Highly deformable porous hydrogel for postoperative abdominal tissue effusion drainage

Abstract

The application discloses a kind of high-strength deformable porous hydrogel for postoperative abdominal cavity tissue effusion drainage, belong to medical porous hydrogel technical field, specifically related to monomer, crosslinking agent and initiator are added to water and mixed to obtain the reaction solution of temperature-sensitive hydrogel, freeze polymerization obtains ice gel;Ice gel is placed in salt solution and is handled to obtain porous hydrogel;Monomer includes at least one of N-isopropyl acrylamide, N-vinyl caprolactam, N,N-diethyl acrylamide, N-vinyl carbazole, acrylic acid, methyl methacrylate, ethylene glycol methyl ether acrylate, butyl methacrylate, maleic anhydride and styrene.The application provides a kind of temperature-sensitive effect, can be dynamically controlled by electric heating, good mechanical property, good drainage effect high-strength deformable porous hydrogel for postoperative abdominal cavity tissue effusion drainage.

Description

Technical Field

[0001] This invention belongs to the field of medical porous hydrogel technology, specifically relating to a high-strength deformable porous hydrogel for postoperative drainage of peritoneal effusion. Background Technology

[0002] Cancer is a serious disease affecting human survival. Surgical removal of tumor lesions is currently the primary treatment. However, postoperative complications consistently threaten the quality of life for patients. Among these, the accumulation of peritoneal fluid due to organ fistulas (pancreatic fistula, intestinal fistula, etc.) is a significant cause of serious complications and even death, with an incidence rate as high as 30%. Postoperative drainage of tissue fluid is an important method to reduce or eliminate this risk. This involves implanting a drainage tube in a fixed position during surgery to continuously guide tissue fluid out of the body.

[0003] Based on literature reports and clinical practice, the materials used for postoperative drainage tubes mainly include latex, silicone, and polyurethane. Latex tubes have good elasticity and extensibility, and are soft in texture; however, they are easily compressed and close, requiring manual perforation on the side to improve drainage efficiency. Silicone tubes have high rigidity, forming a strong and stable drainage tract that is not easily blocked, but prolonged placement can compress the intestines, leading to intestinal fistulas. Polyurethane, on the other hand, has excellent elasticity and fatigue resistance, maintaining patency of the lumen for a long time, making it suitable for high negative pressure drainage, but it is expensive and difficult to mold. Furthermore, due to changes in body position, exudate is generally diffusely distributed, and the location of exudate changes dynamically, making it impossible to effectively drain from a fixed drainage location and achieve the desired effect. Precise and efficient drainage is a significant challenge in postoperative care, and the key lies in developing suitable functional drainage tubes.

[0004] Porous hydrogels possess a hydrophilic network structure, exhibiting excellent biocompatibility and efficient absorption of tissue fluid. Their internal pores also provide channels for fluid transport. Furthermore, hydrogels demonstrate high environmental sensitivity, capable of shape changes under controlled external environments, offering a novel material platform for postoperative drainage tube design. Existing methods for preparing porous hydrogels include phase separation, in-situ foaming, template methods, and 3D printing. Phase separation utilizes the phase separation of the hydrogel from water molecules during polymerization to create pores, but this method has high system requirements and often produces hydrogels with small pore sizes and low porosity. In-situ foaming relies on gas generation and solidification during polymerization to achieve pore formation, making the process difficult to control and resulting in hydrogels with poor mechanical strength. Template methods involve adding a template agent to the hydrogel reaction solution and removing it after polymerization, resulting in numerous steps and significant waste liquid generation. 3D printing utilizes computer-controlled layer-by-layer polymerization to create pores, offering high design flexibility but low molding efficiency and limiting its application to millimeter-scale pores. The recently developed ice-templating method utilizes ice crystals as pore-forming agents, initiating polymerization under freezing conditions to obtain porous hydrogels. The entire process is environmentally friendly and offers strong control over the porous structure. However, using porous hydrogels as drainage channels presents challenges related to their mechanical strength. The recently developed salting-out method based on the Hoffmann effect can improve the mechanical properties of hydrogels by promoting molecular chain aggregation, providing a feasible mechanism for enhancing the mechanical properties of porous materials.

