A preparation method of medical hydrophilic polyurethane sponge

Abstract

The invention discloses a method for preparing a medical hydrophilic polyurethane sponge, belonging to the technical field of polyurethane sponges. The preparation method comprises the following steps: stirring and mixing polyether polyol, polyester polyol, pure water, foam leveling agent 9205, stannous octoate, propylene glycol solution of triethylene diamine with a mass fraction of 33% and nano silver antibacterial agent, adding polyisocyanate thereto, stirring and mixing, adding modified ciprofloxacin thereto, stirring and mixing again, obtaining a mixture, pouring the mixture into a mold, standing, foaming, and demoulding after curing to obtain a medical hydrophilic polyurethane sponge. The invention provides a method for preparing a polyurethane sponge using a one-step foaming process. The invention realizes the comprehensive improvement of the hydrophilicity and antibacterial properties of the polyurethane sponge by introducing homemade nano silver antibacterial agent and modified ciprofloxacin. After testing, the finally prepared medical hydrophilic polyurethane sponge has excellent hydrophilicity, antibacterial property and antibacterial stability.

Description

Technical Field

[0001] The invention belongs to the technical field of polyurethane sponges, and particularly relates to a method for preparing a medical hydrophilic polyurethane sponge. Background Art

[0002] Polyurethane sponge, with its unique three-dimensional porous structure, shows great application potential in the field of wound care. However, the insufficient hydrophilicity of polyurethane sponge itself limits its application in the medical field. In view of this, the hydrophilicity of polyurethane sponge has been improved in the prior art:

[0003] For example, the Chinese invention patent with application number 202010944397.5 discloses a medical hydrophilic polyurethane sponge and a preparation method thereof. The invention introduces polyethylene glycol and polyacrylamide into the polyurethane sponge system and prepares the hydrophilic polyurethane sponge through a two-step method.

[0004] The above-mentioned existing technology can significantly improve the hydrophilicity of polyurethane sponges. However, due to the high risk of bacterial infection in hospital environments and the fact that polyurethane itself does not have antibacterial properties, the development of a hydrophilic polyurethane sponge with antibacterial function is crucial to meet the needs of medical clinical practice. Therefore, it is necessary to improve the existing polyurethane sponges. Summary of the invention

[0005] The present invention provides a method for preparing a polyurethane sponge, which further improves the antibacterial performance of a polyurethane foaming material on the basis of improving its hydrophilicity, thereby meeting the needs of medical clinics.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A method for preparing a medical hydrophilic polyurethane sponge comprises the following steps:

[0008] Polyether polyol, polyester polyol, pure water, foaming agent 9205, stannous octoate, 33% by mass of triethylenediamine propylene glycol solution and nano silver antibacterial agent are stirred and mixed, polyisocyanate is added thereto, stirred and mixed, modified ciprofloxacin is added thereto, stirred and mixed again to obtain a mixture, the mixture is poured into a mold, allowed to stand, foamed and cured, and demolded after 40 to 50 minutes to obtain a medical hydrophilic polyurethane sponge.

[0009] Furthermore, the dosage ratio of the polyether polyol, polyester polyol, pure water, foam leveling agent 9205, stannous octoate, propylene glycol solution of triethylene diamine with a mass fraction of 33%, nanosilver antibacterial agent, polyisocyanate and modified ciprofloxacin is 75 g: 25 g: 3 g: 1.0-1.5 g: 0.15-0.20 g: 0.3-0.5 g: 1.2-1.5 g: 45-50 g: 20 g.

[0010] Furthermore, the polyisocyanate is one of isophorone diisocyanate, 4,4'-diphenylmethane diisocyanate and hexamethylene diisocyanate.

[0011] Furthermore, the nano silver antibacterial agent is prepared by the following steps:

[0012] Carboxymethyl chitosan is added to deionized water with stirring, and then sodium hydroxide is added thereto to adjust the pH of the system to 10.0-10.5 with stirring, and then nanosilver is added thereto with stirring, and the mixture is stirred at a constant temperature for 2-3 hours to obtain a nanosilver antibacterial agent.

[0013] Furthermore, the usage ratio of the deionized water, carboxymethyl chitosan and nano-silver is 100 mL: 0.2-0.3 g: 0.1 g.

