Medical dressing capable of absorbing moisture and releasing sweat and preparation method thereof

Abstract

The invention discloses a medical dressing capable of absorbing moisture and releasing sweat and a preparation method of the medical dressing, and relates to the technical field of medical dressings, the medical dressing comprises a polyurethane copolyester nanofiber membrane, and the preparation method of the polyurethane copolyester nanofiber membrane comprises the following steps: pouring non-isocyanate polyurethane copolyester, levofloxacin and polyacrylonitrile into hexafluoroisopropanol, and stirring uniformly; carrying out electrostatic spinning; and spin-coating a chitosan-gelatin-glycerol mixed solution, and spin-coating a spermidine cross-linking agent to obtain the polyurethane copolyester nanofiber membrane. By introducing the polyglycolic acid-based non-isocyanate polyurethane copolyester and the levofloxacin, the levofloxacin is uniformly dispersed and embedded into a fiber network, so that uniform dispersion and controllable release of an antibacterial drug are realized, growth and reproduction of bacteria at a wound are effectively inhibited, and the problems of wound infection and slow healing are solved; the healing speed is increased; and the complication risk is reduced.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of medical dressings, in particular to a moisture-absorbing and sweat-releasing medical dressing and a preparation method thereof. BACKGROUND

[0002] A medical dressing is a medical material used for covering and protecting a wound and promoting wound healing, and plays a vital role in clinical treatment. It can effectively isolate the wound from the external environment, prevent bacterial infection, and provide a suitable healing environment for the wound.

[0003] Traditional medical dressings such as gauze and bandages can protect wounds to a certain extent, but have the disadvantages of short antibacterial period, poor water absorption performance, etc., and cannot effectively absorb wound exudate, increasing the risk of infection and causing slow wound healing.

[0004] Patent CN103007339B discloses a biological powder medical dressing and a preparation method thereof. The above-mentioned patent realizes the application of various shapes of wounds, is beneficial to the growth of new tissues, promotes wound healing, and reduces the difficulty of debridement and the pain of patients when changing dressings.

[0005] The above-mentioned patent is prepared by using biological materials, has good biocompatibility, can be degraded and absorbed by the human body, solves the defects of complex preparation method and unreliable safety of existing powder dressings, but still has optimization space in the continuous antibacterial aspect of medical dressings. The present application solves the problems of wound infection and slow healing.

[0006] Therefore, the present application provides a moisture-absorbing and sweat-releasing medical dressing with continuous antibacterial function and a preparation method thereof. SUMMARY

[0007] The purpose of the present application is to provide a moisture-absorbing and sweat-releasing medical dressing and a preparation method thereof, to solve the technical problems of wound infection and slow healing raised in the background art.

[0008] To achieve the above-mentioned purpose, the present application provides the following technical scheme: a moisture-absorbing and sweat-releasing medical dressing, comprising a polyurethane copolyester nanofiber membrane, and a preparation method of the polyurethane copolyester nanofiber membrane comprising the following steps:

[0009] Pour non-isocyanate polyurethane copolyester, levofloxacin and polyacrylonitrile into hexafluoroisopropanol to obtain a spinning solution, pour the spinning solution into a syringe, and perform electrospinning, set the spinning voltage to 17kv, and the pushing speed to 0.7mm / h to obtain a single-layer film;

[0010] The single layer film is subjected to plasma treatment, the single layer film after plasma treatment is placed on a spin coater, a chitosan-gelatin-glycerin mixed solution is spin coated on the surface of the single layer film, after drying, a spermidine crosslinking agent is spin coated, and a polyurethane copolyester nanofiber membrane is obtained.

[0011] Preferably, the non-isocyanate polyurethane copolyester comprises the following components by weight: non-isocyanate polyurethane 80-100 parts, polyglycolic acid diol 5-20 parts, chain extender 1-5 parts, catalyst 0.5-5 parts, and the preparation method of the non-isocyanate polyurethane copolyester comprises the following steps:

[0012] The non-isocyanate polyurethane and the polyglycolic acid diol are poured into hexafluoroisopropyl alcohol, stirred and heated to 60°C, and when there are no liquid droplets falling at the outlet of the condenser, the chain extender and the catalyst are added, and the heating is stopped after 0.5h to obtain the reactant;

[0013] The reactant after washing is placed in a vacuum drying oven and dried at 100°C for 24h to obtain the non-isocyanate polyurethane copolyester.

[0014] Preferably, the preparation method of the chitosan-gelatin-glycerin mixed solution comprises the following steps:

[0015] The chitosan powder is poured into the acetic acid aqueous solution to prepare a chitosan mixed solution, the gelatin powder is poured into the deionized water to prepare a gelatin solution, and the chitosan mixed solution and the gelatin solution are mixed to obtain a chitosan-gelatin mixed solution;

[0016] Glycerin is added to the chitosan-gelatin mixed solution and stirred to obtain a chitosan-gelatin-glycerin mixed solution.

