer a with a terminal epoxy group in the side chain, an olefin monomer b with a terminal sulfonic acid group in the side chain, and an olefin monomer c with a terminal sulfonic acid group in the side chain are used to copolymerize to obtain the negatively charged biased active epoxy zwitterionic copolymer;

[0028] Among them, the molar feeding amount of monomer a accounts for 1 - 20% of the total amount of the three olefin monomers; the molar feeding amount of monomer b accounts for 0.1 - 25% of the total amount of the three olefin monomers; the molar feeding amount of monomer c is not less than 70% of the total amount of the three olefin monomers;

[0029] The olefin monomer c containing a zwitterionic functional group is selected from any one of 3-[[2-(methacryloyloxy)ethyl]dimethylammonium]propane-1-sulfonate, (3-(methacrylamido)propyl)dimethyl(3-thiopropyl)ammonium hydroxide inner salt, 3-(methacrylamido)propyldimethyl(3-sulfobutyl)ammonium inner salt, 3-(1-vinyl-1H-imidazole-3-ium-3-yl)propane-1-sulfonate, 3-(2-vinylpyridine-1-ium-1-yl)propane-1-sulfonate, 3-((2-(4-(acrylamidomethyl)-1H-1,2,3-triazole-1-yl)ethyl)dimethylamino)propane-1-sulfonate, dimethyl-(4-vinylphenyl)ammonium propane sulfonate, and 3-(1-(4-vinylbenzyl)-1H-imidazole-3-ium-3-yl)propane-1-sulfonate;

[0030] The binary mixed solvent comprises a protic solvent S1 and an aprotic solvent S2; the volume proportion of the solvent S2 in the mixed solvent is 30-70%;

[0031] Preferably, the molar feed amount of the monomer a accounts for 5-10% of the total amount of the three olefin monomers; the molar feed amount of the monomer b accounts for 0.1-20% of the total amount of the three olefin monomers; and the molar feed amount of the monomer c is not less than 90% of the total amount of the three olefin monomers;

[0032] Preferably, the olefin monomer a containing an active functional group is selected from any one of 1,2-epoxy-5-hexene, 1,2-epoxy-7-octene, 1,2-epoxy-9-decene, allyl glycidyl ether, oxiran-2-yl methacrylate, and glycidyl methacrylate;

[0033] Preferably, the anionic functional group-containing olefin monomer b is selected from any one of 2-ethanesulfonic acid methacrylate monovalent metal salt, 3-sulfopropyl acrylate monovalent metal salt, 3-sulfopropyl methacrylate monovalent metal salt, allyl sulfonic acid monovalent metal salt, and 2-acrylamido-2-methylpropanesulfonic acid monovalent metal salt; the monovalent metal salt includes any one of sodium salt and potassium salt;

[0034] Preferably, the initiator is an azo initiator; preferably, the azo initiator is an oil-soluble azo initiator; more preferably, the oil-soluble azo initiator is selected from any one of azobisisobutyronitrile (AIBN) and azobisisoheptanenitrile (ABVN); more preferably, the oil-soluble azo initiator is azobisisobutyronitrile (AIBN);

[0035] Preferably, the protic solvent S1 is selected from any one or more of water, methanol, and ethanol; more preferably, the protic solvent S1 is methanol;

[0036] Preferably, the aprotic solvent S2 is selected from any one or more of diethyl ether, diisopropyl ether, acetone, and acetonitrile; more preferably, the aprotic solvent S2 is acetonitrile;

[0037] Preferably, the reaction temperature is 60-80°C; preferably, the reaction time is 2-24h; more preferably, the reaction temperature is 70°C; more preferably, the reaction time is 6h.

[0038] The present invention also provides an active polymer liquid material for medical devices, wherein the active polymer liquid material comprises the negatively charged active epoxy zwitterionic copolymer as described above or the negatively charged active epoxy zwitterionic copolymer prepared by the preparation method as described above, and at least one first dispersant;

[0039] Preferably, the first dispersant is selected from any one of sterile purified water, sterile sodium chloride solution, and sterile Ringer's solution;

[0040] Preferably, the mass concentration of the negatively charged active epoxy zwitterionic copolymer in the active polymer liquid material is not higher than 50%.

[0041] The present invention also provides a medical anti-adhesion gel, which comprises the negatively charged active epoxy zwitterionic copolymer as described above, or the negatively charged active epoxy zwitterionic copolymer prepared by the preparation method as described above, or the active polymer liquid material as described above, and at least one additive, and can undergo cross-linking and gelation to form an anti-adhesion gel;

[0042] Preferably, the additive is one or more of synthetic high molecular polymers, natural high molecular polysaccharides, and modified high molecular polysaccharides;

[0043] More preferably, the synthetic high molecular polymer is selected from any one or more high molecular polymers containing polyamino groups or polythiol groups obtained by free radical polymerization, polyaddition reaction, and polycondensation reaction;

[0044] More preferably, the natural high molecular weight polysaccharide is selected from high molecular weight polysaccharides containing multiple amino groups;

[0045] More preferably, the modified polymer polysaccharide is selected from any one or more of amino-modified polymer polysaccharides and thiol-modified polymer polysaccharides; more preferably, the polymer polysaccharide is selected from any one or more of cellulose, starch, agar, carrageenan, chitosan, xanthan gum, and trehalose;

[0046] Preferably, the mass concentration of the negatively charged active epoxy zwitterionic copolymer in the medical anti-adhesion gel is not less than 30%;

[0047] Preferably, the mass concentration of the additive is not higher than 5%.

