Decreased macrophage adhesion on nanophase alumina

Extensive interactions of inflammatory cells (such as macrophages) with biomaterials at the host-implant interface are often blamed for failure of implanted biomedical devices. While previous studies have shown increased in vitro and in vivo bone cell responses on nanophase ceramics, few (if any) studies have been conducted elucidating inflammatory cell responses on such novel materials. Nanophase ceramics are intriguing materials for orthopedic implant applications since they mimic the nanometer grain size of natural bone. In this study, we report for the first time that macrophage adhesion on nanophase (97.7 nm grain size) alumina (AI₂O₃) was significantly less than conventional (187.4 nm grain size) alumina, after 4h. The present in vitro study provides evidence of the ability of nanophase alumina to down-regulate macrophage adhesion, which is imperative for the future consideration of nanophase materials for orthopedic and dental applications.