Preparation And Antimicrobial Performance Of Tea Saponin Loaded Polyacrylonitrile Electrospun Nanofiber Membrane

Tea saponin has good biological activities such as antioxidant,in vitro antibacterial and anti-inflammatory,and is often used in skin contact antibacterial immunotherapy.However,it is difficult to separate and purify,poor water solubility,low loading in traditional preparations and easy to burst release.Therefore,the preparation and purification technology of tea saponin were studied in this paper.Cyclodextrin polymer(?-CDP)was synthesized to encapsulate tea saponin to improve the water solubility of the drug.Dendritic mesoporous silica nanoparticles(DHMONs)were synthesized as carriers to improve drug loading and delivery;Combining with electrospinning technology,?-CDP/DHMONS composite polyacrylonitrile nanofiber films with high tea saponin loading capacity and loose and porous fiber morphology were prepared,and their antibacterial properties were investigated.(1)The tea saponin was separated and purified by macroporous resin adsorption,chloroform extraction,ethanol-water recrystallization and so on.Infrared,ultraviolet and organic elements were used to characterize the structure of the product.The results showed that the characteristic absorption peaks were obvious in the infrared spectrum,and the characteristic absorption peaks were strong in the ultraviolet spectrum at 211nm.The content of C was 69.50%and the content of H was 9.072%.Water soluble?-CDP was prepared from?-cyclodextrin and epichlorohydrin by cross-linking reaction.The structure and stability of?-CDP were characterized by IR,UV,elemental analysis and thermogravimetric analysis.Tea saponin was encapsulated by?-CDP cavity structure.(2)Through SEM analysis,the influence of different polymer substrates on the microstructure of electrospinning fiber membrane was explored.It was found that when polyacrylonitrile(PAN)was used as the polymer substrate,the filament with the smallest diameter and uniform distribution could be obtained.DHMONS were prepared.TEM characterization showed that the particle size was in the range of 180-200nm.BET results show that the specific surface area of the particles is 988.20 m~2/g,and the pore size is 6.98 nm.A novel composite drug-carrying nanofiber membrane was prepared by electrospinning the inclusion complex of DHMONS,?-CDP and tea saponin.Scanning electron microscopy(SEM),thermogravimetric(TG)test and contact Angle test were used to observe and analyze the surface morphology,thermal stability and water wettability of composite fiber membrane as wound dressing.(3)The sustained release and antibacterial properties of the drug-loaded composite nanofiber membrane were studied.The in vitro drug release rates of drug loading liposomes and fiber membrane were compared.The results showed that the drug release rate of drug loading liposomes was 69.30%and the cumulative release rate of drug loading liposomes was81.16%after 36h.The antibacterial effect of the drug-loaded PAN nanofiber membrane was comprehensively evaluated by the method of bacteriostatic zone and shock.The results showed that the antibacterial rate of the drug-loaded PAN nanofiber membrane against Escherichia coli and Staphylococcus aureus was as high as 78.97%and 72.20%.The morphology of the bacteria after treatment with the drug-loaded fiber membrane was observed by scanning electron microscopy,and the mechanism of bacterial death was analyzed:the drug-loaded fiber membrane could significantly inhibit the division of bacteria and destroy the cell wall and cell membrane structure.