[0048] The present invention also provides a medical anti-adhesion peritoneal lavage fluid, comprising the negatively charged active epoxy zwitterionic copolymer as described above, or the negatively charged active epoxy zwitterionic copolymer prepared by the preparation method as described above, or the active polymer liquid material as described above, and at least one second dispersant; the mass concentration of the negatively charged active epoxy zwitterionic copolymer in the peritoneal lavage fluid is greater than 0.1% and less than 15%; preferably, the mass concentration of the negatively charged active epoxy zwitterionic copolymer in the peritoneal lavage fluid is ≥1% and ≤5%;

[0049] Preferably, the second dispersant is selected from any one of sterile purified water, sterile sodium chloride solution, and sterile Ringer's solution.

[0050] The present invention also provides a polymer antifouling coating for medical devices, wherein the polymer antifouling coating comprises the negatively charged active epoxy zwitterionic copolymer as described above, or comprises the negatively charged active epoxy zwitterionic copolymer prepared by the preparation method as described above, or comprises the active polymer liquid material as described above;

[0051] Preferably, the polymer antifouling coating further comprises at least one adhesive and at least one catalyst; the mass concentration of the Lewis base catalyst is 0.1%-9% of the zwitterionic copolymer;

[0052] Preferably, the adhesive is selected from any one or more of polymethoxysilane, polyethoxysilane, dopamine, dopamine derivatives, long-chain alkanes, cyclic alkanes, and adamantane containing amino or mercapto groups;

[0053] Preferably, the catalyst is a Lewis base catalyst; more preferably, the Lewis base catalyst is selected from any one or more of triethylamine, pyridine, and 1,4-diazabicyclo[2.2.2]octane.

[0054] Furthermore, the preparation method of the polymer antifouling coating is: the active polymer liquid material and the catalyst are made into an aqueous dilute solution, and then the medical device with an adhesive on its surface is immersed in the aqueous dilute solution; the medical device with an adhesive on its surface is prepared by forming a continuous interface between the adhesive and the surface of the medical device through silane self-assembly, physical adsorption, and chemical adsorption.

[0055] The present invention also provides an amphiphilic zwitterionic polymer material, which comprises the negatively charged active epoxy zwitterionic copolymer as described above or the negatively charged active epoxy zwitterionic copolymer prepared by the preparation method as described above. The negatively charged active epoxy zwitterionic copolymer can undergo an addition reaction with a hydrophobic molecule; the hydrophobic molecule is selected from any one or more of long-chain alkanes with amino or thiol end groups, cyclic alkanes (4-aminobenzophenone), adamantane, siloxane, and alkoxysilane.

[0056] Compared with the prior art, the present invention has the following beneficial effects:

[0057] (1) The present invention provides for the first time a negatively charged biased active epoxy zwitterionic copolymer, which is composed of a "hydrophobic-hydrophilic-strongly hydrophilic" gradient hydrophilic ternary component (hydrophobic unit A, hydrophilic unit B and super hydrophilic unit C). By establishing a "hydrophobic-hydrophilic-super hydrophilic" gradient hydrophilicity difference structure and the same charge repulsion, the ternary copolymer has a stable and stretchable structure in aqueous solution, and the hydrophobic active functional group with high activity combined with the peritoneal membrane is used to quickly and efficiently play an anchoring role, so that the active epoxy zwitterionic copolymer of the present invention can be used at low The peritoneal lavage fluid with good concentration and fluidity covers the entire cavity as a whole, and quickly and firmly combines with the peritoneum to form an isolation barrier and achieve tissue isolation, which can achieve the effect of postoperative full abdominal adhesion prevention, and achieves the prevention and treatment effect of full abdominal adhesion prevention at the same time by only one-step peritoneal lavage. It is widely applicable to various surgeries, and solves the technical problem that zwitterionic polymers in the prior art can only be used for local adhesion prevention in a high concentration and viscous form. Compared with the Ringer's solution and normal saline used for current peritoneal lavage, it shows a significant adhesion score and adhesion incidence reduction. Moreover, the negatively charged biased active epoxy zwitterionic copolymer of the present invention has a low concentration and a fast lavage speed during peritoneal lavage, so the resident amount in the cavity is low, which will not significantly increase the metabolic burden of the patient. The present invention provides a new design idea for the problem of decreased reactivity caused by the self-conformation of materials with large hydrophilicity differences.

[0058] (2) The negatively charged active epoxy zwitterionic copolymer provided by the present invention can quickly react and covalently bind with the pelvic and abdominal cavity lining during the peritoneal lavage process, and can comprehensively cover the entire cavity. Under the premise of extremely low residual amount in the body, it establishes a low metabolic pressure cavity lining anti-adhesion barrier, avoids the contact between the minimally invasive surface and other environments, and silences factors such as tissue fragments and blood clots that induce tissue adhesion. The zwitterionic polymer itself has the ability to be recognized by the immune system and does not trigger a foreign body response. The low residual polymer has low inflammatory metabolic pressure and avoids inducing tissue adhesion, thus achieving a complete anti-adhesion effect of the entire abdominal cavity through only one-step peritoneal lavage, and is widely applicable to various types of surgeries.

[0059] (3) The present invention provides a method for preparing a copolymer by using a mutually soluble binary mixed solvent to realize monomers containing hydrophilic zwitterionic functional groups and monomers containing hydrophobic active functional groups. A specific protective solvent is used to maintain the stability of the epoxy functional group in a zwitterionic good solvent with strong protonation ability, thereby effectively controlling the molecular weight and molecular weight distribution of the copolymer and maintaining the excellent active covalent binding ability and fast dissolution characteristics of the subsequent zwitterionic copolymer.