[0005] Overall, existing postoperative drainage materials are limited by low drainage efficiency, easy blockage, and inability to dynamically adjust the drainage position. Summary of the Invention

[0006] To address the above problems, this invention discloses a drainage tube material based on a smart-responsive porous hydrogel. This invention utilizes a freeze-polymerization process to fabricate an oriented porous structure through the directional growth of ice crystals, improving mass transfer efficiency. Simultaneously, molecular salting-out further enhances the material's mechanical properties, achieving stable drainage. Furthermore, based on its temperature-sensitive structure design, the porous hydrogel undergoes reversible volume changes under temperature stimulation, which can be further dynamically controlled via electrothermal adjustment to achieve real-time adjustment of the drainage position. The porous hydrogel prepared by this invention can serve as a drainage tube for efficient and intelligent drainage, promoting precise postoperative care and reducing the incidence of complications.

[0007] The purpose of this invention is to provide a high-strength deformable porous hydrogel with temperature-sensitive properties, dynamic control via electrothermal heating, good mechanical properties, and good drainage effect for postoperative peritoneal fluid drainage.

[0008] The technical solution adopted by the present invention to achieve the above objectives is as follows:

[0009] A method for preparing a porous hydrogel for postoperative drainage includes: mixing a monomer, a crosslinking agent, and an initiator in water to obtain a reaction solution for a temperature-sensitive hydrogel; freeze-polymerizing the mixture to obtain an ice gel; and treating the ice gel in a salting-out solution to obtain a porous hydrogel. The monomer includes at least one of N-isopropylacrylamide, N-vinylcaprolactam, N,N-diethylacrylamide, N-vinylcarbazole, acrylic acid, methyl methacrylate, ethylene glycol methyl ether acrylate, butyl methacrylate, maleic anhydride, and styrene. Under low-temperature freezing conditions, the freezing of water repels the contained reactants, leaving the monomer, crosslinking agent, and initiator in the gaps between ice crystals. At this time, the polymer network formed by the initiated polymerization grows around the ice crystals in a low-energy state. When the ice crystals melt, the areas where ice crystals originally grew become porous. During the process, the polymerized ice gel in a frozen state is directly immersed in a salt solution. The salting-out effect further triggers the aggregation of the formed polymer chains, and after the ice crystals melt, a porous hydrogel with high mechanical strength is obtained. Furthermore, due to the use of a temperature-sensitive monomer design, the hydrogel will exhibit volume changes triggered by temperature, and its deformation behavior can be dynamically controlled by a composite electrothermal device, meeting the needs for efficient and precise drainage of postoperative peritoneal effusion.

[0010] Preferably, the monomer can be selected from one or more of N-isopropylacrylamide, N-vinylcaprolactam, N,N-diethylacrylamide, N-vinylcarbazole, etc.; it can also be achieved through a compounding of different monomers, with the system selected from one or more of acrylic acid and methyl methacrylate, ethylene glycol methyl ether acrylate and butyl methacrylate, maleic anhydride and styrene, etc. As a preferred option, monomer formulations with a sensitive temperature of around 40°C, such as N-isopropylacrylamide, acrylic acid and methyl methacrylate, can be selected.

[0011] Preferably, the monomers further include ethylene glycol methyl ether acrylate and γ-methacryloyloxypropyltrimethoxysilane. In the preparation of porous hydrogels using N-vinylcaprolactam and methylenebisacrylamide, the combined use of ethylene glycol methyl ether acrylate and γ-methacryloyloxypropyltrimethoxysilane improves the temperature-dependent properties of the porous hydrogel and enhances its drainage effect.

[0012] Preferably, the crosslinking agent includes at least one of N,N-methylenebisacrylcysteine, N,N-methylenebisacrylamide, and polyethylene glycol diacrylate. The crosslinking agent can be selected from one or more of N,N-methylenebisacrylcysteine, N,N-methylenebisacrylamide, and polyethylene glycol diacrylate, and preferably, N,N-methylenebisacrylamide can be selected.

[0013] Preferably, the initiator includes a photoinitiator or a thermal initiator; the photoinitiator includes at least one selected from 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone, phenyl-2,4,6-trimethylbenzoyl phosphite lithium salt, and riboflavin; the thermal initiator includes at least one selected from the ammonium persulfate-tetramethylethylenediamine system, the potassium persulfate-ferrous sulfate system, and the hydrogen peroxide-horseradish peroxidase system. The initiator can be selected from molecules that satisfy low-temperature initiation polymerization, including photoinitiators and thermal initiators; furthermore, the photoinitiator can be selected from one or more selected from 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone, phenyl-2,4,6-trimethylbenzoyl phosphite lithium salt, riboflavin, etc.; the thermal initiator can be selected from one or more selected from the system composed of ammonium persulfate and N,N,N',N'-tetramethylethylenediamine, potassium persulfate and ferrous sulfate, hydrogen peroxide and horseradish peroxidase, etc. Preferably, 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone can be selected as the photoinitiator, and ammonium persulfate and N,N,N',N'-tetramethylethylenediamine can be selected as the thermal initiation system.

