Enhanced osteoclast-like cell functions on nanophase ceramics

Synthesis of tartrate-resistant acid phosphatase (TRAP) and formation of resorption pits by osteoclast-like cells, the bone-resorbing cells, on nanophase (that is, material formulations with grain sizes less than 100 nm) alumina and hydroxyapatite (HA) were investigated in the present in vitro study. Compared to conventional (that is, grain sizes larger than 100 nm) ceramics, synthesis of TRAP was signi"cantly greater in osteoclast-like cells cultured on nanophase alumina and on nanophase HA after 10 and 13 days, respectively. In addition, compared to conventional ceramics, formation of resorption pits was signi"cantly greater by osteoclast-like cells cultured on nanophase alumina and on nanophase HA after 7, 10, and 13 days, respectively. The present study, therefore, demonstrated, for the "rst time, enhanced osteoclast-like cell function on ceramic surfaces with nanometer-size surface topography.