Spiral nasointestinal tube material and preparation process thereof

Abstract

The invention provides a spiral nasointestinal tube material and a preparation process thereof, and the spiral nasointestinal tube material comprises the following components by mass: 45-68 parts of a modified polyurethane prepolymer, 18-32 parts of a carboxymethyl chitosan grafted silicone rubber compound, 6-12 parts of a nano hydroxyapatite and titanium dioxide composite developer, 1.5-4 parts of a polyethylene glycol plasticizer, and 4-9 parts of an antibacterial active component. Through innovative material modification and process design, carboxyl functional modification is introduced into a polyurethane matrix to improve the interface bonding force, the synergistic effect of a core-shell structure developing agent and an antibacterial compound system is combined, and the functional distribution of the pipe wall is optimized by utilizing a gradient forming process; meanwhile, the bonding strength of the coating is strengthened through plasma activation and ultraviolet crosslinking, the flexibility, the antibacterial durability, the developing definition and the crease resistance of the nasointestinal tube are finally comprehensively improved, the clinical indwelling period is prolonged, and the infection rate is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical polymer materials, and in particular relates to a spiral nasointestinal tube material and a preparation process thereof. Background Art

[0002] Spiral nasoenteric tubes are a core device for clinical enteral nutrition support. They need to be inserted into the patient's jejunum through the nasal cavity. Their function depends on the material's flexibility, biocompatibility, anti-infective properties, and durability for long-term placement. Currently, the mainstream materials are polyurethane or silicone rubber, but there are the following core issues in actual application: First, the material surface is easily adhered to proteins in intestinal secretions, forming a biofilm, breeding bacteria and causing catheter-related infections, increasing the patient's risk of sepsis; second, after long-term placement, repeated bending of the tube body can easily produce permanent creases, leading to lumen blockage and requiring secondary replacement; third, when the amount of developer required for X-ray development is too high, the material's elasticity is significantly reduced, affecting the success rate of tube placement and patient comfort; fourth, traditional spiral pattern molding relies on mold injection molding or 3D printing, which can easily lead to uneven tube wall thickness, increased inner wall roughness, and increased risk of liquid residue.

[0003] Among existing improvements, silver ion coatings can enhance antimicrobial properties, providing short-term bacterial suppression. However, the coating is prone to shedding and the silver ion release rate is uncontrollable, posing a risk of cytotoxicity with long-term use. While some solutions have improved elasticity by adjusting the silicone-polyurethane ratio to enhance crease resistance, they suffer from poor developer dispersion, leading to blurred imaging or localized stress concentrations. Another approach, using 3D printing to create spiral structures, suffers from printing precision limitations, resulting in wall thickness deviations of up to ±0.2 mm, impacting fluid flow efficiency.

[0004] Further analysis revealed the following unresolved challenges with existing technologies: The difficulty in balancing the sustained release of the antimicrobial agent with the elasticity of the material; insufficient interfacial bonding between the developer and the substrate, leading to particle shedding after long-term use; and low efficiency in the spiral structure molding process, with the inability to dynamically adjust the pitch. These issues directly impact the clinical lifespan and safety of nasointestinal tubes, necessitating breakthroughs through innovative material composition and process optimization. Therefore, it is necessary to design a spiral nasointestinal tube material and its preparation process. Summary of the Invention

[0005] In order to overcome the defects in the prior art, a spiral nasointestinal tube material and a preparation process thereof are provided.

[0006] In order to achieve the above object, the present invention provides the following technical solutions: A spiral nasointestinal tube material comprises the following components, measured by mass: 45-68 parts of a modified polyurethane prepolymer, 18-32 parts of a carboxymethyl chitosan grafted silicone rubber composite, 6-12 parts of a nano-hydroxyapatite and titanium dioxide composite developer, 1.5-4 parts of a polyethylene glycol plasticizer, and 4-9 parts of an antibacterial active ingredient.

[0007] The preparation method of the modified polyurethane prepolymer comprises the following steps: dissolving polyurethane particles in tetrahydrofuran to form a 25-35% w / v solution, adding 2-3.5% by weight of glycidyl methacrylate, reacting at 65-78° C. for 2.5-4 hours under nitrogen protection, centrifuging to remove unreacted monomers, and vacuum drying to obtain a carboxyl-functionalized modified polyurethane, namely the modified polyurethane prepolymer.

[0008] The addition of glycidyl methacrylate was completed in two steps: 60% of the total mass was added for the first time and reacted at 65-70° C. for 1 hour; the remaining 40% was added at 78° C. and reacted for 1.5-3 hours.

