Objective This experiment aimed to confirm whether man made porous chitosan scaffold is a appropriate scaffold for chondrocyte culutre of tissue engineering Methods Chondrocytes were seeded onto porous chitosan and chitosan collagen complex scaffolds for culture in a three dimensional environment The scaffolds in hydrophilia and adhesion to chondrocytes were observed with light microscope and scanning electron microscope The number of the cells attached to the scaffolds and the function of the cells were detected with MTT automated colormetric microassay Result Chondrocytes can multiple and secrete the matrix on the poros chitosan and chitosan collagensc scaffolds The cell adhesion rates were 81 25% and 87 50% respectively Conclusion Chitosan can be fabricated into a suitable three dimensional porous scaffold Porous chitosan collagen complex scafflold may be a more suitable scaffold for chondrocyte culutre of tissue engineering

Objective To investigate the action of chondrogenesis differentiation of bone marrow stromal cells (BMSCs) transfected with adeno-hTGF-β1. Methods In the experiment group, replication-deficient a denoviruses carrying human hTGF-β1 complementary DNA (adeno-hTGF-β1 was constructed and applied to transfect to the first generation BMSCs. As a control, each BMSCs was transduced with 200 pfu of adeno-LacZ gene. One day after transfer, BMSCs were trypsinized, counted, and 5×105 cells aliuots were spun down at 500 rpm per minute in 15 ml polypropylene conical tubes and then cultured in a defined medium in an incubator at 37℃ for 21 days. The aggregates were harvested at time points to 21 days and assessed by gross observation, histological analyses and immunohistochemical localization of type Ⅱ collagen. Results When harvested at 21 days, each pellet shrinked to spheroid tissue with apearly opalescence in gross morphology and found to be relatively firm. H.E staining showed elongate dlining cells appeared as perichon drium-like cells at the surface. Some nests of cartilage were observed at the substrate of the tissue. Mature chon drocytes were embeded in the lacuna in the experiment group. In addition, Safranin'O staining confirmed the presence of sulfated proteoglycans in the ECM of chondrogenesis region. Immunohistochemical staining revealed the presence of type Ⅱ collagen in chondrogenesis region. By contrast, HE staining showed no evidence of cartilage formation in the control group. They were fibrous tissue with no architectural feature. Safranin'O staining and Immunohistochemical staining showed no evidence of sulfated proteoglycans or typeⅡ collagen expression. Conclusion BMSCs transfected with adeno-hTGF-β1 could induce its chondro-genesis when aggregate cultured in a defined medium in vitro, laying a foundation for the application of hTGFβ1 gene-transfected BMSCs in cartilage tissue engineering.

OBJECTIVETo investigate the feasibility of chondrogenic phenotype differentiation of adult swine bone marrow stem cells(MSCs) in a defined medium as seeding cells in cartilage tissue engineering.

METHODSA volume of 5 ml bone marrow was aspirated from swine iliac crest and cultured in the complete medium of DMEM-LG for two weeks. The growth and ultrastructure of the cultured MSCs were observed. Immunohistochemistry and in situ hybridization were applied to detect the expression of collagen type II.

RESULTSThe MSCs changed from a spindle-like fibroblastic appearance to a polygonal shape when transferred from the complete medium of DMEM-LG to a defined medium. A large amount of endoplasmic reticulum was observed in large Golgi ccmplex and mitochondria. The differentiation of MSCs toward chondrogenic phenotype was verified by the positive result of collagen type II through immunohistochemistry and in situ hybridization respectively.

CONCLUSIONSBone marrow stem cells obtained from adult swine can differentiate to be chondrogenic phenotype when cultured in vitro. MSCs can likely be served as optimal autogenous cell source for cartilage tissue engineering.

Animals ; Bone Marrow Cells ; physiology ; ultrastructure ; Cell Differentiation ; Cells, Cultured ; Chondrocytes ; physiology ; Collagen Type II ; genetics ; Phenotype ; RNA, Messenger ; analysis ; Stem Cells ; physiology ; ultrastructure ; Swine ; Tissue Engineering ; Transforming Growth Factor beta ; physiology