The effects of functionalized titanium with alendronate and bone morphogenic protein-2 for improving osteoblast activity

Abstract

The aim of this study was to investigate the effect of functionalized titanium (Ti) with alendronate (Aln) and bone morphogenic protein-2 (BMP-2) for enhancement of osteoblast activity in vitro. Aln and/or BMP-2 were sequentially immobilized to the heparinized-Ti (Hep-Ti) surface. The compositions of pristine Ti and Hep-Ti with or without Aln and/or BMP-2 were characterized by scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). Aln and/or BMP-2 onto Hep-Ti surface were released in a sustained manner. Osteoblast activities on all Ti substrates were investigated by cell proliferation assays, alkaline phosphate (ALP) activity, calcium deposition, gene expressions of osteocalcin and osteopontin. Aln/BMP-2/Hep-Ti significantly enhanced ALP activity, calcium mineral deposition, and gene expressions of osteoblast cells when compared with pristine Ti, Aln/Hep-Ti, and BMP-2/Hep-Ti. From these results, functionalized Ti substrates with alendronate and BMP-2 such as Aln/BMP-2/Hep-Ti are a promising material for the enhanced osteoblast activities in orthopedic and dental fields.