OBJECTIVETo investigate effects of intermittent negative pressure on osteogenesis in human bone marrow-derived stroma cells (BMSCs) cultured in vitro.

METHODSThe third passage cells were divided into negative pressure treatment group and control group. The cells in the treatment group were induced by negative pressure intermittently (pressure: 17 kPa, 30 min per time, and four times of each day). The cells in the control group were cultured in conventional condition. The osteogenesis of BMSCs was examined by phase-contrast microscopy. The alkaline phosphatase (ALP) activities were determined. The expression of collagen type I was detected by immunohistochemistry method. The mRNA expressions of osteoprotegerin (OPG) and osteoprotegerin ligand (OPGL) in BMSCs were analyzed by real-time polymerase chain reaction (PCR).

RESULTSBMSCs showed a typical appearance of osteoblast after 2 weeks of induction by intermittent negative pressure. The activity of ALP increased significantly, and the expression of collagen type I was positive. In the treatment group, the mRNA expression of OPG increased significantly (P < 0.05) and the mRNA expression of OPGL decreased significantly (P < 0.05) after 2 weeks, compared with the control. However, 3 days after the exposure to 2-week negative pressure, these were no significantly different from that of the control group (P > 0.05).

CONCLUSIONIntermittent negative pressure could promote osteogenesis in BMSCs in vitro.