High-temperature-resistant antibacterial sputum suction catheter and preparation method thereof

Abstract

The application provides a high-temperature-resistant and antibacterial sputum suction catheter and a preparation method thereof, and belongs to the technical field of medical devices. The preparation method comprises the following steps: modifying chitosan by treating quaternary ammonium salt chitosan with chitosanase to obtain modified chitosan, reacting polytetrahydrofuran, polyethylene glycol and diisocyanate to obtain a prepolymer, reacting the prepolymer, dimethylol propionic acid and the modified chitosan to obtain a polyurethane prepolymer, mixing modified silane and the polyurethane prepolymer to obtain a mixture, and extruding the mixture to obtain the high-temperature-resistant and antibacterial sputum suction catheter. In the application, the hydrophilic groups in the modified silane and the polyurethane polymer can reduce the friction of the surface of the sputum suction catheter and reduce the injury to the vascular endothelium. In addition, the quaternary ammonium salt structure in resveratrol and the modified chitosan can jointly destroy the metabolism of bacteria to achieve good bacteriostatic effect, and the combined non-antibiotic antibacterial strategy can delay the generation of drug-resistant bacteria.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to a high-temperature resistant antibacterial suction catheter and its preparation method. Background Technology

[0002] Suctioning catheters are crucial medical devices in clinical respiratory care, primarily used to clear sputum and secretions from a patient's airway, maintain airway patency, and prevent complications such as pulmonary infections. In various intensive care units and respiratory departments, suctioning is performed extremely frequently, and its effectiveness directly impacts the recovery of respiratory function and the overall rehabilitation process. However, currently used suctioning catheters have numerous problems, severely limiting their effectiveness and safety.

[0003] Currently, most mainstream suction catheters on the market are made of ordinary silicone or PVC. These materials are prone to softening, deformation, and even structural damage during high-temperature and high-pressure sterilization, leading to lumen collapse, surface roughness, or changes in pore size, significantly reducing suction efficiency and increasing the risk of patient injury. Meanwhile, existing antibacterial technologies, such as silver nanoparticle coatings and hydrophilic polymer layers, suffer from degradation, aggregation, or interfacial peeling at high temperatures, resulting in uncontrollable attenuation of antibacterial function. While traditional ethylene oxide sterilization can avoid high-temperature damage, its residual toxicity and insufficient penetrability make it difficult to meet the sterilization requirements of complex catheter structures, resulting in a persistently high risk of catheter-related infections. Therefore, there is an urgent need to develop new catheter materials that combine high-temperature resistance with long-lasting antibacterial properties.

[0004] Chinese patent CN 111423693B discloses a PEEK-based medical tubing, its preparation method, and its application. The method involves drying PEEK, PEI, and PPSU to remove moisture, weighing the raw materials according to a formula, mixing them evenly, and then performing melt blending, extrusion, and granulation in a twin-screw extruder. Finally, the tubing is extruded in a single-screw extruder to produce the PEEK-based medical tubing. The resulting PEEK-based medical tubing exhibits good high-temperature resistance, but this invention does not address its antibacterial effect.

[0005] Therefore, providing a novel catheter material that combines high temperature resistance with good antibacterial properties is an important problem that urgently needs to be solved in this field. Summary of the Invention

[0006] To address the problems existing in the prior art, the present invention provides a high-temperature resistant antibacterial suction catheter and its preparation method. Specifically, the technical solution of the present invention includes the following:

[0007] A method for preparing a high-temperature resistant, antibacterial suction catheter, the method comprising the following steps:

[0008] Quaternary ammonium salt chitosan is treated with chitosanase to obtain modified chitosan. Polytetrahydrofuran, polyethylene glycol and diisocyanate are reacted to obtain a prepolymer. The prepolymer, dimethylolpropionic acid and modified chitosan are reacted to obtain a polyurethane prepolymer. Modified silane and polyurethane prepolymer are mixed to obtain a mixture. The mixture is extruded to obtain a high-temperature resistant antibacterial suction catheter.

[0009] Furthermore, the method for preparing the modified silane includes the following steps:

[0010] Hydroxypropyl-β-cyclodextrin and resveratrol were reacted to obtain modified resveratrol. 3-mercaptopropyltrimethoxysilane, itaconic acid and an initiator were reacted to obtain carboxylated silane. Modified resveratrol and carboxylated silane were mixed and then subjected to acid treatment and alkali treatment in sequence to obtain modified silane.

[0011] Furthermore, the weight ratio of hydroxypropyl-β-cyclodextrin to resveratrol is 2~3:1.5~2.5.

[0012] Furthermore, the reaction conditions for the hydroxypropyl-β-cyclodextrin and resveratrol include a reaction temperature of 55-60°C and a reaction time of 8-12 h.

[0013] Furthermore, the weight ratio of 3-mercaptopropyltrimethoxysilane, itaconic acid, and initiator is 19~22:12~14:0.13~0.15.

[0014] Furthermore, the initiator is benzoin diethyl ether.

[0015] Furthermore, the reaction conditions for the 3-mercaptopropyltrimethoxysilane, itaconic acid, and initiator are irradiation with 365nm ultraviolet light for 30-60 minutes.

[0016] Furthermore, the weight ratio of the modified resveratrol to the carboxylated silane is 1~3:9~11.

[0017] Furthermore, the acid treatment conditions include a solution pH of 3.5 to 4.5, a treatment temperature of 45 to 55°C, and a treatment time of 8 to 12 hours.

[0018] Furthermore, the conditions for the alkali treatment include a solution pH of 8.0 to 8.3, a treatment temperature of 24 to 26°C, and a treatment time of 2 to 3 hours.

[0019] Furthermore, the weight ratio of the polytetrahydrofuran, polyethylene glycol, diisocyanate, dimethylolpropionic acid and modified chitosan is 4.5~5.5:2.5~3.5:0.9~1.5:0.3~0.5:0.15~0.25.

[0020] Furthermore, the diisocyanate includes hexamethylene diisocyanate or isophorone diisocyanate.

