title: PEG-based hydrogels with collagen mimetic peptide-mediated and tunable physical cross-links.
abstract: Mechanical properties of tissue scaffolds have major effects on the morphology and differentiation of cells. In contrast to two-dimensional substrates, local biochemical and mechanical properties of three-dimensional hydrogels are difficult to control due to the geometrical confinement. We designed synthetic 3D hydrogels featuring complexes of four-arm poly(ethylene glycol) (PEG) and collagen mimetic peptides (CMPs) that form hydrogels via physical cross-links mediated by thermally reversible triple helical assembly of CMPs. Here we present the fabrication of various PEG-CMP 3D hydrogels and their local mechanical properties determined by particle tracking microrheology. Results show that CMP mediated physical cross-links can be disrupted by altering the temperature of the gel or by adding free CMPs that compete for triple helix formation. This allowed modulation of both bulk and local stiffness as well as the creation of stiffness gradients within the PEG-CMP hydrogel, which demonstrates its potential as a novel scaffold for encoding physicochemical signals for tissue formation.
authors: Department of Materials Science and Engineering, Institute for NanoBioTechnology, and Johns Hopkins Physical Science Oncology Center, The Johns Hopkins University, Baltimore, Maryland 21218, USA.
authors: Patrick J
authors: PJ
authors: Stahl
authors: Nicole H
authors: NH
authors: Romano
authors: Denis
authors: D
authors: Wirtz
authors: S Michael
authors: SM
authors: Yu
mesh_terms: D032701:Biomimetics; D003094:Collagen / Q000737:chemistry*; D003432:Cross-Linking Reagents; D005109:Extracellular Matrix; D020100:Hydrogels / Q000138:chemical synthesis* / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D010446:Peptide Fragments / Q000138:chemical synthesis* / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*
chemical_list: D003432:Cross-Linking Reagents; D020100:Hydrogels; D010446:Peptide Fragments; D011092:Polyethylene Glycols; D003094:Collagen