[0017] Preferably, the preparation method of the spermidine crosslinking agent comprises the following steps:

[0018] The spermidine is taken out of the refrigerator and thawed using a water bath, and the p-xylylene formaldehyde is poured into anhydrous ethanol and stirred to obtain a p-xylylene formaldehyde solution;

[0019] The thawed spermidine is poured into the p-xylylene formaldehyde solution and stirred to obtain a spermidine crosslinking agent.

[0020] Preferably, the preparation method of the non-isocyanate polyurethane comprises the following steps:

[0021] The ethylene carbonate and the 1,6-hexanediamine are mixed in a nitrogen atmosphere, stirred and heated to 80°C, deionized water is added, and the mixture is subjected to freezing, recrystallization and vacuum drying to obtain a hexanediamine glycol ester diol;

[0022] Put adipic acid glycol ester diol, polyethylene glycol into the reaction container, add stannous chloride dihydrate, stir and heat to 220 DEG C, use vacuum pump to reduce pressure treatment, obtain non-isocyanate polyurethane.

[0023] Preferably, the mass fraction ratio of chitosan to gelatin in the chitosan-gelatin mixed solution is 1:4, and the volume fraction ratio of the chitosan-gelatin mixed solution to glycerol is 7:3.

[0024] Preferably, the preparation method of the polyglycolic acid diol comprises the following steps:

[0025] Mix glycolic acid and neopentyl glycol, add zinc acetate dihydrate and toluene, pass nitrogen and heat to 120 DEG C, obtain polyglycolic acid diol.

[0026] Preferably, the chain extender is sebacoyl chloride, and the catalyst is triethylamine.

[0027] Preferably, the preparation method comprises the following steps:

[0028] S1, the polyurethane copolyester nanofiber membrane, polylactic acid superfine fiber material, viscose fiber material are stacked in turn, and heat pressing treatment is carried out to obtain a medical dressing.

[0029] Preferably, the preparation method further comprises the following steps:

[0030] S11, the polylactic acid chip and the molten polyethylene glycol are blended, sodium dodecyl sulfate chip is added, and a high-speed mixer is used for mixing to obtain a blending raw material;

[0031] S12, the blending raw material is melted into a polymer melt by a screw extruder, the polymer melt is conveyed to the spinneret orifice by a metering pump, and the melt stream is extruded on the receiving screen curtain to form a polylactic acid superfine fiber material.

[0032] Compared with the prior art, the present application has the following advantages:

[0033] 1. The present application introduces polyglycolic acid based non-isocyanate polyurethane copolyester and levofloxacin, which uniformly disperses and embeds in the fiber network, realizes the uniform dispersion and controlled release of the antibacterial drug, effectively inhibits the growth and reproduction of bacteria at the wound, solves the problems of wound infection and slow healing, improves the healing speed and reduces the risk of complications.

[0034] 2. The present application introduces chitosan, gelatin and glycerol, and realizes the humidity regulation at the wound through the water absorption performance of glycerol and the microporous structure of the polyurethane copolyester nanofiber membrane, so that the wound is neither too wet nor too dry, solves the problem of maintaining the balance between wet and dry of the wound, and improves the wound healing speed.

[0035] 3. The application forms a cross-linked network by spin-coating a chitosan-gelatin-glycerol mixed solution, a spermidine cross-linking agent on the polyurethane copolyester nanofiber membrane, ensures the sustained release of the spermidine cross-linking agent, effectively reduces the inflammatory response of the local wound, and accelerates wound healing.

[0036] 4. The application combines non-isocyanate polyurethane and polyglycolic acid diol to generate polyglycolic acid-based non-isocyanate polyurethane copolyester, improves the tensile strength and elongation at break of the membrane, realizes good adhesion of the medical dressing, and improves the safety and environmental protection of the material. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 The figure is a preparation process schematic diagram of the polyurethane copolyester nanofiber membrane of the application.

[0038] Figure 2 The figure is a preparation process schematic diagram of the non-isocyanate polyurethane copolyester of the application.

[0039] Figure 3 The figure is a preparation process schematic diagram of the chitosan-gelatin-glycerol mixed solution of the application.

[0040] Figure 4 The figure is a preparation process schematic diagram of the spermidine cross-linking agent of the application.

[0041] Figure 5 The figure is a preparation process schematic diagram of the non-isocyanate polyurethane of the application.

[0042] Figure 6 The figure is a preparation process schematic diagram of the polyglycolic acid diol of the application.