[0014] More preferably, the photoinitiator initiates the photoinitiator at a light source wavelength of 200-700 nm.

[0015] More preferably, the photoinitiator has a photoinitiator irradiation time of 30s-24h; and the thermal initiator has a reaction time of 12-120h.

[0016] Preferably, in the freeze polymerization, the freezing temperature is between -120°C and -10°C.

[0017] Preferably, the salting-out solution includes at least one of an aqueous solution of sodium citrate, an aqueous solution of sodium sulfate, and an aqueous solution of ammonium sulfate.

[0018] Preferably, a polymer exhibiting salting-out behavior may be added to the reaction solution. The polymer may be selected from at least one of polyvinyl alcohol, polyvinylpyrrolidone, and gelatin. Additional polymers exhibiting salting-out behavior, including one or more of polyvinyl alcohol, polyvinylpyrrolidone, and gelatin, may be added to the reaction solution; polyvinyl alcohol is preferred.

[0019] Preferably, the freezing method employs directional freezing, and the process can be either direct freezing from a cold stage or slow immersion in a cryogenic medium. Preferably, the slow immersion in a cryogenic medium process can be selected to accommodate the fabrication of larger drainage tubes.

[0020] Preferably, the concentration of the salting-out solution is 0.1-10 mol / L, and the treatment temperature of the salting-out solution is 20-40℃. More preferably, the concentration of the salting-out solution can be selected from 1-3 mol / L.

[0021] Preferably, as salting out occurs, the ice gel also melts, forming a porous hydrogel.

[0022] In this invention, the porous hydrogel has high mechanical strength, oriented pore structure, and temperature sensitivity.

[0023] Preferably, increasing the temperature causes the hydrogel to shrink in volume, and decreasing the temperature causes the hydrogel to recover its volume.

[0024] Preferably, heating wires can be composited around the hydrogel, and the deformation behavior can be adjusted by regional shrinkage under electrical control.

[0025] Preferably, a heating wire is composited around the porous hydrogel.

[0026] This invention discloses the porous hydrogel prepared by the above method.

[0027] In this invention, a high-strength deformable porous hydrogel can be used as a drainage tube for postoperative peritoneal tissue effusion, enabling real-time adjustment of the drainage position and efficient drainage.

[0028] Preferably, in the preparation of the porous hydrogel, PVA is added to deionized water to prepare a PVA aqueous solution, then isopropylacrylamide and methylenebisacrylamide are added and mixed, then ammonium persulfate is added, and tetramethylethylenediamine is added and mixed at a temperature of 0-10°C. Then, the mixture is frozen in a mold, and the frozen material is salted out in a sodium sulfate aqueous solution at 20-40°C for 24-96 hours. The material after salting out is the porous hydrogel, which is then stored in PBS aqueous solution.

[0029] More preferably, in the preparation of porous hydrogels, the amount of PVA used is 3-15 wt% of deionized water.

[0030] More preferably, in the preparation of porous hydrogels, the amount of isopropylacrylamide used is 100-300 wt% of PVA.

[0031] More preferably, in the preparation of porous hydrogels, the amount of methylenebisacrylamide used is 0.1-5 wt% of isopropylacrylamide.

[0032] More preferably, in the preparation of porous hydrogels, the amount of ammonium persulfate used is 0.1-10 wt% of isopropylacrylamide.

[0033] More preferably, in the preparation of porous hydrogels, the amount of tetramethylethylenediamine used is 0.5-4 wt% of isopropylacrylamide.

[0034] More preferably, in the preparation of porous hydrogels, the sodium sulfate content in the sodium sulfate aqueous solution is 0.1-10 mol / L.

[0035] More preferably, in the preparation of porous hydrogels, the freezing treatment is first performed at -60°C to -40°C for 6-24 hours, and then at -30°C to -10°C for 6-24 hours.

[0036] Preferably, in the preparation of the porous hydrogel, PVA is added to deionized water to prepare a PVA aqueous solution, then N-vinylcaprolactam and methylenebisacrylamide are added and mixed, then 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone is added, and then the material is frozen in a mold. The frozen material is then irradiated under ultraviolet light for 2-8 hours, and then salted out in sodium citrate aqueous solution at 20-40℃ for 24-96 hours. The material after salting out is the porous hydrogel, which is stored in PBS aqueous solution.

