Biomimetic scaffolds inspired by fields and forces of the natural environment of cells is essential in tissue engineering. This study reports on controlled growth of two model cell lines, NIH/3T3 (promiscuous, fibroblast) and PC-12 (electroresponsive, neural progenitor) cells, given electrical and topographical cues that were delivered from a bionanocomposite of polyaniline-chloride and chitosan (PAn-Cl/CHI). The conductivity and morphology of the scaffold were controlled by varying the wt% of PAn-Cl (0-50 wt%) in CHI and processing methods, air-drying (nanofeatured) versus lyophilization (microporous-reticulated), respectively. Bionanocomposites supported the growth of both cell types independent of the availability of receptor-mediated ligands (laminin). NIH/3T3 cells were less elongated on lyophilized (microporous-reticulated) and more conductive (higher wt% PAn-Cl) composites. PC-12 cells had higher viability and less aggregation when grown on conductive substrates. Air-dried bionanocomposites were more supportive of growth but not attachment of PC-12 cells, suggesting that processing of composites could provide an additional level of engineering control to alter the PC-12 cell attachment and growth. In general, PC-12 cells responded more distinctly and dramatically to the substrate properties than NIH/3T3 cells, supporting a clear role for electrical conductivity on neural cell behavior. Nerve growth factor(NGF)-induced differentiation of PC-12 cells resulted in extensive neurite extension in the presence of adsorbed laminin. In a substrate composition-dependent manner, extension and rate of neurite outgrowth were higher when cultured on the conductive substrates. Overall, this study demonstrates the suitability of conductive PAn-Cl/CHI scaffold to host different cell types and support their responses.
Keywords: Chitosan-bionanocomposites; Electrical-impedance; Laminin; NIH/3T3 cells; PC-12 differentiation; Polyaniline-nanofibers.
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