(624a) Controlling Structure within Hydrogel-Based Synthetic Extracellular Matrices through Self-Assembly and Light-Mediated Reactions (Invited Talk)

Hydrogel-based biomaterials increasingly are used as extracellular matrix (ECM) mimics for cell culture and regenerative medicine applications. Synthetic hydrogels have been designed to afford precise control of mechanical and biochemical properties for directing cell function and fate. However, these materials often are homogeneous on the nanoscale unlike the hierarchically structured native ECM. To address this, we have synthesized self-assembling peptides decorated with reactive groups for incorporation within hydrogels formed by light-mediated thiolâ??ene click chemistry. Specifically, collagen mimetic peptides (CMPs) based on variants of Proline-Hydroxyproline-Glycine repeats [(POG)_n] have been functionalized with alkenes. These multifunctional CMPs assembly to form fibrils ( ~10-250 nm wide, TEM and AFM) and physical gels (G~100 Pa, rheometry). Pendant groups on these multifunctional CMPs have been reacted with various thiols (e.g., thiol-functionalized peptides, PEG) by photoinitiated, radically-mediated thiolâ??ene reaction. This approach is promising for controlling the nanostructure within well-defined hydrogels for various biological applications, including controlled cell culture and regenerative medicine.