[0021] Furthermore, the reaction conditions for the polytetrahydrofuran, polyethylene glycol, and diisocyanate include a reaction temperature of 80-90°C and a reaction time of 3-4 hours.

[0022] Furthermore, the reaction conditions for the prepolymer, dimethylolpropionic acid, and modified chitosan include a reaction temperature of 55-65°C and a reaction time of 4-6 hours.

[0023] Furthermore, the weight ratio of the modified silane to the polyurethane prepolymer is 30~40:70~90.

[0024] Furthermore, the mixing conditions for the modified silane and polyurethane prepolymer include a mixing temperature of 180~190℃ and a mixing time of 15~25min.

[0025] Furthermore, the extrusion molding conditions include a zone temperature of 175°C, a zone temperature of 185°C, a zone temperature of 190°C, a zone temperature of 190°C, and a die temperature of 185°C.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] (1) In this invention, resveratrol is encapsulated in the hydrophobic cavity of hydroxypropyl-β-cyclodextrin through hydrophobic interaction to obtain modified resveratrol. Itaconic acid is grafted onto 3-mercaptopropyltrimethoxysilane through mercapto-olefin click reaction to obtain carboxylated silane. The carboxylated silane is hydrolyzed and condensed to form a Si-O-Si network. The modified resveratrol is embedded into the Si-O-Si network through hydrogen bonding to obtain modified silane. Quaternary ammonium salt chitosan is degraded by chitosanase to obtain low-viscosity modified chitosan. Dimethylolpropionic acid and modified carboxymethyl chitosan are used as chain extenders to obtain polyurethane polymer. The polyurethane polymer and modified silane are mixed and extruded to obtain a high-temperature resistant antibacterial suction catheter. This system stabilizes the antibacterial activity of resveratrol through cyclodextrin encapsulation technology, improves the thermal stability of the material through siloxane network, and enhances the mechanical properties of modified chitosan as a chain extender while also having a good antibacterial effect. The synergistic effect of multiple functions ultimately achieves that the antibacterial catheter has good mechanical properties and antibacterial activity.

[0028] (3) In this invention, the hydrophilic groups in the modified silane and polyurethane polymer can reduce the friction on the surface of the suction catheter and reduce vascular endothelial damage; in addition, the quaternary ammonium salt structure in resveratrol and modified chitosan can jointly disrupt bacterial metabolism to achieve good antibacterial effect, and the combined non-antibiotic antibacterial strategy can delay the emergence of drug-resistant bacteria. Detailed Implementation

[0029] The technical solution of the present invention will be clearly and completely described below through embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. 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.

[0030] Unless otherwise stated, all raw materials and reagents used in this invention are commercially available or can be prepared by known methods.

[0031] Preparation Example 1:

[0032] The preparation method of modified silane includes the following steps:

[0033] Two parts by weight of hydroxypropyl-β-cyclodextrin were dispersed in 60 parts by weight of deionized water and stirred at 60°C for 10 min to obtain stock solution A. 1.5 parts by weight of resveratrol were dispersed in 50 parts by weight of anhydrous ethanol to obtain stock solution B. Stock solution B was added dropwise to stock solution A, and the mixture was stirred and reacted at 55°C in the dark under nitrogen protection for 8 h to obtain modified resveratrol.

[0034] 19 parts by weight of 3-mercaptopropyltrimethoxysilane, 13 parts by weight of itaconic acid and 0.3 parts by weight of benzoin diethyl ether were dispersed in anhydrous ethanol and stirred for 15 min. Then, under nitrogen protection, the mixture was irradiated with 365 nm ultraviolet light for 30 min while stirring. After the reaction was completed, the anhydrous ethanol was removed by rotary evaporation, and the product was collected after washing with cold diethyl ether. The product was then dried under vacuum at 40 °C to obtain carboxylated silane.

[0035] 1 part by weight of modified resveratrol dispersed in a mixed solvent (V 无水乙醇 V 去离子水 =5:3) was stirred and mixed at 35℃ for 10 min, then 9 parts by weight of carboxylated silane were added and stirred and mixed for another 10 min. The pH was adjusted to 3.5 with 0.1M dilute hydrochloric acid solution, and the mixture was stirred at 200 r / min at 45℃ for 8 h. After the reaction was completed, the mixture was allowed to stand at 24℃ for 24 h. The mixture was then analyzed using a mixed solution (V 无水乙醇 V 去离子水 =1:1) Washed alternately 3 times, and dried under vacuum at 40℃ for 24h to obtain an intermediate product. The intermediate product was dispersed in a sodium bicarbonate solution with pH 8.0, soaked at 24℃ for 2h, washed with deionized water until neutral, and dried under vacuum to obtain modified silane.

[0036] Preparation Example 2:

[0037] The preparation method of modified silane includes the following steps:

[0038] 2.3 parts by weight of hydroxypropyl-β-cyclodextrin were dispersed in 60 parts by weight of deionized water and stirred at 60°C for 12 min to obtain stock solution A. 1.7 parts by weight of resveratrol were dispersed in 50 parts by weight of anhydrous ethanol to obtain stock solution B. Stock solution B was added dropwise to stock solution A, and the mixture was stirred and reacted at 57°C in the dark under nitrogen protection for 9 h to obtain modified resveratrol.

[0039] 20 parts by weight of 3-mercaptopropyltrimethoxysilane, 14 parts by weight of itaconic acid and 0.34 parts by weight of benzoin diethyl ether were dispersed in anhydrous ethanol and stirred for 16 min. Then, under nitrogen protection, the mixture was irradiated with 365 nm ultraviolet light for 40 min while stirring. After the reaction was completed, the anhydrous ethanol was removed by rotary evaporation, and the product was collected after washing with cold diethyl ether. The product was then dried under vacuum at 42 °C to obtain carboxylated silane.

