Genetic effect of zirconium oxide coating on osteoblast-like cells

Zirconium is widely used as material for prosthetic devices because its good mechanical and chemical properties. When exposed to oxygen, zirconium becomes zirconium oxide (ZrO(2)), which is biocompatible. ZrO(2) can be also prepared as a colloidal suspension and then used to coat surfaces. Zirconium oxide coating (ZrO(2)C) can potentially have specific biologic effects, and among them is bone formation related to implant osseointegration. How this biomaterial alters osteoblast activity to promote bone formation is poorly understood. We therefore attempted to address this question by using microarray techniques to identify genes that are differently regulated in osteoblasts exposed to ZrO(2)C. By using DNA microarrays containing 20,000 genes, we identified in osteoblast-like cell lines (MG-63) cultured with ZrO(2)C several genes whose expression was significantly upregulated or downregulated. The differentially expressed genes cover a broad range of functional activities: (a) cell cycle regulation, (b) signal transduction, (c) immunity, and (d) cytoskeleton component. The data reported are, to our knowledge, the first genetic portrait of ZrO(2)C effects. They can be relevant to better understand the molecular mechanism of bone regeneration and as a model for comparing other materials with similar clinical effects.