[0043] Figure 7 The figure is a preparation process schematic diagram of the polylactic acid superfine fiber material of the application.

[0044] Figure 8 The figure is a preparation process schematic diagram of the medical dressing of the application. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the application will be described clearly and completely below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the application.

[0046] Example 1, please refer to Figure 1The application discloses a moisture-absorbing and sweat-releasing medical dressing which comprises a polyurethane copolyester nanofiber membrane, and the non-isocyanate polyurethane copolyester comprises the following components in parts by weight: non-isocyanate polyurethane 100 parts, polyglycolic diol 20 parts, chain extender 5 parts and catalyst 5 parts.

[0047] The non-isocyanate polyurethane and the polyglycolic diol are poured into hexafluoroisopropanol, stirred and heated to 60 DEG C, the chain extender sebacoyl chloride and the catalyst triethylamine are added when no liquid drops fall at the outlet of the condenser, heating is stopped after 0.5 h, the reactant is obtained, the deionized water is used for washing treatment, the washed reactant is placed in a vacuum drying box and dried at 100 DEG C for 24 h, and the non-isocyanate polyurethane copolyester is obtained.

[0048] The non-isocyanate polyurethane copolyester, levofloxacin and polyacrylonitrile are poured into hexafluoroisopropanol to obtain a spinning solution, the spinning solution is poured into a syringe, electrospinning is carried out, the spinning voltage is set to 17 kv, and the advancing speed is 0.7 mm / h, and a single-layer film is obtained.

[0049] The single-layer film is subjected to plasma treatment, the single-layer film after the plasma treatment is placed on a spin coater, a chitosan-gelatin-glycerol mixed solution is spin-coated on the surface of the single-layer film, after drying, a spermidine crosslinking agent is spin-coated, and the polyurethane copolyester nanofiber membrane is obtained.

[0050] Further, in the process of preparing the polyurethane copolyester nanofiber membrane, levofloxacin is added to the spinning solution as an antibacterial drug, the spinning solution is stretched into nanofibers under the action of a high-voltage electric field, the levofloxacin is uniformly dispersed and embedded into the nanofibers, the polyurethane copolyester nanofiber has a diameter of 300-500 nm, and the porosity is greater than 85%, so that a huge drug loading surface area is provided, and the levofloxacin molecules are embedded into the fiber network through hydrogen bonds and van der Waals forces; in the initial burst release stage, the levofloxacin is rapidly released from the surface layer of the fibers, an antibacterial concentration is rapidly established, an initial high-concentration antibacterial effect is achieved, and then, in the sustained slow-release stage, the deep levofloxacin drug is slowly released through fiber degradation and diffusion, and a sustained antibacterial effect is formed.

[0051] When the polyurethane copolyester nanofiber membrane is applied to the wound surface, the levofloxacin is continuously released after the dressing contacts with the wound exudate, ensuring the sustained effect of the drug in the wound area. Levofloxacin effectively inhibits the proliferation of bacteria and the synthesis of biofilm matrix by blocking the key function of bacteria in catalyzing the breakage, cross-linking and reconnection of DNA double strands during DNA replication, thereby inhibiting or directly killing the bacteria causing infection and significantly reducing the risk of chronic wound infection, providing a strong guarantee for the recovery of patients; by effectively controlling the infection of the wound, the polyurethane copolyester nanofiber membrane creates a clean and healing microenvironment for the recovery of the wound, which reduces the bacterial load, relieves the inflammatory response of the wound surface, avoids tissue damage caused by excessive release of inflammatory factors, achieves an indirect anti-inflammatory effect, improves the speed of wound healing, and reduces the risk of complications caused by infection.

[0052] By introducing polyacrylonitrile, the mechanical strength of the polyurethane copolyester nanofiber is enhanced, the carrier degradation is delayed, and the drug release period is prolonged; using hexafluoroisopropanol as the solvent, the fluorine-containing groups in hexafluoroisopropanol produce hydrophobic interaction with the fluorine-containing segments of non-isocyanate polyurethane and the fluorine atoms of levofloxacin, promoting the uniform dispersion of the drug in the spinning solution. At the same time, the fluorine-containing polymer reduces the surface energy of the polyurethane copolyester nanofiber membrane, reduces the initial adhesion of bacteria, and forms a double protection with the bactericidal effect of levofloxacin.

[0053] Example 2, please refer to Figure 1 and Figure 3 A moisture-wicking medical dressing, comprising a polyurethane copolyester nanofiber membrane, a non-isocyanate polyurethane copolyester comprising the following components by weight: non-isocyanate polyurethane 95 parts, polyglycolic acid diol 15 parts, chain extender 4 parts, catalyst 4 parts, the preparation method of the polyurethane copolyester nanofiber membrane comprising the following steps;

[0054] Pour the non-isocyanate polyurethane copolyester, levofloxacin and polyacrylonitrile into hexafluoroisopropanol to obtain a spinning solution. Pour the spinning solution into a syringe and perform electrospinning. Set the spinning voltage to 17kv and the pushing speed to 0.7mm / h to obtain a single-layer membrane.

