A strategy was shown for manipulating individual mammalian stem cells in defined
synthetic hydrogels through selective optical activation of Rac, which
is an intracellular signaling protein that plays a key role in cell
migration. Photoactivated cell migration in synthetic hydrogels depended
on mechanical and biological cues in the biomaterial.
Real-time hydrogel photodegradation was employed to create geometrically
defined channels and spaces in which cells could be photoactivated to
migrate. Cell migration speed was significantly higher in the
photo-etched channels and cells could easily change direction of
movement compared to the bulk hydrogels.