Capacitive electrical stimulation of a conducting polymeric thin film induces human mesenchymal stem cell osteogenesis

Electroactive materials based on conductive polymers are promising options for tissue engineering and regenerative medicine applications. In the present work, the conducting copolymers of poly (3,4-ethylenedioxythiophene) and poly (d, l-lactic acid) (PEDOT-co-PDLLA) with PEDOT:PDLLA molar ratios of 1:50, 1:25, and 1:5 were synthesized and compared to the insulating macromonomer of EDOT-PDLLA as an experimental control. Bone marrow-derived human mesenchymal stem cells (hMSC-BM) were cultured on the copolymers and the macromonomer thin films inside a bioreactor that induced a capacitive electrical stimulation (CES) with an electric field of 100 mV/mm for 2 h per day for 21 days. Under CES, the copolymers exhibited good cell viability and promoted the differentiation from hMSC-BM to osteogenic lineages, revealed by higher mineralization mainly when the contents of conducting segments of PEDOT (i.e., copolymer with 1:25 and 1:5 PEDOT:PDLLA ratios) were increased. The results indicate that the intrinsic electrical conductivity of the substrates is an important key point for the effectiveness of the electric field generated by the CES, intending to promote the differentiation effect for bone cells.