[0055] Pour the chitosan powder into the acetic acid aqueous solution to prepare a chitosan mixed solution. Pour the gelatin powder into the deionized water to prepare a gelatin solution. Mix the chitosan mixed solution and the gelatin solution to obtain a chitosan-gelatin mixed solution. Add glycerol to the chitosan-gelatin mixed solution and stir to obtain a chitosan-gelatin-glycerol mixed solution.

[0056] The single-layer film is subjected to plasma treatment, the single-layer film after plasma treatment is placed on a spin coater, a chitosan-gelatin-glycerol mixed solution is spin-coated on the surface of the single-layer film, after drying, a spermidine crosslinking agent is spin-coated, and a polyurethane copolyester nanofiber film is obtained.

[0057] Further, chitosan, as a natural polymer material, has excellent biocompatibility and biodegradability, and can significantly promote cell adhesion and proliferation, providing a good growth environment for cells. In addition, chitosan also has certain anti-inflammatory effect, which can effectively inhibit the activation of inflammatory cells and the release of inflammatory factors, thereby significantly reducing the inflammatory reaction around the wound and helping the rapid healing of the wound. At the same time, gelatin also has good biocompatibility, which can promote cell growth and tissue regeneration. In the wound healing process, gelatin can effectively promote the progress of the anti-inflammatory stage and accelerate the healing of the wound. The components of chitosan and gelatin are similar to the extracellular matrix, thereby providing a microenvironment similar to natural tissue for cell growth, and further promoting the interaction between cells and dressings. In addition, chitosan and gelatin can promote cell proliferation and differentiation by providing necessary growth factors and cytokines for cells, thereby accelerating the wound healing process. Moreover, chitosan and gelatin molecules contain active functional groups such as amino and carboxyl groups, which can tightly bind to the receptors on the cell surface, effectively promoting cell adhesion. Glycerol has excellent water absorption performance, which can effectively absorb water in the surrounding environment, improve the hydrophilicity and hygroscopicity of the dressing material, and keep the wound neither too wet nor too dry.

[0058] Example 3, please refer to Figure 1 and Figure 4 A moisture-wicking medical dressing includes a polyurethane copolyester nanofiber film, a non-isocyanate polyurethane copolyester includes the following components by weight: non-isocyanate polyurethane 90 parts, polyglycolic acid diol 10 parts, chain extender 3 parts, catalyst 2 parts. The preparation method of the polyurethane copolyester nanofiber film includes the following steps:

[0059] The non-isocyanate polyurethane copolyester, levofloxacin, and polyacrylonitrile are poured into hexafluoroisopropanol to obtain a spinning solution. The spinning solution is poured into a syringe, and electrospinning is performed. The spinning voltage is set to 17kv, and the pushing speed is 0.7mm / h to obtain a single-layer film.

[0060] The spermidine is taken out of the refrigerator and thawed using a water bath. The p-xylylene formaldehyde is poured into anhydrous ethanol and stirred to obtain a p-xylylene formaldehyde solution. The thawed spermidine is poured into the p-xylylene formaldehyde solution and stirred to obtain a spermidine crosslinking agent.

[0061] The single-layer film is subjected to plasma treatment, and the single-layer film after plasma treatment is placed on a spin coater to spin coat a chitosan-gelatin-glycerol mixed solution on the surface of the single-layer film. After drying, a spermidine crosslinking agent is spin coated to obtain a polyurethane copolyester nanofiber membrane.

[0062] Further, spermidine can effectively induce the polarization transformation of macrophages through its unique biological activity. Spermidine promotes the transformation of M1 macrophages with pro-inflammatory properties into M2 macrophages with pro-repair functions, thereby reducing the expression level of pro-inflammatory cytokines in the local wound area, significantly increasing the expression amount of anti-inflammatory cytokines, effectively reducing the inflammatory response at the wound site through a bidirectional regulation mechanism, creating a favorable environment for wound healing, and accelerating the repair process of the wound. In the preparation of the medical dressing, a chitosan-gelatin-glycerol mixed solution is first uniformly spin coated on the single-layer film substrate, and then a spermidine crosslinking agent is spin coated on the chitosan-gelatin-glycerol layer. The aldehyde groups in the crosslinking agent can react with the amino groups in the chitosan and gelatin molecules to form a stable crosslinking network structure, which enhances the mechanical strength and stability of the dressing and fixes the spermidine crosslinking agent in the dressing, ensuring its continuous and stable release during use. The continuous release of spermidine enables it to fully exert its anti-inflammatory immune regulation effect, effectively inhibiting the immune rejection reaction caused by the dressing itself and reducing the resulting inflammatory response. At the same time, spermidine can also alleviate the stress-induced inflammatory response caused by skin damage, further promoting wound healing. Through multiple regulation mechanisms, the anti-inflammatory effect and the potential of the medical dressing to promote wound healing are significantly enhanced.