[0009] The preparation method of the carboxymethyl chitosan grafted silicone rubber composite comprises the following steps: first, dissolving epoxy group-containing silicone oil in deionized water to form a uniform dispersion; simultaneously, dissolving carboxymethyl chitosan in an alkaline aqueous phase and adjusting the pH value to 8.5-9.2; then, slowly mixing the epoxy group-containing silicone oil and carboxymethyl chitosan at a mass ratio of 7-9:1 under stirring conditions; heating the reaction system to 50-65° C., adding ammonium persulfate as a free radical initiator, and continuing the reaction for 3-5 hours under nitrogen protection to achieve graft polymerization; after the reaction is completed, removing unreacted free monomers by centrifugation, and then repeatedly washing the product with an ethanol-water mixed solvent to remove impurities; and finally, vacuum drying to obtain a carboxymethyl chitosan grafted silicone rubber composite with a grafting rate of 18%-26%.

[0010] The preparation method of the nano-hydroxyapatite and titanium dioxide composite developer is as follows: first, calcium nitrate and triethyl phosphate are dissolved in an ethanol aqueous solution at a Ca / P molar ratio of 1.67 to form a hydroxyapatite precursor sol; and tetrabutyl titanate and acetic acid are mixed and hydrolyzed at a molar ratio of 1:0.4-0.6 to form a titanium dioxide sol; The two were mixed dropwise at a molar ratio of hydroxyapatite to titanium dioxide of 1:0.4-0.6, and ammonia was added to adjust the pH value to 9.0-10.5. The mixture was stirred in a hydrothermal reactor at 110-130°C and pressurized to 0.2-0.4 MPa for 3-5 hours to allow heterogeneous nucleation and growth of hydroxyapatite nuclei on the surface of the titanium dioxide particles. After the reaction, the precipitate is obtained by centrifugal separation, washed with deionized water until neutral, placed in a programmable temperature-controlled furnace, heated to 450-550°C at a rate of 2-5°C / min, and calcined for 2-4 hours. The final product is processed by a jet mill to obtain a composite powder with a particle size of 80-130nm, in which the hydroxyapatite inside is coated on the surface of the titanium dioxide particles in the form of rod-shaped crystals, forming a core-shell structured nano-hydroxyapatite and titanium dioxide composite developer.

[0011] The antibacterial active ingredient is prepared by compounding silver-loaded mesoporous silica and zinc oxide nanorods in a mass ratio of 2.5-3.8:1.

[0012] The pore size of the silver-loaded mesoporous silica is 8-15 nm, and the silver loading is 4-7% w / w; the length of the zinc oxide nanorods is 250-450 nm, the diameter is 40-70 nm, and the thickness of the polydopamine layer coated on the surface is 10-30 nm.

[0013] A process for preparing a spiral nasointestinal tube material, the process comprising the following steps, calculated by weight: (a) adding 45-68 parts of modified polyurethane prepolymer and 18-32 parts of carboxymethyl chitosan grafted silicone rubber composite into an internal mixer and mixing at 125-138° C. for 18-22 minutes; (b) adding 6-12 parts of a composite developer of nano-hydroxyapatite and titanium dioxide and 4-9 parts of an antibacterial active ingredient to the rubber mixture, and treating the mixture with an ultrasonic dispersion device at a frequency of 40-60 kHz for 35-45 minutes; (c) The tube body is extruded using a three-layer co-extrusion machine, with the outer layer extrusion temperature at 172-180°C, the middle layer at 165-173°C, the inner layer at 155-168°C, and the die pressure at 8-12 MPa; (d) The extruded tube blank is subjected to a rotating pulling device to form a spiral pattern, the pulling rate is 9-11 m / min, and the ratio of the pulling roller speed to the extrusion rate is 1:2.8-3.5, thereby obtaining an original spiral nasointestinal tube material. The original spiral nasointestinal tube material is subjected to surface treatment to obtain the spiral nasointestinal tube material.

[0014] In step (c), the ratio of the content of the antimicrobial active ingredient in the inner layer, the middle layer and the outer layer of the tube extruded by the three-layer co-extruder is 1:6-15:1.5-4.

[0015] The specific steps of the surface treatment are: (a) Argon plasma treatment: Using the original spiral nasointestinal tube material as the substrate, a plasma power of 350-480 W was applied in an argon atmosphere for 3-6 minutes. Through high-energy particle bombardment, a micron-scale concave-convex structure was formed on the material surface, and the roughness Ra was improved to 0.8-1.2 μm. (b) Immersion treatment: immersing the argon plasma treated pipe in a polylysine-heparin sodium composite solution, wherein the solution is composed of polylysine and heparin sodium in a mass ratio of 1:0.7-1.1, and 0.2%-0.45% carbodiimide hydrochloride is added. The solution is maintained at a pH of 6.8-7.1 and a temperature of 40-50°C for 10-15 minutes to react and form a prefabricated coating; (c) During the UV curing stage, the impregnated pipe is irradiated with UV light at a wavelength of 365 nm and a dose of 250-380 mJ / cm², causing the photosensitive groups between the polylysine molecular chains to undergo a cross-linking reaction, forming a dense functional coating with a thickness of 2-5 μm.

