Increased, Directed Osteoblast Adhesion at Nanophase Ti and Ti6Al4V Particle Boundaries

ABSTRACTIncreased functions of osteoblasts (bone-forming cells) have been demonstrated on nanophase compared to conventional ceramics (specifically, alumina, titania, and hydroxyapatite), polymers (such as poly-lactic-glycolic acid and polyurethane), carbon nanofibers, and composites thereof. Nanophase materials are materials that simulate dimensions of constituent components of bone since they possess particle or grain sizes less than 100 nm. However, to date, interactions of osteoblasts on nanophase compared to conventional metals remain to be elucidated. For this reason, the objective of the present in vitro study was to design, fabricate, and evaluate osteoblast adhesion on nanophase metals (specifically, Ti and Ti6Al4V). Results of this study provided the first evidence of increased osteoblast adhesion on nanophase compared to conventional Ti-based metals. Moreover, directed osteoblast adhesion was observed preferentially at metal particle boundaries. It is speculated that since more particle boundaries were created through the use of nanophase compared to conventional metals, increased osteoblast adhesion resulted. Because adhesion is a necessary prerequisite for subsequent functions of osteoblasts (such as deposition of calcium-containing mineral), the present study suggests that Ti-based nanophase metals should be further considered for orthopedic implant applications.