Self assembled bi-functional peptide hydrogels with biomineralization-directing peptides.
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.
Gungormus
Mustafa
M
Materials Science and Engineering, University of Washington, Seattle, WA, USA. musgun@u.washington.edu
Branco
Monica
M
Fong
Hanson
H
Schneider
Joel P
JP
Tamerler
Candan
C
Sarikaya
Mehmet
M
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
D001672:Biocompatible Materials; D020100:Hydrogels; D010455:Peptides; D017886:Durapatite