[0037] More preferably, in the preparation of porous hydrogels, the amount of PVA used is 3-15 wt% of deionized water.

[0038] More preferably, in the preparation of porous hydrogels, the amount of N-vinylcaprolactam used is 100-300 wt% of PVA.

[0039] More preferably, in the preparation of porous hydrogels, the amount of methylenebisacrylamide used is 0.1-5 wt% of N-vinylcaprolactam.

[0040] More preferably, in the preparation of the porous hydrogel, the amount of 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone used is 0.1-10 wt% of N-vinylcaprolactam.

[0041] More preferably, in the preparation of porous hydrogels, the sodium citrate content in the sodium citrate aqueous solution is 0.1-10 mol / L.

[0042] More preferably, in the preparation of porous hydrogels, the wavelength of ultraviolet light is 365 nm.

[0043] More preferably, in the preparation of porous hydrogels, the freezing process involves first treating the gel at -100°C to -80°C for 6-24 hours.

[0044] More preferably, ethylene glycol methyl ether acrylate can be added during the preparation of the porous hydrogel, and the amount of ethylene glycol methyl ether acrylate used is 0.1-1 wt% of N-vinylcaprolactam.

[0045] More preferably, γ-methacryloxypropyltrimethoxysilane can be added during the preparation of the porous hydrogel, wherein the amount of γ-methacryloxypropyltrimethoxysilane used is 0.1-1 wt% of N-vinylcaprolactam.

[0046] More preferably, N-vinylcarbazole can be added during the preparation of the porous hydrogel, and the amount of N-vinylcarbazole used is 0.1-0.6 wt% of N-vinylcaprolactam. In the preparation of the porous hydrogel using N-vinylcaprolactam and methylenebisacrylamide, ethylene glycol methyl ether acrylate, γ-methacryloyloxypropyltrimethoxysilane, and N-vinylcarbazole can also be added together. The combined use of ethylene glycol methyl ether acrylate, γ-methacryloyloxypropyltrimethoxysilane, and N-vinylcarbazole further improves the performance of the porous hydrogel as a function of temperature change and enhances its drainage effect.

[0047] Preferably, in the preparation of the porous hydrogel, PVA is added to deionized water to prepare a PVA aqueous solution, then isopropylacrylamide and methylenebisacrylamide are added and mixed, then phenyl-2,4,6-trimethylbenzoyl lithium phosphite is added, and then the mixture is placed in a mold. The mold is then immersed in ethanol at -60°C to -40°C for freezing. After freezing, the material is irradiated under blue light for 2-8 hours, and then salted out in sodium sulfate aqueous solution at 20-40°C for 24-96 hours. The material after salting out is the porous hydrogel, which is then stored in PBS aqueous solution.

[0048] More preferably, in the preparation of porous hydrogels, the amount of PVA used is 3-15 wt% of deionized water.

[0049] More preferably, in the preparation of porous hydrogels, the amount of isopropylacrylamide used is 100-300 wt% of PVA.

[0050] More preferably, in the preparation of porous hydrogels, the amount of methylenebisacrylamide used is 0.1-5 wt% of isopropylacrylamide.

[0051] More preferably, in the preparation of the porous hydrogel, the amount of phenyl-2,4,6-trimethylbenzoyl lithium phosphite used is 0.1-10 wt% of isopropylacrylamide.

[0052] More preferably, in the preparation of porous hydrogels, the sodium sulfate content in the sodium sulfate aqueous solution is 0.1-10 mol / L.

[0053] More preferably, in the preparation of the porous hydrogel, the wavelength of blue light is 405 nm. In the freezing treatment, the freezing time is 6-24 hours.

[0054] This invention employs a temperature-sensitive hydrogel reaction solution to achieve the pore-forming process under an ice template. Based on this, the pore structure is controlled by adjusting the ice template process, thereby improving drainage efficiency. Simultaneously, the introduction of the salting-out effect further enriches the polymer on the pore walls, increasing strength and meeting the mechanical performance requirements for in vivo applications. Furthermore, electrothermal control enables the material to deform as needed under external field control, demonstrating its application value in precise drainage.