[0040] 1.5 parts by weight of modified resveratrol were dispersed in a mixed solvent (V 无水乙醇 V 去离子水 =5:3) was stirred and mixed at 36℃ for 12 min, then 9.5 parts by weight of carboxylated silane were added and stirred and mixed for another 12 min. The pH was adjusted to 3.7 with 0.1M dilute hydrochloric acid solution, and the mixture was stirred at 220 r / min at 47℃ for 9 h. After the reaction was completed, the mixture was allowed to stand at 25℃ for 24 h. The mixture was then analyzed using a mixed solution (V 无水乙醇 V 去离子水 =1:1) Washed alternately 3 times, and dried under vacuum at 40℃ for 24h to obtain an intermediate product. The intermediate product was dispersed in a sodium bicarbonate solution with pH 8.1, soaked at 25℃ for 2.3h, washed with deionized water until neutral, and dried under vacuum to obtain modified silane.

[0041] Preparation Example 3:

[0042] The preparation method of modified silane includes the following steps:

[0043] 2.6 parts by weight of hydroxypropyl-β-cyclodextrin were dispersed in 60 parts by weight of deionized water and stirred at 60°C for 16 min to obtain stock solution A. 2.1 parts by weight of resveratrol were dispersed in 50 parts by weight of anhydrous ethanol to obtain stock solution B. Stock solution B was added dropwise to stock solution A, and the mixture was stirred and reacted at 58°C in the dark under nitrogen protection for 10 h to obtain modified resveratrol.

[0044] 21 parts by weight of 3-mercaptopropyltrimethoxysilane, 14 parts by weight of itaconic acid and 0.38 parts by weight of benzoin diethyl ether were dispersed in anhydrous ethanol and stirred for 18 min. Then, under nitrogen protection, the mixture was irradiated with 365 nm ultraviolet light for 50 min while stirring. After the reaction was completed, the anhydrous ethanol was removed by rotary evaporation, and the product was collected after washing with cold diethyl ether. The product was then dried under vacuum at 47 °C to obtain carboxylated silane.

[0045] 2 parts by weight of modified resveratrol were dispersed in a mixed solvent (V 无水乙醇 V 去离子水 =5:3) was stirred and mixed at 38℃ for 13 min, then 10 parts by weight of carboxylated silane were added and stirred and mixed for 14 min. The pH was adjusted to 4.2 with 0.1M dilute hydrochloric acid solution, and the mixture was stirred at 250 r / min at 52℃ for 10 h. After the reaction was completed, the mixture was allowed to stand at 26℃ for 24 h. The mixture was then used as a solution (V 无水乙醇 V 去离子水 =1:1) Washed alternately 3 times, and dried under vacuum at 40℃ for 24h to obtain intermediate product. The intermediate product was dispersed in sodium bicarbonate solution with pH 8.3, soaked at 26℃ for 3h, washed with deionized water until neutral and dried under vacuum to obtain modified silane.

[0046] Preparation Example 4:

[0047] The preparation method of modified silane includes the following steps:

[0048] 3 parts by weight of hydroxypropyl-β-cyclodextrin were dispersed in 60 parts by weight of deionized water and stirred at 60°C for 20 min to obtain stock solution A. 2.5 parts by weight of resveratrol were dispersed in 50 parts by weight of anhydrous ethanol to obtain stock solution B. Stock solution B was added dropwise to stock solution A. Modified resveratrol was prepared by stirring at 60°C in the dark under nitrogen protection for 12 h.

[0049] 22 parts by weight of 3-mercaptopropyltrimethoxysilane, 15 parts by weight of itaconic acid and 0.4 parts by weight of benzoin diethyl ether were dispersed in anhydrous ethanol and stirred for 20 min. Then, under nitrogen protection, the mixture was irradiated with 365 nm ultraviolet light for 60 min while stirring. After the reaction was completed, the anhydrous ethanol was removed by rotary evaporation, and the product was collected after washing with cold diethyl ether. The product was then dried under vacuum at 50 °C to obtain carboxylated silane.

[0050] 3 parts by weight of modified resveratrol were dispersed in a mixed solvent (V 无水乙醇 V 去离子水 =5:3) was stirred and mixed at 40℃ for 15 min, then 11 parts by weight of carboxylated silane were added and stirred and mixed for another 15 min. The pH was adjusted to 4.5 with 0.1M dilute hydrochloric acid solution, and the mixture was stirred at 300 r / min at 55℃ for 12 h. After the reaction was completed, the mixture was allowed to stand at 26℃ for 24 h. The mixture was then analyzed using a mixed solution (V 无水乙醇 V 去离子水 =1:1) Washed alternately 3 times, and dried under vacuum at 40℃ for 24h to obtain intermediate product. The intermediate product was dispersed in sodium bicarbonate solution with pH 8.3, soaked at 26℃ for 3h, washed with deionized water until neutral and dried under vacuum to obtain modified silane.

[0051] Preparation Example 5:

[0052] The preparation method of modified silane includes the following steps:

[0053] 3 parts by weight of β-cyclodextrin were dispersed in 60 parts by weight of deionized water and stirred at 60°C for 20 min to obtain stock solution A. 2.5 parts by weight of resveratrol were dispersed in 50 parts by weight of anhydrous ethanol to obtain stock solution B. Stock solution B was added dropwise to stock solution A. Modified resveratrol was prepared by stirring and reacting at 60°C in the dark under nitrogen protection for 12 h.

[0054] 22 parts by weight of 3-mercaptopropyltrimethoxysilane, 15 parts by weight of itaconic acid and 0.4 parts by weight of benzoin diethyl ether were dispersed in anhydrous ethanol and stirred for 20 min. Then, under nitrogen protection, the mixture was irradiated with 365 nm ultraviolet light for 60 min while stirring. After the reaction was completed, the anhydrous ethanol was removed by rotary evaporation, and the product was collected after washing with cold diethyl ether. The product was then dried under vacuum at 50 °C to obtain carboxylated silane.

