In vitro effect of mineralized and demineralized bone allografts on proliferation and differentiation of MG-63 osteoblast-like cells.

Abstract

Due to the extensive use of bone allografts in bone reconstruction and periodontal therapy as suitable alternatives to autografts, they are now marketed under different commercial brands. Considering the controversial reports regarding the osteoinductive properties of bone allografts, this study sought to assess the effect of type (mineralized/demineralized), amount and particle size of several allografts on the proliferation and differentiation of MG-63 osteoblast-like cells. MG-63 cells (24-h culture) were exposed to 20 and 40 mg amounts of nine different commercially available freeze-dried bone allografts. After 24 and 72 h of incubation, the effect of water-soluble allograft released materials on cell viability and proliferation was assessed using methyl thiazol tetrazolium (MTT) assay after 24 and 72 h of exposure. Cell differentiation and mineralization was assessed by real-time quantitative reverse transcription PCR and alizarin red staining after 72 h of exposure. The amount and particle size of understudy allografts had significant effects on cell viability after 24 h of exposure (in contrast to 72 h). Higher rate of proliferation was seen in non-differentiated or slow-differentiated groups. The amount and particle size factors had no significant effect on the amount of calcified nodules or the expression of osteogenic marker genes in most groups. Faster and more distinct differentiation and mineralization was noted in mineralized compared to demineralized groups during the 3-day study period. Based on the results, the understudy mineralized (non-demineralized) bone allografts had greater effect on osteogenic differentiation of the MG-63 cells and showed more in vitro osteoinductive activity compared to partially demineralized and fully demineralized types.