title: Self-assembled pH-responsive hydrogels composed of the RATEA16 peptide.
abstract: Peptide RATEA16 spontaneously self-assembled into higher-order nanofiber hydrogels with extremely high water content (>99.5% (wt/vol)) under physiological condition. The hydrogels could undergo pH-reversible transitions from viscous solution to elastic hydrogel and to precipitate. The supramolecular self-assembly and the three phase transitions are driven by hydrophobic interactions, intermolecular hydrogen bonds, and a combination of attractive or repulsive electrostatic interactions. These hydrogels are rich in beta-sheet nanofibers, as demonstrated by CD and FTIR data. Rheological measurements reveal that the viscoelasticity of the material can be tuned by environmental pH and peptide concentration. The storage modulus of the hydrogels increases with increasing peptide concentration, and the self-assembled hydrogels are able to recover from mechanical breakdowns. AFM images show that the elasticity is attributed to a network nanostructure consisting of fibrous self-assemblies. The hydrogels are promising for a variety of possible biomedical applications, including drug delivery.
authors.affiliation: Department of Materials Science and Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhao
authors.forename: Hidenori
authors.initials: H
authors.lastname: Yokoi
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Tanaka
authors.forename: Takatoshi
authors.initials: T
authors.lastname: Kinoshita
authors.forename: Tianwei
authors.initials: T
authors.lastname: Tan
mesh_terms: D002942:Circular Dichroism; D004337:Drug Carriers / Q000737:chemistry; D004548:Elasticity; D020100:Hydrogels / Q000138:chemical synthesis* / Q000737:chemistry*; D006860:Hydrogen Bonding; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D018625:Microscopy, Atomic Force; D049329:Nanostructures / Q000737:chemistry; D009842:Oligopeptides / Q000138:chemical synthesis* / Q000737:chemistry*; D044367:Phase Transition; D017433:Protein Structure, Secondary; D012212:Rheology; D017550:Spectroscopy, Fourier Transform Infrared; D055672:Static Electricity
chemical_list: D004337:Drug Carriers; D020100:Hydrogels; D009842:Oligopeptides