An electrically conductive 3D scaffold based on a nonwoven web of poly(l -lactic acid) and conductive poly(3,4-ethylenedioxythiophene)

This study was to demonstrate that an extremely thin coating of poly(3,4-ethylenedioxythiophene) (PEDOT) on nonwoven microfibrous poly(l-lactic acid) (PLLA) web is of sufficient electrical conductivity and stability in aqueous environment to sustain electrical stimulation (ES) to cultured human skin fibroblasts. The PEDOT imparted the web a surface resistivity of approximately 0.1 KΩ/square without altering the web morphology. X-ray photoelectron spectroscopy demonstrated that the surface chemistry of the PLLA/PEDOT is characteristic of both PLLA and PEDOT. The PEDOT-coated web also showed higher hydrophilicity, lower glass transition temperature and unchanged fiber crystallinity and thermal stability compared with the PLLA web. The addition of PEDOT to the web marginally increased the web's tensile strength and lowered the elongation. An electrical stability test showed that the PLLA/PEDOT structure was more stable than a polypyrrole treated PLLA fabric, showing only a slow deterioration in conductivity when exposed to culture medium. The cytotoxicity test showed that the PLLA/PEDOT scaffold was not cytotoxic and supported human dermal fibroblast adhesion, migration, and proliferation. Preliminary ES experiments have demonstrated that this conductive web mediated effective ES to fibroblasts. Therefore, this new conductive biodegradable scaffold may be used to electrically modulate cellular activity and tissue regeneration.