Novel Development of Phosphate Treated Porous Hydroxyapatite

• Main Authors: Kazuya Doi, Yasuhiko Abe, Reiko Kobatake, Yohei Okazaki, Yoshifumi Oki, Yoshihito Naito, Widyasri Prananingrum, Kazuhiro Tsuga
• Format: Article
• Language: English
• Published: MDPI AG 2017-12-01
• Series: Materials
• Subjects: porous hydroxyapatite; phosphoric acid-etching; phosphate treated hydroxyapatite
• Online Access: https://www.mdpi.com/1996-1944/10/12/1405

Phosphoric acid-etching treatment to the hydroxyapatite (HA) surface can modify the solubility calcium structure. The aim of the present study was to develop phosphate treated porous HA, and the characteristic structures and stimulation abilities of bone formation were evaluated to determine its suitability as a new type of bone graft material. Although the phosphoric acid-etching treatment did not alter the three-dimensional structure, a micrometer-scale rough surface topography was created on the porous HA surface. Compared to porous HA, the porosity of phosphate treated porous HA was slightly higher and the mechanical strength was lower. Two weeks after placement of the cylindrical porous or phosphate treated porous HA in a rabbit femur, newly formed bone was detected in both groups. At the central portion of the bone defect area, substantial bone formation was detected in the phosphate treated porous HA group, with a significantly higher bone formation ratio than detected in the porous HA group. These results indicate that phosphate treated porous HA has a superior surface topography and bone formation abilities in vivo owing to the capacity for both osteoconduction and stimulation abilities of bone formation conferred by phosphoric acid etching.