title: Mechanical characterization of self-assembling peptide hydrogels by microindentation.
abstract: Hydrogels formed from self-assembling synthetic oligopeptides have been studied for almost 2 decades for use in tissue engineering and drug delivery. Although a great deal has been learned about the microstructure of these materials, there remain questions about how peptide filaments are ordered to form a gel. These unanswered questions leave a disconnect between our understanding of the observed nanoscale mechanical properties of peptide filaments and the macroscale properties of the gels they constitute. This study helps to bridge this gap by examining the role of filament length and interfilament crosslinks in determining bulk mechanical properties. Microindentation was used for mechanical characterization, and microstructure was observed using thin-section transmission electron microscopy images of gels embedded in resin. Results suggest a gel structure in which filaments are not densely bundled as previously suggested and confirm that crosslinking can be an effective strategy to increase the stiffness of self-assembling oligopeptide gels.
authors.affiliation: Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: Nathan A
authors.initials: NA
authors.lastname: Hammond
authors.forename: Roger D
authors.initials: RD
authors.lastname: Kamm
mesh_terms: D001696:Biomechanical Phenomena; D003432:Cross-Linking Reagents; D016503:Drug Delivery Systems; D005976:Glutaral; D020100:Hydrogels / Q000737:chemistry; D008422:Materials Testing; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D009842:Oligopeptides / Q000737:chemistry; D010455:Peptides / Q000737:chemistry*; D012212:Rheology; D013314:Stress, Mechanical; D023822:Tissue Engineering; D054457:Tissue Scaffolds / Q000737:chemistry
chemical_list: D003432:Cross-Linking Reagents; D020100:Hydrogels; D009842:Oligopeptides; D010455:Peptides; C098328:RAD16 peptide; D005976:Glutaral
keywords: hydrogel; mechanical properties; microindentation; microstructure; self-assembly