Experimental Study on the Construction of Tissue Engineered Bone by Bone Marrow Mesenchymal Stem Cells Induced by MiR-29b Composite Bionic Scaffold

Abstract

MiR-29b promotes osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). Our study aims to evaluate MiR-29b's role in composite bionic scaffold-induced BMSCs in the construction of tissue engineered bone. Rat BMSCs were isolated and transfected with NC (negative control) and MiR-29b plasmid. Cell proliferation was assessed by MTT assay and the expression of osteogenic genes Runx2 and OC was analyzed by Real time PCR. Healthy male SD rats were divided into fracture group; negative control group; and MiR-29b group followed by analysis of the changes of bone mineral density, ALP activity, and expression of MiR-29b, type I collagen and Runx2 by Real time PCR. Up-regulation of MiR-29b significantly promoted BMSCs cell proliferation, inhibited Caspase 3 activity, and promoted Runx2 and OC expression compared to NC group (P < 0 05). NC group showed significantly increased bone density, ALP activity and the expression of type I collagen and Runx2 compared with control group (P < 0 05). Transfection of BMSCs induced by MiR-29b combined with biomimetic scaffold significantly promoted the expression of MiR-29b in fractured rats, increased bone mineral density and ALP activity, as well as upregulated type I collagen and Runx2, compared to NC group (P < 0 05). Up-regulation of MiR-29b promotes cell proliferation and osteogenic differentiation of BMSCs. Implantation of BMSCs induced by MiR-29b composite bionic scaffold can promote osteogenic differentiation and promote bone healing in bone defects.