title: Repeated rapid shear-responsiveness of peptide hydrogels with tunable shear modulus.
abstract: A pair of mutually attractive but self-repulsive decapeptides, with alternating charged/neutral amino acid sequence patterns, was found to co-assemble into a viscoelastic material upon mixing at a low total peptide concentration of 0.25 wt %. Circular dichroism spectroscopy of individual decapeptide solutions revealed their random coil conformation. Transmission electron microscopy images showed the nanofibrillar network structure of the hydrogel. Dynamic rheological characterization revealed its high elasticity and shear-thinning nature. Furthermore, the co-assembled hydrogel was capable of rapid recoveries from repeated shear-induced breakdowns, a property desirable for designing injectable biomaterials for controlled drug delivery and tissue engineering applications. A systematic variation of the neutral amino acids in the sequence revealed some of the design principles for this class of biomaterials. First, viscoelastic properties of the hydrogels can be tuned through adjusting the hydrophobicity of the neutral amino acids. Second, the beta-sheet propensity of the neutral amino acid residue in the peptides is critical for hydrogelation.
authors.affiliation: Department of Pharmaceutics and Pharmaceutical Chemistry and Department of Bioengineering, University of Utah, Salt Lake City, Utah, USA.
authors.forename: Sivakumar
authors.initials: S
authors.lastname: Ramachandran
authors.forename: Yiider
authors.initials: Y
authors.lastname: Tseng
authors.forename: Y Bruce
authors.initials: YB
authors.lastname: Yu
mesh_terms: D020100:Hydrogels / Q000737:chemistry*; D010446:Peptide Fragments / Q000737:chemistry*; D012212:Rheology; D033081:Shear Strength
chemical_list: D020100:Hydrogels; D010446:Peptide Fragments