[Experimental study on the proliferation of postirradiated osteoblast transfected with Ad-hBMP-2]

To investigate the exact relationship at which Ad-hBMP-2 can exert its effects on postirradiated proliferation of osteoblasts in rats.

The osteoblasts used were isolated from the calvariae of neonatal (one-day-old) Wistar rats by sequential enzymatic digestion. The third passage of the cells were irradiated with X-ray at the doses of 0, 100, 300, 500,700 and 900 cGy. The medium was changed immediately and the Ad-hBMP-2 were added. After 6 days of culture the cells were examined and measured for proliferation ability by MTT test, and the data were analyzed with SPSS13.0 software package for Student's t test.

After irradiation, the proliferation ability of osteoblasts was inhibited and the effects were more remarkable as the dose increased. Ad-hBMP-2 could counteract the inhibitory effects when irradiation dose was lower (100 cGy),and partially when the dose was higher (500 cGy). There was significant difference between the cells transfected with Ad-hBMP-2 and the cells of control groups (P<0.05). When the dose was over 700 cGy, the damages of the cells seemed irreversible and there was no significant difference between the two groups (P>0.05).

Ad-hBMP-2 could increase the proliferation ability of postirradiation osteoblasts, and the effect depends on the dose of radiation.