Injectable Solids: Solution Construction of Hydrogel Biomaterials with Beta-Hairpin Peptides

D.J. Pochan
University of Delaware, US

Keywords: biomaterials, solution assembly, hydrogels, shear-thinning

Summary:

The local nano- and overall network structure, and resultant viscoelastic and cell-level biological properties, of hydrogels that are formed via beta-hairpin self-assembly will be presented. These peptide hydrogels are potentially excellent scaffolds for tissue repair and regeneration, as well as local drug delivery, due to inherent cytocompatibility, porous morphology, and shear-thinning but instant recovery viscoelastic properties. The hydrogel is composed of a network of fibrils that are 3 nm wide and heavily branched and entangled with no covalent crosslinking required for gel stiffness. In addition, slight design variations of the MAX1 sequence allow for tunability of the self-assembly/hydrogelation kinetics as well as the tunability of the local peptide nanostructure and hierarchical network structure. During assembly and gelation, desired components can be encapsulated within the hydrogel network such as drug compounds and/or living cells. Importantly, once formed into a solid, the system can shear thin and flow but immediately reheal to preshear stiffness on the cessation of the shear stress. This shear thinning behavior of these physical networks makes them interesting candidates for injectable delivery in vivo where no post injection chemistry is required to set up the network.