Roles of Nanofiber Scaffold Structure and Chemistry in Directing Human Bone Marrow Stromal Cell Response
Sumona Sarkar, Bryan A. Baker, Desu Chen, Patrick S. Pine, Jennifer H. McDaniel, Marc L. Salit, Wolfgang Losert, Carl G. Simon Jr., Joy P. Dunkers
Nanofiber technology has emerged as a promising tool to recapitulate the native extracellular matrix structure; however the properties of nanofibers governing cell-material interactions are still largely undetermined. In this study we have systematically investigated the role of both nanofiber structure and chemistry in directing the response of human bone marrow stromal cells (hBMSCs). We have developed a poly(ε-caprolactone) (PCL) nanofiber material system where scaffold structure is kept constant while surface chemistry is modified via mild sodium hydroxide (NaOH) hydrolysis to introduce surface carboxyl groups. Introduction of surface carboxyl groups was verified via x-ray photoelectronspectroscopy (XPS), water contact angle (WCA), and toluidine blue-O biochemical assay for carboxyl groups and scaffold structure was verified with scanning electron microscopy (SEM). hBMSCs were cultured on un-modified and NaOH-modified (Modified) scaffolds and cultures were investigated for proliferation, cell morphology, differentiation (alkaline phosphatase activity and mineralization) and microarray gene expression profiles. We found that both nanofiber structure and chemistry play a role in hBMSC osteogenic differentiation. PCL nanofiber scaffolds were able to elicit an osteogenic phenotype, while modified PCL nanofiber scaffolds did not. Scaffold structure was also found to have a more dominant effect on cell morphology and extracellular matrix gene expression than nanofiber chemistry while nanofiber chemistry had a larger effect on metabolism and cytoskeleton related gene expression.
Advances in Tissue Engineering and Regenerative Medicine