[0063] Example 4, please refer to Figure 1 、 Figure 2 、 Figure 5 and Figure 6 , a moisture-wicking medical dressing, comprising a polyurethane copolyester nanofiber membrane, a non-isocyanate polyurethane copolyester comprising the following components by weight: non-isocyanate polyurethane 85 parts, polyglycolic acid diol 8 parts, chain extender 2 parts, catalyst 1 part, the preparation method of the polyurethane copolyester nanofiber membrane comprising the following steps:

[0064] Ethylene carbonate and 1,6-hexanediamine are mixed in a nitrogen atmosphere, stirred and heated to 80°C, deionized water is added, and the mixture is subjected to freezing, recrystallization and vacuum drying to obtain hexanediamine glycol ester diol. The hexanediamine glycol ester diol and polyethylene glycol are poured into a reaction container, stannous chloride dihydrate is added, and the mixture is stirred and heated to 220°C. A vacuum pump is used for vacuum treatment to obtain a non-isocyanate polyurethane. The non-isocyanate polyurethane and polyglycolic acid diol are poured into hexafluoroisopropanol, decanedioyl chloride and triethylamine are added, and the mixture is washed with deionized water and dried at 100°C for 24 h to obtain a non-isocyanate polyurethane copolymer.

[0065] The non-isocyanate polyurethane copolyester, levofloxacin, and polyacrylonitrile are poured into hexafluoroisopropanol to obtain a spinning solution, the spinning solution is poured into a syringe, electrospinning is performed, the spinning voltage is set to 17kv, and the pushing speed is 0.7mm / h, to obtain a single-layer film;

[0066] The single-layer film is subjected to plasma treatment, the single-layer film after plasma treatment is placed on a spin coater, a chitosan-gelatin-glycerol mixed solution is spin-coated on the surface of the single-layer film, after drying, a spermidine crosslinking agent is spin-coated, to obtain a polyurethane copolyester nanofiber film.

[0067] Further, the hexanediamine glycol ester diol is generated by the cycloaddition reaction of ethylene carbonate and 1,6-hexanediamine, and then polyethylene glycol is subjected to polycondensation under stannous chloride catalysis, avoiding the use of toxic isocyanate monomers in traditional polyurethane synthesis, and significantly improving the safety and environmental protection of the material; the ether bond in the polyglycolic acid-based non-isocyanate polyurethane copolyester molecular chain forms a water molecule transmission channel, so that the medical dressing can quickly absorb wound exudate, realize efficient moisture conduction function, and effectively prevent the accumulation of exudate at the wound site; the long alkyl chain introduced by sebacoyl chloride constructs a hydrophobic microzone, which blocks the reverse osmosis of liquid water and is beneficial to wound healing.

[0068] Example 5, please refer to Figure 1 A moisture-wicking medical dressing includes a polyurethane copolyester nanofiber film, the non-isocyanate polyurethane copolyester includes the following components by weight: non-isocyanate polyurethane 80 parts, polyglycolic acid diol 5 parts, chain extender 1 part, and catalyst 0.5 part, and the preparation method of the polyurethane copolyester nanofiber film includes the following steps:

[0069] The non-isocyanate polyurethane copolyester, levofloxacin, and polyacrylonitrile are poured into hexafluoroisopropanol to obtain a spinning solution, the spinning solution is poured into a syringe, electrospinning is performed, the spinning voltage is set to 17kv, and the pushing speed is 0.7mm / h, to obtain a single-layer film;

[0070] The single-layer film is subjected to plasma treatment, the single-layer film after plasma treatment is placed on a spin coater, a chitosan-gelatin-glycerol mixed solution is spin-coated on the surface of the single-layer film, after drying, a spermidine crosslinking agent is spin-coated, to obtain a polyurethane copolyester nanofiber film.

[0071] Further, the non-isocyanate polyurethane copolyester combines the flexibility of non-isocyanate polyurethane and the strength of polyglycol diol. As a component, the non-isocyanate polyurethane, through the soft segment and hard segment structure in the molecular chain of the non-isocyanate polyurethane, imparts good flexibility and strength to the film. At the same time, the introduction of polyglycol acid segments in the polyglycol diol increases the crystallinity of the material, further improving the tensile strength and elongation at break of the film, so that the polyurethane copolyester nanofiber film can better fit the wound surface, provide stable support and protection, and prevent secondary injury caused by the movement or shedding of the dressing.