[0014] Furthermore, the modified ciprofloxacin is prepared by the following steps:

[0015] Add ciprofloxacin, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide to dichloromethane with stirring, stir and mix at room temperature for 1 h, then add the amino-terminated monomer with stirring, heat to 35-40°C, stir and react for 12 h, and after completion, cool to room temperature, remove dichloromethane by rotary evaporation, and obtain modified ciprofloxacin. The preparation process of modified ciprofloxacin is as follows:

[0016] .

[0017] Furthermore, the usage ratio of the dichloromethane, ciprofloxacin, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, N-hydroxysuccinimide and amino-terminated monomer is 100 mL: 0.1 mol: 14-15 g: 9-10 g: 21-22 g.

[0018] Furthermore, the amino-terminated monomer is prepared by the following steps:

[0019] S1. Add tris(hydroxymethyl)aminomethane and triethylamine to dimethyl sulfoxide, stir for 30 min, fill with nitrogen, add 2-chloro-5-nitropyridine, heat to 85-90°C, stir and react for 5-6 h. After completion, cool to room temperature, remove dimethyl sulfoxide by rotary evaporation, and obtain an intermediate. The preparation process of the intermediate is as follows:

[0020] .

[0021] S2. Add anhydrous ethanol, 18% hydrochloric acid aqueous solution and iron powder to deionized water, heat to 80-90°C, stir for 30 minutes, cool to room temperature, add the intermediate with stirring, heat to 80-90°C, stir at constant temperature for 5-6 hours, cool to room temperature, filter, add ammonia water to the filtrate to adjust the pH of the system to 8.5-9.0, let stand at room temperature for 12 hours, filter, wash and dry to obtain the terminal amino monomer. The preparation process of the terminal amino monomer is as follows:

[0022] .

[0023] Furthermore, the usage ratio of dimethyl sulfoxide, tris(hydroxymethyl)aminomethane, triethylamine and 2-chloro-5-nitropyridine in S1 is 100 mL: 0.11-0.12 mol: 10-11 g: 0.1 mol.

[0024] Furthermore, the usage ratio of the deionized water, anhydrous ethanol, 18% hydrochloric acid aqueous solution, iron powder and intermediate in S2 is 100 mL: 20 mL: 6-8 mL: 20 g: 40-45 g.

[0025] Beneficial effects of the present invention:

[0026] The invention provides a method for preparing a polyurethane sponge by utilizing a one-step foaming process. The invention realizes comprehensive improvement of the hydrophilicity and antibacterial properties of the polyurethane sponge by introducing a homemade nano-silver antibacterial agent and modified ciprofloxacin. After testing, the finally prepared medical hydrophilic polyurethane sponge has excellent hydrophilicity, antibacterial property and antibacterial stability, and meets the needs of medical clinics.

[0027] First, the present invention adds a nano-silver antibacterial agent to the polyurethane sponge, and the nano-silver antibacterial agent is prepared by carboxymethyl chitosan carrying nano-silver. The present invention utilizes the broad-spectrum and efficient antibacterial properties of nano-silver to achieve effective antibacterial. At the same time, when the hydrophilic polyurethane sponge is repeatedly subjected to liquid adsorption and extrusion discharge, the nano-silver powder on the polyurethane sponge is easily detached and lost, resulting in poor stability of the antibacterial performance of the polyurethane sponge, and the detached nano-silver is easy to cause damage to human health through the skin or wounds. Therefore, the present invention utilizes the abundant carboxyl groups on the carboxymethyl chitosan to chelate with nano-silver, improves the adhesion stability of nano-silver on the polyurethane sponge, and the carboxymethyl chitosan also has good antibacterial performance, and the hydrophilic carboxyl groups on the carboxymethyl chitosan can assist in improving the hydrophilicity of the polyurethane sponge. Finally, the introduction of the nano-silver antibacterial agent can significantly improve the antibacterial performance and stability of the polyurethane sponge.

[0028] Then, the present invention adds modified ciprofloxacin to the polyurethane sponge, wherein the modified ciprofloxacin is prepared by amidation reaction between the carboxyl group on ciprofloxacin and the terminal amino group of the terminal amino group monomer, wherein the ciprofloxacin has a broad-spectrum antibacterial property, ciprofloxacin mainly interferes with bacterial DNA replication, repair and transcription processes by inhibiting bacterial DNA helicase and topoisomerase IV, while nano-silver destroys bacterial cell walls and cell membranes by releasing silver ions, and interferes with bacterial metabolism and reproduction, and the two have different action mechanisms and can complement each other to enhance the antibacterial effect, and at the same time, the combined use of ciprofloxacin and nano-silver can reduce the use concentration of a single drug, reduce the selection pressure of drug-resistant strains, and delay the generation of drug resistance. Antibacterial performance detection shows that ciprofloxacin and nano-silver have a synergistic effect.

