title: Self assembled bi-functional peptide hydrogels with biomineralization-directing peptides.
abstract: A peptide-based hydrogel has been designed that directs the formation of hydroxyapatite. MDG1, a twenty-seven residue peptide, undergoes triggered folding to form an unsymmetrical beta-hairpin that self-assembles in response to an increase in solution ionic strength to yield a mechanically rigid, self supporting hydrogel. The C-terminal portion of MDG1 contains a heptapeptide (MLPHHGA) capable of directing the mineralization process. Circular dichroism spectroscopy indicates that the peptide folds and assembles to form a hydrogel network rich in beta-sheet secondary structure. Oscillatory rheology indicates that the hydrogel is mechanically rigid (G' 2500Pa) before mineralization. In separate experiments, mineralization was induced both biochemically and with cementoblast cells. Mineralization-domain had little effect on the mechanical rigidity of the gel. SEM and EDXS show that MDG1 gels are capable of directing the formation of hydroxapatite. Control hydrogels, prepared by peptides either lacking the mineral-directing portion or reversing its sequence, indicated that the heptapeptide is necessary and its actions are sequence specific.
authors.affiliation: Materials Science and Engineering, University of Washington, Seattle, WA, USA. musgun@u.washington.edu
authors.forename: Mustafa
authors.initials: M
authors.lastname: Gungormus
authors.forename: Monica
authors.initials: M
authors.lastname: Branco
authors.forename: Hanson
authors.initials: H
authors.lastname: Fong
authors.forename: Joel P
authors.initials: JP
authors.lastname: Schneider
authors.forename: Candan
authors.initials: C
authors.lastname: Tamerler
authors.forename: Mehmet
authors.initials: M
authors.lastname: Sarikaya
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry; D002113:Calcification, Physiologic; D002460:Cell Line; D002470:Cell Survival; D002942:Circular Dichroism; D017886:Durapatite / Q000737:chemistry; D020100:Hydrogels / Q000737:chemistry*; D008422:Materials Testing; D051379:Mice; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry* / Q000235:genetics; D017510:Protein Folding; D017433:Protein Structure, Secondary; D014961:X-Ray Diffraction
chemical_list: D001672:Biocompatible Materials; D020100:Hydrogels; D010455:Peptides; D017886:Durapatite