Effect of laser induced topography with moderate stiffness on human mesenchymal stem cell behavior

Abstract

Though the effects of scaffold properties such as stiffness and topography on stem cell behavior was well known of, there were multiple theories that explain such behavior and there has been no common consensus thus far. This study deals with using polydimethylsiloxane (PDMS) to mimic a specific microenvironment that favors human mesenchymal stem cells (hMSCs) differentiation into myogenic lineages through the manipulation of specific surface topography and appropriate substrate stiffness. Femtosecond laser was applied to machine microchannels on PDMS substrates in this work. hMSCs were seeded and cultured on lasercut substrates, uncut substrates and controls. Quantitative and qualitative analyses of stem cell behavior were discussed herein with the use of Picogreen Assay for cell proliferation, staining of cytoskeleton for cell orientation, immunostaining of Myosin Heavy Chain for a myogenic biomarker, and quantitative real time polymerase chain reaction for gene expression analysis. It was found that both myogenic differentiation of hMSCs could be achieved by moderate stiffness or microchannels. And differentiation was further boosted by such PDMS substrates with additional microchannels.