Interactions of Stem Cells and Components of the Extracellular Matrix

The extracellular matrix (ECM) acts to provide a supportive scaffold for cells, but also modulates cell fate and function through chemical, topographical, and mechanical interactions. Understanding the interactions between stem cells and the ECM is vital in order to engineer substrates that more closely mimic the natural ECM niche. Stem cells encounter specialized conditions depending on the tissue in which they are located, and these niche systems are highly varied in regards to organization, orientation, and physical dimensions within the body. Utilizing biomimetic tactics to engineer ECM is a powerful new approach to the culture and incorporation of stem cells into engineered tissue. From a chemical perspective, stem cells bind to and interact with either soluble or bound growth factors in the ECM. The differentiation and maintenance of stem cells is affected by nanoscale topography, including grooves, fibers, pits, and pillars. Manipulation of substrate stiffness also presents a strategy to modulate differentiation, although the overlapping range of stiffness found in different tissues mandates the use of other design implications in addition to stiffness. Studies aimed at understanding the interactions of stem cells with the chemical, topographical, and mechanical components of the extracellular matrix enhance our knowledge of how stem cells function and enable use of stem cells in a variety of applications. This research establishes the basis for further exploration into how stem-cell differentiation, migration, and proliferation are regulated in vivo and the application of stem cells in tissue engineering and regenerative medicine.