Biological characterization of the zinc-modified hydroxyapatite coated by a pulsed laser deposition method

Abstract

Pure Hydroxyapatite (Ca10(PO4)6(OH)2) and Zn-HA nanoparticles were successfully deposited on steel substrates, and laser ablation was performed by the pulsed laser deposition (PLD) technique using an Nd: YAG laser (λ = 532 nm, τ = 12 ns). The bioactivity of the thin film was investigated by its immersing in a simulated body fluid solution of pH 7.4 at 37 °C for incubation of 14 days. The growth of the apatite layer after immersion was studied. The analysis showed the formation of needle-like crystals after immersion in solution. Wettability angles decreased for the HA coating after post-deposition compared to pure HA coatings at room temperature and ion substitutions in bioceramics lead to wettability modification. The findings confirm that Zn doping with different concentrations improved antibacterial activity. The results demonstrate that coating the surface with bioactive materials modified with metal ions, yields good biological responses, and varied compositions differentially affect the water contact angles as well as HA layer growth.