Figure 3. Hydrogels constructed from collagen-mimetic peptides.

(A) The structure of a peptide synthesized by the Chmielewski group, with metal-binding groups at the ends and middle of a peptide bearing collagen-mimetic repeats. The peptides self-assemble into triple helices, and addition of metal ions crosslinks them into a hydrogel. (B) Three peptides with collagen-like repeats, developed by the Hartgerink laboratory, self-assemble into staggered, heterotrimeric helices. Interactions between the ends and middle of these helices result in the formation of bundled nanofibers that form a hydrogel. (C) Schematic of the sticky-end interactions that result in formation of the nanofibers observed. Arrows indicate charged residues that promote additional inter-helical bundling. [(A): ref. 53; (B, C): ref. 54]