Protein expression profiles in osteoblasts in response to differentially shaped hydroxyapatite nanoparticles.

The use of synthetic hydroxyapatite as bone substitute calls for the knowledge of the influence on adjacent cells. The aim of this study was to investigate the proteins with differential protein expression levels in the proteome of human osteoblast cell line incubated separately with various nano sized hydroxyapatite powders with different shapes and chemical compositions using iTRAQ-coupled 2D LC-MS/MS approach. In the present study, we investigated several intracellular signaling molecules involved in calcium regulation to analyze how osteoblast cells respond to dissimilar HA nanoparticles. It was found there was a significant decrease in cell population after adding the HA nanoparticles to the osteoblasts. Our results combining proteomics analysis and RT-PCR validation on targeted genes involved in calcium regulation confirmed the differences in the cellular response to dissimilar HA nanoparticles.