DYNAMIC MECHANICAL PROPERTIES CONTROL ADULT STEM CELL FATE

摘要

Stem cells respond to many microenvironmental cues towards their decisions to spread, migrate, and differentiate and these cues can he incorporated into materials for regenerative medicine.1 In the last decade, matrix stiffness alone has heen implicated in regulating cellular functions such as migration, proliferation and differentiation.2 With this in mind, a variety of natural and synthetic polymer systems were used in vitro to mimic the elasticity of native tissues. Despite helping to develop this important field and gather valuable information, these substrates are primarily static and lack the dynamic nature that is observed during many cellular processes such as development, fibrosis and cancer. Thus, it is of great interest to temporally manipulate matrix elasticity in vitro to better understand and develop strategies to control these biological processes. In this work, we utilize a sequential crosslinking approach3 (initial gelation via addition reaction, secondary crosslinking through light-mediated radical polymerization) to fabricate hydrogel substrates that stiffen (e.g., ～3 to 30 kPa) either immediately or at later times and in the presence of cells.