Effect Of Disinfection Methods On The Physicochemical Properties And Biocompatibility Of PLA Electrospun Tissue Engineering Scaffold

ObjectiveThe main purpose of this article is to investigate the effect of three different disinfection methods(ultraviolet radiation,ethylene oxide fumigation,ethanol immersion)on the physicochemical properties and biocompatibility of electrospun polylactic acid(PLA)scaffolds,so as to provide a reference for the selection of disinfection methods for tissue engineering scaffolds.MethodsThe spinning solution with a mass fraction of 8% was prepared by mixing the PLA material of a certain mass in the mixed solvent of trifluoroacetic acid and dichloromethane.The PLA electrospinning scaffold was obtained by electrospinning.Then the PLA electrospinning scaffold was made into a circular sample with a diameter of 13 mm.The sample was disinfected by ultraviolet radiation,ethylene oxide fumigation and ethanol immersion.Fourier transform infrared spectroscopy(FTIR),X ray diffraction(XRD)and thermogravimetric analysis(TGA)were used to detect the change in chemical properties,crystallinity properties and thermal properties of scaffold.The surface hydrophilicity of the scaffolds was measured by water contact angle(WAC).The cytotoxicity of the scaffold was evaluated by methyl thiazolyl tetrazolium(MTT)colorimetry,and the cell proliferation rate on the scaffold was quantitatively analyzed.The microscopic morphology of the scaffold was observed by scanning electron microscope(SEM).The changes of fibers and the adhesionand extension of cells on scaffolds were also analyzed.At the same time,the cytotoxicity,cell adhesion and extension of sterilized scaffolds treated with sterile PBS after ethylene oxide disinfection were analyzed.ResultsIn the experiment of detecting the physicochemical properties of PLA electrospinning scaffolds after disinfection,the SEM results showed that the fibers of PLA scaffolds in the control group were cylindrical in shape and crisscrossed into reticular fibers,while the fibers in ethylene oxide group were most seriously fused after disinfection.The whole presented a spongy structure,while the fibers were striped,and their diameters and interfibrous pore sizes changed.The morphology of the fibers in the ultraviolet radiation group and ethanol group did not change significantly.The results of FTIR test close to that of the control group showed that the characteristic peaks of infrared spectra of PLA scaffolds treated with different disinfection methods were similar.The results of XRD test showed that the crystallization peak strength of the scaffold was enhanced after different disinfection methods.The results of thermogravimetric analysis showed that the initial decomposition temperature of the scaffold increased after disinfection,and that of ethanol group was the highest.The results of WCA test showed that the contact angle of PLA scaffold decreased after disinfection.The decrease of ethanol group was the most significant.In the experiment of biocompatibility of PLA electrospinning scaffold after disinfection,the results of MTT on the 7th day showed that the OD value of ethanol group was the highest in the experimental group,followed by ethylene oxide-PBS group(P > 0.05),but higher than that of ethylene oxide group(P <0.001).The OD value of the ultraviolet radiation group was higher than that of ethylene oxide group(P < 0.001).The growth state was observed by scanning electron microscope after disinfection,the cells adhered and stretched best inethanol group,showing typical Schwann cell morphology.Followed by ethylene oxide-PBS group and ultraviolet radiation group,the cells on the scaffold of ethylene oxide group were mostly spherical,and could not be adhered and stretched well.ConclusionsUltraviolet radiation,ethylene oxide fumigation and ethanol immersion can be used to sterilize PLA electrospinning scaffolds.However,ethanol immersion has little effect on physicochemical properties of PLA electrospinning scaffolds,which can obviously improve the biocompatibility of the scaffolds.It has high application value in disinfection of medical tissue engineering scaffolds.The biocompatibility of ethylene oxide sterilizing scaffold can be improved obviously after the treatment of sterile PBS,which has certain guiding significance for the modification of disinfection method.