In situ processing of fibrous hydrogels by photochemistry for adaptive cellular microenvironments.

Omnipresent in biology, fibrous networks like collagen possess unique properties: dynamic network via crosslinking and degradation. This intrinsic adaptivity plays a critical role in regulating cell behavior via cell-matrix interactions. Built from biological building blocks, however, these networks are challenging to manipulate or even control. Here, we introduce dynamic network regulation via photochemical control in a synthetic and fibrous highly biomimetic hydrogel. As a proof-of-concept, we demonstrate that the dynamic control over the mechanical properties of this adaptive in vitro model can be used to modulate cell spreading and mechanotransduction in three-dimensional (3D) mesenchymal stromal cell cultures. Our approach not only opens the door to on-demand mechanically adaptive gels with unprecedented control, but simultaneously offers easy processibility and cell extraction of the used synthetic gel.