[0055] 3 parts by weight of modified resveratrol were dispersed in a mixed solvent (V 无水乙醇 V 去离子水 =5:3) was stirred and mixed at 40℃ for 15 min, then 11 parts by weight of carboxylated silane were added and stirred and mixed for another 15 min. The pH was adjusted to 4.5 with 0.1M dilute hydrochloric acid solution, and the mixture was stirred at 300 r / min at 55℃ for 12 h. After the reaction was completed, the mixture was allowed to stand at 26℃ for 24 h. The mixture was then analyzed using a mixed solution (V 无水乙醇 V 去离子水 =1:1) Washed alternately 3 times, and dried under vacuum at 40℃ for 24h to obtain intermediate product. The intermediate product was dispersed in sodium bicarbonate solution with pH 8.3, soaked at 26℃ for 3h, washed with deionized water until neutral and dried under vacuum to obtain modified silane.

[0056] Preparation Example 6:

[0057] The preparation method of modified silane includes the following steps:

[0058] 3 parts by weight of hydroxypropyl-β-cyclodextrin were dispersed in 60 parts by weight of deionized water and stirred at 60°C for 20 min to obtain stock solution A. 2.5 parts by weight of resveratrol were dispersed in 50 parts by weight of anhydrous ethanol to obtain stock solution B. Stock solution B was added dropwise to stock solution A. Modified resveratrol was prepared by stirring at 60°C in the dark under nitrogen protection for 12 h.

[0059] 3 parts by weight of modified resveratrol were dispersed in a mixed solvent (V 无水乙醇 V 去离子水=5:3) was stirred and mixed at 40℃ for 15 min, then 11 parts by weight of 3-mercaptopropyltrimethoxysilane were added and stirred and mixed for another 15 min. The pH was adjusted to 4.5 with 0.1M dilute hydrochloric acid solution, and the mixture was stirred at 300 r / min at 55℃ for 12 h. After the reaction was completed, the mixture was allowed to stand at 26℃ for 24 h. The mixture was then analyzed using a mixed solution (V 无水乙醇 V 去离子水 =1:1) Washed alternately 3 times, and dried under vacuum at 40℃ for 24h to obtain intermediate product. The intermediate product was dispersed in sodium bicarbonate solution with pH 8.3, soaked at 26℃ for 3h, washed with deionized water until neutral and dried under vacuum to obtain modified silane.

[0060] Preparation Example 7:

[0061] The preparation method of modified silane includes the following steps:

[0062] 22 parts by weight of 3-mercaptopropyltrimethoxysilane, 15 parts by weight of itaconic acid and 0.4 parts by weight of benzoin diethyl ether were dispersed in anhydrous ethanol and stirred for 20 min. Then, under nitrogen protection, the mixture was irradiated with 365 nm ultraviolet light for 60 min while stirring. After the reaction was completed, the anhydrous ethanol was removed by rotary evaporation, and the product was collected after washing with cold diethyl ether. The product was then dried under vacuum at 50 °C to obtain carboxylated silane.

[0063] 11 parts by weight of carboxylated silane dispersed in a mixed solvent (V 无水乙醇 V 去离子水 =5:3) After stirring and mixing at 40℃ for 15 min, the pH was adjusted to 4.5 with 0.1M dilute hydrochloric acid solution. The mixture was then stirred at 300 r / min at 55℃ for 12 h. After the reaction was completed, the mixture was allowed to stand at 26℃ for 24 h. The mixture was then used to extract the final product (V 无水乙醇 V 去离子水 =1:1) Washed alternately 3 times, and dried under vacuum at 40℃ for 24h to obtain intermediate product. The intermediate product was dispersed in sodium bicarbonate solution with pH 8.3, soaked at 26℃ for 3h, washed with deionized water until neutral and dried under vacuum to obtain modified silane.

[0064] Example 1:

[0065] A method for preparing a high-temperature resistant, antibacterial suction catheter includes the following steps:

[0066] A 0.2M acetic acid solution and a 0.2M sodium acetate solution were mixed at a weight ratio of 1:1, and the pH was adjusted to 5.0 to obtain an acetate-sodium acetate buffer solution. Two parts by weight of quaternary ammonium salt chitosan were dispersed in 100 parts by weight of the acetate-sodium acetate buffer solution. After stirring at 25°C for 2 hours, 0.02 parts by weight of chitosanase were added, and the mixture was stirred at 45°C for 4 hours. After the reaction was completed, the temperature was raised to 75°C and held for 10 minutes. The mixture was then purified by centrifugation and dialysis to obtain modified chitosan. 45 parts by weight of polytetrahydrofuran (Mn=1000) and 25 parts by weight of polyethylene glycol (Mn=2000) were dehydrated in a vacuum environment at 100°C for 2 hours. The mixture was then cooled to 60°C, and 9 parts by weight of hexamethylene diisocyanate were added. The mixture was stirred at 80°C under nitrogen protection. The reaction was stirred for 3 hours to obtain a prepolymer. After the reaction was completed, the temperature was lowered to 55°C, and 3 parts by weight of dimethylolpropionic acid and 1.5 parts by weight of modified chitosan were added and stirred for 4 hours. After cooling to 24°C, the prepolymer was precipitated with deionized water and then filtered and vacuum dried to obtain a polyurethane polymer. The internal mixer was preheated to 180°C, and 30 parts by weight of the modified silane prepared in Preparation Example 1 and 70 parts by weight of the polyurethane polymer were added and mixed at 60 r / min for 15 min to obtain a mixture. The mixture was extruded through a single screw extruder with the following temperature settings: zone 1 temperature 175°C, zone 2 temperature 185°C, zone 3 temperature 190°C, zone 4 temperature 190°C, and die temperature 185°C. After extrusion molding, the mixture was subjected to high-pressure sterilization, drying, and packaging to obtain a high-temperature resistant antibacterial suction catheter.

