Initial cell response to functionally graded hydroxyapatite coating

초록

Plasma sprayed hydroxyapatite (HA) and calcium phosphate (CaP) coatings on titanium (Ti) implants are used to improve initial osseointegration. However, numerous problems with these plasma sprayed coatings are cited. Materials Preparation and Characterization: Functionally graded hydroxyapatite (FGHA) coatings were prepared using ion beam sputtering. ATCC CRL 1486 human embryonic palatal mesenchymal cell, an osteoblast precursor cell line, was used to evaluate the initial cell adhesion and cell differentiation on HA coatings. Results and Discussion TEM analysis indicated that the FGHA coating has a graded crystallinity and graded grain size across the thickness of the coating. The interface with the substrate had larger grains and higher crystallinity, whereas the outermost surface was amorphous and had smaller grains. As shown in Figure 1, the amorphous outermost surface was confirmed by XRD analysis. Conclusions It was concluded that coatings with graded crystallinity can be achieved by varying the temperatures during ion beam sputter deposition. It was also concluded that the functionally graded hydroxyapatite (FGHA) coating exhibited good biocompatibility with respect to initial cell response and enhanced osteoblast differentiation as compared to the controls.