Photoresponsive Hydrogels with Photoswitchable Stiffness: Emerging Platforms to Study Temporal Aspects of Mesenchymal Stem Cell Responses to Extracellular Stiffness Regulation

• Published in: Advances in experimental medicine and biology Vol. 1144; p. 53
• Main Authors: Richards, David, Swift, Joe, Wong, Lu Shin, Richardson, Stephen M
• Format: Journal Article
• Language: English
• Published: United States 01.01.2019
• Subjects: Cell Culture Techniques; Cell Differentiation; Extracellular Matrix; Humans; Hydrogels - radiation effects; Light; Mechanotransduction, Cellular; Mesenchymal Stem Cells - cytology; Photoresponsive; Temporal; Regenerative medicine; Hydrogel substrates; Polyacrylamide; Cell adhesion; Cell-matrix interaction; Photoswitchable stiffness; Biophysical regulation; Mechanotransduction; Stiffness regulation; Mesenchymal stem cells
• ISSN: 0065-2598
• DOI: 10.1007/5584_2018_293

An extensive number of cell-matrix interaction studies have identified matrix stiffness as a potent regulator of cellular properties and behaviours. Perhaps most notably, matrix stiffness has been demonstrated to regulate mesenchymal stem cell (MSC) phenotype and lineage commitment. Given the therapeutic potential for MSCs in regenerative medicine, significant efforts have been made to understand the molecular mechanisms involved in stiffness regulation. These efforts have predominantly focused on using stiffness-defined polyacrylamide (PA) hydrogels to culture cells in 2D and have enabled elucidation of a number of mechano-sensitive signalling pathways. However, despite proving to be a valuable tool, these stiffness-defined hydrogels do not reflect the dynamic nature of living tissues, which are subject to continuous remodelling during processes such as development, ageing, disease and regeneration. Therefore, in order to study temporal aspects of stiffness regulation, researchers have developed and exploited novel hydrogel substrates with in situ tuneable stiffness. In particular, photoresponsive hydrogels with photoswitchable stiffness are emerging as exciting platforms to study MSC stiffness regulation. This chapter provides an introduction to the use of PA hydrogel substrates, the molecular mechanisms of mechanotransduction currently under investigation and the development of these emerging photoresponsive hydrogel platforms.