Structure Design And Performance Of Nanofiber-Based Unidirectional Water-Transport Wound Dressing

With the continuous increase of human production activities,it is inevitable to encounter trauma,which also makes the development of wound dressing very fast.However,wound healing is a complex and dynamic process involving the interaction between tissues and cells,so it is of great significance to choose wound dressing reasonably for wound healing.Studies have shown that wet micro-environment is conducive to wound repair,which makes the development of wet wound dressings more rapid.However,traditional wet dressings are easy to lead to repeated infiltration of wound fluid,and accelerate the breeding of bacteria,which significantly affects the wound healing.Therefore,there is an urgent need to develop a multi-functional wound dressing with a single guide wet,long-term antibacterial effect,which can remove excessive exudate around the wound and avoid the growth of bacteria,so as to achieve rapid wound healing.This paper based on polymer materials inherent feeling of water features,combined with large molecules polymer antibacterial agent,using the electrostatic spinning technology was prepared with different inner and outer layer structure and properties of nano fiber membrane,through the design of nanometer fiber membrane assembly sequence and form,successfully developed a nanometer fiber wiki low moisture gradient structure of single wizard,adhesion,long-acting antibacterial wound dressings.The main research contents are as follows:(1)Using polyurethane(PU)with good mechanical properties,hydrophilic polyacrylonitrile(PAN)and superabsorbent sodium polyacrylate(SPA)as raw materials,the PU/PAN-SPA nanofiber membrane was prepared by electrospinning technology,and the effects of SPA concentration and PU component on the morphology,structure and properties of the fiber membrane were studied.The results showed that SPA could significantly improve the hydrophilicity of the prepared PU/PAN-SPA nanofiber membrane.When SPA concentration was 10 wt%,the dynamic contact Angle of the prepared PU/PAN-SPA nanofiber membrane was reduced from 90°to 0°in only 1.2 s,the hydrophobicity reached 970%,the equilibrium water content was 94%,and the fracture strength was 6.2 MPa.The air permeability is 7 mm/s,the moisture permeability is 1975g/(m~2·d),has good morphology,structure,water absorption and mechanical properties,the comprehensive performance is the best.(2)The above PU/PAN-SPA nanofiber membrane was used as the outer absorbent layer and the PU nanofiber membrane as the anti-adhesion inner layer.The different diametres and hydrophilicity characteristics of the two kinds of fiber membranes were used to construct the double-layer nanofiber wound dressing,and the effects of the thickness and hydrophilicity of the nanofiber membrane on the performance of wound dressing were investigated.The results show that when the spinning time of PU inner layer film is 1h,the double layer composite dressing can remove the liquid from inside to outside in 3.9 s,and the wetting performance of single guide is the best.The cytotoxicity and adhesion tests showed that the prepared double-layer nanofiber wound dressing had no cytotoxicity,and the inner layer of PU had low cell adhesion,which realized the low adhesion and single wet guide function of the double-layer wound dressing.(3)On the basis of double-layer wound dressings,three layers of PU,PU/PAN-SPA and PAN-SPA wound dressings were designed with increasing hydrophilicity layer by layer and decreasing fiber diameter layer by layer,and self-made polyhexamylene guanidine hydrochloride(PHGC)antibacterial agent was introduced to improve the antibacterial properties of the dressings,and various properties and single-guide wettability mechanism of the three-layer wound dressings were analyzed.The results showed that when the spinning time of PU inner film was 1 h,the three layers of composite wound dressing could rapidly transfer liquid from the inside to the outside in 1.8 s,and the wetting effect of single guide was the best.The single-guide wetting mechanism of the three-layer nanofiber membrane is hydrophobic-hydrophilic gradient structure and self-priming pump effect.When the PHGC content was 0.06 wt%,the antibacterial performance of the three-layer nano-fiber wound dressing was the best.