Construction Of Drug-loaded Graphene Oxide Coating Films And Neuron Growth Induced By Electrically Controlled Drug Release

Objective:The precise delivery of drug molecules to target tissues on demand is a very effective delivery method that can reduce the adverse effects of large systemic drug release,and the development of drug-carrying scaffolds with specific responses to promote nerve growth remains challenging.Therefore,this thesis uses conductive materials graphene oxide(GO)and poly(3,4-ethylenedioxythiophene)(PEDOT)to design a conductive drug-carrying thin film scaffold with good electrochemical performance and biocompatibility with the model drug of 7,8-dihydroxyflavone(7,8-DHF).The drug dose can be adjusted by changing electrical stimulus parameters.To promote the growth of neurons.Methods:1.GO-PEDOT film was prepared by electrochemical deposition method,and then the surface coating was further coated with dopa-grafted modified Chitosan(Chitosan-G-DOPA,CD)to prepare GO-PEDOT/CD.The electrical conductivity and microstructure of the scaffold were detected by cyclic voltammetry(CV),electrical impedance(EIS),scanning electron microscopy(SEM),Raman spectroscopy(Raman)and atomic force microscopy(AFM).The dorsal root ganglia cells(DRG)were cultured on the membrane to test the biocompatibility of the material,and electrical stimulation(ES)DRG with different voltage parameters was designed to explore the regulatory effect of potential on DRG.2.The GO-PEDOT film loaded with 7,8-DHF(DHF@GO-PEDOT)was prepared by electrochemical deposition technology,and the electrical conductivity and microstructure of the film were detected by X-ray photoelectron spectroscopy(XPS),CV,Raman,etc.The release of 7,8-DHF from DHF@GO-PEDOT/CD film was detected by ultraviolet spectrophotometer(UV).The effects of on-demand release of 7,8-DHF from ES on DRG growth were studied by in vitro cell experiments.Results:1.Three kinds of composite films,GO-PEDOT,GO-PEDOT/CD and DHF@GO-PEDOT/CD,were successfully prepared by electrochemical workstation.2.The excellent conductivity and electrochemical stability of GO-PEDOT,GOPEDOT/CD and DHF@GO-PEDOT/CD were detected by CV and EIS.3.ES stimulated the release of 7,8-DHF,and the release of drug increased with the increase of voltage and time.Through data comparison,the best release effect was achieved at-0.6V and 1.5hours.4.In vitro ES experiment,30 m V can promote DRG axon growth and Schwann cell(SCS)migration;The cytotoxicity test showed that neurons were dependent on the concentration of 7,8-DHF.Combined ES and 7,8-DHF can further promote DRG axon growth and Schwann cell(SC)migration.Conclusion:GO-PEDOT/CD has good cell compatibility and electrical conductivity.The drug-loaded nerve repair materials prepared by GO loaded with 7,8-DHF have good electrochemical properties,physical stability and biocompatibility.The release amount of 7,8-DHF is dependent on ES voltage and time.Under the action of ES,the release of 7,8-DHF combined with ES can promote the axon growth and SC migration of DRG neurons.