[0029] Next, the modified ciprofloxacin has an amide group (-CONH-), which has excellent hydrophilicity. The introduction of the modified ciprofloxacin can improve the hydrophilicity of the polyurethane sponge. At the same time, the terminal amino monomer contains abundant hydroxyl groups, which can further improve the hydrophilicity of the polyurethane sponge.

[0030] Finally, the modified ciprofloxacin contains abundant nitrogen-containing structures, such as nitrogen-containing ring structures (piperazine ring, quinoline ring and pyridine ring), amide group and amino group (-NH-). The nitrogen atoms in the nitrogen-containing structure can form coordination bonds with the silver in the nanosilver antibacterial agent, further improving the stability of the antibacterial properties of the polyurethane sponge and comprehensively improving the antibacterial properties of the polyurethane sponge. DETAILED DESCRIPTION

[0031] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0032] Example 1

[0033] Preparation of nano silver antibacterial agent:

[0034] Take 100 mL of deionized water, add 0.2 g of carboxymethyl chitosan (substitution degree ≥ 80%; purchased from Sinopharm Chemical Reagent Co., Ltd.) thereto with stirring, then add sodium hydroxide thereto to adjust the pH of the system to 10.0 with stirring, then add 0.1 g of nanosilver (99.9%; 20-40 nm; purchased from Sinopharm Chemical Reagent Co., Ltd.) thereto with stirring, and stir at constant temperature for 2 h to obtain a nanosilver antibacterial agent.

[0035] Example 2

[0036] Preparation of nano silver antibacterial agent:

[0037] Take 100 mL of deionized water, add 0.28 g of carboxymethyl chitosan (substitution degree ≥ 80%; purchased from Sinopharm Chemical Reagent Co., Ltd.) thereto with stirring, then add sodium hydroxide thereto with stirring to adjust the pH of the system to 10.5, then add 0.1 g of nanosilver (99.9%; 20-40 nm; purchased from Sinopharm Chemical Reagent Co., Ltd.) thereto with stirring, and stir at constant temperature for 3 hours to obtain a nanosilver antibacterial agent.

[0038] Example 3

[0039] Preparation of nano silver antibacterial agent:

[0040] Take 100 mL of deionized water, add 0.3 g of carboxymethyl chitosan (degree of substitution ≥ 80%; purchased from Sinopharm Chemical Reagent Co., Ltd.) thereto with stirring, then add sodium hydroxide thereto to adjust the pH of the system to 10.5 with stirring, then add 0.1 g of nanosilver (99.9%; 20-40 nm; purchased from Sinopharm Chemical Reagent Co., Ltd.) thereto with stirring, and stir at constant temperature for 3 h to obtain a nanosilver antibacterial agent.

[0041] Example 4

[0042] Preparation of amino-terminated monomers:

[0043] S1. Take 100 mL of dimethyl sulfoxide, add 0.11 mol of tris(hydroxymethyl)aminomethane (AR; purchased from Sinopharm Chemical Reagent Co., Ltd.) and 10 g of triethylamine (AR; purchased from Sinopharm Chemical Reagent Co., Ltd.), stir for 30 min, fill with nitrogen, then add 0.1 mol of 2-chloro-5-nitropyridine (98%; purchased from Sinopharm Chemical Reagent Co., Ltd.), heat to 85°C, stir and react for 5 h, cool to room temperature after completion, and remove dimethyl sulfoxide by rotary evaporation to obtain an intermediate;

[0044] S2. Take 100 mL of deionized water, add 20 mL of anhydrous ethanol, 6 mL of 18% hydrochloric acid aqueous solution and 20 g of iron powder (particle size 3 μm; purchased from Sinopharm Chemical Reagent Co., Ltd.), heat to 80°C, stir for 30 min, then cool to room temperature, add 40 g of the intermediate with stirring, heat to 80°C, stir at constant temperature for 5 h, cool to room temperature, filter, add ammonia water to the filtrate to adjust the pH of the system to 8.5, let stand at room temperature for 12 h, filter, wash and dry to obtain the terminal amino monomer.

