Effect of Implant Surface Microtopography by Hydroxyapatite Grit-Blasting on Adhesion, Proliferation and Differentiation of Osteoblast-like Cell Line, MG-63

Abstract

Objective: The purpose of this study is to evaluate the potential of the in vitro osteogenesis of microtopographically modified surfaces, RBM (resorbable blasting media) surfaces that generate a hydroxyapatite grit-blasting.

Methods: First, to produce microtopographically modified surfaces, we made the RBM surfaces using a hydroxyapatite grit-blasting and examined the surface morphology, roughness or elements. And then, to investigate the potential of the in vitro osteogenesis, we experimented the osteoblastic cell adhesion, proliferation and differentiation using the human osteoblast-like cell line, MG-63 cells. Osteoblastic cell proliferation was performed to time-course. Also osteoblastic cell differentiation was verified by four different methods of ALP activity assay, mineralization assay using alizarin red-s staining and gene expression of osteoblastic differentiation marker using RT-PCR or ELISA.

Results: Comparing with machined group, osteoblastic cell adhesion, proliferation and ALP activity of RBM surfaces were shown higher. Also, they exhibited high level of gene expression of osteoblastic differentiation makers (osteonectin, type I collagen, Runx-2, osterix). Similar data was represented in the ELISA that RBM surface increased secretion of osteocalcin, osteopontin, TGF-beta1 and PGE2 which was known to stimulate the osteogenesis. Moreover, alizarin red-s staining revealed that there were significantly more mineralized nodules on RBM surfaces compared with machined discs.

Conclusions: Our results demonstrated the RBM surfaces modified with hydroxyapatite grit-blasting which stimulate the in vitro osteogenesis in MG-63 cells and raises the potential that RBM surfaces that accelerate the bone formation and finally increase bone-implant contact.