Osteoclast Response to Bioactive Surface Modification of Hydroxyapatite

The aim of this study was to evaluate the in vitro response of osteoclast-like cells (RAW 264.7 cells) to a bioactive hydroxyapatite (HAP) surface that was modified using the 30 % phosphoric ac-id-etching procedure reported in our previous paper (2013). The cells on the bioactive HAP sur-face were multinucleated and were larger than those on the untreated HAP surface. The cell occu-pancies were greater on the bioactive HAP surface than on the untreated HAP surface at 7, 14, 21, and 28 days of differentiation; in particular, the values at 21 and 28 days were significantly larger (P < 0.05 and P < 0.01, respectively). These findings show that the bioactive HAP surface may en-hance the adhesion and differentiation of RAW 264.7 cells as well as osteoblast-like cells, indicat-ing its potential as a superior surface for bone tissue engineering