[0045] Example 5

[0046] Preparation of amino-terminated monomers:

[0047] S1. Take 100 mL of dimethyl sulfoxide, add 0.12 mol of tris(hydroxymethyl)aminomethane (AR; purchased from Sinopharm Chemical Reagent Co., Ltd.) and 10.5 g of triethylamine (AR; purchased from Sinopharm Chemical Reagent Co., Ltd.), stir for 30 min, fill with nitrogen, then add 0.1 mol of 2-chloro-5-nitropyridine (98%; purchased from Sinopharm Chemical Reagent Co., Ltd.), heat to 90°C, stir and react for 6 h, cool to room temperature after completion, and remove dimethyl sulfoxide by rotary evaporation to obtain an intermediate;

[0048] S2. Take 100 mL of deionized water, add 20 mL of anhydrous ethanol, 7 mL of 18% hydrochloric acid aqueous solution and 20 g of iron powder (particle size 3 μm; purchased from Sinopharm Chemical Reagent Co., Ltd.), heat to 90°C, stir for 30 min, then cool to room temperature, add 44 g of the intermediate with stirring, heat to 90°C, stir at constant temperature for 6 h, cool to room temperature, filter, add ammonia water to the filtrate to adjust the pH of the system to 9.0, let stand at room temperature for 12 h, filter, wash and dry to obtain the terminal amino monomer.

[0049] Example 6

[0050] Preparation of amino-terminated monomers:

[0051] S1. Take 100 mL of dimethyl sulfoxide, add 0.12 mol of tris(hydroxymethyl)aminomethane (AR; purchased from Sinopharm Chemical Reagent Co., Ltd.) and 11 g of triethylamine (AR; purchased from Sinopharm Chemical Reagent Co., Ltd.), stir for 30 min, fill with nitrogen, then add 0.1 mol of 2-chloro-5-nitropyridine (98%; purchased from Sinopharm Chemical Reagent Co., Ltd.), heat to 90°C, stir and react for 6 h, cool to room temperature after completion, and remove dimethyl sulfoxide by rotary evaporation to obtain an intermediate;

[0052] S2. Take 100 mL of deionized water, add 20 mL of anhydrous ethanol, 8 mL of 18% hydrochloric acid aqueous solution and 20 g of iron powder (particle size 3 μm; purchased from Sinopharm Chemical Reagent Co., Ltd.), heat to 90°C, stir for 30 min, then cool to room temperature, add 45 g of the intermediate with stirring, heat to 90°C, stir at constant temperature for 6 h, cool to room temperature, filter, add ammonia water to the filtrate to adjust the pH of the system to 9.0, let stand at room temperature for 12 h, filter, wash and dry to obtain the terminal amino monomer.

[0053] Example 7

[0054] Preparation of modified ciprofloxacin:

[0055] Take 100 mL of dichloromethane, add 0.1 mol of ciprofloxacin (98%; purchased from Shanghai MacLean Biochemical Technology Co., Ltd.), 14 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (98%; purchased from Shanghai MacLean Biochemical Technology Co., Ltd.) and 9 g of N-hydroxysuccinimide (98%; purchased from Shanghai MacLean Biochemical Technology Co., Ltd.) into it with stirring, mix at room temperature for 1 h, then add 21 g of the amino-terminated monomer prepared in Example 4 into it with stirring, heat to 35° C., stir and react for 12 h, cool to room temperature after completion, and remove dichloromethane by rotary evaporation to obtain modified ciprofloxacin.

[0056] Example 8

[0057] Preparation of modified ciprofloxacin:

[0058] Take 100 mL of dichloromethane, add 0.1 mol of ciprofloxacin (98%; purchased from Shanghai MacLean Biochemical Technology Co., Ltd.), 14.5 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (98%; purchased from Shanghai MacLean Biochemical Technology Co., Ltd.) and 10 g of N-hydroxysuccinimide (98%; purchased from Shanghai MacLean Biochemical Technology Co., Ltd.) into it with stirring, mix at room temperature for 1 h, then add 22 g of the amino-terminated monomer prepared in Example 5 into it with stirring, heat to 40°C, stir and react for 12 h, cool to room temperature after completion, and remove dichloromethane by rotary evaporation to obtain modified ciprofloxacin.