[0072] Example 6, see Figure 1 , Figure 7 and Figure 8 A moisture-wicking medical dressing comprising a polyurethane copolyester nanofiber film, the preparation method of the medical dressing comprising the following steps:

[0073] The non-isocyanate polyurethane copolyester, levofloxacin, and polyacrylonitrile are poured into hexafluoroisopropanol to obtain a spinning solution. The spinning solution is poured into a syringe, and electrospinning is performed. The spinning voltage is set to 17kv, and the pushing speed is 0.7mm / h to obtain a single-layer film.

[0074] The single-layer film is subjected to plasma treatment. The plasma-treated single-layer film is placed on a spin coater, and a chitosan-gelatin-glycerol mixed solution is spin-coated on the surface of the single-layer film. After drying, a spermidine crosslinking agent is spin-coated to obtain a polyurethane copolyester nanofiber film.

[0075] The polylactic acid chips and molten polyethylene glycol are blended, and sodium dodecyl sulfate chips are added. A high-speed blender is used for mixing to prepare a blended raw material. The blended raw material is melted into a polymer melt by a screw extruder. The polymer melt is delivered to the spinneret orifice of the die head by a metering pump. The extruded melt stream is adhered to a poly-lactic acid ultra-fine fiber material on a receiving screen curtain. The polyurethane copolyester nanofiber film, the poly-lactic acid ultra-fine fiber material, and the viscose fiber material are sequentially stacked and subjected to hot pressing treatment to obtain a medical dressing.

[0076] Further, the polylactic acid ultrafine fiber material prepared by the melt-blown forming process has excellent mechanical properties, so that the medical dressing can withstand certain external force during use and is not easy to break, thereby providing stable protection for the wound; the polylactic acid is modified by blending with polyethylene glycol and sodium dodecyl sulfate, thereby improving the moisture absorption and liquid management capability of the polylactic acid ultrafine fiber material, and at the same time, the sodium dodecyl sulfate improves the wettability of the surface of the polylactic acid ultrafine fiber material, so that the medical dressing can further absorb wound exudates, thereby promoting wound healing; the polylactic acid ultrafine fiber material, the viscose fiber material and the polyurethane copolyester nanofiber membrane having different wettability are laminated and compounded, so that a wettability gradient effect can be formed, the asymmetric transmission of liquid is realized, the medical dressing can unidirectionally guide the wettability, and the risk of infection is reduced.

[0077] Comparative Example 1: A moisture-absorbing and sweat-releasing medical dressing includes a polyurethane copolyester nanofiber membrane, and the non-isocyanate polyurethane copolyester includes the following components by weight: non-isocyanate polyurethane 100 parts, polyglycolic acid diol 20 parts, chain extender 5 parts, and catalyst 5 parts, and the preparation method of the polyurethane copolyester nanofiber membrane includes the following steps:

[0078] The non-isocyanate polyurethane and the polyglycolic acid diol are poured into hexafluoroisopropanol, the chain extender sebacoyl chloride and the catalyst triethylamine are added to obtain a reactant, the deionized water is used for washing treatment, and the washed reactant is placed in a vacuum drying box to obtain the non-isocyanate polyurethane copolyester.

[0079] The non-isocyanate polyurethane copolyester and the polyacrylonitrile are poured into hexafluoroisopropanol to obtain a spinning solution, the spinning solution is poured into a syringe, electrospinning is performed, the spinning voltage is set to 17kv, and the pushing speed is 0.7mm / h to obtain a single-layer film.

[0080] The single-layer film is subjected to plasma treatment, the single-layer film after plasma treatment is placed on a spin coater, a chitosan-gelatin-glycerol mixed solution is spin-coated on the surface of the single-layer film, and after drying, a spermidine crosslinking agent is spin-coated to obtain the polyurethane copolyester nanofiber membrane.

[0081] Comparative Example 2: A moisture-absorbing and sweat-releasing medical dressing includes a polyurethane copolyester nanofiber membrane, and the non-isocyanate polyurethane copolyester includes the following components by weight: non-isocyanate polyurethane 100 parts, polyglycolic acid diol 20 parts, chain extender 5 parts, and catalyst 5 parts, and the preparation method of the polyurethane copolyester nanofiber membrane includes the following steps:

[0082] The non-isocyanate polyurethane and the polyglycolic acid diol are poured into hexafluoroisopropanol, the chain extender sebacoyl chloride and the catalyst triethylamine are added to obtain a reactant, the deionized water is used for washing treatment, and the washed reactant is placed in a vacuum drying box to obtain the non-isocyanate polyurethane copolyester.