[0055] Compared with existing technologies, the advantages of this invention are as follows: The porous hydrogel in this invention is prepared using an ice-templating process, which is environmentally friendly. Simultaneously, its oriented pore structure enhances internal mass transfer processes, reduces flow resistance, and strengthens tissue fluid drainage. The porous hydrogel manufactured in this invention can further improve its mechanical strength through the salting-out effect, making it more stable for use in organisms and reducing immune responses and drainage failures caused by material fragmentation. Unlike traditional drainage tubes that cannot change the drainage position, the porous hydrogel prepared in this invention has temperature-triggered volume shrinkage properties, allowing for the introduction of electrothermal devices to achieve on-demand control of deformation behavior, thereby changing the drainage position in real time during drainage and achieving high-precision drainage. Therefore, this invention is a temperature-sensitive, electrothermally controllable, mechanically sound, and highly effective high-strength deformable porous hydrogel for postoperative peritoneal effusion drainage. Attached Figure Description

[0056] Figure 1 This is a laser confocal micrograph of the porous hydrogel prepared in Example 1.

[0057] Figure 2 This is a scanning electron microscope image of the porous hydrogel prepared in Example 2.

[0058] Figure 3 This is a laser confocal micrograph of the porous hydrogel prepared in Example 3.

[0059] Figure 4 This is a tensile test diagram of a porous hydrogel.

[0060] Figure 5 This is a diagram of a device for testing the effectiveness of external drainage.

[0061] Figure 6 This is a diagram of a porous hydrogel device controlled by electrothermal heating. Detailed Implementation

[0062] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0063] The concepts involved in this application will first be described with reference to the accompanying drawings. It should be noted that the following descriptions of various concepts are only for the purpose of making the content of this application easier to understand and do not constitute a limitation on the scope of protection of this application; furthermore, the embodiments and features in the embodiments of this application can be combined with each other unless otherwise specified. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0064] Example 1: A method for preparing a porous hydrogel

[0065] Preparation of porous hydrogel: PVA was added to deionized water to prepare a PVA aqueous solution. Isopropylacrylamide and methylenebisacrylamide were then added and mixed, followed by ammonium persulfate. Tetramethylethylenediamine was then added at 4°C and mixed. The mixture was then frozen in a mold. The frozen material was then salted out in a sodium sulfate aqueous solution at 25°C for 72 hours. The salted-out material was the porous hydrogel, which was stored in PBS aqueous solution. The amount of PVA used was 10 wt% of deionized water, the amount of isopropylacrylamide was 200 wt% of PVA, the amount of methylenebisacrylamide was 1 wt% of isopropylacrylamide, the amount of ammonium persulfate was 0.8 wt% of isopropylacrylamide, the amount of tetramethylethylenediamine was 2 wt% of isopropylacrylamide, and the sodium sulfate aqueous solution contained 2 mol / L sodium sulfate. For the freezing treatment, the mixture was first treated at -50°C for 12 hours, and then at -20°C for 24 hours.

[0066] Example 2: A method for preparing a porous hydrogel

[0067] Preparation of porous hydrogel: PVA was added to deionized water to prepare PVA aqueous solution, then N-vinylcaprolactam and methylenebisacrylamide were added and mixed, then 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone was added, and then the mixture was frozen in a mold. The frozen material was then irradiated under ultraviolet light for 4 hours, and then salted out in sodium citrate aqueous solution at 25℃ for 48 hours. The material after salting out was the porous hydrogel, which was stored in PBS aqueous solution.

[0068] The amount of PVA used was 5 wt% of deionized water, N-vinylcaprolactam was 200 wt% of PVA, methylenebisacrylamide was 0.5 wt% of N-vinylcaprolactam, 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone was 5 wt% of N-vinylcaprolactam, and the sodium citrate concentration in the sodium citrate aqueous solution was 1.5 mol / L. The wavelength of ultraviolet light was 365 nm. For the freezing treatment, it was first treated at -90°C for 24 hours.

[0069] Example 3: A method for preparing a porous hydrogel

[0070] Preparation of porous hydrogel: PVA was added to deionized water to prepare PVA aqueous solution, then isopropylacrylamide and methylenebisacrylamide were added and mixed, followed by phenyl-2,4,6-trimethylbenzoyl phosphite lithium salt, and then placed in a mold. The mold was immersed in ethanol at -50°C for freezing treatment. After freezing, the material was irradiated under blue light for 3 hours, and then salted out in sodium sulfate aqueous solution at 25°C for 72 hours. The material after salting out treatment is the porous hydrogel, which is stored in PBS aqueous solution.

[0071] The amount of PVA used was 10 wt% of deionized water, isopropylacrylamide was 200 wt% of PVA, methylenebisacrylamide was 1 wt% of isopropylacrylamide, phenyl-2,4,6-trimethylbenzoyl lithium phosphite was 10 wt% of isopropylacrylamide, and the sodium sulfate solution contained 2 mol / L of sodium sulfate. The wavelength of blue light was 405 nm. The freezing time was 24 h.