[0067] Example 2:

[0068] A method for preparing a high-temperature resistant, antibacterial suction catheter includes the following steps:

[0069] A 0.2M acetic acid solution and a 0.2M sodium acetate solution were mixed at a weight ratio of 1:1, and the pH was adjusted to 5.0 to obtain an acetate-sodium acetate buffer solution. Two parts by weight of quaternary ammonium salt chitosan were dispersed in 100 parts by weight of the acetate-sodium acetate buffer solution. After stirring at 25°C for 2 hours, 0.02 parts by weight of chitosanase were added, and the mixture was stirred at 45°C for 4.5 hours. After the reaction was completed, the temperature was raised to 78°C and held for 11 minutes. The mixture was then purified by centrifugation and dialysis to obtain modified chitosan. 47 parts by weight of polytetrahydrofuran (Mn=1000) and 28 parts by weight of polyethylene glycol (Mn=2000) were dehydrated in a vacuum environment at 100°C for 2.3 hours. The mixture was then cooled to 63°C, and 11 parts by weight of isophorone diisocyanate were added. The mixture was stirred at 83°C under nitrogen protection. The reaction was stirred for 3.4 h to obtain a prepolymer. After the reaction was completed, the temperature was lowered to 58°C, and 3.5 parts by weight of dimethylolpropionic acid and 1.9 parts by weight of modified chitosan were added and stirred for 4.5 h. After cooling to 25°C, the prepolymer was precipitated with deionized water and then filtered and vacuum dried to obtain a polyurethane polymer. The internal mixer was preheated to 183°C, and 33 parts by weight of the modified silane prepared in Preparation Example 2 and 75 parts by weight of polyurethane polymer were added and mixed at 63 r / min for 18 min to obtain a mixture. The mixture was extruded through a single screw extruder with the following temperature settings: zone 1 temperature 175°C, zone 2 temperature 185°C, zone 3 temperature 190°C, zone 4 temperature 190°C, and die temperature 185°C. After extrusion molding, the mixture was subjected to high-pressure sterilization, drying, and packaging to obtain a high-temperature resistant antibacterial suction catheter.

[0070] Example 3:

[0071] A method for preparing a high-temperature resistant, antibacterial suction catheter includes the following steps:

[0072] A 0.2M acetic acid solution and a 0.2M sodium acetate solution were mixed at a weight ratio of 1:1, and the pH was adjusted to 5.0 to obtain an acetate-sodium acetate buffer solution. Two parts by weight of quaternary ammonium salt chitosan were dispersed in 100 parts by weight of the acetate-sodium acetate buffer solution. After stirring at 25°C for 2 hours, 0.02 parts by weight of chitosanase were added, and the mixture was stirred at 45°C for 5 hours. After the reaction was completed, the temperature was raised to 82°C and held for 13 minutes. The mixture was then purified by centrifugation and dialysis to obtain modified chitosan. 52 parts by weight of polytetrahydrofuran (Mn=1000) and 32 parts by weight of polyethylene glycol (Mn=2000) were dehydrated in a vacuum environment at 100°C for 2.8 hours. The mixture was then cooled to 67°C, and 13 parts by weight of hexamethylene diisocyanate were added. The mixture was then dehydrated in a nitrogen-protected environment at 87°C. The prepolymer was obtained by stirring and reacting for 3.6 h. After the reaction was completed, the temperature was lowered to 62 °C, and 4 parts by weight of dimethylolpropionic acid and 2.1 parts by weight of modified chitosan were added and stirred for 5 h. After cooling to 26 °C, the prepolymer was precipitated with deionized water and then filtered and vacuum dried to obtain polyurethane polymer. The internal mixer was preheated to 187 °C, and 37 parts by weight of the modified silane prepared in Preparation Example 3 and 80 parts by weight of polyurethane polymer were added and mixed at 68 r / min for 22 min to obtain a mixture. The mixture was extruded by a single screw extruder with the following temperature settings: zone 1 temperature 175 °C, zone 2 temperature 185 °C, zone 3 temperature 190 °C, zone 4 temperature 190 °C, and die temperature 185 °C. After extrusion molding, the mixture was subjected to high-pressure sterilization, drying, and packaging to obtain a high-temperature resistant antibacterial suction catheter.

[0073] Example 4:

[0074] A method for preparing a high-temperature resistant, antibacterial suction catheter includes the following steps:

[0075] A 0.2M acetic acid solution and a 0.2M sodium acetate solution were mixed at a weight ratio of 1:1, and the pH was adjusted to 5.0 to obtain an acetate-sodium acetate buffer solution. Two parts by weight of quaternary ammonium salt chitosan were dispersed in 100 parts by weight of the acetate-sodium acetate buffer solution. After stirring at 25°C for 2 hours, 0.02 parts by weight of chitosanase were added, and the mixture was stirred at 45°C for 6 hours. After the reaction was completed, the temperature was raised to 85°C and held for 15 minutes. The mixture was then purified by centrifugation and dialysis to obtain modified chitosan. 55 parts by weight of polytetrahydrofuran (Mn=1000) and 35 parts by weight of polyethylene glycol (Mn=2000) were dehydrated in a vacuum environment at 100°C for 3 hours. The temperature was then lowered to 70°C, and 15 parts by weight of isophorone diisocyanate were added. The mixture was then dehydrated in a nitrogen-protected environment at 90°C. The prepolymer was obtained by stirring and reacting for 4 hours. After the reaction was completed, the temperature was lowered to 65°C, and 5 parts by weight of dimethylolpropionic acid and 2.5 parts by weight of modified chitosan were added and stirred for 6 hours. After cooling to 26°C, the prepolymer was precipitated with deionized water and then filtered and vacuum dried to obtain a polyurethane polymer. The internal mixer was preheated to 190°C, and 40 parts by weight of the modified silane prepared in Preparation Example 4 and 90 parts by weight of the polyurethane polymer were added and mixed at 70 r / min for 25 min to obtain a mixture. The mixture was extruded by a single screw extruder with the following temperature settings: zone 1 temperature 175°C, zone 2 temperature 185°C, zone 3 temperature 190°C, zone 4 temperature 190°C, and die temperature 185°C. After extrusion molding, the mixture was subjected to high-pressure sterilization, drying, and packaging to obtain a high-temperature resistant antibacterial suction catheter.

