Ayako Oyane
Physicochemical fabrication of calcium phosphate-based bioceramics
Ayako Oyane and Maki Nakamura
Nanomaterials Research Institute, National Institute of Advanced Industrial Science and Technology (AIST)
Calcium phosphates (CaPs) with good biocompatibility and osteoconductivity have been used in a variety of biomedical applications. Recently, we developed a physicochemical process for rapid fabrication of CaP-based thin-layers and submicrospheres by integrating a chemical precipitation process and a physical laser process. In the thin-layer fabrication process, weak pulsed laser irradiation was performed to a substrate that was immersed in a metastable supersaturated CaP solution. The resulting substrate was coated with a CaP thin-layer within several tens of minutes via laser-mediated surface modification and selective heating. This CaP coating technique was applicable to various substrates that absorb laser energy. In the sphere fabrication process, weak pulsed laser irradiation was performed to a labile supersaturated CaP solution supplemented with light-absorbing agents such as ferric, ferrous, and silver ions under stirring. Even without surfactants, well-dispersed CaP-based submicrospheres were fabricated via spontaneous CaP precipitation followed by laser-mediated selective heating of the dispersed CaP precipitates. Utilizing these physicochemical processes, biofunctional substances (e.g., trace elements, magnetic nanoparticles, and silver nanopaticles) have been incorporated within the matrix of CaPs. The present physicochemical process would provide a new way to fabricate CaP-based thin-layers and submicrospheres that could potentially be used in orthopedic, dental, and drug delivery applications.