[0016] Compared with the prior art, the advantages and beneficial effects of the present invention are: 1. This application has significant advantages in improving the comprehensive performance of nasointestinal tubes through the collaborative innovation of material components and processes. Specifically, glycidyl methacrylate is introduced into the modified polyurethane prepolymer, and the carboxyl group is grafted onto the polyurethane chain through the ring-opening reaction of the epoxy group. This not only enhances the polarity of the polyurethane itself, but also provides chemical bonding sites for it and the amino group in the carboxymethyl chitosan grafted silicone rubber composite, thereby increasing the interfacial bonding strength of the two phases by about 40%, thereby significantly reducing the risk of delamination of the tube under bending stress, which is impossible with traditional physical blending materials.

[0017] 2. In the preparation process of the carboxymethyl chitosan-grafted silicone rubber composite, by controlling the mass ratio of silicone oil to carboxymethyl chitosan and the reaction pH, the amino groups on the carboxymethyl chitosan molecular chain are directed to graft with the epoxy groups of the silicone rubber prepolymer, forming a stable chemical cross-linked network. This structure not only retains the flexibility of the silicone rubber, but also imparts the material with inherent antibacterial properties. The cationic properties of carboxymethyl chitosan can destroy bacterial cell membranes, forming a dual protection mechanism with the subsequently added antimicrobial active ingredients. Compared with a single coating antibacterial solution, the biofilm formation rate is reduced by over 60%.

[0018] 3. The core-shell structure of the nano-hydroxyapatite and titanium dioxide composite developer cleverly balances developing performance and material elasticity. The titanium dioxide core provides high-density X-ray blocking capabilities, while the surface-coated hydroxyapatite rod-shaped crystals form hydrogen bonds with the carboxyl groups in the polyurethane matrix, significantly improving the developer's dispersibility.

[0019] 4. The antimicrobial active ingredient is a combination of silver-loaded mesoporous silica and polydopamine-coated zinc oxide nanorods, which extend the antimicrobial lifespan through a sustained-release synergistic mechanism. The pore structure of the silver-loaded mesoporous silica controls the slow release of silver ions, while the polydopamine layer on the surface of the zinc oxide nanorods not only enhances compatibility with the matrix but also selectively decomposes in the acidic infection microenvironment, accelerating the release of zinc ions. This pH-responsive property results in extremely low antimicrobial release in normal tissues, while rapidly acting at the site of infection, reducing the risk of cytotoxicity.

[0020] 5. The three-layer co-extrusion process combined with gradient temperature control is key to achieving functional zoning of the tube wall structure. The outer layer utilizes a higher extrusion temperature to rapidly solidify the material surface, forming a dense protective layer. The middle layer concentrates the antimicrobial ingredients and maintains their activity at a moderate temperature. The lower temperature of the inner layer helps maintain the integrity of the developer's crystal structure. This design creates a slow-release reservoir of antimicrobial ingredients in the middle layer of the tube wall, preventing premature loss of active ingredients from direct contact with body fluids.

[0021] 6. The rotary pull-off device achieves adaptive spiral pattern formation by precisely controlling the ratio of pull-off rate to roller speed. When the extrusion rate and pull-off rate reach the optimal ratio of 1:2.8-3.5, the molten tube naturally forms spiral protrusions under the action of centrifugal force. The pitch uniformity is more than three times that of traditional mold forming, and the inner wall smoothness reaches Ra ≤ 0.4μm, effectively reducing the growth of bacteria caused by residual nutrient solution.

[0022] 7. During the surface treatment process, argon plasma treatment creates a micron-scale rough surface, which improves the adhesion of subsequent coatings by 2-3 orders of magnitude. The construction principle of the polylysine and sodium heparin composite coating is that the amino groups of polylysine form amide bonds with the carboxyl groups generated by plasma treatment, while the sulfate groups of sodium heparin are activated by carbodiimide and bond to the remaining amino groups of polylysine. This step-by-step bonding creates a three-dimensional network structure, which ensures that the coating remains intact for 28 days in a simulated intestinal fluid flushing test, while also controlling platelet adhesion to below 5%.

[0023] 8. The UV curing stage utilizes a specific wavelength and irradiation dose to precisely control crosslink density. Under UV excitation, the tyrosine residues in the polylysine molecule generate free radicals, initiating intermolecular crosslinking while retaining the antimicrobial activity of some amino groups. This selective crosslinking ensures the coating possesses both sufficient mechanical strength and biological activity, a balance difficult to achieve with conventional thermal curing processes. DETAILED DESCRIPTION

[0024] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0025] In this application, the sources of various raw materials are briefly described as follows: Polyurethane particles: purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., CAS No. 9009-54-5, model is industrial grade polyether type.

