PDGF-BB initiates vascular smooth muscle-like phenotype differentiation of human bone marrow mesenchymal stem cells in vitro / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate the feasibility of human bone marrow mesenchymal stem cells (hBMSCs) in vitro differentiation into vascular smooth muscle cells with induction of platelet-derived growth Factor BB (PDGF-BB).</p><p><b>METHODS</b>Bone marrow mesenchymal stem cells of adult healthy donors were separated from iliac crest aspiration and expanded in DMEM-LG medium. Cells at passage 1 were transferred to EGM-2 medium containing PDGF-BB (20 ng/ml) and cultured for 14 days. The expression of SM alpha-actin, SM calponin, SMMHC and SM 22alpha were detected by immunofluorescence and observed with fluorescence microscope. mRNA expression of SMalpha-actin, SM calponin, SMMHC as well as SM 22alpha was analyzed by RT-PCR. The method of Western-Blot was applied to determine protein expression of SM 22alpha. Cells with induction were observed for the expression of SM alpha-actin,SM calponin,SMMHC by FACs analysis.</p><p><b>RESULTS</b>With the induction of PDGF-BB, the morphology of cells changed to a spindle fibroblastic appearance. By fluorescence microscope observation, expression of SM alpha-actin, SM calponin and SMMHC was found intracellularly in PDGF-BB treated hBMSCs at 14 days. Western-Blot detection confirmed SM 22alpha expression by 14 days induction. RT-PCR of characteristic vascular smooth muscle cells related genes, such as SM alpha-actin, SM calponin, SMMHC and SM 22alpha revealed differentiation of vascular smooth muscle cells phenotype in monolayer culture upon stimulation with PDGF-BB for 14 days. The positive expression of SM alpha-actin, SM calponin and SMMHC in induced cells was significantly higher than that in non-induced cells (P < 0.05, n=3).</p><p><b>CONCLUSION</b>These results suggested hBMSCs could be differentiated into vascular smooth muscle cell phenotype with PDGF-BB induction in vitro.</p>

The Influence of Several Chief Parameters in Electrospinning on the Morphology and the Fiber Diameter of PLGA Fiber Scaffolds / 中国生物工程杂志

To prepare PLGA fiber scaffolds by electrospinning process and investigate the influence of preparation parameters on the structure of the scaffolds. With the compound of THF and DMF as the solvent, the PLGA fiber scaffolds with different surface morphology were fabricated via altering PLGA solution concentration, flowing rate and applied electric field strength. The morphology and diameter of the fibers were observed using a scanning electron microscope (SEM). The biocompatibility of cell-scaffold complex was also evaluated by seeding human dermal fibroblasts onto the PLGA fiber scaffolds, including cell adhesion and proliferation. The results show that the diameter of fibers and the bound of distributing increase with the increase in the concentration of PLGA solution. As the flowing rate increases, the diameter of fibers increases. However, with the increase in the applied electric field strength, no significant difference in the diameter of the fiber can be observed. Furthermore, both the increase in the concentration of PLGA solution and applied electric field strength in the volume range of current investigation can lead to the reduction in the beads formation within the scaffold. The results of in vitro cell culture on the PLGA scaffolds also confirm that the PLGA fiber can support the adhesion and proliferation of huaman dermal fibroblasts.