The guidance of stem cell differentiation by substrate alignment and mechanical stimulation

• Published in: Biomaterials Vol. 34; no. 8; pp. 1942 - 1953
• Main Authors: Subramony, Siddarth D, Dargis, Booth R, Castillo, Mario, Azeloglu, Evren U, Tracey, Michael S, Su, Amanda, Lu, Helen H
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 01.03.2013
• Subjects: Advanced Basic Science; Alignment; Biomimetic material; Bioreactor; Bioreactors; Cell Adhesion; Cell Differentiation; Cell Proliferation; Cues; Dentistry; Differentiation; Extracellular Matrix - metabolism; Gene Expression Regulation; Humans; Integrin; Integrins - genetics; Integrins - metabolism; Ligament; Male; Mesenchymal stem cell; Mesenchymal Stromal Cells - cytology; Mesenchymal Stromal Cells - metabolism; Nanofibers - chemistry; Nanofibers - ultrastructure; Nanostructure; Nanotopography; Protein Subunits - genetics; Protein Subunits - metabolism; Regeneration; Regenerative; Stem cells; Stimulation; Stimuli; Stress, Mechanical; Tissue Scaffolds - chemistry; Young Adult; Mesenchymal stem cell; Nanotopography; Ligament; Bioreactor; Integrin; Biomimetic material
• ISSN: 0142-9612; 1878-5905
• DOI: 10.1016/j.biomaterials.2012.11.012

Abstract Mesenchymal stem cells (MSC) represent a promising and clinically relevant cell source for tissue engineering applications. As such, guiding MSCs toward specific lineages and maintaining these phenotypes have been particularly challenging as the contributions of mechanical, chemical and structural cues to the complex differentiation process are largely unknown. To fully harness the potential of MSCs for regenerative medicine, a systematic investigation into the individual and combined effects of these stimuli is needed. In addition, unlike chemical stimulation, for which temporal and concentration gradients are difficult to control, mechanical stimulation and scaffold-based cues may be relatively more biomimetic and can be applied with greater control to ensure fidelity in MSC differentiation. The objective of this study is to investigate the role of nanofiber matrix alignment and mechanical stimulation on MSC differentiation, focusing on elucidating the relative contribution of each parameter in guided regeneration of functional connective tissues. It is observed that nanofiber alignment directs MSC response to physiological loading and that fibroblastic differentiation requires a combination of physiologically-relevant cell–material interactions in conjunction with mechanical stimulation. Importantly, the results of this study reveal that systemic and readily controllable cues, such as scaffold alignment and optimized mechanical stimulation, are sufficient to drive MSC differentiation, without the need for additional chemical stimuli. Moreover, these findings yield a set of fundamental design rules that can be readily applied to connective tissue regeneration strategies.