[0026] Tetrahydrofuran: purchased from Sinopharm Chemical Reagent Co., Ltd., CAS No. 109-99-9, type is chromatographic grade solvent.

[0027] Glycidyl methacrylate: purchased from Tokyo Chemical Industry Co., Ltd. (Shanghai), CAS No. 106-91-2, model number is monomer containing stabilizer.

[0028] Silicone oil containing epoxy group: purchased from Myrel Chemical Technology Co., Ltd., CAS No. 68611-44-9, model with epoxy value of 0.42-0.45 mol / 100 g.

[0029] Carboxymethyl chitosan: purchased from Hubei Weideli Chemical Technology Co., Ltd., CAS number 83512-85-0, model viscosity 200-500 mPa·s.

[0030] Ammonium persulfate: purchased from Sigma-Aldrich Trading Co., Ltd., CAS No. 7727-54-0, model is analytical grade.

[0031] Calcium nitrate: purchased from Shanghai MacLean Biochemical Technology Co., Ltd., CAS No. 10124-37-5, model 99.5% high purity.

[0032] Triethyl phosphate: purchased from Sinopharm Chemical Reagent Co., Ltd., CAS No. 78-40-0, type chemically pure.

[0033] Tetrabutyl titanate: purchased from Aladdin Reagent Co., Ltd., CAS No. 5593-70-4, model 99% metal basis.

[0034] Acetic acid: purchased from Tianjin Kemeiou Chemical Reagent Co., Ltd., CAS No. 64-19-7, model is high grade.

[0035] Ammonia: purchased from Sinopharm Chemical Reagent Co., Ltd., CAS No. 1336-21-6, model 25%-28% electronic grade.

[0036] Polyethylene glycol: purchased from Sigma-Aldrich Trading Co., Ltd., CAS No. 25322-68-3, a plasticizer with an average molecular weight of 400.

[0037] Silver-loaded mesoporous silica: purchased from Nanjing Efort Nanotechnology Co., Ltd., CAS No. is a proprietary process for silver loading.

[0038] Zinc oxide nanorods: purchased from Beijing Dekedaojin Technology Co., Ltd., CAS number 1314-13-2.

[0039] Polylysine: purchased from Hubei Weideli Chemical Technology Co., Ltd., CAS No. 25988-63-0, model is food grade ε-polylysine hydrochloride.

[0040] Heparin sodium: purchased from Shandong Qianhe Bioengineering Co., Ltd., CAS number 9041-08-1, model is medical grade 170 IU / mg.

[0041] Carbodiimide hydrochloride: purchased from Tokyo Chemical Industry Co., Ltd. (Shanghai), CAS No. 1788-79-0, model EDC·HCl for cross-linking agent.

[0042] Argon: purchased from Wuhan Zhonghe Gas Co., Ltd., CAS No. 7440-37-1, model high-purity industrial gas 99.999%.

[0043] Anhydrous ethanol: purchased from Tianjin Fuyu Fine Chemical Co., Ltd., CAS No. 64-17-5, model 99.7% dehydrated grade.

[0044] The technical solution of the present application is: a spiral nasointestinal tube material, which contains the following components, calculated by mass: 45-68 parts of modified polyurethane prepolymer, 18-32 parts of carboxymethyl chitosan grafted silicone rubber composite, 6-12 parts of nano-hydroxyapatite and titanium dioxide composite developer, 1.5-4 parts of polyethylene glycol plasticizer, and 4-9 parts of antibacterial active ingredients.

[0045] The preparation method of the modified polyurethane prepolymer comprises the following steps: dissolving polyurethane particles in tetrahydrofuran to form a 25-35% w / v solution, adding 2-3.5% by weight of glycidyl methacrylate, reacting at 65-78° C. for 2.5-4 hours under nitrogen protection, centrifuging to remove unreacted monomers, and vacuum drying to obtain a carboxyl-functionalized modified polyurethane, namely the modified polyurethane prepolymer.

[0046] The addition of glycidyl methacrylate was completed in two steps: 60% of the total mass was added for the first time and reacted at 65-70° C. for 1 hour; the remaining 40% was added at 78° C. and reacted for 1.5-3 hours.

[0047] The preparation method of the carboxymethyl chitosan grafted silicone rubber composite comprises the following steps: first, dissolving epoxy group-containing silicone oil in deionized water to form a uniform dispersion; simultaneously, dissolving carboxymethyl chitosan in an alkaline aqueous phase and adjusting the pH value to 8.5-9.2; then, slowly mixing the epoxy group-containing silicone oil and carboxymethyl chitosan at a mass ratio of 7-9:1 under stirring conditions; heating the reaction system to 50-65° C., adding ammonium persulfate as a free radical initiator, and continuing the reaction for 3-5 hours under nitrogen protection to achieve graft polymerization; after the reaction is completed, removing unreacted free monomers by centrifugation, and then repeatedly washing the product with an ethanol-water mixed solvent to remove impurities; and finally, vacuum drying to obtain a carboxymethyl chitosan grafted silicone rubber composite with a grafting rate of 18%-26%.

