Effect of enamel matrix protein derivative on the attachment, proliferation, and viability of human SaOs(2) osteoblasts on titanium implants.

The purpose of the present study was to investigate the effects of an enamel matrix protein derivative (EMD) on attachment, proliferation, and viability of human SaOs(2) osteoblasts on titanium implants. A total of 220 sand-blasted and acid-etched (SLA) titanium discs were placed into 24-well culture plates. Before cell inoculation, McCoy's 5A medium (MCM) containing EMD at 25 micro g/ml, 50 micro g/ml, 100 micro g/ml, and 200 micro g/ml was added, and the culture plates were incubated for 30 min. As control, MCM alone was used. Human osteoblast-like cells (SaOs(2)) (2 x 10(4) cells, fourth passage) were suspended in MCM containing 1% penicillin/streptomycin and 10% fetal bovine serum and then inoculated into the well chambers. The medium was changed after 3 days without the addition of EMD. At days 1, 3, and 6, DNA content of the cells was assessed using the CyQuant cell proliferation assay kit, and mitochondrial activity of the cells was measured using a CellTiter-Glo luminescent cell viability assay. The presence of EMD on the titanium discs at days 1 and 6 was evaluated using immunofluorescence stain (IFS) by means of polyclonal antibodies against amelogenin. Additionally, cell morphology was investigated using scanning electron microscopy. Enamel matrix derivative at 25 micro g/ml, 50 micro g/ml, 100 micro g/ml, and 200 micro g/ml demonstrated similar increases in cell proliferation as the control medium at days 3 and 6 ( P>0.05 between groups, respectively). Proliferation, however, appeared to be ameliorated with increasing EMD concentrations. At 25 micro g/ml and 50 micro g/ml, EMD also demonstrated an increase in cell viability similar to the control medium at days 3 and 6 ( P>0.05 between groups, respectively), while EMD at 100 micro g/ml and 200 micro g/ml resulted in statistically significant higher increase in cell viability than in the control medium at day 6 ( P<0.001 between groups, respectively). In all test groups, IFS at day 6 was markedly lower than at day 1. Scanning electron microscopy revealed comparable cell morphology in all groups. Within the limits of the present study, it was concluded that EMD enhanced cell proliferation and viability of human SaOs(2) osteoblasts on SLA titanium implants in a concentration-dependent manner.