[0060] (4) The present invention provides a variety of practical and high-value-added application solutions, including the preparation of polymer materials modified with low-concentration zwitterionic polymers, antifouling coatings, anti-adhesion gel preparations, and the design of intraoperative anti-adhesion peritoneal lavage fluids. These solutions effectively avoid the long-term cleaning problem of small molecule and oligomer residues present in zwitterionic products prepared by surface-initiated free radical polymerization, simplifying the process and improving efficiency.

[0061] (5) The functionalized zwitterionic multipolymer described in the present invention is applicable to a wide range of medical scenarios. It can form a hydrogel by simple blending with multiple nucleophilic functional group components, and the gelation state and time can be controlled by the epoxy content. It can also be used as a medical dressing, thickener, medical implant, and filler. It can also be combined with the surface of materials with nucleophilic functional groups to form a strong anti-nonspecific binding (anti-NSB) coating for use in in vitro label-free high-sensitivity diagnosis, blood-contact catheters / guidewires, contact lenses, and other fields.

[0062] In summary, the negatively charged active epoxy zwitterionic copolymer of the present invention has broad application prospects in the process of zwitterionic productization. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 This is the NMR spectrum of the negatively charged biased active epoxy zwitterionic copolymer in Example 1 of the present invention.

[0064] Figure 2 This is a gel liquid chromatogram of the negatively charged biased active epoxy zwitterionic copolymer in Example 1 of the present invention.

[0065] Figure 3 Schematic diagram of the process of surface modification of the negatively charged biased active epoxy zwitterionic copolymer and the active neutral zwitterionic copolymer of the present invention.

[0066] Figure 4 This is a graph showing the relative nonspecific protein binding of the negatively charged active epoxy zwitterionic copolymer synthesized in Example 2-1 of the present invention measured by enzyme-linked immunosorbent assay in 1 mg / ml bovine serum albumin.

[0067] Figure 5 This is a graph showing the zwitterionic postoperative anti-adhesion peritoneal lavage fluid prepared in Example 8 of the present invention and the rat peritoneal anti-adhesion score of Comparative Example 8.

[0068] Figure 6 Pathological sections of the abdominal wall wound and cecal wound after peritoneal lavage using the zwitterionic postoperative intracavitary anti-adhesion product configured in Example 8 of the present invention. DETAILED DESCRIPTION

[0069] The following detailed description of the negatively charged active epoxy zwitterionic copolymers of the present invention and their applications in medical devices is based on specific examples. The implementation steps of all examples are the same as those described in the Summary of the Invention. It should be noted that these examples do not constitute limitations of the present invention, and all variations that can be directly derived or imagined by one of ordinary skill in the art from the present disclosure are considered to be within the scope of protection of the present invention.

[0070] Detection method:

[0071] The molecular weight and molecular weight distribution of the copolymer were characterized by liquid chromatography using 0.5 mol / L sodium nitrate as the mobile phase, passing through a Sephadex column at 35°C, and monitoring using a parallax display. The standard was a linear polyethylene glycol (PEG) molecule. The smaller the molecular weight distribution value, the better. The molecular weight distribution range applicable to the present invention is no greater than 4, and preferably, the molecular weight distribution range is no greater than 2.

[0072] Solubility Testing: Prepare a 25% (w / v) concentration of a negatively charged reactive epoxy zwitterionic copolymer liquid material using sterile saline as a dispersant. Record the time it takes for the copolymer to completely dissolve and become clear. The shorter the time, the better the solubility. Based on surveys with clinicians, zwitterionic copolymers suitable for clinical surgery should dissolve in a 25% (w / v) saline solution within 600 seconds. Therefore, the dissolution time for the present invention should be no greater than 600 seconds, and preferably, no greater than 60 seconds.

[0073] Relative non-specific protein binding (NSB) assay: Anti-protein non-specific adsorption in a single protein solution was determined by ELISA. Zwitterionic copolymers were modified with the Lewis base catalyst DABCO (0.01 mg / ml) using square amino-polyurethane sheets approximately 10 mm in length as templates for 24 hours. Subsequently, zwitterionic amino-polyurethane sheets and unmodified amino-polyurethane sheets were placed in a 24-well plate. 1 mL of PBS buffer containing 1 μg / mL HRP-IgG was added to each well, and the plates were shaken on a horizontal shaker for 1 hour. The samples were washed five times with PBS buffer and placed in new wells. A TMB colorimetric kit was used for color development. The reaction was terminated by adding 1 mL of 1 mol / L HCl solution to each well. 200 μL of each solution was added to a 96-well plate, and the absorbance (OD) at 450 nm was measured using a microplate reader. The relative anti-protein non-specific adsorption ratio of the zwitterionic materials was evaluated, with the protein binding to the unmodified amino-polyurethane sheet defined as 100% adsorption. The smaller the NSB value, the lower the nonspecific adsorption ratio of proteins and the better the anti-adhesion effect. The NSB applicable to the present invention is not greater than 20%, preferably, the NSB of the present invention is not greater than 10%.

[0074] Example 1:

[0075] Preparation process of negatively charged active epoxy zwitterionic copolymer: 80 parts of zwitterionic component 3-[[2-(acryloyloxy)ethyl]dimethylammonio]propane-1-sulfonate, 10 parts of anionic component 3-sulfonic acid propyl methacrylate potassium salt, 10 parts of active component glycidyl methacrylate were added to a three-necked flask, and then 200 parts of methanol-acetonitrile mixed solution (V 甲醇 :V 乙腈 =1:1). After complete dissolution, 2.5 parts of azo initiator AIBN was added. After full dissolution, the temperature was raised to 70°C under N2 protection and sealed conditions. After reaction for 6 hours, a transparent viscous precipitate was obtained. The precipitate was washed with methanol three times, and then the viscous precipitate was redissolved in deionized water. The residual organic solvent was removed by rotary evaporation and freeze-dried to obtain a negatively charged active epoxy zwitterionic copolymer (1).