[0048] The preparation method of the nano-hydroxyapatite and titanium dioxide composite developer is as follows: first, calcium nitrate and triethyl phosphate are dissolved in an ethanol aqueous solution at a Ca / P molar ratio of 1.67 to form a hydroxyapatite precursor sol; and tetrabutyl titanate and acetic acid are mixed and hydrolyzed at a molar ratio of 1:0.4-0.6 to form a titanium dioxide sol; The two were mixed dropwise at a molar ratio of hydroxyapatite to titanium dioxide of 1:0.4-0.6, and ammonia was added to adjust the pH value to 9.0-10.5. The mixture was stirred in a hydrothermal reactor at 110-130°C and pressurized to 0.2-0.4 MPa for 3-5 hours to allow heterogeneous nucleation and growth of hydroxyapatite nuclei on the surface of the titanium dioxide particles. After the reaction, the precipitate is obtained by centrifugal separation, washed with deionized water until neutral, placed in a programmable temperature-controlled furnace, heated to 450-550°C at a rate of 2-5°C / min, and calcined for 2-4 hours. The final product is processed by a jet mill to obtain a composite powder with a particle size of 80-130nm, in which the hydroxyapatite inside is coated on the surface of the titanium dioxide particles in the form of rod-shaped crystals, forming a core-shell structured nano-hydroxyapatite and titanium dioxide composite developer.

[0049] The antibacterial active ingredient is prepared by compounding silver-loaded mesoporous silica and zinc oxide nanorods in a mass ratio of 2.5-3.8:1.

[0050] The pore size of the silver-loaded mesoporous silica is 8-15 nm, and the silver loading is 4-7% w / w; the length of the zinc oxide nanorods is 250-450 nm, the diameter is 40-70 nm, and the thickness of the polydopamine layer coated on the surface is 10-30 nm.

[0051] A process for preparing a spiral nasointestinal tube material, the process comprising the following steps, calculated by weight: (a) adding 45-68 parts of modified polyurethane prepolymer and 18-32 parts of carboxymethyl chitosan grafted silicone rubber composite into an internal mixer and mixing at 125-138° C. for 18-22 minutes; (b) adding 6-12 parts of a composite developer of nano-hydroxyapatite and titanium dioxide and 4-9 parts of an antibacterial active ingredient to the rubber mixture, and treating the mixture with an ultrasonic dispersion device at a frequency of 40-60 kHz for 35-45 minutes; (c) The tube body is extruded using a three-layer co-extrusion machine, with the outer layer extrusion temperature at 172-180°C, the middle layer at 165-173°C, the inner layer at 155-168°C, and the die pressure at 8-12 MPa; (d) The extruded tube blank is subjected to a rotating pulling device to form a spiral pattern, the pulling rate is 9-11 m / min, and the ratio of the pulling roller speed to the extrusion rate is 1:2.8-3.5, thereby obtaining an original spiral nasointestinal tube material. The original spiral nasointestinal tube material is subjected to surface treatment to obtain the spiral nasointestinal tube material.

[0052] In step (c), the ratio of the content of the antimicrobial active ingredient in the inner layer, the middle layer and the outer layer of the tube extruded by the three-layer co-extruder is 1:6-15:1.5-4.

[0053] The specific steps of the surface treatment are: (a) Argon plasma treatment: Using the original spiral nasointestinal tube material as the substrate, a plasma power of 350-480 W was applied in an argon atmosphere for 3-6 minutes. Through high-energy particle bombardment, a micron-scale concave-convex structure was formed on the material surface, and the roughness Ra was improved to 0.8-1.2 μm. (b) Immersion treatment: immersing the argon plasma treated pipe in a polylysine-heparin sodium composite solution, wherein the solution is composed of polylysine and heparin sodium in a mass ratio of 1:0.7-1.1, and 0.2%-0.45% carbodiimide hydrochloride is added. The solution is maintained at a pH of 6.8-7.1 and a temperature of 40-50°C for 10-15 minutes to react and form a prefabricated coating; (c) During the UV curing stage, the impregnated pipe is irradiated with UV light at a wavelength of 365 nm and a dose of 250-380 mJ / cm², causing the photosensitive groups between the polylysine molecular chains to undergo a cross-linking reaction, forming a dense functional coating with a thickness of 2-5 μm.

[0054] The present invention uses innovative material modification and process design to introduce carboxyl functionalization into the polyurethane matrix to enhance interfacial bonding strength, combines the synergistic effect of the core-shell structure developer and the antibacterial compound system, and utilizes a gradient molding process to optimize the functional distribution of the tube wall. At the same time, plasma activation and UV cross-linking are used to enhance the coating bonding strength, ultimately achieving a comprehensive improvement in the flexibility, antibacterial durability, imaging clarity, and crease resistance of the nasointestinal tube, thereby extending the clinical retention period to 6-8 weeks and reducing the infection rate to less than 5%.

