Osteogenic differentiation of bone marrow mesenchymal stem cells induced by demineralized bone matrix in vitro

Junyi CHEN

ABSTRACT

BACKGROUND:

Demineralized bone matrix contains many kinds of active factors such as bone morphogenetic protein 2, which can promote bone marrow mesenchymal stem cells to transform into chondrocytes and promote their proliferation under specific joint microenvironment.

OBJECTIVE:

To explore the osteogenic differentiation of bone marrow mesenchymal stem cells in vitro induced by demineralized bone matrix and its research value as cell carrier scaffold in the treatment of bone defect.

METHODS:

Rat femur bone marrow mesenchymal stem cells were isolated and adhered with whole bone marrow. Bone marrow mesenchymal stem cells at passage 3 were selected and cultured with complete medium and 50 mg/L demineralized bone matrix inducer. The proliferation and viability of bone marrow mesenchymal stem cells were determined by CCK-8 assay. Alkaline phosphatase activities were quantitatively measured by enzyme labeling at 7 and 14 days after culture. Calcium nodule formation was observed by alizarin red staining 21 days after culture. The expression of osteogenesis-related factors was detected by qRT-PCR 21 days after culture. Demineralized bone matrix and bone marrow mesenchymal stem cells were cultured for 21 days. The adhesion of them was observed by ordinary optical inverted phase contrast microscope and scanning electron microscope. RESULTS AND

CONCLUSION:

(1) The number of cells on days 5 and 6 in the demineralized bone matrix group was higher than that in the complete medium group (P < 0.05). (2) Alkaline phosphatase activities were significantly higher in the demineralized bone matrix group than in the complete medium group at 7 and 14 days (P < 0.05). (3) Calcium nodules were more in the demineralized bone matrix group than in the complete medium group. (4) The expression of RUNX2, ALP, OCN and OPN was significantly higher in the demineralized bone matrix group than in the complete medium group (P < 0.05). (5) The adherence of bone marrow mesenchymal stem cells was good on the demineralized bone matrix; cells were distributed in the space between scaffolds and crawled with each other. (6) The results showed that demineralized bone matrix could induce bone marrow mesenchymal stem cells to differentiate into osteoblasts, and the adhesion was good, which provided theoretical reference for the research of tissue engineering composite materials.