[0076] Comparative Example 1:

[0077] A method for preparing a high-temperature resistant, antibacterial suction catheter includes the following steps:

[0078] A 0.2M acetic acid solution and a 0.2M sodium acetate solution were mixed at a weight ratio of 1:1, and the pH was adjusted to 5.0 to obtain an acetate-sodium acetate buffer solution. Two parts by weight of quaternary ammonium salt chitosan were dispersed in 100 parts by weight of the acetate-sodium acetate buffer solution. After stirring at 25°C for 2 hours, 0.02 parts by weight of chitosanase were added, and the mixture was stirred at 45°C for 6 hours. After the reaction was completed, the temperature was raised to 85°C and held for 15 minutes. The mixture was then purified by centrifugation and dialysis to obtain modified chitosan. 55 parts by weight of polytetrahydrofuran (Mn=1000) and 35 parts by weight of polyethylene glycol (Mn=2000) were dehydrated in a vacuum environment at 100°C for 3 hours. The temperature was then lowered to 70°C, and 15 parts by weight of isophorone diisocyanate were added. The mixture was then dehydrated in a nitrogen-protected environment at 90°C. The prepolymer was obtained by stirring and reacting for 4 hours. After the reaction was completed, the temperature was lowered to 65°C, and 5 parts by weight of dimethylolpropionic acid and 2.5 parts by weight of modified chitosan were added and stirred for 6 hours. After cooling to 26°C, the prepolymer was precipitated with deionized water and then filtered and vacuum dried to obtain polyurethane polymer. The internal mixer was preheated to 190°C, and 40 parts by weight of the modified silane prepared in Preparation Example 5 and 90 parts by weight of polyurethane polymer were added and mixed at 70 r / min for 25 min to obtain a mixture. The mixture was extruded by a single screw extruder with the following temperature settings: zone 1 temperature 175°C, zone 2 temperature 185°C, zone 3 temperature 190°C, zone 4 temperature 190°C, and die temperature 185°C. After extrusion molding, the mixture was subjected to high-pressure sterilization, drying, and packaging to obtain a high-temperature resistant antibacterial suction catheter.

[0079] Comparative Example 2:

[0080] A method for preparing a high-temperature resistant, antibacterial suction catheter includes the following steps:

[0081] A 0.2M acetic acid solution and a 0.2M sodium acetate solution were mixed at a weight ratio of 1:1, and the pH was adjusted to 5.0 to obtain an acetate-sodium acetate buffer solution. Two parts by weight of quaternary ammonium salt chitosan were dispersed in 100 parts by weight of the acetate-sodium acetate buffer solution. After stirring at 25°C for 2 hours, 0.02 parts by weight of chitosanase were added, and the mixture was stirred at 45°C for 6 hours. After the reaction was completed, the temperature was raised to 85°C and held for 15 minutes. The mixture was then purified by centrifugation and dialysis to obtain modified chitosan. 55 parts by weight of polytetrahydrofuran (Mn=1000) and 35 parts by weight of polyethylene glycol (Mn=2000) were dehydrated in a vacuum environment at 100°C for 3 hours. The temperature was then lowered to 70°C, and 15 parts by weight of isophorone diisocyanate were added. The mixture was then dehydrated in a nitrogen-protected environment at 90°C. The prepolymer was obtained by stirring and reacting for 4 hours. After the reaction was completed, the temperature was lowered to 65°C, and 5 parts by weight of dimethylolpropionic acid and 2.5 parts by weight of modified chitosan were added and stirred for 6 hours. After cooling to 26°C, the prepolymer was precipitated with deionized water and then filtered and vacuum dried to obtain polyurethane polymer. The internal mixer was preheated to 190°C, and 40 parts by weight of the modified silane prepared in Preparation Example 6 and 90 parts by weight of polyurethane polymer were added and mixed at 70 r / min for 25 min to obtain a mixture. The mixture was extruded by a single screw extruder with the following temperature settings: zone 1 temperature 175°C, zone 2 temperature 185°C, zone 3 temperature 190°C, zone 4 temperature 190°C, and die temperature 185°C. After extrusion molding, the mixture was subjected to high-pressure sterilization, drying, and packaging to obtain a high-temperature resistant antibacterial suction catheter.

[0082] Comparative Example 3:

[0083] A method for preparing a high-temperature resistant, antibacterial suction catheter includes the following steps:

[0084] A 0.2M acetic acid solution and a 0.2M sodium acetate solution were mixed at a weight ratio of 1:1, and the pH was adjusted to 5.0 to obtain an acetate-sodium acetate buffer solution. Two parts by weight of quaternary ammonium salt chitosan were dispersed in 100 parts by weight of the acetate-sodium acetate buffer solution. After stirring at 25°C for 2 hours, 0.02 parts by weight of chitosanase were added, and the mixture was stirred at 45°C for 6 hours. After the reaction was completed, the temperature was raised to 85°C and held for 15 minutes. The mixture was then purified by centrifugation and dialysis to obtain modified chitosan. 55 parts by weight of polytetrahydrofuran (Mn=1000) and 35 parts by weight of polyethylene glycol (Mn=2000) were dehydrated in a vacuum environment at 100°C for 3 hours. The temperature was then lowered to 70°C, and 15 parts by weight of isophorone diisocyanate were added. The mixture was then dehydrated in a nitrogen-protected environment at 90°C. The prepolymer was obtained by stirring and reacting for 4 hours. After the reaction was completed, the temperature was lowered to 65°C, and 5 parts by weight of dimethylolpropionic acid and 2.5 parts by weight of modified chitosan were added and stirred for 6 hours. After cooling to 26°C, the prepolymer was precipitated with deionized water and then filtered and vacuum dried to obtain polyurethane polymer. The internal mixer was preheated to 190°C, and 40 parts by weight of the modified silane prepared in Preparation Example 7 and 90 parts by weight of polyurethane polymer were added and mixed at 70 r / min for 25 min to obtain a mixture. The mixture was extruded by a single screw extruder with the following temperature settings: zone 1 temperature 175°C, zone 2 temperature 185°C, zone 3 temperature 190°C, zone 4 temperature 190°C, and die temperature 185°C. After extrusion molding, the mixture was subjected to high-pressure sterilization, drying, and packaging to obtain a high-temperature resistant antibacterial suction catheter.