[0055] The technical solution of the present invention is further illustrated by the following examples and comparative examples, but the protection scope of the present invention is not limited thereto. Example 1

[0056] The modified polyurethane prepolymer (45 parts), carboxymethyl chitosan grafted silicone rubber composite (18 parts), nano-developer (6 parts), polyethylene glycol plasticizer (1.5 parts), and antimicrobial active ingredient (4 parts) were prepared. To prepare the modified polyurethane prepolymer, glycidyl methacrylate was added in two portions: 60% of the total weight of glycidyl methacrylate was added initially and reacted at 65°C for 1 hour, followed by the remaining 40% at 78°C for 1.5 hours. To prepare the carboxymethyl chitosan grafted silicone rubber composite, the epoxy-containing silicone oil to carboxymethyl chitosan mass ratio was 9:1, the reaction temperature was 65°C, the pH was adjusted to 9.2, and the reaction was continued for 5 hours. To prepare the nano-developer, the molar ratio of hydroxyapatite to titanium dioxide was 0.6, the hydrothermal temperature was 130°C, the pressure was 0.4 MPa, and the calcination temperature was 550°C. In the three-layer co-extrusion process, the outer layer temperature was 180°C, the middle layer 173°C, and the inner layer 168°C. The die pressure was 12 MPa, the take-off speed was 11 m / min, and the take-off roller speed ratio was 1:3.5. The surface treatment phase employed argon plasma treatment at 480 W for 6 minutes, with a polylysine to sodium heparin mass ratio of 1:1.1 and a UV irradiation dose of 380 mJ / cm². Example 2

[0057] In this embodiment, the same points as in Example 1 are not described in detail, and the differences are as follows: The modified polyurethane prepolymer (68 parts), carboxymethyl chitosan grafted silicone rubber composite (32 parts), nanohydroxyapatite and titanium dioxide composite developer (12 parts), polyethylene glycol plasticizer (4 parts), and antimicrobial active ingredient (9 parts) were added. 60% of the total weight was initially added and reacted at 70°C for 1 hour, followed by the remaining 40% at 78°C for 3 hours. The weight ratio of epoxy-containing silicone oil to carboxymethyl chitosan was 7:1, the reaction temperature was 50°C, the pH was 8.5, and the reaction was continued for 3 hours. The molar ratio of the nano-developer was 0.5, the hydrothermal temperature was 120°C, the pressure was 0.3 MPa, and the calcination temperature was 500°C. The coextrusion temperature was 176°C for the outer layer, 169°C for the middle layer, and 162°C for the inner layer. The die pressure was 10 MPa, the pull-off speed was 10 m / min, and the rotational speed ratio was 1:3.2. The surface treatment plasma power was 415 W for 4.5 minutes, the mass ratio of polylysine to sodium heparin was 1:0.9, and the UV dose was 315 mJ / cm². Example 3

[0058] In this embodiment, the same points as in Example 1 are not described in detail, and the differences are as follows: The modified polyurethane prepolymer was prepared using 56 parts, carboxymethyl chitosan grafted silicone rubber composite was prepared using 25 parts, nano-developer was prepared using 9 parts, polyethylene glycol plasticizer was prepared using 2.8 parts, and antimicrobial active ingredient was prepared using 6.5 parts. Glycidyl methacrylate was added in two portions: the first 60% was reacted at 68°C for 1 hour, and the remaining 40% was reacted at 78°C for 2.2 hours. The mass ratio of epoxy-containing silicone oil to carboxymethyl chitosan was 8:1, the pH was 8.8, the temperature was 58°C, and the reaction time was 4 hours. The molar ratio of nano-developer was 0.4, the hydrothermal temperature was 110°C, the pressure was 0.2 MPa, and the calcination temperature was 450°C. The coextrusion temperature was 172°C for the outer layer, 165°C for the middle layer, and 155°C for the inner layer. The die pressure was 8 MPa, the pull-off speed was 9 m / min, and the rotational speed ratio was 1:2.8. The surface treatment was performed at a plasma power of 350 W for 3 minutes, a polylysine to heparin sodium mass ratio of 1:0.7, and a UV dose of 250 mJ / cm². Comparative Example 1

[0059] In this comparative example, the same points as in Example 1 are not repeated here, and the differences are as follows: The carboxymethyl chitosan-grafted silicone rubber composite was replaced with a physical blend of ordinary silica gel and chitosan, without chemical grafting. The antimicrobial active ingredient was silver-loaded mesoporous silica alone, without zinc oxide nanorods. Comparative Example 2

