title: Structural effects of crosslinking a biopolymer hydrogel derived from marine mussel adhesive protein.
abstract: In an effort to explore new biocompatible substrates for biomedical technologies, we present a structural study on a crosslinked gelatinous protein extracted from marine mussels. Prior studies have shown the importance of iron in protein crosslinking and mussel adhesive formation. Here, the structure and properties of an extracted material were examined both before and after crosslinking with iron. The structures of these protein hydrogels were studied by SEM, SANS, and SAXS. Viscoelasticity was tested by rheological means. The starting gel was found to have a heterogeneous porous structure on a micrometer scale and, surprisingly, a regular structure on the micron to nanometer scale. However disorder, or "no periodic structure", was deduced from scattering on nanometer length scales at very high q. Crosslinking with iron condensed the structure on a micrometer level. On nanometer length scales at high q, small angle neutron scattering showed no significant differences between the samples, possibly due to strong heterogeneity. X-ray scattering also confirmed the absence of any defined periodic structure. Partial crosslinking transformed the viscoelastic starting gel into one with more rigid and elastic properties.
authors.affiliation: Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803, USA.
authors.forename: Elena
authors.initials: E
authors.lastname: Loizou
authors.forename: Jaime T
authors.initials: JT
authors.lastname: Weisser
authors.forename: Avinash
authors.initials: A
authors.lastname: Dundigalla
authors.forename: Lionel
authors.initials: L
authors.lastname: Porcar
authors.forename: Gudrun
authors.initials: G
authors.lastname: Schmidt
authors.forename: Jonathan J
authors.initials: JJ
authors.lastname: Wilker
mesh_terms: D000818:Animals; D001704:Biopolymers / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000494:pharmacology*; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000138:chemical synthesis* / Q000737:chemistry; D007501:Iron / Q000737:chemistry; D008855:Microscopy, Electron, Scanning / Q000379:methods; D008954:Models, Biological; D049880:Mytilus edulis / Q000737:chemistry; D033363:Neutron Diffraction / Q000379:methods; D011506:Proteins / Q000737:chemistry*; D012212:Rheology / Q000379:methods; D014783:Viscosity; D014961:X-Ray Diffraction / Q000379:methods
chemical_list: D001704:Biopolymers; D003432:Cross-Linking Reagents; D011506:Proteins; C037403:adhesive protein, mussel; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D007501:Iron