Preparation And Properties Of Chitosan-based Biodegradable Antibacterial Film

In recent years,the medical and health industry in China has developed vigorously,building a solid line of defense for the health of the most people.However,nosocomial infections still occur.According to the source of infectious pathogens,it can be divided into endogenous infection and exogenous infection,and exogenous infection is the key work of hospital infection prevention and control.The use of antibacterial medical packaging materials will reduce the rate of exogenous infection.In this paper,three composite films were prepared by tape casting method based on biodegradable materials:chitosan/starch/zinc oxide nanoparticles（CS/ST/Zn O-NPs）film,chitosan/gelatin/poly vinyl alcohol（CS/Gel/PVA）film,chitosan/gelatin/poly（vinyl alcohol）/ciprofloxacin hydrochloride（CS/Gel/PVA/CIP）film.The composition,structure,morphology and thermal performance of the composite films were analyzed by X-ray diffraction（XRD）,X-ray photoelectron spectrometer（XPS）,Fourier infrared transform spectrometer（FT-IR）,scanning electron microscope（SEM）,atomic force microscope（AFM）thermogravimetric analyzer（TGA）,and the mechanical properties,water vapor transmission rate,antibacterial and sustained release properties,cytotoxicity and sustained drug release kinetics of the composite films were also investigated.The specific research content are as follows:（1）In the preparation and research of CS/ST/Zn O-NPs film,the optimal ratio of film formation was 1:1 by solution mass ratio of CS/ST and 6%of Zn O-NPs content.In this time,the composite film has the best tensile strength 19.64±0.75MPa,the lowest water vapor transmission rate（4.56±0.01）×10^-11 g·m^-1·s^-1·Pa^-1and showed the best thermal stability.The results of XRD and XPS showed that the existence of zinc oxide in the composite film.SEM results showed that the CS/ST/Zn O-NPs（6%）film have good compatibility.The antibacterial results showed that the composite film showed a positive antibacterial effect on both Staphylococcus aureus and Escherichia coli,especially the better antibacterial effect on Staphylococcus aureus.The cytotoxicity results showed that CS/ST/Zn O-NPs（6%）composite film had no cytotoxicity and had good biocompatibility.Because starch is easy to absorb water and destroy the structure of CS/ST/Zn O-NPs film,the antibacterial sustained release experiment cannot be completed.（2）In the preparation and research of CS/Gel/PVA film,the best film-forming ratio was the mass ratio of CS/Gel/PVA was 2:1:1,through the analysis of the mechanical properties and water vapor permeability of the composite film.In this time,the tensile strength and elongation at break of the composite film were 7.26±0.43MPa and 119.30±9.13%,respectively,water vapor transmission rate was（2.58±0.03）×10^-11 g·m^-1·s^-1·Pa^-1.The results of FT-IR,XRD,and SEM showed that the different components have good compatibility,and the thermal performance results showed that the CS/Gel/PVA film has better thermal stability than the CS/Gel film or CS/PVA film.（3）In the preparation and research of CS/Gel/PVA/CIP film,based on the optimal film-forming ratio of CS/Gel/PVA in the previous chapter,the optimal addition amount of CIP was0.01%.The antibacterial properties,cytotoxicity,pharmacokinetic release behavior and the surface morphology of the composite film after different time of sustained release were explored.The antibacterial results showed that the composite film was sustained-released in PBS for 30 days,still had certain antibacterial properties,and the diameter of its bacteriostatic circle was 15mm.The 30d sustained release of the drug was divided into a rapid release phase and a slow-release phase,and 87.80%of the total drug release in the 0～3 days sustained release.The results of SEM and AFM morphologies showed that the drug was released rapidly on the surface of the composite film at the early stage of sustained release.In the late stage of sustained release,the drug molecules inside the compound film began to be released slowly to achieve long-term antibacterial effect.The cytotoxicity results showed that the composite film had no cytotoxicity and had good cytocompatibility.