Gu xing tai fa sheng dan bai 2/7 yi er ju ti dui ren zhi fang jian chong zhi gan xi bao cheng gu fen hua de cu jin zuo yong

Objective：To investigate the role of bone morphogenetic protein 2/7 heterodimer (BMP-2/7) in the osteogenesis of human adipose-derined stem cells (hASCs). Methods: hASCs were exposed to three different treatments in vitro: osteogenic medium with 150 μg/L BMP-2/7 (experimental group), osteogenic medium alone (OM group) and proliferation medium (PM group). After 1, 4 and 7 days of osteogenic induction, the amount of cellular DNA was measured to investigate the cytotoxicity. After 7 and 14 days, alkaline phosphatase (ALP) staining and quantification were performed to test the activity of ALP. After 21 and 28 days, the calcification deposition was determined by Alizarin Red S (ARS) staining and quantification. The expressions of the osteoblast-related genes were tested on days 1, 4, 7 and 14. In the in vivo study, 6 nude mice were used and 4 groups were set and implanted subcutaneously into the back of nude mice: (1) β-TCP scaffold only (scaffold control group); (2) β-TCP scaffold with hASCs cultured by PM in vitro for 1 week (PM control group); (3) β-TCP scaffold with hASCs cultured by OM in vitro for 1 week (OM control group); (4) β-TCP scaffold with hASCs cultured by OM with 150 μg/L BMP-2/7 in vitro for 1 week (test group). After 4 weeks of implantation, histological staining was performed to evaluate the in vivo osteogenesis of hASCs. Results: After induction for 1 day, there was no significant difference between the experimental group and the PM group on the cellular DNA content (P>0.05). After 4 days, the cellular DNA content increased under the stimulation of BMP-2/7 (P0.05). ALP activity was higher by the induction of BMP-2/7 than in OM alone and PM (P<0.05). More mineralization deposition and more expressions of osteoblast-related genes such as Runx2, ALP, COL-1A1 and OC were determined in the experimental group at different time points (P