InjectabIe nano-hydroxyapatite/chitosan composite scaffoIds combined with bone marrow mesenchymaI stem ceIIs and bone morphogenetic protein 2 for bone defect repair in vitro / 中国组织工程研究

ABSTRACT

BACKGROUND: Bone morphogenetic protein 2 (BMP-2) has a strong ability to induce and promote the osteogenic differentiation of mesenchymal stem cells. OBJECTIVE: To evaluate the BMP-2 effect on the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) on an injectable nano-hydroxyapatite/chitosan (nHA/CS) composite scaffold. METHODS: (1) Experiment 1 Passage 3 BMSCs were divided into two groups and cultured with the nHA/CS scaffold or cultured alone. Cell counting kit-8 was used to detect cell proliferation at 1, 3, 5, 7, 14 days of culture. (2) Experiment 2 Passage 3 BMSCs were seeded onto the nHA/CS scaffold and cultured in culture medium containing BMP-2 or not. Alkaline phosphatase activity in cells was detected at 3, 6, 9, 12, 15 days of culture. Cell counting kit-8 was used to detect cell proliferation at 1, 3, 5, 7, 14 days of culture. Alizarin red staining was used to observe the osteogenic differentiation of cells at 1 and 2 weeks of culture. RESULTS AND CONCLUSION: (1) Experiment 1 With the prolongation of culture time, the absorbance values in the two groups were gradually increased, but there was no significant difference between the two groups. At 7 days of culture, the BMSCs adhered tightly to the scaffold surface. (2) Experiment 2 With the prolongation of culture time, the alkaline phosphatase activities in the two groups were gradually increased, and moreover, the alkaline phosphatase activity in the experimental group was higher than that in the control group at different culture time (P < 0.05). The absorbance values in the two groups were also gradually increased, and the value in the experimental group was higher than that in the control group at different culture time (P < 0.05). At 1 and 2 weeks of culture, the number of calcified nodules was higher in the experimental group than the control group. To conclude, BMP-2 has a promotion role in the proliferation and differentiation of BMSCs cultured on the injectable nHA/CS scaffold.