[0072] Example 4: A method for preparing a porous hydrogel

[0073] Preparation of porous hydrogel: PVA aqueous solution was prepared by adding PVA to deionized water. Then, N-vinylcaprolactam, ethylene glycol methyl ether acrylate, γ-methacryloyloxypropyltrimethoxysilane and methylenebisacrylamide were added and mixed. Then, 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone was added. The mixture was then frozen in a mold. After freezing, the material was irradiated under ultraviolet light for 4 hours and then salted out in sodium citrate aqueous solution at 25°C for 48 hours. The material after salting out was the porous hydrogel. The porous hydrogel was stored in PBS aqueous solution.

[0074] The dosage of PVA was 5 wt% of deionized water, N-vinylcaprolactam was 200 wt% of PVA, ethylene glycol methyl ether acrylate was 0.8 wt% of N-vinylcaprolactam, γ-methacryloyloxypropyltrimethoxysilane was 0.8 wt% of N-vinylcaprolactam, methylenebisacrylamide was 0.5 wt% of N-vinylcaprolactam, 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone was 5 wt% of N-vinylcaprolactam, and the sodium citrate aqueous solution contained 1.5 mol / L of sodium citrate. The wavelength of ultraviolet light was 365 nm. In the freezing treatment, the solution was first treated at -90°C for 24 hours.

[0075] Example 5: A method for preparing a porous hydrogel

[0076] The difference between this embodiment and Example 4 is that the amount of ethylene glycol methyl ether acrylate used is 0.3 wt% of N-vinylcaprolactam, and the amount of γ-methacryloyloxypropyltrimethoxysilane used is 0.3 wt% of N-vinylcaprolactam.

[0077] Example 6: A method for preparing a porous hydrogel

[0078] Preparation of porous hydrogel: PVA aqueous solution was prepared by adding PVA to deionized water. Then, N-vinylcaprolactam, ethylene glycol methyl ether acrylate, γ-methacryloyloxypropyltrimethoxysilane, N-vinylcarbazole and methylenebisacrylamide were added and mixed. Then, 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone was added. The mixture was then frozen in a mold. After freezing, the material was irradiated under ultraviolet light for 4 hours and then salted out in sodium citrate aqueous solution at 25°C for 48 hours. The material after salting out was the porous hydrogel. The porous hydrogel was stored in PBS aqueous solution.

[0079] The dosage of PVA was 5 wt% of deionized water, N-vinylcaprolactam was 200 wt% of PVA, ethylene glycol methyl ether acrylate was 0.8 wt% of N-vinylcaprolactam, γ-methacryloyloxypropyltrimethoxysilane was 0.8 wt% of N-vinylcaprolactam, N-vinylcarbazole was 0.5 wt% of N-vinylcaprolactam, methylenebisacrylamide was 0.5 wt% of N-vinylcaprolactam, 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone was 5 wt% of N-vinylcaprolactam, and the sodium citrate aqueous solution contained 1.5 mol / L of sodium citrate. The wavelength of ultraviolet light was 365 nm. In the freezing treatment, the solution was first treated at -90°C for 24 hours.

[0080] Example 7: A method for preparing a porous hydrogel

[0081] The difference between this embodiment and Example 6 is that the amount of ethylene glycol methyl ether acrylate used is 0.8 wt% of N-vinylcaprolactam, the amount of γ-methacryloyloxypropyltrimethoxysilane used is 0.8 wt% of N-vinylcaprolactam, and the amount of N-vinylcarbazole used is 0.2 wt% of N-vinylcaprolactam.

[0082] Comparative Example 1: A method for preparing a porous hydrogel

[0083] The difference between this comparative example and Example 4 lies in the preparation of the porous hydrogel; ethylene glycol methyl ether acrylate was not added during the preparation of the porous hydrogel.

[0084] Comparative Example 2: A method for preparing a porous hydrogel

[0085] The difference between this comparative example and Example 4 lies in the preparation of the porous hydrogel; γ-methacryloyloxypropyltrimethoxysilane was not added during the preparation of the porous hydrogel.

[0086] Comparative Example 3: A method for preparing a porous hydrogel

[0087] The difference between this comparative example and Example 4 lies in the preparation of the porous hydrogel. In the preparation of the porous hydrogel, the amount of ethylene glycol methyl ether acrylate used is 0.05 wt% of N-vinylcaprolactam, and the amount of γ-methacryloyloxypropyltrimethoxysilane used is 0.05 wt% of N-vinylcaprolactam.

