| With the development of modernization and the improving of living qualities,medical dressing market will face new challenge.The requirements of dressing are not just confined to covering of the wound,but the acceleration of wound healing and the creating of environment for wound healing.?New wound dressing‘ with good moisture absorption and maintain has emerged,which was based on "Moist wound healing " theory.Chitosan come from the deacetylation of chitin,it has biocompatibility,antibacterial property and can be used for hemostasis,anti-corrosion and wound healing,so it is widely used in medical dressing.However,due to the poor hygroscopicity of chitosan fiber,it can not meet the requirements of New wound dressing.Carboxymethyl chitosan dressing not only retains the excellent properties of chitosan,but also greatly improve the moisture absorption and moisture of the dressing.It has great improtance in the medical dressing market with a great market competitiveness.Spunlaced nonwoven materials were widely used in the field of medical products as it soft handle and good hygroscopicity.The adding of ES fiber,not only reduces the carding difficulty caused by the stiffness of chitosan fiber.ES fiber has good alkali resistance and has its unique skin core structure,so it will not get damage by the reagent corrosion.The fiber cortex can get melt bonding under a certain temperature while the core layer still exist due to the lower melting point of fiber cortex than core layer.So the ES fiber can be used as a framework to maintain the fabric of space structure,which can also improve the hand feeling of the material.In this paper,it has confirmed the optimum parameter of carboxymethyl modification,prepared a chitosan spunlaced wound dressing by the Chitosan fiber and ES fiber,then modified it with the best carboxymethyl modification parameter.Tests of physical properties and biological properties needed by wound dressing has been done.This paper mainly obtained several conclusions as following from those research:(1)Carboxymethyl modification reaction is divided into two processes: alkalization and etherification reaction.Based on the results of orthogonal experiments,three main factors has been set: the concentration of Na OH,alkali acid molar ratio and etherification time.The liquid absorption rate was defined as the evaluation index of orthogonal experiment.Through the L9(33)orthogonal experiment,it has determined the optimal parameters: Na OH 20%,alkali acid molar ratio(6:1),etherification time: 6h.(2)After the carboxymethyl modification,the chitosan fiber‘s diameter increased and bonded more closely,the wound dressing‘s surface density has increased but its permeability and softness decreased.By adding ES fiber in raw materials,the problem of the decline in the permeability and softness due to carboxymethyl modification can be effectively improved.(3)The moisture permeability,liquid absorption and retention of the wound dressing were significantly improved through the carboxymethyl modification.ES fiber didn‘t participate in the carboxymethyl modification.After the adding of ES fiber in the raw material,the wound dressing after carboxymethyl modification could become a stable composite hydrogel system with the ES fiber as its three-dimensional skeleton.After modified treatment,the dressing infiltration effect has been improved,the dressing could quickly absorb the surface of the liquid and complete the diffusion in a short period of time.(5)The wound dressing proved no cytotoxicity to cells and it could promote the proliferation and differentiation of L-929 fibroblast.The wound dressing performed lower cell proliferation after modification.After bacteriostatic test of Staphylococcus aureus and Escherichia coli using the antibacterial dressing circle method,the wound dressing showed bacteriostatic ring within a certain range,which mean the dressing after modification antibacterial property. |
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