[0059] Example 9

[0060] Preparation of modified ciprofloxacin:

[0061] Take 100 mL of dichloromethane, add 0.1 mol of ciprofloxacin (98%; purchased from Shanghai MacLean Biochemical Technology Co., Ltd.), 15 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (98%; purchased from Shanghai MacLean Biochemical Technology Co., Ltd.) and 10 g of N-hydroxysuccinimide (98%; purchased from Shanghai MacLean Biochemical Technology Co., Ltd.) into it with stirring, mix at room temperature for 1 h, then add 22 g of the amino-terminated monomer prepared in Example 6 into it with stirring, heat to 40°C, stir and react for 12 h, cool to room temperature after completion, and remove dichloromethane by rotary evaporation to obtain modified ciprofloxacin.

[0062] Example 10

[0063] Preparation of medical hydrophilic polyurethane sponge:

[0064] 75 g of polyether polyol (elastomeric polyether polyol; average Mn 2000; purchased from Shanghai Yuanye Biotechnology Co., Ltd.), 25 g of polyester polyol (VANTHANOL ® WHP-204; purchased from Wanhua Chemical Group Co., Ltd.), 3 g of pure water, 1.0 g of leveling agent 9205 (purchased from Zhangjiagang Shoubo Electronic Materials Co., Ltd.), 0.15 g of stannous octoate (analytical grade; purchased from Sinopharm Chemical Reagent Co., Ltd.), 0.3 g of 33% mass fraction of triethylenediamine propylene glycol solution (triethylenediamine purchased from Sinopharm Chemical Reagent Co., Ltd.) and 1.2 g of the nano silver antibacterial agent prepared in Example 1, stirred and mixed for 20 min, and then 45 g of polyisocyanate isophorone diisocyanate, 4,4'-diphenylmethane diisocyanate and hexamethylene diisocyanate (analytical grade; purchased from Sinopharm Chemical Reagent Co., Ltd.) were added thereto, stirred and mixed for 20 min, and then 20 g of modified ciprofloxacin prepared in Example 7 was added thereto, and stirred and mixed for 8 min to obtain a mixed material, and the mixed material was poured into a mold for standing, foaming, and curing, and demolded after 40 min to obtain a medical hydrophilic polyurethane sponge.

[0065] Embodiment 11

[0066] Preparation of medical hydrophilic polyurethane sponge:

[0067] 75 g of polyether polyol (elastomeric polyether polyol; average Mn 2000; purchased from Shanghai Yuanye Biotechnology Co., Ltd.), 25 g of polyester polyol (VANTHANOL ® WHP-204; purchased from Wanhua Chemical Group Co., Ltd.), 3 g of pure water, 1.4 g of leveling agent 9205 (purchased from Zhangjiagang Shoubo Electronic Materials Co., Ltd.), 0.20 g of stannous octoate (analytical grade; purchased from Sinopharm Chemical Reagent Co., Ltd.), 0.45 g of 33% mass fraction of triethylenediamine propylene glycol solution (triethylenediamine purchased from Sinopharm Chemical Reagent Co., Ltd.) and 1.5 g of the nano silver antibacterial agent prepared in Example 2, stirred and mixed for 30 min, and then 50 g of polyisocyanate isophorone diisocyanate, 4,4'-diphenylmethane diisocyanate and hexamethylene diisocyanate (analytical grade; purchased from Sinopharm Chemical Reagent Co., Ltd.) were added thereto, stirred and mixed for 30 min, and then 20 g of modified ciprofloxacin prepared in Example 8 was added thereto, and stirred and mixed for 10 min to obtain a mixed material, and the mixed material was poured into a mold for standing, foaming, and curing, and demolded after 50 min to obtain a medical hydrophilic polyurethane sponge.

[0068] Example 12

[0069] Preparation of medical hydrophilic polyurethane sponge:

[0070] 75 g of polyether polyol (elastomeric polyether polyol; average Mn 2000; purchased from Shanghai Yuanye Biotechnology Co., Ltd.), 25 g of polyester polyol (VANTHANOL ® WHP-204; purchased from Wanhua Chemical Group Co., Ltd.), 3 g of pure water, 1.5 g of leveling agent 9205 (purchased from Zhangjiagang Shoubo Electronic Materials Co., Ltd.), 0.20 g of stannous octoate (analytical grade; purchased from Sinopharm Chemical Reagent Co., Ltd.), 0.5 g of 33% mass fraction of triethylenediamine propylene glycol solution (triethylenediamine purchased from Sinopharm Chemical Reagent Co., Ltd.) and 1.5 g of the nano silver antibacterial agent prepared in Example 3, stirred and mixed for 30 min, and then 50 g of polyisocyanate isophorone diisocyanate, 4,4'-diphenylmethane diisocyanate and hexamethylene diisocyanate (analytical grade; purchased from Sinopharm Chemical Reagent Co., Ltd.) were added thereto, stirred and mixed for 30 min, and then 20 g of modified ciprofloxacin prepared in Example 9 was added thereto, and stirred and mixed for 10 min to obtain a mixed material, and the mixed material was poured into a mold for standing, foaming, and curing, and demolded after 50 min to obtain a medical hydrophilic polyurethane sponge.

