Laser-Assisted Biomimetic Process for Calcium Phosphate Coating on a Hydroxyapatite Ceramic
The present authors recently developed a new calcium phosphate (CaP) coating technique on an ethylene-vinyl alcohol copolymer substrate utilizing a laser-assisted biomimetic (LAB) process. In the present study, the LAB process was applied to a sintered hydroxyapatite (sHA) substrate for CaP coating. The LAB process was carried out by irradiating the sHA substrate immersed in a supersaturated CaP solution with a low-energy Nd-YAG pulsed laser. Within 30 min of irradiation, contiuous CaP layers with different morphologies were successfully formed on the laser-irradiated sHA surface. A submicron cavernous structure of the CaP layer was developed into a micron flake-like structure as the laser power increased from 1 to 3 W. This result suggests that the secondary nucleation and growth of CaP crystals were accelerated by laser irradiation in a power-dependent manner. Laser absorption by the sHA substrate and the resulting increase in ambient temperature locally near the surface should be responsible for the accelerated CaP nucleation and growth. The present CaP coating technique using the LAB process is simple and quick, hence it would be useful in orthopedic and dental applications as an on-demand surface-functionalization method for biomaterials consisting of sHA.
Kunio Ishikawa and Yukihide Iwamoto
A. Oyane et al., "Laser-Assisted Biomimetic Process for Calcium Phosphate Coating on a Hydroxyapatite Ceramic", Key Engineering Materials, Vols. 529-530, pp. 217-222, 2013