Electrophoretic coatings of hydroxyapatite with various nanocrystal shapes.

Highlights • Various nanocrystal shapes of HA were prepared by hydrothermal process. • The synthesized HA's crystals were used for EPD to produce nanostructured coatings. • The rMSC viability on SHA coatings was higher that MHA and LHA coatings. • MHA coatings showed higher cell adhesion compare to SHA and LHA (MHA > SHA > LHA). • MHA coatings showed higher spreading compare to SHA and LHA at 12 and 24 h. Abstract Bioactive nanostructured coating has been a key strategy to improve the cell adhesion and osseointegration of metallic implants. This study presents the electrophoretic coatings of hydroxyapatite with tunable nanocrystal morphologies. The hydroxyapatite nanocrystals were prepared with three different elongated dimensions by the hydrothermal method (∼80 nm; SHA, ∼300 nm; MHA, and ∼900 nm; LHA), which were used in combination with a fugitive biopolymer chitosan for the electrophoretic deposition on titanium. All the HA coatings were densely and homogeneously deposited and had different and unique nanotopologies and corresponding surface areas. The coating parameter significantly altered the cell behaviors including anchorage, spreading and proliferation; the cell adhesion was better on the small- and middle-sized nanocrystals (SHA, MHA > LHA), which was interestingly opposite in cell spreading (LHA > SHA, MHA), and then the cell proliferation was again up-regulated on SHA and MHA. Although more studies are needed to elucidate the biological phenomenon, the sets of results imply the importance of tailored nanocrystal morphology in the initial (adhesion and growth) cellular events. [ABSTRACT FROM AUTHOR]