| Mesenchymal Stem Cells (MSCs) are a rare population of non-hematopoietic stromal cells. They present in most connective tissues of the body, including bone marrow, peripheral blood, cord blood, cord, adipose tissue, amniotic fluid, compact bone, periosteum, synovial membrane, synovial fluid, articular cartilage and foetal tissues. Most of the modern isolation methods of MSCs still take a colony-forming unit-fibroblasts (CFU-F) approach. MSCs show phenotypic heterogeneity, great in vitro growth abilities and the differentiation potential of multiple lineages including osteoblasts, adipocytes, chondrocytes, myocytes, neurons, hepatocytes and so on. Even though MSCs have no specific marker, they have been defined following isolation and culture expansion, by their multiple lineage differentiation potential and the expression of various surface markers including CD33, CD73, CD90and CD105and absence of hematopoietic markers like CD34and CD45.Based on their extensive advantages including wide variety of sources, in vitro proliferative ability in culture in an uncommitted state, multilineage differentiation potential, MSCs are believed to be attractive candidates for biological cell-based tissue repair approaches. To date, bone marrow mesenchymal stem cells (BMSCs) are the most frequently used cell source for bone tissue engineering. In this study, all our works aimed to elaborate the problems related to BMSCs-based cell therapy, especially bone tissue cell therapy, which included the quality control of in vitro cell expansion, the regulation of directed differentiation, postponing of replicative senescence and retaining of differentiation potential, the interaction of BMSCs and bioactive scaffold materials and so on.We observed the dynamics of proliferation and differentiation status during spontaneous dedifferentiation process after inducers withdrawn, and detected the effect of hydroxyapaptite (major inorganic component of bone) condition medium and several antioxidants, including Vitamin C, taurine and N-acetylcycteine, on the proliferation, replicative senescence, differentiation potential and differentiation efficiency. Antioxidants we selected have biological safety and general protective effect in human body, and even are used as food or health care product additions. This feature made them more feasible to be conducted as potential additions of cell therapy injection and tissue engineering complex. We found them have diverse effect on BMSCs proliferation, self-renewal and differentiations.To date, researchs into the in vitro osteogenic differentiation of BMSCs for the fabrication of bone tissue-like engineering complexes using various2D/3D supporting matrices has been conducted popularly. Bioactive glass (BG) is the kind of glass incorporated with inorganic Calcium and Phosphorus, which has the ability to bond to both soft and hard tissue with minimal inflammation and toxicity for the host, and are thought to be one type of third generation biomaterials, which are bioactive, resorbable, and osteoproductive. Herein, we prepared nano-porous bioactive glass film (nBGF) with sol-gel method and verified its bioactivity of apaptite crystal formation, tight cell-film junction and promoting effect of osteogenic differentiation. As a coating film, nBGF/BGF over acrossed the restriction of scaffold form, were a promising surface modification for both traditional scaffold and newly developed scaffold material.The above studies showed some valuable results about the regulation of BMSCs proliferation and differation, laid specific foundations for future studies and applications of BMSCs-based cell therapy and tissue engineerin. |
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