Process Optimization Of High Conductivity And Piezoelectric PEDOT/CS Nanofiber Scaffolds And Electrical Stimulation Effects On Nerve Cells Behavior

Conductive polymers(CPs)have been widely used to construct cellular ES membranes because of their unique electrical stimulation(ES)response characteristics.However,the application of CPs is often limited by their inherent non-biodegradability.Therefore,for biomedical applications,doping CPs into biodegradable biomaterials is often used to make biodegradable CPs cellular ES membranes.However,in order to achieve the electrical conductivity(>10^-1 S/cm)required for effective cellular ES in clinical trials,a large number of non-degradable CPs components are often doped into biodegradable biomaterials,but this is usually with a potential inflammatory reaction.Reducing the doping amount of CPs will lead to the conductivity cannot meet the effective ES requirements.Therefore,the fabrication of biodegradable CPs cellular ES scaffolds with low CPs doping and excellent conductivity and biocompatibility is of great significance to clinical cellular ES.In this study,a nanofiber membrane with a shell-core structure was designed based on electrospinning in combination with non-in situ permeation method,and the sulfuric acid(H₂SO₄)chemical treatment process was used to further optimize the the electrical performance of the membrane.Meanwhile,in order to test the cellular ES effect of the membranes,the membranes were applied to culture brain neuroglioma cells(BNCs),and the effect of membranes on cell growth and differentiation was explored by applying external ES.The main research processes are as follows:(1)Chitosan(CS)nanofiber membranes were prepared using an electrostatic spinning,and a layer of poly(3,4-ethylenedioxythiophene):polystyrene sulfonate(PEDOT:PSS)was coated on the surface of CS nanofibers to prepare PEDOT:PSS/CS nanofiber membranes.The properties of PEDOT:PSS/CS nanofiber membranes prepared with different concentrations of PEDOT:PSS coating were explored,and the optimal coating concentration was determined.(2)PEDOT/CS nanofiber membranes were prepared by exploring the optimal H₂SO₄ treatment process,removing excess PSS in the PEDOT:PSS shell and recrystallizing PEDOT.(3)The membranes were co-cultured with BNCs and ES was applied to observe the cells growth on the membranes.At the same time,explore the synergistic effect of piezoelectric charge and external charge on cells growth.Based on the research,the conclusions are drawn as follows:(1)The PEDOT:PSS/CS nanofiber membranes prepared with 0.6 wt%PEDOT:PSS aqueous dispersion have stable shell-core structure and good electrical conductivity of 0.01259±0.0001 S/cm,while the content of PEDOT is only?1.0 wt%;(2)The PEDOT/CS nanofiber membranes prepared under the optimal conditions of H₂SO₄ treatment(concentration of H₂SO₄ 0.8 mol/L,temperature 60?,time 5 mins)have the highest conductivity,up to 0.1945±0.0001 S/cm,and generate a high output voltage of 0.93 V/cm³ under the low frequency of 1 Hz and micro pressure of?8.87 Pa.(3)BNCs show strong surface adhesion on PEDOT/CS nanofiber membranes,and the external charge of ES and the piezoelectric charge of PEDOT/CS nanofibers synergistically promote cell growth and development.In this study,the PEDOT/CS nanofiber membrane prepared combines the biodegradability of CS,a small amount of PEDOT.It is expected to be widely used in various clinical applications involving cellular ES.