Formation of Porous Apatite Layer after Immersion in SBF of Fluorine-Hydroxyapatite Coatings by Pulsed Laser Deposition Improved Cell Proliferation.

Fluorine (F), a trace element in bone tissues, promotes cell proliferation and colonization. In this study, fluorine-hydroxyapatite (F-HA) coating was manufactured onto titanium substrates using pulsed laser deposition (λ = 1024 nm). The results confirmed that the surface roughness of F-HA coatings was the highest when the deposition time was 60 min. To evaluate the biological activity of the coatings, the coatings were immersed in simulated body fluids at 37 °C for 7 days. It was clearly observed that a new apatite layer showed a micro/nano foam-like porous structure. After annealing treatment, the F-HA coating can promote the transformation of the calcium phosphate crystal phase into the HA phase. Moreover, the mass of F-HA coatings with annealing was increased by 2.3% after immersion. cytocompatibility of the coatings was evaluated; the cell adhesion and proliferation exposed to F-HA coatings were significantly stimulated and promoted when compared with the control group in the first and second weeks of co-culture ( < 0.05). Thus, F-HA coatings can potentially act as osteoinductive materials for surface functionalization of the bone tissue scaffold.