[0088] Experimental example:

[0089] The porous hydrogel prepared in Example 1 was characterized using laser confocal microscopy, and the results are as follows: Figure 1 As shown.

[0090] The porous hydrogel prepared in Example 2 was characterized using scanning electron microscopy, and the results are as follows: Figure 2 As shown.

[0091] The porous hydrogel prepared in Example 3 was characterized using laser confocal microscopy, and the results are as follows: Figure 3 As shown.

[0092] The porous hydrogels prepared in Examples 1-3 were subjected to tensile tests, and the results are as follows: Figure 4 As shown.

[0093] The present invention statistically analyzed the volume changes of porous hydrogels prepared in each embodiment and comparative example at different temperatures, and the results are shown in Table 1.

[0094] Table 1. Volume changes of porous hydrogels at different temperatures

[0095]

[0096] This invention involves mixing monomers, crosslinking agents, and initiators in water to obtain a reaction solution for a temperature-sensitive hydrogel, followed by freeze polymerization to obtain an ice gel. The ice gel is then treated in a salting-out solution to obtain a porous hydrogel. The monomers include at least one of N-isopropylacrylamide, N-vinylcaprolactam, N,N-diethylacrylamide, N-vinylcarbazole, acrylic acid, methyl methacrylate, ethylene glycol methyl ether acrylate, butyl methacrylate, maleic anhydride, and styrene. The crosslinking agent includes at least one of N,N-methylenebisacrylamide, N,N-methylenebisacrylamide, and polyethylene glycol diacrylate. The initiator includes a photoinitiator or a thermal initiator. The porous hydrogel prepared by this invention exhibits good temperature-dependent properties. This invention can be prepared using N-isopropylacrylamide and methylenebisacrylamide, or N-vinylcaprolactam and methylenebisacrylamide. A porous hydrogel with good temperature-dependent properties was obtained. When using N-vinylcaprolactam and methylenebisacrylamide, ethylene glycol methyl ether acrylate and γ-methacryloxypropyltrimethoxysilane can be added to prepare the porous hydrogel, further enhancing its temperature-dependent properties. The use of ethylene glycol methyl ether acrylate or γ-methacryloxypropyltrimethoxysilane requires specific dosages and simultaneous use of both to improve the temperature-dependent properties. This invention further discovers that using ethylene glycol methyl ether acrylate, γ-methacryloxypropyltrimethoxysilane, and N-vinylcarbazole in the preparation of the porous hydrogel can further improve its temperature-dependent properties.

[0097] This invention designs an in vitro drainage effect testing device for porous hydrogels, the device as follows: Figure 5 As shown, a porous hydrogel was immersed in simulated tissue exudate, and drainage was performed under the action of an external peristaltic pump. The drainage volume of simulated tissue fluid per unit time was tested under different pressure drops formed by the peristaltic pump, thus realizing the construction and evaluation of an in vitro drainage test model.

[0098] This invention is based on Figure 5 The apparatus shown was used to test the porous hydrogels prepared in each embodiment and comparative example. The statistical results of the unit drainage mass under different pressure differences are shown in Table 2.

[0099] Table 2 Statistical Results of Drainage Quality per Unit

[0100]

[0101] This invention involves mixing monomers, crosslinking agents, and initiators in water to obtain a reaction solution for a temperature-sensitive hydrogel, followed by freeze polymerization to obtain an ice gel. The ice gel is then treated in a salting-out solution to obtain a porous hydrogel. The monomers include at least one of N-isopropylacrylamide, N-vinylcaprolactam, N,N-diethylacrylamide, N-vinylcarbazole, acrylic acid, methyl methacrylate, ethylene glycol methyl ether acrylate, butyl methacrylate, maleic anhydride, and styrene. The crosslinking agent includes at least one of N,N-methylenebisacrylamide, N,N-methylenebisacrylamide, and polyethylene glycol diacrylate. The initiator includes a photoinitiator or a thermal initiator. The porous hydrogel prepared by this invention exhibits good drainage properties. This invention can utilize N-isopropylacrylamide and methylenebisacrylamide, N-vinylcaprolactam and methylenebisacrylamide... Acrylamide is used to prepare porous hydrogels, which exhibit good drainage effects. When using N-vinylcaprolactam and methylenebisacrylamide, ethylene glycol methyl ether acrylate and γ-methacryloxypropyltrimethoxysilane can be added to further enhance the drainage effect. The use of ethylene glycol methyl ether acrylate or γ-methacryloxypropyltrimethoxysilane requires specific dosages and simultaneous use of both to improve the drainage effect. This invention further discovers that using ethylene glycol methyl ether acrylate, γ-methacryloxypropyltrimethoxysilane, and N-vinylcarbazole in the preparation of porous hydrogels can further improve the drainage effect.

