Effects Of TiO₂ Nanoparticles On Proliferation, Differentiation And Mineralization Function Of Primary Osteoblasts In Vitro

Nanomaterials in recent years have been greatly concerned and more and more used in biomedical fields because of unique properies, such as disease prevention, diagnosis and treatment. Especially, due to good biocompatibility and gradient structure, titanium dioxide nanoparticals (TiO2 NPs) have been widely used to prepare nano-titanium dioxide / hydroxyapatite composite ceramics and then treat the bone diseases as artificial bone, for example, bone repair and bone graft. Whether the balance of bone metabolism and bone tissue function would be affected when nanoparticles entered bone marrow, still required further study. In this article, we studied the effect of TiO2 NPs on proliferation, adipogenic trans-differentiation and mineralization by using model of osteoblasts (OB) and methods of MTT, ALP activity assay, red O stain assay and ARS stain assay. All the results above are consistent with the morphological observation.The results show that:1. Both 3nm and 160nm TiO2 NPs can promote osteoblasts proliferation. Size of 160nm and action time 72h, the proliferation is highest, 53.30%.2. For the ALP activity, when the action time is 24h and 48h, TiO2 NPs mostly show inhibition on osteoblasts, although show proliferation at 72h, the max ALP activity is 179.56%.3. TiO2 NPs inhibit the adipogenic trans-differentiation of OB, and the max inhibition is 58.37%.4. For the mineralization of OB, TiO2 NPs also show inhibition, and the max is 44.20%. This paper obtained results suggest that: TiO2 NPs promote proliferation of primary osteoblast while inhibiting their adipogenic trans-differentiation and mineralization, and for the ALP activity is in both promotion and inhibition. The biological effects of TiO2 NPs on primary osteoblasts basically show a dose-dependent relationship with concentration and time.