Synergistic effects of conductivity and cell-imprinted topography of chitosan-polyaniline based scaffolds for neural differentiation of adipose-derived stem cells

Smart nano-environments that mimic the stem cell niche can guide cell behavior to support functional repair and regeneration of tissues. The specific microenvironment of nervous tissue is composed of several physical signaling factors, including proper topography, flexibility, and electric conductance, to support the electrical conduction of neuronal communication. In this study, a cell-imprinting technique was used to obtain a hierarchical topographical conductive scaffold based on chitosan-polyaniline (PANI) hydrogels for directing the neural differentiation of rat adipose-derived stem cells (rADSCs). A chitosan-polyaniline hydrogel was synthesized, followed by characterization tests, such as Fourier transform infrared spectroscopy (FTIR), electrical conductivity, Young modulus, and contact angle measurements. A chitosan-PANI scaffold with a biomimetic topography was fabricated by molding it on a chemically fixed culture of PC12 cells. This substrate was used to test the hypothesis that the PC12 cell-imprinted chitosan-PANI hydrogel provides the required hierarchical topographical surface to induce neural differentiation. To test the importance of spatial imprinting, rADSCs were seeded on these conductive patterned substrates, and the resulting cultures were compared to those of the same cells grown on flat conductive chitosan-polyaniline, and flat pure chitosan substrates for evaluation of adhesion, cell viability, and expression of neural differentiation markers. The morphology of rADSCs grown on conductive patterned scaffolds noticeably was significantly different from that of stem cells cultivated on flat scaffolds. This difference suggests that the change in cell and nuclear shape imposed by the patterned conductive substrate leads to altered gene expression and neural differentiation of cultured cells. In addition, the percentage of rADSCs that differentiated into neural-like cells was almost 80 % on the imprinted chitosan-PANI scaffold. In summary, a conductive chitosan-polyaniline scaffold with biomimetic topography demonstrates a promising method for enhancing the neural differentiation of rADSCs for the treatment of neurodegenerative diseases.Competing Interest StatementThe authors have declared no competing interest.View Full Text