A new perspective for stem-cell mechanobiology: biomechanical control of stem-cell behavior and fate

Biomechanics is known to play an important role in cell metabolism. Cell phenotype, tissue-specific functions, and fate critically depend on the extracellular mechanical environment. The mechanical properties of the cell itself, such as cytoskeleton elasticity, membrane tension, and adhesion strength, may also play an important role in cell homeostasis and differentiation. Pluripotent bone marrow-derived human mesenchymal stem cells, for example, can be differentiated into many tissue-specific lineages. While cellular biomechanical properties are significantly altered during stem-cell specification to a particular phenotype, the complexity of events associated with transformation of these precursor cells leaves many questions unanswered about morphological, structural, proteomic, and functional changes in differentiating stem cells. A thorough understanding of stem-cell behavior would allow the development of more effective approaches to the expansion of stem cells in vitro and the regulation of their commitment to a specific phenotype. Control of cell behaviors might be feasible through manipulation of the cellular biomechanical properties using various external physical stimuli, including electric fields, mechanical stimuli, and genetic manipulation of the expression of particular genes. Biomechanical regulation of stem-cell differentiation can greatly minimize the number of chemicals and growth factors that would otherwise be required for composite tissue engineering. Determination and the appropriate use of the known physicochemical cues will facilitate current research effort toward designing and engineering functional tissue constructs.