The effect of immobilization of heparin and bone morphogenic protein-2 (BMP-2) to titanium surfaces on inflammation and osteoblast function

The aim of this study was to investigate biologic function of bone morphorgenic protein-2 (rhBMP-2) immobilized on the heparin-grafted Ti surface Ti surfaces were first modified by 3-amino-propyltriethoxysilane (ATPES) followed by grafting of heparin BMP-2 was then immobilized on the heparin-grafted Ti surfaces Pristine Ti and functionalized Ti surfaces were characterized by X-ray photoelectron spectroscopy (XPS) measurement of water contact angles and protein adsorption The biological activity of MG-63 cells on pristine and functionalized Ti surfaces was investigated by cell proliferation assays measurement of alkaline phosphate (ALP) activity and determination of calcium deposition Anti-inflammatory effects were assessed by RT-PCR to measure the transcript levels of IL-6 and TNF-alpha XPS revealed that heparin and BMP-2 were successfully grafted and immobilized on the Ti surfaces respectively In addition Ti surfaces with BMP-2 immobilized were more hydrophilic than pristine Ti Furthermore BMP-2 immobilized Ti promoted significantly higher ALP activity and calcium deposition by MG-63 cells than pristine Ti The inflammatory response was also decreased when cells were grown on heparin-grafted BMP-2-immobilized Ti surfaces The results of this study suggest that by grafting heparin and immobilizing BMP-2 on Ti surfaces inflammation can be inhibited and osteoblast function promoted (C) 2010 Elsevier Ltd All rights reserved