[0076] The structure of the negatively charged active epoxy zwitterionic copolymer (1) was determined by H NMR spectroscopy (H 1 NMR) characterization, such as Figure 1 shown.

[0077] The properties of the negatively charged active epoxy zwitterionic copolymer prepared in this example are characterized by the following characteristic parameters and summarized in Table 6. The molecular weight and molecular weight distribution of the copolymer are characterized by liquid chromatography, as shown in FIG. Figure 2 As shown, the molecular weight distribution of this example is 1.93.

[0078] The solubility test of the copolymer in this embodiment uses sterile physiological saline as a dispersant to prepare a negatively charged active epoxy zwitterionic copolymer liquid material with a concentration of 25% (w / v), and records the time for the copolymer to completely dissolve to clarify, the shorter the time, the better. Due to the spontaneous hydrolysis caused by the epoxy functional group itself, the copolymer of the present invention cannot be pre-prepared into the form of an anti-adhesion product solution for long-term storage, so the ideal preparation method should be in the form of a penicillin ampoule. When in use, physiological saline is injected into the ampoule to completely dissolve the polymer, and then diluted to the use concentration. Since the anti-adhesion product is used for peritoneal lavage, the copolymer needs to dissolve as quickly as possible to avoid medical problems such as prolonged surgery time due to excessive dissolution time. The dissolution time of the copolymer in this embodiment is as low as 20s, and the solubility is excellent.

[0079] The relative non-specific protein binding (NSB) of this example was determined by ELISA, and the value was only 8.3%.

[0080] The copolymer of this embodiment has both fast dissolution effect and excellent resistance to nonspecific protein binding.

[0081] Comparative Example 1:

[0082] This comparative example is used to compare the active neutral zwitterionic copolymer without negative charge bias and the active epoxy zwitterionic copolymer with negative charge bias of the present invention. The only difference compared with Example 1 is that the anionic component methacrylic acid sulfonate is not added.

[0083] 80 parts of zwitterion component sulfobetaine methacrylate and 20 parts of active component glycidyl methacrylate were added to a three-necked flask, followed by 200 parts of methanol-acetonitrile mixed solution (V 甲醇 :V 乙腈 =1:1). After complete dissolution, 2.5 parts of azo initiator AIBN was added. After full dissolution, the temperature was raised to 70°C under N2 protection and sealed conditions. After reaction for 6 hours, a transparent viscous precipitate was obtained. The precipitate was washed three times with methanol, and then the viscous precipitate was redissolved in deionized water. The residual organic solvent was removed by rotary evaporation, and the mixture was freeze-dried to obtain an active electrically neutral zwitterionic copolymer (Comparative Example 1).

[0084] The copolymers were characterized using the same method as in Example 1 and are summarized in Table 6;

[0085] The results showed that the dissolution time of the active electrically neutral zwitterionic copolymer in Comparative Example 1 exceeded 600 s, which was not suitable for use as a liquid material for clinical use. Figure 3The present invention vividly shows the process schematic diagram of the active epoxy zwitterionic copolymer with negative charge bias in the peritoneum. Compared with the active electrically neutral zwitterionic copolymer of Comparative Example 1, the fast-dissolving characteristics of the copolymer of the present invention depend on the structure and molecular weight distribution of the zwitterionic copolymer. When the copolymer lacks enough anionic B unit components, the hydrophobic A unit component and the hydrophilic C unit component cause the copolymer to easily form a core-shell structure in physiological solution. This requires the outer shell barrier of the zwitterionic component to break through the active A component and the inner membrane. And with the addition of the B unit component, the electrostatic repulsion between the anions makes the core-shell assembly of the polymer disturbed due to the limitation of steric hindrance, and the combination of the active A unit component and the inner membrane is easier. In terms of performance, it is embodied as the active electrically neutral zwitterionic copolymer lacking the B unit component has a longer dissolution time and a lower anchoring efficiency. Furthermore, during surface densification, polymer chains are prone to entanglement due to dipole interactions, reducing surface freedom. From a thermodynamic perspective, low surface freedom also affects the polymer's ability to resist nonspecific binding (NSB). However, the appropriate addition of B units can improve surface freedom and, in synergy with A and C units, achieve more reliable performance. Furthermore, among the factors influencing component solubility, when the copolymer's molecular weight distribution is too broad, high molecular weight components are difficult to dissolve, which also increases dissolution time.

[0086] Example 2 and Comparative Example 2:

[0087] In this example, the content of the zwitterionic olefin monomer c was fixed, and the ratio of the reactive functional group-containing olefin monomer a to the anionic functional group-containing olefin monomer b was adjusted. The preparation steps were the same as in Example 1. The specific components of each example are summarized in Table 1.

[0088] Table 1. Raw material parameters of Example 2 and Comparative Example 2

[0089] serial number Monomer a% Monomer b% Monomer c% Example 2-1 19.9 0.1 80 Example 2-2 19 1 80 Example 2-3 15 5 80 Examples 2-4 5 15 80 Examples 2-5 1 19 80 Comparative Example 2-1 19.99 0.01 80 Comparative Example 2-2 0.1 19.9 80

[0090] The copolymers were characterized in the same manner as in Example 1 and are summarized in Table 6. The relative nonspecific protein binding capacity of the surface formed by the copolymers prepared in Example 2-1 is shown in Table 6. Figure 4 After 18 h, the relative nonspecific protein binding amount of the surface formed by the copolymer was only 2%.