[0083] The non-isocyanate polyurethane copolyester, levofloxacin, and polyacrylonitrile were poured into hexafluoroisopropanol to obtain a spinning solution, the spinning solution was poured into a syringe, electrospinning was performed, the spinning voltage was set to 17kv, and the pushing speed was 0.7mm / h to obtain a single-layer film;

[0084] The single-layer film was subjected to plasma treatment, the single-layer film after plasma treatment was placed on a spin coater, and spermidine crosslinking agent was spin-coated on the surface of the single-layer film to obtain a polyurethane copolyester nanofiber film.

[0085] Performance test

[0086] Test 1: Tensile property test: the samples prepared in Examples 1-5 and Comparative Examples 1-2 were tested by using a universal material testing machine, cut into standard dumbbell-shaped samples, tested according to the national standard GB / T 1040.1-2006, and the tensile strength was recorded;

[0087] Test 2: Antibacterial property test: the samples prepared in Examples 1-5 and Comparative Examples 1-2 were mixed with nutrient broth on a culture dish, the samples were pasted on the culture dish, and placed in a constant temperature incubator, and the diameter of the inhibition zone was calculated;

[0088] Test 3: Water vapor transmission property test: the samples prepared in Examples 1-5 and Comparative Examples 1-2 were placed in a moisture cup according to the standard JIS1099A, the moisture cup was covered and sealed with the sample, and the moisture cup was placed in a constant temperature and humidity incubator, and the water vapor transmission rate was recorded;

[0089] Test 4: Swelling property test: the samples prepared in Examples 1-5 and Comparative Examples 1-2 were cut into 2cm ×2cm, and the sample swelling rate was calculated according to the standard YY / T 0471.1-2004.

[0090] Table 1: Test results of sample performance test

[0091] Example Tensile strength (MPa) Inhibition zone diameter (cm) water vapor transmission rate (g.m -2 ·d -1 ) Swelling rate (%) Example 1 62.24 4.2 3425.7 732.45 Example 2 56.35 3.8 3262.4 715.34 Example 3 51.43 3.4 3092.4 697.35 Example 4 47.38 3.1 2914.2 681.75 Example 5 43.64 2.8 2796.6 675.46 Comparative Example 1 60.17 2.9 3387.2 728.46 Comparative Example 2 55.35 3.9 3568.4 683.64

[0092] According to Examples 1-5, Comparative Examples 1-2 and Table 1, the introduction of levofloxacin enhances the antibacterial property of the medical dressing; the non-isocyanate polyurethane copolyester improves the mechanical property of the fiber fabric; and the polyurethane copolyester nanofiber film has good moisture permeability and moisture absorption.

[0093] Working principle: by introducing non-isocyanate polyurethane copolyester, levofloxacin and polyacrylonitrile, levofloxacin can inhibit or kill bacteria, reduce the risk of wound infection, achieve indirect anti-inflammatory, polyacrylonitrile enhances the mechanical strength of polyurethane copolyester nanofiber, and prolongs the drug release period;

[0094] In the molecular chain of the non-isocyanate polyurethane copolyester, the ether bond forms a water molecule transmission path, realizes the efficient moisture conducting effect of the medical dressing, avoids the accumulation of the exudate at the wound, prevents the reverse osmosis of the liquid water, helps the rapid healing of the wound, and improves the perspiration effect.

[0095] The chitosan and gelatin have good biocompatibility and can promote wound healing, the glycerol has excellent water absorption performance and can improve the moisture absorption of the medical dressing, the stable cross-linking network structure formed by the spermidine cross-linking agent and the chitosan-gelatin-glycerol layer ensures the stable release during the use of the spermidine.

[0096] It will be obvious to a person skilled in the art that the application is not limited to the details of the above-described exemplary embodiments but can be implemented in other embodiments without departing from the scope of the application. The application is therefore not to be considered as being limited to the exemplary embodiments described above, but can be modified in other ways within the scope of the application. The scope of the application is defined by the appended claims rather than by the description above and therefore all changes falling within the meaning of the claims are intended to be embraced therein. No reference signs in the claims should be considered to limit the scope of the claims in any way.

Claims

1. A moisture-absorbing and perspiration-wicking medical dressing, characterized in that: The invention comprises a polyurethane copolyester nanofiber membrane, and the preparation method of the polyurethane copolyester nanofiber membrane comprises the following steps: Non-isocyanate polyurethane copolyester, levofloxacin, and polyacrylonitrile were poured into hexafluoroisopropanol to obtain a spinning solution, which was then poured into a syringe for electrospinning. The spinning voltage was set to 17 kV and the propulsion speed was set to 0.7 mm / h to obtain a single-layer membrane. The monolayer membrane was plasma treated, and the plasma treated monolayer membrane was placed on a spin coater. A chitosan-gelatin-glycerol mixed solution was spin-coated on the surface of the monolayer membrane. After drying, a spermidine cross-linking agent was spin-coated to obtain a polyurethane copolyester nanofiber membrane.

