Preparation And Properties Of Multi-Component Medical Dressing Based On Electrospinning Method

Skin is the largest organ of human body,which can protect human body.Once the skin is destroyed,a large number of bacteria will enter the human body,causing wound infection.Therefore,it is of great significance to protect human immune system how to resist bacteria,promote the rapid healing of damaged skin and develop new medical dressings.Electrospun nanofiber membrane has the advantages of softness,lightness,high specific surface area and porosity,which makes it breathable and suitable for application on wound surface.Adding some antibacterial substances into the electrospinning solution can make the composite fiber membrane have good antibacterial properties.In this paper,polyvinylidene fluoride(PVDF)/levofloxacin(LEV)composite nanofiber membrane dressing was prepared by electrospinning method,and a certain amount of polyacrylonitrile(PAN)was added to improve its hydrophilicity.The morphology,chemical composition,crystal form,hydrophilicity,wet absorption,drug release in vitro,antibacterial performance,piezoelectric performance,hemolysis performance and cytotoxicity of the composite nanofiber membrane medical dressing were tested and analyzed.The specific research contents include:(1)PVDF and levofloxacin with different mass(PVDF10%,levofloxacin content 1.5%,2.5%,3.5%)were dissolved in mixed solvent(7:1)of N-N dimethylformamide(DMF)and dichloromethane(DCM),and mixed spinning was carried out by electrostatic spinning technology to obtain three kinds of PVDF/levofloxacin composite nanofiber membranes with different contents.The infrared test after electrospinning showed that PVDF and levofloxacin were spun into the composite fiber membrane with complete structure.X-ray diffraction results show that PVDF is transformed fromαcrystal form toβcrystal form with certain piezoelectric effect after electrospinning.In vitro drug release showed that the drug-loaded composite fiber membrane released drug quickly,and the final cumulative drug release rate could reach 70%-80%.Antibacterial properties show that the drug-loaded composite fiber membrane has excellent antibacterial effect on both gram-negative bacteria and positive bacteria,and the antibacterial performance is gradually enhanced with the increase of drug content.The moisture absorption and wetting performance test shows that the swelling ratio of the composite fiber membrane can reach about 300%,and the highest water vapor permeability can reach about 1000g/m~2/day,so it is suitable for medical dressing.(2)PVDF(PVDF10%),levofloxacin with different mass(levofloxacin content 1.5%,2.5%and 3.5%)PAN(PAN with different mass(PAN content 0.5%,1.5%and 2.5%)were dissolved in mixed solvent(DMF and DCM)by electrostatic spinning technology.Nine kinds of PVDF/PAN/levofloxacin composite nanofiber membranes with different contents were obtained.The fiber morphology,chemical composition,crystal form,hydrophilicity,moisture absorption and wetting properties,specific surface area and pore size,drug release in vitro,antibacterial properties,piezoelectric properties,hemolytic properties and cytotoxicity were tested and analyzed.Infrared and X-ray diffraction show that all three substances are spun in the composite fiber membrane in the form of complete structure,and PVDF is transformed fromαcrystal form toβcrystal form.After adding PAN spinning,the diameter of composite fiber increased obviously(up to micron level),and the hydrophilicity was gradually enhanced.The tests of moisture absorption,specific surface area and pore size show that the total pore volume of the composite fiber membrane is significantly increased after adding PAN,and the maximum moisture absorption and swelling ratio can reach about 1000%,and the maximum water vapor permeability can reach about 2000g/m~2/day.The piezoelectric test results show that the composite fiber membrane after electrospinning has certain piezoelectric properties,which can generate voltage under stress and play a certain role in electrical stimulation of the wound.In vitro drug release and antibacterial tests show that the PVDF/PAN/levofloxacin composite nanofiber membrane prepared in this study has excellent antibacterial effect,and the final drug release rate can reach about 80%.The hemolysis test shows that the composite fiber membrane prepared in this study will not produce hemolytic toxicity at the general drug concentration.The cytotoxicity test showed that L929 cells still had high activity after being treated for 12h,24h and 48h.The composite fiber membrane had good biocompatibility and was very suitable for medical dressing.To sum up,this study puts forward a preparation method of medical dressing with antibacterial and electrical stimulation,and tests its hydrophilicity,moisture absorption,drug release in vitro,antibacterial performance,piezoelectric performance,hemolytic performance and cytotoxicity,which has certain reference value for the development of medical dressing.