[0091] The copolymer prepared in Comparative Example 2-1 had a dissolution time exceeding 600 s and was not suitable for use as a liquid material for clinical use. The copolymer prepared in Comparative Example 2-2 had a relative nonspecific protein binding capacity exceeding 20% and had no anti-adhesion effect. Both comparative examples are not suitable for the applications described in the present invention.

[0092] Example 3 and Comparative Example 3:

[0093] In this example, the three components of olefin monomer a containing a reactive functional group, olefin monomer b containing anionic functional groups, and olefin monomer c containing zwitterionic functional groups were adjusted to determine their applicable ranges. The preparation steps were the same as in Example 1. The specific components of each example are summarized in Table 2.

[0094] Table 2. Raw material parameters of Example 3 and Comparative Example 3

[0095] serial number Monomer a% Monomer b% Monomer c% Example 3-1 20 10 70 Example 3-2 10 20 70 Example 3-3 5 25 70 Comparative Example 3-1 25 5 70 Comparative Example 3-2 1 29 70 Comparative Example 3-3 20 20 60

[0096] The copolymers were characterized using the same method as in Example 1 and are summarized in Table 6;

[0097] The results show that the copolymer described in Comparative Example 3-1 has too high a content of reactive side chain units, resulting in a molecular weight distribution greater than 4. Comparative Example 3-2 has a high content of anionic side chain units, while Comparative Example 3-3 has a low content of zwitterionic polymer units. The NSB values of all these copolymers exceed 20%, making them unsuitable for use in the present invention. The NSB value in Example 3-3 exceeds 10%. Based on the results from Examples 2 and 3, the content of monomer a should be within the range of 1-20%, the content of monomer c should not be less than 70%, and the content of monomer b should be within the range of 0.1-25%, with a preferred range of 0.1-20%.

[0098] Example 4 and Comparative Example 4:

[0099] In this example, the molecular structures of the olefin monomer a containing a reactive functional group, the olefin monomer b containing an anionic functional group, and the olefin monomer c containing a zwitterionic functional group are combined and varied, and the component ratios and preparation steps are the same as in Example 1. The specific components of each example are summarized in Table 3.

[0100] Table 3. Raw material selection and corresponding copolymer unit structure of Example 4

[0101]

[0102]

[0103] Table 3. Raw material selection and corresponding copolymer unit structure of Example 4

[0104]

[0105]

[0106] The copolymers were characterized using the same method as in Example 1 and are summarized in Table 6;

[0107] The results demonstrate that all combinations described in Example 4 are suitable for the applications described herein. In Comparative Example 4-1, replacing the anionic functional groups of component B with carboxyl functional groups significantly increased the molecular weight distribution of the copolymer to above 4. Similarly, similar results were observed in Comparative Examples 4-2 and 4-3, confirming that in the zwitterionic copolymers described herein, the anionic functional groups of components B and C can only be sulfonate functional groups.

[0108] Example 5 and Comparative Example 5:

[0109] This example evaluates a binary mixed solvent combination. The copolymer is prepared in the same manner as in Example 1, and the proportions of the binary mixed solvents are the same as in Example 1. The specific mixed solvent combinations are summarized in Table 4.

[0110] Table 4. Effect of solvent selection on copolymer properties in Example 5 and Comparative Example 5

[0111]

[0112] The copolymers were characterized using the same method as in Example 1 and are summarized in Table 6;

[0113] The results show that the polymers in Comparative Example 5-1 (mixture of two protic solvents) and Comparative Example 5-2 (single protic solvent) have very large molecular weight distribution and poor solubility, and are not suitable for the application of the present invention.

[0114] Example 6 and Comparative Example 6:

[0115] The present invention evaluated the ratio of the aprotic solvent in the combination of a protic solvent and an aprotic mixed solvent (methanol and acetonitrile). The polymer preparation method was the same as in Example 1, and the changes in the ratio of the aprotic solvent are summarized in Table 5.

[0116] Table 5. Effect of mixed solvent ratios of Example 6 and Comparative Example 6 on copolymer properties

[0117] serial number Aprotic solvent S2% Example 6-1 70 Example 6-2 50 Example 6-3 30 Comparative Example 6 20

[0118] The copolymers were characterized using the same method as in Example 1 and are summarized in Table 6;

[0119] The results show that the copolymer in Comparative Example 6 has a large molecular weight distribution and poor solubility, and is not suitable for the application described in the present invention.

[0120] Table 6. Content and performance index of zwitterionic copolymers of Examples 1-6 and Comparative Examples 1-6

[0121]

[0122]

[0123] Example 7 and Comparative Example 7:

[0124] This example evaluates the preparation of a polymer antifouling coating using a negatively charged active epoxy zwitterionic copolymer and its performance.

[0125] Preparation of a negatively charged active epoxy zwitterionic copolymer antifouling coating: 30 mg of the negatively charged active epoxy zwitterionic copolymer prepared in Example 2-1 and 3 ml of an aqueous solution of the Lewis base 1,4-diazabicyclo[2.2.2]octane were added to a 5 ml centrifuge tube. After complete dissolution, the amino-modified surface material to be modified was placed in the mixture. After 18 hours, the material was removed, rinsed with deionized water, and dried to obtain a coating. The catalyst concentration changes are summarized in Table 7. The NSB performance of the prepared negatively charged active epoxy zwitterionic copolymer coating was characterized according to the method described in Example 1.