[0102] This invention designs an electrothermally controlled porous hydrogel device, and the results are as follows: Figure 6 As shown, heating wires are embedded in four directions on the side of the hydrogel and ultimately connected to a control device. The heating wire on the energized side generates heat, inducing the area to shrink and deform towards that side. When the electrical energy is removed, the hydrogel absorbs water and expands, returning to its original shape. By dynamically controlling the on / off state of the external circuit, the deformation behavior of the hydrogel can be realized and further adjusted. The porous hydrogel includes the porous hydrogel prepared by any of the methods in Examples 1-7.

[0103] Under ultrasound guidance, the porous hydrogel of Example 3 was implanted into the location requiring drainage and fixed in vitro. The drainage rate was tested under three modes: no pressure, intraperitoneal pressure, and external drainage pressure. The drainage effect was evaluated, and the changes in drainage effect over time were recorded. The changes in drainage rate over time under different conditions are shown in Table 3.

[0104] Table 3 Results of changes in the drainage rate of porous hydrogels

[0105]

[0106] This invention utilizes Figure 5 The device shown uses a porous hydrogel with externally controllable deformation behavior, which serves as a drainage tube. Under ultrasound guidance, it is implanted at the desired drainage location, utilizing the negative pressure inherent in the body for drainage. The drainage effect is evaluated. Simultaneously, under electric field control, the shape of the hydrogel is changed, thereby altering the drainage location and draining tissue fluid from another location. During this dynamic control process, the drainage rate and volume are characterized, further demonstrating the alteration of the material's drainage behavior under dynamic control.

[0107] The embodiments and / or implementation methods described above are merely preferred embodiments and / or implementation methods for implementing the technology of the present invention, and are not intended to limit the implementation methods of the technology of the present invention in any way. Any person skilled in the art can make some modifications or alterations to other equivalent embodiments without departing from the scope of the technical means disclosed in the content of the present invention, but they should still be regarded as the technology or embodiments that are substantially the same as the present invention.

[0108] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. The above descriptions are only preferred embodiments of this application. It should be noted that due to the limitations of written expression, while there are objectively infinite specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of this application, and can also combine the above technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered within the scope of protection of this application.

Claims

1. A porous hydrogel for postoperative drainage, characterized in that, include: The monomer, crosslinking agent, and initiator are added to water and mixed to obtain a reaction solution for a temperature-sensitive hydrogel. Freeze polymerization is then carried out to obtain an ice gel. The ice gel is then treated in a salting-out solution to obtain a porous hydrogel. The monomer includes at least one of N-isopropylacrylamide and N-vinylcaprolactam; the salting-out solution includes at least one of sodium citrate aqueous solution, sodium sulfate aqueous solution, and ammonium sulfate aqueous solution. Polyvinyl alcohol, which exhibits salting-out behavior, is added to the reaction solution, with the amount of polyvinyl alcohol used being 3-15 wt% of water. The amount of the monomer used is 100-300 wt% of polyvinyl alcohol. In the aforementioned freeze polymerization, the freezing temperature is between -120°C and -10°C; The freezing method employs directional freezing, specifically direct freezing on a cold table or slow immersion in a low-temperature medium; The concentration of the salting-out solution is 0.1-10 mol / L, and the treatment temperature of the salting-out solution is 20-40℃; The crosslinking agent is N,N-methylenebisacrylamide, and the amount of the crosslinking agent used is 0.5-1 wt% of the monomer. The porous hydrogel is surrounded by composite heating wires.

2. The porous hydrogel for postoperative drainage according to claim 1, characterized in that, The initiator includes a photoinitiator or a thermal initiator; the photoinitiator includes at least one of 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone, phenyl-2,4,6-trimethylbenzoyl lithium phosphite, and riboflavin; the thermal initiator includes at least one of the following: ammonium persulfate-tetramethylethylenediamine system, potassium persulfate-ferrous sulfate system, and hydrogen peroxide-horseradish peroxidase system.

3. The porous hydrogel for postoperative drainage according to claim 2, characterized in that, The photoinitiator is activated at a light source wavelength of 200-700 nm.

4. The porous hydrogel for postoperative drainage according to claim 2, characterized in that, The photoinitiator is exposed to light for 30 seconds to 24 hours; the thermal initiator is exposed to light for 12 to 120 hours.

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