Nanocrystalline hydroxyapatite enhances osteoblast function

Osteoblast (bone-forming cells) adhesion, proliferation and formation of calcium-containing mineral deposits is enhanced on ceramics (such as alumina and titania) of grain sizes less than 100 nm. Conventional hydroxyapatite (HA), the major inorganic constitutent of physiological bone, has been shown to enhance osteoblast function. The present in vitro study, the first of its kind, investigated osteoblast function (specifically, adhesion and proliferation) on nanocrystalline (that is, grain sizes less than 100 nm) HA. Osteoblast adhesion as well as proliferation were significantly (p<0.01) greater on nanocrystalline (50 nm grain size) than on conventional (250 nm grain size) HA at all time periods tested. Since enhanced osteoblast function undoubtedly contributes to greater biomaterial bonding to juxtaposed bone (an event that will aid in the clinical success of orthopaedic/dental implants), the improved cytocompatibility properties of nanocrystalline HA should be considered when designing biomaterials of the future