[0071] Comparative Example 1

[0072] Comparative Example 1 is the control group of Example 11, except that 1.5 g of the nano silver antibacterial agent prepared in Example 2 in Example 11 is removed, and the remaining raw materials, raw material amounts and preparation methods remain unchanged, and finally a medical hydrophilic polyurethane sponge is obtained.

[0073] Comparative Example 2

[0074] Comparative Example 2 is the control group of Example 11, in which 20 g of the modified ciprofloxacin prepared in Example 8 in Example 11 is replaced with 20 g of ciprofloxacin, and the other raw materials, raw material amounts and preparation methods remain unchanged, and finally a medical hydrophilic polyurethane sponge is obtained.

[0075] Comparative Example 3

[0076] Comparative Example 2 is the control group of Example 11, except that 20 g of the modified ciprofloxacin prepared in Example 8 in Example 11 is removed, and the remaining raw materials, raw material amounts and preparation methods remain unchanged, and finally a medical hydrophilic polyurethane sponge is obtained.

[0077] Test Example 1

[0078] The performance test of the medical hydrophilic polyurethane sponge (hereinafter referred to as: sponge) prepared in Examples 10 to 12 and Comparative Examples 1 to 3 was performed. The test process is as follows, and the following test process is described based on a single embodiment. Examples 10 to 12 and Comparative Examples 1 to 3 were tested according to the same steps, and the specific test results are shown in Table 1 below:

[0079] Hydrophilicity: The wettability of the sponge surface was characterized using an FCA2000A4R contact angle meter. Specifically, 4.5 μL of water was dropped onto the sponge surface for observation and the water contact angle was measured. Multiple measurements (10 times in this test example) were taken as the average value.

[0080] Antibacterial properties: On a 37°C constant temperature shaker, 10 mg of sponge was mixed with 1 mL of 10 7 The Escherichia coli suspension and Staphylococcus aureus suspension (hereinafter referred to as bacterial suspension) were mixed and co-cultured at a speed of 200 r / min for 12 h, which was recorded as the experimental group; at the same time, the bacterial suspension without sponge was used as the control group. After 12 h of co-culture, the co-cultured bacterial suspensions of the experimental group and the control group were diluted to 10 using PBS phosphate buffer (0.05 mol / L; pH 7.0; containing 0.05M NaCl; purchased from Shanghai Yuanye Biotechnology Co., Ltd.) 5 CFU / mL, and then 100 μL of the diluted experimental group / control group bacterial suspension was spread on the surface of the agar plate, and then the agar plate was placed in a 37°C shaking incubator for 24 h. After the incubation, the number of colonies was recorded by the plate colony counting method, and the antibacterial rate was calculated according to the following formula, where N0 is the number of colonies in the control group; N1 is the number of colonies in the experimental group.

[0081] Antibacterial rate = (N0-N1) × 100% / N0.

[0082] Antibacterial stability: fully immerse the sponge in pure water, then take it out and squeeze it until there are no droplets. Repeat the water absorption-squeezing process 100 times. After squeezing the sponge dry for the last time, place it in a drying oven and dry it to constant weight at room temperature. Then calculate the antibacterial rate by referring to the above antibacterial performance test process.

[0083] Table 1 Performance test results

[0084]

[0085] It can be seen from Table 1 that the addition of the nano silver antibacterial agent and modified ciprofloxacin prepared by the present invention can significantly improve the hydrophilicity and antibacterial properties of the polyurethane sponge; at the same time, the nano silver antibacterial agent and the modified ciprofloxacin have a synergistic effect on the antibacterial performance; finally, the modification process of ciprofloxacin and the modified ciprofloxacin have a significant effect on the stability of the antibacterial properties of the polyurethane sponge.

[0086] It should be noted that, in this article, terms such as "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or equipment that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment.