[0060] In this comparative example, the same points as Example 2 are not repeated here, and the differences are as follows: The nano-contrast agent is a physical mixture of hydroxyapatite and titanium dioxide powder, without forming a core-shell structure. The surface treatment omits the plasma activation step and is directly dip-coated with a polylysine-heparin sodium solution. Comparative Example 3

[0061] In this comparative example, the same points as in Example 3 are not repeated here, and the differences are as follows: The three-layer coextrusion temperature was uniformly set at 170°C, with no gradient temperature control. The rotary puller speed ratio was fixed at 1:2, and the dynamic matching parameters were not adjusted. Comparative Example 4

[0062] In this comparative example, the same points as in Example 1 are not repeated here, and the differences are as follows: The spiral structure was injection molded using a traditional mold, with a tube wall thickness deviation of ±0.2 mm. The developer was barium sulfate, with an addition amount of 15 parts, and no core-shell composite structure was used. Comparative Example 5

[0063] In this comparative example, the same points as in Example 1 are not repeated here, and the differences are as follows: The antibacterial component is a silver ion coating, not a silver-loaded mesoporous silica and zinc oxide composite system. The surface coating is heat-cured, not UV cross-linked.

[0064] Performance test results and analysis

[0065] The spiral nasointestinal tube materials obtained according to the parameters of the embodiment and the comparative example were tested, and the test results are shown in Table 1.

[0066] As can be seen from Table 1, the antibacterial rates of Examples 1-3 are significantly higher than those of the comparative example, mainly due to the synergistic effect of the chemical grafting of carboxymethyl chitosan and the antibacterial compound system. The amino groups of carboxymethyl chitosan and the silicon epoxy groups form a stable cross-linked network, destroying the bacterial cell membrane, while the pore structure of the silver-loaded mesoporous silica controls the sustained release of silver ions, and the polydopamine-coated zinc oxide nanorods accelerate the release of zinc ions in the infected microenvironment. Comparative Example 1, due to the lack of grafting and the use of only a single antibacterial component, has a 23% lower antibacterial rate, verifying the necessity of chemical bonding and compound design.

[0067] In terms of imaging resolution, the core-shell structure developer (0.15-0.18 mm) of the Example significantly outperforms the physically mixed powder (0.45 mm) of Comparative Example 2 and the barium sulfate (0.50 mm) of Comparative Example 4. Hydroxyapatite is anchored to the polyurethane matrix through hydrogen bonds, while the titanium dioxide core provides high-density X-ray blocking. The high developer loading in Comparative Example 4 results in decreased elasticity and a 40% reduction in tensile strength, highlighting the core-shell structure's superior performance balance.

[0068] The tensile strength decay rate is directly related to the interfacial bonding strength of the materials. The modified polyurethane in Example 1, crosslinked through carboxyl groups, exhibited a decay rate of only 9%. However, in Comparative Example 3, the lack of gradient temperature control resulted in weak interlayer bonding, resulting in a decay rate of 18%. Conventional mold injection molding (Comparative Example 4) exhibited a decay rate of up to 40% due to uneven wall thickness, demonstrating the uniformity advantage of the coextrusion process.

[0069] Table 1 Analysis and test results

[0070] The spiral structure uniformity index shows that the rotary traction molding of the embodiment (≥97.8%) is significantly better than the mold injection molding of comparative example 4 (88.4%). The dynamic matching of the traction rate and the rotation speed allows the molten tube to naturally form a spiral under centrifugal force, reducing deformation. The platelet adhesion data of the surface coating show that the embodiment inhibits thrombosis through plasma activation and a three-dimensional cross-linked network. The heat-cured coating adhesion of comparative example 5 reaches 25%, the UV cross-linking selectively retains the amino activity, and the plasma-treated micron-scale rough surface enhances adhesion. Test results demonstrate that this invention organically combines chemical material modification, nanocomposite technology, functional gradient molding, and surface engineering. The modified polyurethane provides reactive groups, the nanocomposite developer optimizes the mechanical-developmental balance, the antimicrobial compound system achieves intelligent release, and the multi-layer co-extrusion process achieves structural and functional integration. The synergistic effect of these technical elements has extended the clinical indwelling period of nasoenteric tubes from the conventional 2-3 weeks to 6-8 weeks, and reduced the incidence of related infections to below 5%, demonstrating significant clinical application value.

[0071] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A spiral nasointestinal tube material, characterized in that: The material comprises the following components in parts by mass: 45-68 parts of modified polyurethane prepolymer, 18-32 parts of carboxymethyl chitosan grafted silicone rubber compound, 6-12 parts of nano-hydroxyapatite and titanium dioxide composite developer, 1.5-4 parts of polyethylene glycol plasticizer, and 4-9 parts of antibacterial active ingredients.

2. A spiral nasointestinal tube material according to claim 1, characterized in that: The preparation method of the modified polyurethane prepolymer comprises the following steps: dissolving polyurethane particles in tetrahydrofuran to form a 25-35% w / v solution, adding 2-3.5% glycidyl methacrylate by weight of the polyurethane, and vacuum drying to obtain a carboxyl-functionalized modified polyurethane, namely the modified polyurethane prepolymer.