[0126] Table 7 Mass concentration of catalyst in polymer antifouling coating and antifouling performance of Example 7 and Comparative Example 7

[0127] serial number Mass concentration of catalyst relative to copolymer % NSB% Example 7-1 0.1 2 Example 7-2 1 8 Example 7-3 9 13 Comparative Example 7-1 0.01 46 Comparative Example 7-2 10 25

[0128] The results show that catalyst concentration significantly affects antifouling performance. As the Lewis base catalyst concentration increases, the coating's antifouling performance decreases. In Comparative Example 7-2, the relative nonspecific protein binding (NSB) is already greater than 20%. In Comparative Example 7-1, the catalyst concentration is too low to catalyze the coating's binding to the modified surface and form a complete antifouling coating. Therefore, the catalyst concentration relative to the copolymer ranges from 0.1% to 9%.

[0129] Example 8:

[0130] Preparation process of negatively charged active epoxy zwitterionic copolymer anti-adhesion peritoneal lavage fluid: At room temperature (preferably 25°C), 4 g of the negatively charged active epoxy zwitterionic copolymer lyophilized powder prepared in Example 1 was dissolved in 20 ml of normal saline within 25 seconds until clear, and diluted to 400 ml to obtain 1% (w / v) anti-adhesion peritoneal lavage fluid (8).

[0131] The rat's abdominal cavity was opened, the cecum was removed, and a 1 cm × 1 cm abrasion wound was created. Subsequently, a defect wound of the same size was created on the abdominal wall. Both wounds were irrigated with 10 ml of a 1% (w / v) negatively charged reactive epoxy zwitterionic copolymer in saline solution, ensuring that no irrigant flowed into the abdominal cavity. The cecal wound and the abdominal wall wound were sutured at two points with 4-0 sutures, facing each other. The abdominal cavity was then irrigated with 10 ml of a 1% (w / v) negatively charged reactive epoxy zwitterionic copolymer in saline solution three times, and the abdomen was then closed layer by layer.

[0132] The performance of the prepared negatively charged active epoxy zwitterionic copolymer anti-adhesion peritoneal lavage fluid was characterized by the following characteristic parameters and summarized in Table 9.

[0133] Residual fluid volume in the cavity after lavage: Record the volume of fluid extracted from the peritoneal cavity after lavage and calculate the difference between this volume and the volume of the lavage fluid added. A certain amount of residual fluid is necessary during lavage to allow the lavage fluid to quickly form an isolation barrier with the peritoneum and evenly and completely cover the cavity. However, excessive residual fluid can lead to increased metabolic stress. Therefore, the smaller the residual fluid, the better, while ensuring the anti-adhesion effect.

[0134] Evaluation of the anti-adhesion ability of peritoneal lavage fluid: The evaluation was performed using the scoring table in Table 8, with at least 5 volunteers participating in the scoring, and the final results were statistically analyzed.

[0135] Table 8. Anti-adhesion evaluation criteria

[0136]

[0137] Comparative Example 8:

[0138] In this comparative example, Ringer's solution, a clinically used product, was selected as comparative example 8-1, 4% icodextrin was selected as comparative example 8-2, and an inactive zwitterionic homopolymer prepared according to the literature was selected as comparative example 8-3. The usage was the same as in Example 6. The performance of the prepared anti-adhesion peritoneal lavage fluid was characterized using the method described in Example 8. The specific product parameters and application performance are summarized in Table 9.

[0139] The inactive zwitterionic homopolymer preparation process in Comparative Example 8-3 involved adding 10 wt% carboxylic acid betaine methacrylate monomer and 0.5% ammonium persulfate thermal initiator to a three-necked flask, followed by reaction at 60°C for 24 hours. The reaction product was purified by dialysis with an 8000 Da molecular weight cutoff membrane and then freeze-dried to obtain the inactive zwitterionic homopolymer.

[0140] Table 9. Parameters and application performance of peritoneal lavage products in Example 8 and Comparative Example 8

[0141]

[0142] The results showed that in Comparative Example 8-1, peritoneal lavage with Ringer's solution alone could not effectively prevent whole-abdominal adhesions, i.e., local adhesions and distal adhesions; in Comparative Examples 8-2 and 8-3, peritoneal lavage alone could slightly reduce local adhesions, but the effect on preventing distal adhesions was similar to that of Ringer's solution, and it was also unable to effectively prevent distal adhesions.

[0143] Comparative Example 8-1 was used as the blank group and Example 8 was used as the experimental group. The whole abdominal cavity anti-adhesion score was summarized in Figure 5 As shown in the figure, the adhesion score of the proximal direct abdominal wall-cecum (AW-CE) wound surface decreased to 1 after using the product described in Example 8, while the adhesion score of the product described in Comparative Example 8-1 was 3.7; the scores of the distal adhesion areas of cecum-cecum (CE-CE), small intestine-other organs (Int-Others), and uterine appendages-other organs (UT-Others) also showed that Example 8 had lower adhesion scores than Comparative Example 8-1.

[0144] The performance of local adhesion (wound side) was visually evaluated by H&E staining and Masson staining of pathological sections. In the blank group, the cecum was fused with the abdominal wall and connected by a dense collagen layer, such as Figure 6 As shown in a; the mesothelial layer of the abdominal wall and cecum of the experimental group grew healthily, without adhesions formed by collagen, and the thickness of the peritoneal lining was about 20 μm, consistent with the healthy peritoneum, without peritoneal hyperplasia. Figure 6 As shown in b.

[0145] Example 9 and Comparative Example 9:

[0146] This example is used to compare the effects of different concentrations of active negative charge biased epoxy zwitterionic copolymer peritoneal lavage fluid on the whole abdominal cavity anti-adhesion performance. The performance evaluation method of the peritoneal lavage fluid is the same as that of Example 8. The specific concentration variation parameters and application performance are summarized in Table 10.

