Biomimetic Remineralization Of Type Ⅰ Collagen Induced By A Polypeptide Inspired From Dentin Matrix Protein-1

Objective To design a kind of biomimetic polypeptide of dentin matrix protein-1(DMP-1), which can bind to dentine collagen fibers and initiate mineralization. Remineralization of the collagen of dentin can be reached via a polymer-induced liquid-precursor process.Methods A novel polypeptide was developed by connecting the collagen binding domain of dentine matrix protein1"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(FITC) 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 (HA) was initiated by immersing the polypeptide into calcium chloride and sodium hypophosphate solutions respectively. Scanning electron microscopy(SEM), transmission electron microscopy(TEM) and selected area diffraction(SAD) were used to examine the HA formed.Put the dentin collagen and the collagen1into the solution contain polypeptide and the mineral ions, SEM and TEM were used to examine the HA 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. SAD confirmed the crystals were hydroxyapatites. The collagen1and the dentine collagen were both remineralized.Conclusion The polypeptide of "DSESSEEDRTKREEVD" can simulate DMP-I binding collagen and initiate hydroxyapatite nucleation and growth. It may be a potential molecular tool for dentin remineralization. Dentine remineralization can be reached.