Metformin affects the behavior of stem cells cultured on allograft

Reconstruction of bone defects can be accomplished using allografts, autogenous and synthetic materials which may enhanced their desirable properties by some agents. The present study aims to assess the effects of metformin _owing its osteogenic criterion_ on attachment, proliferation and differentiation of human dental pulp stem cells (hDPSCs) on frizzed dried bone allograft (FDBA). In this in vitro study, samples divided into four groups: A: hDPSCs+ allograft+ metformin, B: hDPSCs+ allograft, C: hDPSCs+ metformin D: hDPSCs as a control group. Attachment of hDPSCs on bone allograft was observed by scanning electron microscopy on day 1 and 7 after cultivation. We evaluated cell viability and proliferation by MTT analysis on days 1, 3, and 7 after cell seeding. Alkaline phosphatase activity was measured on days 3, 7, 14 and 21. ANOVA analysis was performed and p-value 0.05 was considered as a significant result. Images of electron microscopy showed firmly attachment of human dental pulp stem cells to FDBA. Increment of the cell proliferation detected in all groups from day 1 to day 7. The highest cell proliferation belonged to group C followed by the control group and groups A and B. Alkaline phosphatase activity increased in all groups between days 3 to 21 as well. Presence of metformin in groups A and C brought higher alkaline phosphatase activity in osteogenic media. Employment of metformin can be effective on attachment, proliferation and osteogenic differentiation of human dental pulp stem cells on frizzed dried bone allograft