[0147] Table 10. Anti-adhesion products and effect evaluation of Example 9 and Comparative Example 9

[0148]

[0149]

[0150] The results show that compared with the 1% concentration effect of Example 8, when the concentration of the active negative charge biased epoxy zwitterionic copolymer in Comparative Example 9-1 is lower than 0.1%, the anti-adhesion effect is significantly reduced. When the concentration is ≥1%, the prevention and treatment effect on local adhesion is significant, but as the concentration increases further, the prevention and treatment effect on distal adhesion decreases slightly. This performance is also related to the residual amount in the cavity after flushing. When the concentration of Comparative Example 9-2 reaches 15%, the viscosity of the peritoneal lavage fluid increases significantly, which may have defects in infiltration into the cavity, and the excessive polymer remaining in the body still needs to be metabolized through inflammation, which is not conducive to the anti-adhesion performance.

[0151] It should be understood that the above embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art may make various changes or modifications to the present invention, and these equivalent forms also fall within the scope limited by the appended claims of the application.

Claims

1. A negatively charged active epoxy zwitterionic copolymer, characterized in that: The copolymer comprises unit A, ternary B and unit C, wherein the molar content of unit A is 1%-20%, the molar content of unit B is 0.1%-25%, and the molar content of unit C is not less than 70%. The copolymer has the structure shown in Structural Formula I: -A x -B y -C z - Formula I Among them, A x 、B y 、C z Different and randomly arranged, 0 <x,y,z≤1000,0<x / (x+y+z)≤0.2,0<y / (x+y+z)≤0.25; The unit A contains an active functional group, and the side chain end of the unit A is an epoxy group; preferably, the unit A is Any one of, wherein R1=H or CH3, a=1, 2 or 3; The unit B contains an anionic functional group, and the side chain end of the unit B is a sulfonic acid group; preferably, the unit B is Any one of the following, wherein R1=H or CH3, b=2 or 3; The unit C contains a zwitterionic functional group, and the side chain end of the unit C is a terminal sulfonic acid group; the unit C is Any one of wherein R1=H or CH3; Preferably, the molar content of unit A in the copolymer is 5%-10%; Preferably, the molar content of unit B in the copolymer is 0.1%-20%; Preferably, the molar content of unit C in the copolymer is not less than 90%.

2. The negatively charged active epoxy zwitterionic copolymer according to claim 1, characterized in that: The copolymer has the structure shown in Structural Formula II: In Formula II, 0 < x, y, z ≤ 1000, 0 < x / (x + y + z) ≤ 0.2, 0 < y / (x + y + z) ≤ 0.25, b = 2 or 3, R1 = H or CH3, R2 = O or NH, m = 1 or 2, n = 3 or 4.

3. The method for preparing the negatively charged biased active epoxy zwitterionic copolymer according to claim 1-2, characterized in that: The negatively charged biased active epoxy zwitterionic copolymer is prepared by copolymerizing an azo thermal initiator and an olefin monomer a containing a terminal epoxy group, an olefin monomer b containing a terminal sulfonic acid group, and an olefin monomer c containing a terminal sulfonic acid group and an amphoteric ion functional group in a binary mixed solvent; wherein, the molar feeding amount of the monomer a accounts for 1-20% of the total amount of the three olefin monomers; the molar feeding amount of the monomer b accounts for 0.1-25% of the total amount of the three olefin monomers; the molar feeding amount of the monomer c is not less than 70% of the total amount of the three olefin monomers; The olefin monomer c containing an amphoteric ion functional group is selected from any one of 3-[[2-(methacryloyloxy)ethyl]dimethylammonio]propane-1-sulfonate, (3-(methacrylamido)propyl)dimethyl(3-sulfopropyl)ammonium hydroxide inner salt, 3-(methacrylamido)propyl dimethyl(3-sulfobutyl)ammonium inner salt, 3-(1-vinyl-1H-imidazol-3-ium-3-yl)propane-1-sulfonate, 3-(2-vinylpyridin-1-ium-1-yl)propane-1-sulfonate, 3-((2-(4-(acrylamidomethyl)-1H-1,2,3-triazol-1-yl)ethyl)dimethylamino)propane-1-sulfonate, dimethyl-(4-vinylphenyl)ammonium propane sulfonate, 3-(1-(4-vinylbenzyl)-1H-imidazol-3-ium-3-yl)propane-1-sulfonate; The binary mixed solvent comprises a proton solvent S1 and an aprotic solvent S2; the volume ratio of the solvent S2 in the mixed solvent is 30-70%; Preferably, the molar feeding amount of the monomer a accounts for 5-10% of the total amount of the three olefin monomers; the molar feeding amount of the monomer b accounts for 0.1-20% of the total amount of the three olefin monomers; the molar feeding amount of the monomer c is not less than 90% of the total amount of the three olefin monomers; Preferably, the olefin monomer a containing an active functional group is selected from any one of 1,2-epoxy-5-hexene, 1,2-epoxy-7-octene, 1,2-epoxy-9-decene, allyl glycidyl ether, 2-(epoxyethanyl)methyl acrylate, glycidyl methacrylate; Preferably, the olefin monomer b containing an anionic functional group is selected from any one of 2-ethanesulfonic acid methacrylate monovalent metal salt, 3-sulfopropyl acrylate monovalent metal salt, 3-sulfopropyl methacrylate monovalent metal salt, allyl sulfonic acid monovalent metal salt, 2-acrylamido-2-methylpropanesulfonic acid monovalent metal salt; the monovalent metal salt includes sodium salt, potassium salt Preferably, the initiator is an azo initiator; preferably, the azo initiator is an oil-soluble azo initiator; more preferably, the oil-soluble azo initiator is selected from any one of azobisisobutyronitrile (AIBN) and azobisisoheptanenitrile (ABVN); more preferably, the oil-soluble azo initiator is azobisisobutyronitrile (AIBN); Preferably, the protic solvent S1 is selected from any one or more of water, methanol, and ethanol; more preferably, the protic solvent S1 is methanol; Preferably, the aprotic solvent S2 is selected from any one or more of diethyl ether, diisopropyl ether, acetone, and acetonitrile; more preferably, the aprotic solvent S2 is acetonitrile; Preferably, the reaction temperature is 60-80°C; preferably, the reaction time is 2-24h; more preferably, the reaction temperature is 70°C; more preferably, the reaction time is 6h.