[0085] Comparative Example 4:

[0086] A method for preparing a high-temperature resistant, antibacterial suction catheter includes the following steps:

[0087] 55 parts by weight of polytetrahydrofuran (Mn=1000) and 35 parts by weight of polyethylene glycol (Mn=2000) were dehydrated in a vacuum environment at 100°C for 3 hours. The mixture was then cooled to 70°C, and 15 parts by weight of isophorone diisocyanate were added. The mixture was stirred and reacted at 90°C for 4 hours under nitrogen protection to obtain a prepolymer. After the reaction was completed, the mixture was cooled to 65°C, and 5 parts by weight of dimethylolpropionic acid and 2.5 parts by weight of a quaternary ammonium salt were added. The mixture was stirred and reacted for 6 hours, then cooled to 26°C and precipitated with deionized water. The precipitate was then filtered and vacuum dried to obtain the final product. The polyurethane polymer was added; the internal mixer was preheated to 190°C, and 40 parts by weight of the modified silane prepared in Example 4 and 90 parts by weight of the polyurethane polymer were added and mixed at 70 r / min for 25 min to obtain a mixture. The mixture was extruded through a single screw extruder with the following temperature settings: zone 1 temperature 175°C, zone 2 temperature 185°C, zone 3 temperature 190°C, zone 4 temperature 190°C, and die temperature 185°C. After extrusion molding, the mixture was then subjected to high-pressure sterilization, drying, and packaging to obtain a high-temperature resistant antibacterial suction catheter.

[0088] Comparative Example 5:

[0089] A method for preparing a high-temperature resistant, antibacterial suction catheter includes the following steps:

[0090] 55 parts by weight of polytetrahydrofuran (Mn=1000) and 35 parts by weight of polyethylene glycol (Mn=2000) were dehydrated in a vacuum environment at 100°C for 3 hours. The mixture was then cooled to 70°C, and 15 parts by weight of isophorone diisocyanate were added. The mixture was stirred and reacted at 90°C for 4 hours under nitrogen protection to obtain a prepolymer. After the reaction was completed, the mixture was cooled to 65°C, and 5 parts by weight of trimethylolpropane were added. The mixture was stirred and reacted for 6 hours, then cooled to 26°C and precipitated with deionized water. The precipitate was then filtered and vacuum dried to obtain a polyurethane polymer. The mixture was prepared by preheating the internal mixer to 190°C, adding 40 parts by weight of the modified silane prepared in Example 4 and 90 parts by weight of the polyurethane polymer, and mixing at 70 r / min for 25 min to obtain a mixture. The mixture was then extruded through a single screw extruder with the following temperature settings: zone 1 temperature 175°C, zone 2 temperature 185°C, zone 3 temperature 190°C, zone 4 temperature 190°C, and die temperature 185°C. After extrusion molding, the mixture was then subjected to high-pressure sterilization, drying, and packaging to obtain a high-temperature resistant antibacterial suction catheter.

[0091] Comparative Example 6:

[0092] A method for preparing a high-temperature resistant, antibacterial suction catheter includes the following steps:

[0093] A 0.2M acetic acid solution and a 0.2M sodium acetate solution were mixed at a weight ratio of 1:1, and the pH was adjusted to 5.0 to obtain an acetate-sodium acetate buffer solution. Two parts by weight of quaternary ammonium chitosan were dispersed in 100 parts by weight of the acetate-sodium acetate buffer solution. After stirring at 25°C for 2 hours, 0.02 parts by weight of chitosanase were added, and the mixture was stirred at 45°C for 6 hours. After the reaction was completed, the temperature was raised to 85°C and held for 15 minutes. The mixture was then purified by centrifugation and dialysis to obtain modified chitosan. 55 parts by weight of polytetrahydrofuran (Mn=1000) and 35 parts by weight of polyethylene glycol (Mn=2000) were dehydrated in a vacuum environment at 100°C for 3 hours. The temperature was then lowered to 70°C, and 15 parts by weight of isophorone diisocyanate were added. The prepolymer was obtained by stirring at 90°C for 4 hours under nitrogen protection. After the reaction, the temperature was lowered to 65°C, and 5 parts by weight of dimethylolpropionic acid and 2.5 parts by weight of modified chitosan were added and stirred for 6 hours. After cooling to 26°C, the prepolymer was precipitated with deionized water and then filtered and vacuum dried to obtain polyurethane polymer. The internal mixer was preheated to 190°C, and 90 parts by weight of polyurethane polymer were added and treated at 70 r / min for 25 minutes. The polymer was then extruded through a single screw extruder with the following temperature settings: zone 1 temperature 175°C, zone 2 temperature 185°C, zone 3 temperature 190°C, zone 4 temperature 190°C, and die temperature 185°C. The polymer was then subjected to high-pressure sterilization, drying, and packaging to obtain a high-temperature resistant antibacterial suction catheter.

[0094] Experimental Example 1: Hydrophilicity Test

[0095] The high-temperature resistant antibacterial suction catheters prepared in Examples 1-4 and Comparative Examples 1-6 were cut open, and their surface water contact angles were tested using a contact angle tester. The test results are shown in Table 1.

[0096] Table 1. Hydrophilicity Test

[0097]

[0098] The test results in Table 1 show that the high-temperature resistant antibacterial suction catheters prepared in Examples 1-4 of this invention have good hydrophilicity. The decrease in hydrophilicity of Comparative Examples 1-3 may be due to the reduction of hydrophilic groups in the modified silane.