2. The moisture-absorbing and perspiration-wicking medical dressing according to claim 1, characterized in that: The non-isocyanate polyurethane copolyester comprises the following components in parts by weight: 80-100 parts of non-isocyanate polyurethane, 5-20 parts of polyglycolic acid diol, 1-5 parts of chain extender, and 0.5-5 parts of catalyst. The preparation method of the non-isocyanate polyurethane copolyester comprises the following steps: Pour non-isocyanate polyurethane and polyglycolic acid diol into hexafluoroisopropanol, stir and heat to 60°C, add chain extender and catalyst when no liquid drops from the condenser outlet, stop heating after 0.5h to obtain the reactant; The reactant was washed with deionized water, and the washed reactant was placed in a vacuum drying oven and dried at 100° C. for 24 hours to obtain a non-isocyanate polyurethane copolyester.

3. The moisture-absorbing and perspiration-wicking medical dressing according to claim 1, characterized in that: The preparation method of the chitosan-gelatin-glycerol mixed solution comprises the following steps: Pour chitosan powder into acetic acid aqueous solution to prepare a chitosan mixed solution, pour gelatin powder into deionized water to prepare a gelatin solution, and mix the chitosan mixed solution and the gelatin solution to obtain a chitosan-gelatin mixed solution; Glycerol is added to the chitosan-gelatin mixed solution and stirred to obtain a chitosan-gelatin-glycerol mixed solution.

4. The moisture-absorbing and perspiration-wicking medical dressing according to claim 1, characterized in that: The preparation method of the spermidine cross-linking agent comprises the following steps: Take out spermidine from the refrigerator and thaw it in a water bath. Pour terephthalaldehyde into anhydrous ethanol and stir to obtain a terephthalaldehyde solution. The thawed spermidine is poured into the terephthalaldehyde solution and stirred to obtain a spermidine cross-linking agent.

5. The moisture-absorbing and perspiration-wicking medical dressing according to claim 2, characterized in that: The preparation method of the non-isocyanate polyurethane comprises the following steps: Ethylene carbonate and 1,6-hexanediamine were mixed in a nitrogen atmosphere, stirred and heated to 80° C., deionized water was added, and the mixture was frozen, recrystallized, and vacuum dried to obtain hexamethylenediamine glycol ester diol; Hexamethylenediamine glycol and polyethylene glycol were poured into a reaction container, stannous chloride dihydrate was added, the mixture was stirred and heated to 220° C., and a vacuum pump was used for decompression treatment to obtain non-isocyanate polyurethane.

6. The moisture-absorbing and perspiration-wicking medical dressing according to claim 3, characterized in that: The mass fraction ratio of chitosan to gelatin in the chitosan-gelatin mixed solution is 1:4, and the volume fraction ratio of the chitosan-gelatin mixed solution to glycerol is 7:

3.

7. The moisture-absorbing and perspiration-wicking medical dressing according to claim 2, characterized in that: The preparation method of the polyglycolic acid diol comprises the following steps: Glycolic acid and neopentyl glycol are mixed, zinc acetate dihydrate and toluene are added, nitrogen is introduced, and the mixture is heated to 120° C. to obtain polyglycolic acid diol.

8. The moisture-absorbing and perspiration-wicking medical dressing according to claim 2, characterized in that: The chain extender is sebacyl chloride, and the catalyst is triethylamine.

9. A method for preparing a moisture-wicking medical dressing, suitable for the moisture-wicking medical dressing according to any one of claims 1 to 8, characterized in that: The preparation method comprises the following steps: S1. Stacking a polyurethane copolyester nanofiber membrane, a polylactic acid ultrafine fiber material, and a viscose fiber material in sequence, and performing a hot pressing treatment to obtain a medical dressing.

10. The method for preparing a moisture-absorbing and perspiration-wicking medical dressing according to claim 9, wherein: The preparation method further comprises the following steps: S11, blending polylactic acid chips and molten polyethylene glycol, adding sodium lauryl sulfate chips, and mixing using a high-speed stirrer to prepare a blending raw material; S12. The blended raw materials are melted into a polymer melt by a screw extruder, and the polymer melt is transported to the spinneret hole of the die by a metering pump, and a thin stream of the melt is extruded and adhered to a receiving mesh curtain to form a polylactic acid ultrafine fiber material.

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