Using biomaterials to study stem cell mechanotransduction, growth and differentiation.

Self-renewal and differentiation are two fundamental characteristics of stem cells. Stem cell self-renewal is critical for replenishing the stem cell population, while differentiation is necessary for maintaining tissue homeostasis. Over the last two decades a great deal of effort has been applied to discovering the processes that control these opposing stem cell fates. One way of examining the role of the physical environment is the use of biomaterial strategies that have the ability to manipulate cells without any requirement for chemical factors. The mechanism whereby cells have been found to respond to a mechanical stimulus is termed mechanotransduction, the process by which a mechanical cue (or alteration in cell spreading changing internal cellular mechanics, i.e. intracellular tension) is transduced into a chemical signal inside the cell, eliciting changes in gene expression. This can occur either directly, as a result of changes in the cell cytoskeleton, or indirectly through a series of biochemical signalling cascades. The main focus of this review is to examine the role of mechanotransduction in the differentiation and self-renewal of stem cells. In particular, we will focus on the use of biomaterials as a tool for examining mechanotrandsuctive effects on self-renewal and differentiation.