Enhancement of neurite adhesion, alignment and elongation on conductive polypyrrole-poly(lactide acid) fibers with cell-derived extracellular matrix

Extracellular matrix (ECM) can promote peripheral nerve repair. In this study, a conductive fiber-film (CFF) with core-sheath structure and conductivity of similar to 10 S cm(-1) was prepared by electrospinning of aligned poly(L-lactide acid) (PLLA) fibers and electrochemical deposition of polypyrole (PPy) nanopartides. Then the multiple components of ECM, including laminin, fibronectin and collagen, were coated on the surface of CFF by culturing and lysing L929 cells to fabricate the bioactive scaffold of ECM-linked CFF (ECM-CFF). The electrical stimulation (ES) of 100 mV/cm for 14 days and 2 h per day did not significantly decrease the conductivity of ECM-CFF. The results of PC12 cells test indicated that, cells adhesion rate, neurite-bearing cell rate and neurite alignment rate on ECM-CFF were similar to 95%, similar to 77%, similar to 70%, respectively, significantly larger than the corresponding values on bare CFF (17%, 29% and 14%, respectively). The neurites length on ECM-CFF (similar to 79 mm) was also larger than that on bare CFF (similar to 25 mm). ES of 100 mV/cm onto PC12 cells through ECM-CFF could significantly promote neurite extension in first 3 days of the neurite growth. These results indicated that, the combination of ECM-CFF with ES could improve the nerve regeneration by encouraging neural-cell adhesion, neurite growth and extension. (C) 2016 Elsevier B.V. All rights reserved.