[0087] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a medical hydrophilic polyurethane sponge, characterized in that: The following steps are involved: The polyether polyol, polyester polyol, pure water, foam leveling agent 9205, stannous octoate, a propylene glycol solution of triethylene diamine with a mass fraction of 33% and a nano-silver antibacterial agent are stirred and mixed, polyisocyanate is added thereto, the mixture is stirred and mixed, modified ciprofloxacin is added thereto, the mixture is stirred and mixed again to obtain a mixture, the mixture is poured into a mold, allowed to stand, foamed, and cured, and demolded after 40 to 50 minutes to obtain a medical hydrophilic polyurethane sponge; The nano silver antibacterial agent is prepared by the following steps: adding carboxymethyl chitosan to deionized water with stirring, then adding sodium hydroxide to the deionized water with stirring to adjust the pH of the system to 10.0-10.5, then adding nano silver to the deionized water with stirring, and stirring at a constant temperature for 2-3 hours to obtain the nano silver antibacterial agent; The structure of the modified ciprofloxacin is as follows: 。 2. The method for preparing a medical hydrophilic polyurethane sponge according to claim 1, characterized in that: The dosage ratio of the polyether polyol, polyester polyol, pure water, foam leveling agent 9205, stannous octoate, propylene glycol solution of triethylene diamine with a mass fraction of 33%, nano silver antibacterial agent, polyisocyanate and modified ciprofloxacin is 75 g: 25 g: 3 g: 1.0-1.5 g: 0.15-0.20 g: 0.3-0.5 g: 1.2-1.5 g: 45-50 g: 20 g.

3. The method for preparing a medical hydrophilic polyurethane sponge according to claim 1, characterized in that: The polyisocyanate is one of isophorone diisocyanate, 4,4'-diphenylmethane diisocyanate and hexamethylene diisocyanate.

4. The method for preparing a medical hydrophilic polyurethane sponge according to claim 1, characterized in that: The usage ratio of the deionized water, carboxymethyl chitosan and nano silver is 100 mL: 0.2-0.3 g: 0.1 g.

5. The method for preparing a medical hydrophilic polyurethane sponge according to claim 1, characterized in that: The modified ciprofloxacin is prepared by the following steps: adding ciprofloxacin, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide to dichloromethane with stirring, stirring and mixing at room temperature for 1 hour, then adding the amino-terminated monomer with stirring, heating to 35-40° C., stirring and reacting for 12 hours, cooling to room temperature after completion, and removing dichloromethane by rotary evaporation to obtain the modified ciprofloxacin.

6. The method for preparing a medical hydrophilic polyurethane sponge according to claim 5, characterized in that: The usage ratio of the dichloromethane, ciprofloxacin, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, N-hydroxysuccinimide and amino-terminated monomer is 100 mL: 0.1 mol: 14-15 g: 9-10 g: 21-22 g.

7. The method for preparing a medical hydrophilic polyurethane sponge according to claim 5, characterized in that: The amino-terminated monomer is prepared by the following steps: S1. Add tris(hydroxymethyl)aminomethane and triethylamine to dimethyl sulfoxide, stir for 30 min, fill with nitrogen, add 2-chloro-5-nitropyridine, heat to 85-90°C, stir to react for 5-6 h, and after completion, cool to room temperature, remove dimethyl sulfoxide by rotary evaporation to obtain an intermediate; S2. Add anhydrous ethanol, 18% hydrochloric acid aqueous solution and iron powder to deionized water, heat to 80-90°C, stir for 30 min, cool to room temperature, add the intermediate and stir, heat to 80-90°C, stir at constant temperature for 5-6 h. After completion, cool to room temperature, filter, add ammonia water to the filtrate to adjust the pH of the system to 8.5-9.0, let stand at room temperature for 12 h, filter, wash and dry to obtain the terminal amino monomer.

8. The method for preparing a medical hydrophilic polyurethane sponge according to claim 7, characterized in that: The usage ratio of dimethyl sulfoxide, tris(hydroxymethyl)aminomethane, triethylamine and 2-chloro-5-nitropyridine in S1 is 100 mL: 0.11-0.12 mol: 10-11 g: 0.1 mol.

9. The method for preparing a medical hydrophilic polyurethane sponge according to claim 7, characterized in that: The usage ratio of deionized water, anhydrous ethanol, 18% hydrochloric acid aqueous solution, iron powder and intermediate in S2 is 100 mL: 20 mL: 6-8 mL: 20 g: 40-45 g.

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