Nano-HA Coating on Titanium Surface Fabricated by Modulation of Self-Assembled Monolayer and Bovine Serum Albumin

Bone-like hydroxyapatite (HA) coatings were fabricated on titanium implants by a self-assembled technique and biomimetic method. After titanium plates were oxidized in a mixture of H2SO4/H2O2, a hexadecanoic acid self-assembled onto titanium surfaces. Contact angles of water and tricresyl phosphate on the surfaces were measured to characterize the self-assembled monolayer (SAM) and confirm the presence of the functional group. The titanium plates with SAM were used to fabricate HA coatings. In the simulate body fluid (SBF) with and without bovine serum albumin (BSA), Ca2+ and PO4 3- ions could spontaneously deposit onto the titanium surfaces and form bone-like HA coatings. The morphology, component and structure of samples were examined by scanning electronic microscopy, X-ray photoelectron spectroscopy, X-ray diffraction and attenuated total reflection Fourier transform infrared spectroscopy. The results suggested that the SAM can induce the formation of the nano-HA coating with a network and microporous structure. For the biomimetical HA coating induced by HDA-SAM, BSA could modulate the growth of HA crystal and decreased the grain size.