Subcutaneous implantation of tissue-engineered heart valve leaflets in nude mice / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the viability of tissue-engineered heart valve leaflets prepared with cell-polymer constructs in nude mice.</p><p><b>METHODS</b>Sheep endothelial cells and smooth muscle cells/fibroblasts were seeded on patches of PHA and implanted subcutaneously in athymic mice (BALB/C). The cell-polymer constructs were harvested 12, 14, 21 and 28 days after implantation.</p><p><b>RESULTS</b>Fourteen days after implantation, the cell-polymer constructs exhibited similar color with the autologous tissues, and HE staining showed more numerous cells in the implant. At 28 days following implantation, muscular fibers were formed in the cell-polymer constructs. V-G staining showed positive collagen staining in the implant at 12 days after implantation, while the control implants retrieved 28 days after implantation did not show extensive tissue formation or muscular fiber formation.</p><p><b>CONCLUSION</b>The cell-polymer constructs can survive in vivo and has the potential to grow into autologous valve leaflets in the nude mice.</p>

Effect of basic fibroblast growth factor and hyaluronic acid on proliferation of rabbit chondrocytes in vitro / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the effect of basic fibroblast growth factor (bFGF) and hyaluronic acid (HA) on the proliferation of rabbit chondrocytes in vitro.</p><p><b>METHODS</b>Chondrocytes from the knee joints of New Zealand white rabbits were cultured. bFGF or HA or both were added into the culture medium respectively, and the proliferation of the chondrocytes was measured with MTT 3-(4, 5-dimethylthiazol-2-yl) 2, 5-diphenyl-tetra-zolium bromide. (MTT, Sigma, M2128).</p><p><b>RESULTS</b>Basic fibroblast growth factor (10 ng/ml) with low concentration of fetal bovine serum in the culture medium promoted the proliferation of chondrocytes significantly, and this effect reached its maximum when concentration of bFGF reached 50 ng/ml. HA itself had no effect on the proliferation of chondrocytes. However, when bFGF was used in combination with HA, especially when the concentration of bFGF was 50-500 ng/ml and that of HA was 10-50 ng/ml, the effect on the proliferation of chondrocytes was much more than when bFGF or HA was used alone.</p><p><b>CONCLUSIONS</b>bFGF can promote the proliferation of chondrocytes. HA, which has no effect on the proliferation of the cells, can maintain a normal growth of chondrocytes. When bFGF is used in combination with HA, more proliferation is obtained.</p>

An improved method for the isolation of rat hepatic stellate cells / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To present an improved method to obtain pure, viable, freshly isolated hepatic stellate cells.</p><p><b>METHODS</b>Adult male SD rats were used. All procedures were performed with the animals under sodium pentobarbital anesthesia. Three days after the single intravenous administration of 1 ml liposome-encapsulated CL2MDP, which has selective cytotoxicity of Kupffer cells, livers were perfused with D-Hank's solution containing 100 U/ml heparin for 10 to 15 minutes, and then with 0.05% collagenase dissolved in D-Hank's solution for 25 to 30 minutes. The liver was then gently homogenized and further incubated in 0.025% collagenase, and 0.005% DNAase I for 30 minutes at 37 degrees C under constant stirring. This suspension was filtered through stainless steel gauze and centrifuged for 2 minutes at 50 x g to remove parenchymal cells. Sinusoidal cells in the supernatant were recovered by centrifugation for 10 minutes at 300 x g. The cells were resuspended in the presence of 28.7% Nycodenz stock solution. The final concentration of Nycodenz at this stage was 11.5%. Following centrifugation for 17 minutes at 1400 x g, The cells at the top of this Nycodenz solution were collected. Cells were resuspended in Dulbecco's modified Eagle medium supplemented with 10% fetal calf serum, The cells were seeded in 50 ml culture flask at a density of 500,000 cells/ml, The cell viability was determined by trypan blue exclusion staining, the purity of hepatic stellate cells was identified by the expression of Desmin using immunocytochemistry method. Endogenous peroxidase staining was used to detect Kupffer cells.</p><p><b>RESULTS</b>The yield rate of hepatic stellate cells was 3 x 10(7) per rat, the cell viability was more than 95%, the desmin positive cell rate was 90%, no endogenous peroxidase positive cells were detected.</p><p><b>CONCLUSION</b>The method for the isolation of hepatic stellate cells was developed without Kupffer cells confusion. The availability of highly purified stellate cells will facilitate the investigation of their functions in primary culture.</p>