Specific proteins mediate enhanced osteoblast adhesion on nanophase ceramics

Osteoblast, fibroblast, and endothelial cell adhesion on nanophase (that is , materials with grain sizes less than 100 nm) alumina, titania, and hydrox yapatite (HA) was investigated using in vitro cellular models. Osteoblast a dhesion was significantly (p < 0.01) greater after 4 h on nanophase alumina , titania, and HA than it was on conventional formulations of the same cera mics. In contrast, compared to conventional alumina, titania, and HA, after 4 h fibroblast adhesion was significantly (p < 0.01) less on nanophase cer amics. Examination of the underlying mechanism(s) of cell adhesion on nanop hase ceramics revealed that these ceramics adsorbed significantly (p < 0.01 ) greater quantities of vitronectin, which, subsequently, may have contribu ted to the observed select enhanced adhesion of osteoblasts. Select enhance d osteoblast adhesion was independent of surface chemistry and material pha se but was dependent on the surface topography (specifically on grain and p ore size) of nanophase ceramics. The capability of synthesizing and process ing nanomaterials with tailored (through, for example, specific grain and p ore size) structures and topographies to control select subsequent cell fun ctions provides the possibility of designing the novel proactive biomateria ls (that is, materials that elicit specific, timely and desirable responses from surrounding cells and tissues) necessary for improved implant efficac y. (C) 2000 John Wiley & Sons, Inc.