[0099] Test Example 2: Antibacterial Test

[0100] The high-temperature resistant antibacterial suction catheters prepared in Examples 1-4 and Preparation Examples 1-6 were used as samples. The bacterial strains were diluted with sterile water to prepare appropriate concentration bacterial suspensions. 0.2 ml of the bacterial suspension was dropped onto the sample surface and covered with a 0.1 mm thick polyethylene film to form a uniform liquid film between the sample and the film. After incubation at 37°C and 90% relative humidity for 18-24 hours, the bacterial suspension was washed off with sterile water and diluted to an appropriate concentration gradient. 0.1 ml of this solution was evenly spread on prepared sterile light culture medium and incubated at 37°C for 18-24 hours. The results were observed. A sterile Petri dish was used as a negative control, with the other procedures remaining the same. The bacteria used for detection were *Escherichia coli* ATCC 25922 and *Staphylococcus aureus* ATCC 6538. The detection results are shown in Table 2.

[0101] Table 2. Antibacterial performance test

[0102]

[0103] As can be seen from the test results in Table 2, the high-temperature resistant antibacterial suction catheters prepared in Examples 1-4 of this invention have good antibacterial properties. The decrease in antibacterial properties of Comparative Example 3 may be due to the lack of modified resveratrol, which weakens its antibacterial properties. The decrease in antibacterial properties of Comparative Example 5 may be due to the lack of modified chitosan, which leads to the absence of quaternary ammonium salt groups, thus resulting in a decrease in its antibacterial properties.

[0104] Test Example 3: Heat Distortion Temperature Detection

[0105] The heat distortion temperature of the high-temperature resistant antibacterial suction catheters prepared in Examples 1-4 and Preparation Examples 1-6 was tested according to ISO 75-2:2013 standard, and the test results are shown in Table 3.

[0106] Table 3. Heat distortion temperature detection

[0107]

[0108] The data in Table 3 show that the heat distortion temperature of the high-temperature resistant antibacterial suction catheters prepared in Examples 1-4 of the present invention is higher than that of the high-temperature resistant antibacterial suction catheters prepared in Comparative Examples 1-6. The lower heat distortion temperature of Comparative Example 3 may be due to the absence of hydroxypropyl-β-cyclodextrin, which reduces its heat resistance. The lower heat distortion temperature of Comparative Example 6 may be due to the simultaneous absence of hydroxypropyl-β-cyclodextrin and siloxane network, which reduces its thermal stability.

[0109] Test Example 4: Mechanical Property Testing

[0110] Using an Instron 5567 universal testing machine, the high-temperature resistant antibacterial suction catheters prepared in Examples 1-5 and Comparative Examples 1-6 were placed on the testing machine. The longitudinal axis of the specimen was aligned with the center lines of the upper and lower clamps. The test speed was 10 mm / min. The test was stopped when the specimen broke. The test results are shown in Table 4.

[0111] Table 4. Mechanical property testing

[0112]

[0113] The test results in Table 4 show that the high-temperature resistant antibacterial suction catheters prepared in Examples 1-4 of this invention have good mechanical properties, while the mechanical properties of Comparative Examples 1-6 are significantly reduced. This may be because the flexibility and high elongation at break of the modified silane complement the high tensile strength of the polyurethane polymer. The two form a homogeneous structure through hydrogen bonding or physical interaction, which synergistically improves the mechanical properties of the high-temperature resistant antibacterial suction catheter. The absence of some raw materials may affect this synergistic effect, leading to a decrease in the mechanical properties of the high-temperature resistant antibacterial suction catheter.

[0114] The embodiments described above provide a detailed explanation of the technical solutions and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Various changes and modifications can be made to the present invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed.

Claims

1. A method for preparing a high-temperature resistant, antibacterial suction catheter, characterized in that, The preparation method includes the following steps: Quaternary ammonium salt chitosan is treated with chitosanase to obtain modified chitosan. Polytetrahydrofuran, polyethylene glycol and diisocyanate are reacted to obtain a prepolymer. The prepolymer, dimethylolpropionic acid and modified chitosan are reacted to obtain a polyurethane prepolymer. Modified silane and polyurethane prepolymer are mixed to obtain a mixture. The mixture is extruded to obtain a high-temperature resistant antibacterial suction catheter. The method for preparing the modified silane includes the following steps: Hydroxypropyl-β-cyclodextrin and resveratrol were reacted to obtain modified resveratrol. 3-mercaptopropyltrimethoxysilane, itaconic acid and an initiator were reacted to obtain carboxylated silane. Modified resveratrol and carboxylated silane were mixed and then subjected to acid treatment and alkali treatment in sequence to obtain modified silane. The weight ratio of the modified resveratrol to the carboxylated silane is 1~3:9~11.

2. The method for preparing a high-temperature resistant antibacterial suction catheter as described in claim 1, characterized in that, The reaction conditions for hydroxypropyl-β-cyclodextrin and resveratrol include a reaction temperature of 55-60°C and a reaction time of 8-12 h.

3. The method for preparing a high-temperature resistant antibacterial suction catheter as described in claim 1, characterized in that, The initiator is benzoin diethyl ether.

4. The method for preparing a high-temperature resistant antibacterial suction catheter as described in claim 1, characterized in that, The reaction conditions for the 3-mercaptopropyltrimethoxysilane, itaconic acid and initiator are: irradiation with 365nm ultraviolet light for 30-60 minutes.

5. The method for preparing a high-temperature resistant antibacterial suction catheter as described in claim 1, characterized in that, The diisocyanate includes hexamethylene diisocyanate or isophorone diisocyanate.

6. The method for preparing a high-temperature resistant antibacterial suction catheter as described in claim 1, characterized in that, The reaction conditions for the prepolymer, dimethylolpropionic acid, and modified chitosan include a reaction temperature of 55-65°C and a reaction time of 4-6 hours.

7. The method for preparing a high-temperature resistant antibacterial suction catheter as described in claim 1, characterized in that, The conditions for mixing the modified silane and polyurethane prepolymer include a mixing temperature of 180~190℃ and a mixing time of 15~25min.

8. A high-temperature resistant, antibacterial suction catheter, characterized in that, It is prepared by the method described in any one of claims 1 to 7 for preparing a high-temperature resistant antibacterial suction catheter.

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