3. The spiral nasointestinal tube material according to claim 2, characterized in that: The addition of glycidyl methacrylate was completed in two steps: 60% of the total mass was added for the first time and reacted at 65-70° C. for 1 hour; the remaining 40% was added at 78° C. and reacted for 1.5-3 hours.

4. The spiral nasointestinal tube material according to claim 1, characterized in that: The preparation method of the carboxymethyl chitosan grafted silicone rubber composite comprises the following steps: firstly dissolving silicone oil containing epoxy groups in deionized water, and simultaneously dissolving carboxymethyl chitosan in an alkaline aqueous phase; then slowly mixing the silicone oil containing epoxy groups and carboxymethyl chitosan in a mass ratio of 7-9:1; heating the mixture to 50-65° C., adding ammonium persulfate as a free radical initiator, and conducting a graft polymerization reaction; and after the reaction is completed, centrifuging, washing, and vacuum drying to obtain a carboxymethyl chitosan grafted silicone rubber composite with a grafting rate of 18%-26%.

5. The spiral nasointestinal tube material according to claim 1, characterized in that: The preparation method of the nano-hydroxyapatite and titanium dioxide composite developer is as follows: first, calcium nitrate and triethyl phosphate are dissolved in an ethanol aqueous solution at a Ca / P molar ratio of 1.67 to form a hydroxyapatite precursor sol; and tetrabutyl titanate and acetic acid are mixed and hydrolyzed at a molar ratio of 1:0.4-0.6 to form a titanium dioxide sol; The two were mixed dropwise for reaction at a molar ratio of hydroxyapatite to titanium dioxide of 1:0.4-0.6; After the reaction, the composite powder with a particle size of 80-130 nm is obtained through centrifugation, washing, calcination and crushing, forming a core-shell structured nano-hydroxyapatite and titanium dioxide composite developer.

6. The spiral nasointestinal tube material according to claim 1, characterized in that: The antibacterial active ingredient is prepared by compounding silver-loaded mesoporous silica and zinc oxide nanorods in a mass ratio of 2.5-3.8:

1.

7. The spiral nasointestinal tube material according to claim 6, characterized in that: The pore size of the silver-loaded mesoporous silica is 8-15 nm, and the silver loading is 4-7% w / w; the length of the zinc oxide nanorods is 250-450 nm, the diameter is 40-70 nm, and the thickness of the polydopamine layer coated on the surface is 10-30 nm.

8. A process for preparing the spiral nasointestinal tube material according to any one of claims 1 to 7, characterized in that: By mass, the process comprises the following steps: (a) adding 45-68 parts of modified polyurethane prepolymer and 18-32 parts of carboxymethyl chitosan grafted silicone rubber composite into an internal mixer and mixing at 125-138° C. for 18-22 minutes; (b) adding 6-12 parts of a composite developer of nano-hydroxyapatite and titanium dioxide and 4-9 parts of an antibacterial active ingredient to the rubber mixture, and treating the mixture with an ultrasonic dispersion device at a frequency of 40-60 kHz for 35-45 minutes; (c) The tube body is extruded using a three-layer co-extrusion machine, with the outer layer extrusion temperature at 172-180°C, the middle layer at 165-173°C, the inner layer at 155-168°C, and the die pressure at 8-12 MPa; (d) The extruded tube blank is subjected to a rotating pulling device to form a spiral pattern, the pulling rate is 9-11 m / min, and the ratio of the pulling roller speed to the extrusion rate is 1:2.8-3.5, thereby obtaining an original spiral nasointestinal tube material. The original spiral nasointestinal tube material is subjected to surface treatment to obtain the spiral nasointestinal tube material.

9. The process for preparing a spiral nasointestinal tube material according to claim 8, characterized in that: In step (c), the ratio of the content of the antimicrobial active ingredient in the inner layer, the middle layer and the outer layer of the tube extruded by the three-layer co-extruder is 1:6-15:1.5-4.

10. The process for preparing a spiral nasointestinal tube material according to claim 8, characterized in that: The specific steps of the surface treatment are: (a) Argon plasma treatment stage: the original spiral nasointestinal tube material was used as the substrate and plasma treated in an argon atmosphere; (b) dipping treatment, wherein the argon plasma treated pipe is immersed in a polylysine-heparin sodium composite solution, wherein the solution is composed of polylysine and heparin sodium in a mass ratio of 1:0.7-1.1, and 0.2%-0.45% carbodiimide hydrochloride is added to form a prefabricated coating; (c) In the UV curing stage, the impregnated pipe is irradiated with UV light of 365 nm wavelength at a dose of 250-380 mJ / cm² to form a dense functional coating.

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