Osteoblast and chrondrocyte proliferation in the presence of alumina and titania nanoparticles

Proliferation of osteoblasts (bone-forming cells) and chondrocytes (cartilage-synthesizing cells) exposed to different sizes of alumina as well as titania particles at various concentrations (from 10,000 to 100 mug/ml of culture media) was investigated in the present in vitro study. Compared to respective conventional (i.e., micron) particle size ceramics, results provided the first evidence of increased osteoblast and chondrocyte proliferation in the presence of nanoparticles. Material characterization studies revealed that the only difference between respective ceramic particles was nano- and conventional-dimensions; specifically, phase, charge, and chemical properties were similar between different size alumina and titania particles, respectively. Thus, the present study provided the first evidence of a less detrimental effect of nano- as compared to conventional-dimension wear debris on cell function; such wear debris may result from friction between articulating components of orthopedic implants composed of novel nanophase ceramic materials. In this manner, results provided additional evidence to the literature that nanophase ceramics may become the next generation of bone prosthetic materials with improved osseointegrative (i.e., ability to bond to juxtaposed bone in situ) properties.