4. An active polymer liquid material for medical devices, characterized in that: The active polymer liquid material comprises the negatively charged active epoxy zwitterionic copolymer according to any one of claims 1 to 2 or the negatively charged active epoxy zwitterionic copolymer prepared by the preparation method according to claim 3, and at least one first dispersant; Preferably, the first dispersant is selected from any one of sterile purified water, sterile sodium chloride solution, and sterile Ringer's solution; Preferably, the mass concentration of the negatively charged active epoxy zwitterionic copolymer in the active polymer liquid material is not higher than 50%.

5. A medical anti-adhesion gel, characterized in that: The medical anti-adhesion gel comprises the negatively charged active epoxy zwitterionic copolymer according to any one of claims 1 to 2, or the negatively charged active epoxy zwitterionic copolymer prepared by the preparation method according to claim 3, or the active polymer liquid material according to claim 4, and at least one additive, and can undergo cross-linking and gelation to form an anti-adhesion gel; Preferably, the additive is one or more of synthetic high molecular polymers, natural high molecular polysaccharides, and modified high molecular polysaccharides; More preferably, the synthetic high molecular polymer is selected from any one or more high molecular polymers containing polyamino groups or polythiol groups obtained by free radical polymerization, polyaddition reaction, and polycondensation reaction; More preferably, the natural high molecular weight polysaccharide is selected from high molecular weight polysaccharides containing multiple amino groups; More preferably, the modified polymer polysaccharide is selected from any one or more of amino-modified polymer polysaccharides and thiol-modified polymer polysaccharides; more preferably, the polymer polysaccharide is selected from any one or more of cellulose, starch, agar, carrageenan, chitosan, xanthan gum, and trehalose; Preferably, the mass concentration of the negatively charged active epoxy zwitterionic copolymer in the medical anti-adhesion gel is not less than 30%; Preferably, the mass concentration of the additive is not higher than 5%.

6. A medical anti-adhesion peritoneal lavage fluid, characterized in that: The peritoneal lavage fluid comprises the negatively charged active epoxy zwitterionic copolymer according to any one of claims 1 to 2, or the negatively charged active epoxy zwitterionic copolymer prepared by the preparation method according to claim 3, or the active polymer liquid material according to claim 4, and at least one second dispersant; the mass concentration of the negatively charged active epoxy zwitterionic copolymer in the peritoneal lavage fluid is greater than 0.1% and less than 15%; preferably, the mass concentration of the negatively charged active epoxy zwitterionic copolymer in the peritoneal lavage fluid is ≥1% and ≤5%; Preferably, the second dispersant is selected from any one of sterile purified water, sterile sodium chloride solution, and sterile Ringer's solution.

7. A polymer antifouling coating for medical devices, characterized in that: The polymer antifouling coating comprises the negatively charged active epoxy zwitterionic copolymer according to any one of claims 1 to 2, or comprises the negatively charged active epoxy zwitterionic copolymer prepared by the preparation method according to claim 3, or comprises the active polymer liquid material according to claim 4; Preferably, the polymer antifouling coating further comprises at least one adhesive and at least one catalyst; the mass concentration of the Lewis base catalyst is 0.1%-9% of the zwitterionic copolymer; Preferably, the adhesive is selected from any one or more of polymethoxysilane, polyethoxysilane, dopamine, dopamine derivatives, long-chain alkanes, cyclic alkanes, and adamantane containing amino or mercapto groups; Preferably, the catalyst is a Lewis base catalyst; more preferably, the Lewis base catalyst is selected from any one or more of triethylamine, pyridine, and 1,4-diazabicyclo[2.2.2]octane.

8. The polymer antifouling coating according to claim 7, characterized in that: The preparation method of the polymer antifouling coating is as follows: the active polymer liquid material and the catalyst are made into a diluted aqueous solution, and then a medical device with an adhesive on its surface is immersed in the diluted aqueous solution; the medical device with an adhesive on its surface is prepared by forming a continuous interface between the adhesive and the surface of the medical device through a silane self-assembly method, a physical adsorption method, or a chemical adsorption method.

9. An amphiphilic zwitterionic polymer material, characterized in that: The amphiphilic zwitterionic polymer material comprises the negatively charged active epoxy zwitterionic copolymer described in any one of claims 1-2 or the negatively charged active epoxy zwitterionic copolymer prepared by the preparation method described in claim 3, and the negatively charged active epoxy zwitterionic copolymer can undergo addition reaction with hydrophobic molecules.

10. The amphiphilic zwitterionic polymer material according to claim 9, characterized in that The hydrophobic molecules are selected from any one or more of long-chain alkanes with amino or mercapto terminal groups, cyclic alkanes (4-aminobenzophenone), adamantane, siloxane, and alkoxysilane.

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