Modification of calcium–phosphate coatings on titanium by recombinant amelogenin

Abstract

Amelogenin proteins, the principal components of the developing dental enamel extracellular matrix, have been postulated to facilitate the elongated and oriented growth of the carbonated apatite crystals during enamel formation. We previously reported that amelogenin caused modulation of apatite crystals nucleated on a bioactive glass (Bioglass(R)) in vitro. Here, the effects of amelogenin on the growth morphology of calcium-phosphate crystals nucleated on a titanium surface were investigated in order to gain a better understanding of the role of amelogenins during enamel biomineralization and to explore their potential application in the design and development of novel biomaterials. The dose-dependent effects of a recombinant mouse amelogenin (rM179) were found to be different from those of bovine serum albumin, which significantly inhibited apatite crystal growth and caused the octacalcium phosphate (OCP) crystals to change from a plate-like shape to a curved shape, indicating a general inhibitory effect. The effects of rM179 on the crystal growth of OCP at 12.5-100 microg/mL and of apatite at 50 microg/mL were insignificant while the apatite crystals were remarkably elongated along their c-axes upon the use of 100 microg/mL of rM179. The unique modulation of the calcium-phosphate coatings on titanium by rM179 supports the view that amelogenins have a great potential for applications designed to develop novel biomimetic materials.

Apatite/Amelogenin Coating on Titanium Promotes Osteogenic Gene Expression

“…The blank apatite and the coating prepared with 25 g/mL amelogenin did not promote the spreading of cells, and neither showed any enhancement on target gene expression. These two coatings have similar surface morphologies (Wen and Moradian-Oldak, 2003). Coatings prepared with 50 g/mL protein had plate-like crystals, but of a slightly reduced size.…”

One-Step Purification of Recombinant Human Amelogenin and Use of Amelogenin as a Fusion Partner

“…Amelogenin seems to enhance the proliferation of PDL cells [17]–[18], regulate genes associated with cementoblasts [19]–[20], and have been found to induce chondrogenic and osteogenic phenotype in embryonic muscle fibroblasts [21]. Apart from use as a therapeutic, amelogenin has also been proposed to promote creation of new biomaterials, such as coatings on titanium implants, giving further applications to amelogenin proteins [22].…”

Amelogenin-assisted ex vivo remineralization of human enamel: Effects of supersaturation degree and fluoride concentration

“…Many in vitro studies have shown that amelogenin is a crucial promoter of mineralization and a modulator of calcium phosphate nanocrystal structure 15, 16, 17. The cooperation mechanism of protein assembly and mineralization was first demonstrated by Beniash et al who reported the alignment of hydroxyapatite crystals in the presence of full-length amelogenin using homogenous nucleation18.…”