The feasibility of using gene therapy to treat full-thickness articular cartilage defects was investigated with respect to the transfection and expression of exogenous transforming growth factor (TGF)-β1 genes in bone marrow-derived mesenchymal stem cells (MSCs)in vitro. The full-length rat TGF-β1 cDNA was transfected to MSCs mediated by lipofectamine and then selected with G418, a synthetic neomycin analog. The transient and stable expression of TGF-β1 by MSCs was detected by using immunohistochemical staining. The lipofectamine-mediated gene therapy efficiently transfected MSCsin vitro with the TGF-β1 gene causing a marked up-regulation in TGF-β1 expression as compared with the vector-transfected control groups, and the increased expression persisted for at least 4 weeks after selected with G418. It was suggested that bone marrow-derived MSCs were susceptible toin vitro lipofectamine mediated TGF-β1 gene transfer and that transgene expression persisted for at least 4 weeks. Having successfully combined the existing techniques of tissue engineering with the novel possibilities offered by modern gene transfer technology, an innovative concept, i.e. molecular tissue engineering, are put forward for the first time. As a new branch of tissue engineering, it represents both a new area and an important trend in research. Using this technique, we have a new powerful tool with which: (1) to modify the functional biology of articular tissue repair along defined pathways of growth and differentiation and (2) to affect a better repair of full-thickness articular cartilage defects that occur as a result of injury and osteoarthritis.
To investigate the effects of Ligustrazine on histogenesis of bone marrow in the early phase of hematopoietic reconstruction in bone marrow transplantation (BMT) mice. The syngeneic BMT mice model was established. The syngeneic BMT mice were orally given 2 mg Ligustrazine twice a day. 1, 3, 5, 7, 10, 15 and 21 day(s) after BMT, peripheral blood granulocytes and bone marrow nucleated cells (BMNC) were counted and the diameter of central vein and the area of micro-vessel in femur were measured. The effect of Ligustrazine on hematopoietic stem cells was observed by colony forming unit of spleen (CFU-S). The effect of Ligustrazine on hemopoietic progenitors was studied by observing the number of progenitors of Granulocytes/Macrophage on day 10 and day 20 after BMT. In Ligustrazine-treated group, the diameter of center veins and the area of micro-vessel of femur were all significantly less than the control group 7, 10, 15, 21 days after BMT (P<0.01). In addition, Ligustrazine significantly increased the number of CFU-S on day 10 and the number of CFU-GM on day 10, 20 after BMT. These results indicate that Ligustrazine can accelerate the histogenesis of hemopoietic bone marrow, which may be one mechanism by which Ligustrazine promotes hematopoietic reconstitution after BMT.