Abstract:

[Abstract]  Objective  To design a kind of biomimetic polypeptide of dentin matrix protein-1（DMP-1）, which canbind to dentine collagen fibers and initiate mineralization. Methods A novel polypeptide was developed by connectingthe collagen binding domain of DMP-1“DSESSEEDR”to the hydrophilic C-terminal of amelogenin“TKREEVD”. The polypeptide was synthetically prepared by standard solid-phase peptide synthesis. Human dentine slices were completely demineralized by hydrochloric acid to expose the dentine collagen. Fluorescein isothiocyanate coupled polypeptide was applied to the exposed dentine collagen. Fluorescent microscopy was used to examine the polypeptide specially bond to the dentine collagen. Nucleation and growth of hydroxyapatite was initiated by immersing the polypeptide into calciumchloride and sodium hypophosphate solutions respectively. Scanning electron microscopy（SEM）, transmission electronmicroscopy（TEM） and selected area diffraction（SAD） were used to examine the hydroxyapatites formed. Results  Fluorescent dentine collagen was identified in the demineralized dentine specimens. Nucleation and growth of crystals were detected after immersing the polypeptide into calcium chloride and sodium hypophosphate solutions by SEM andTEM. SAD confirmed the crystals were hydroxyapatites. Conclusion The polypeptide of “DSESSEEDRTKREEVD”cansimulate DMP-1 binding collagen and initiate hydroxyapatite nucleation and growth. It may be a potential moleculartool for dentine remineralization.

Key words: dentin matrix protein-1, polypeptide, biomimetics, biomineralization