Mechanical Stimulation of Mesenchymal Stem Cells

Stem cells’ research reached an advanced stage with clear understanding of the ability of multipotent mesenchymal stem cells to maturate to different metabolically mature cells of the connective tissue. In combination with advancement in genetic research it is now possible to start decoding basic cellular mechanotransduction pathways in stem cells. This novel research field has the potential to lead to the discovery of new and important niche in the biomedicine with a prospective of reaching important clinical advancements. Although important research success has been reached recently the exact mechanisms of the MSC’s determination of the fate are still elusive and require further extensive research efforts. In order to reveal the basic mechanisms of stem cell differentiation two distinct areas of investigation are mostly considered – the biochemical perspective and the physical or biomechanical perspective. In dealing with the biomechanical prospective, an attempt to mimic the mechanically active milieu for the MSCs was introduced using different research methods (see Chapter 2). Because mesenchymal derived cells differentiate into tissues that usually have mechanically supportive function, it is only logical to hypothesize that mechanical stimuli might cause changes on the cellular level. In this chapter we review the effects of mechanical stimulation of mesenchymal stem cells (MSCs) according to different features and parameters of the stimulus: shear stress applied to MSCs by fluid, micro-environmental scale cellular mechanical stimuli, substrate stiffness, cell shape and surface topography effects, the genomic level control of external mechanical force, micro-environmental nano-fibres’ stretch and reorientation with the directional effect of the mechanical stimulation. Clearly the understanding of the numerous mechanical effects with different mechanical parameters of the stimuli that are applied to MSCs has been advanced recently but still requires further extensive and thorough research in order to manipulate these cells biomechanically for a clinical use.

Keywords: Cell differentiation, ECM, mechanical stimuli.