Preliminary Research On Gradient Nanofibrous Scaffold And BMSCs For Osteochondral Construction In Vitro

Complex of collagen I and nano-HAp was prepared and characterized by TEM, IR and XRD, and the integrated bilayed osteochondral scaffold was manufactured by combining nano-HAp, collagen I, PLGA and sodium hyaluronate(HA) and PLGA with sodium leaching method. The surface topography, biocompatibility and cytoxicity of the scaffold were assessed by SEM, MTT assay when seeded with bone marrow stem cells (BMSCs).Complex of different concentration of nano-HAp and PLGA was prepared by electrospinning. With alkaline phosphatase and alizarin red staining after co-culturing with BMSCs and PLGA/HAp electrospun membrane for 14 and 21 days, the osteogenic differentiation of BMSCs and osteoblasts activity expression were observed.PLGA/HAp/Zein co-electrospun fibers were prepared and evaluated by FT-IR and DSC separately. With multi-layer deposit under electrospinning, PLGA/HAp/Zein and PLGA/HA electrospun to 3-D scaffolds, while the density of HAp and HA in gradient, and was transplanted into osteochondral defects of rabbits. The change of the scaffold and the repair status of defects were also evaluated preliminarily.The results indicated that the integrated bilayed osteochondral scaffold had good micro-structure and biocompatibility for rat BMSCs, BMSCs were able to adhere to the surface of the nano- or microfibrous PLGA/HAp electrospun scaffold with different HAp contents and good proliferation. The results of alkaline phosphatase and alizarin red staining indicated that BMSCs has the tendency of osteogenic differentiation. Nanofibrous gradient osteochondral scaffold was successfully prepared by multi-layed deposit electrospinning. After 4 weeks of scaffold transplation in rabbits articular cartilage in vivo, the results indicated that the scaffold had good biocompatibility, and integrated with osteochondral defects well, neo-tissue adhesion and growth were found in the interface of scaffold and osteochondral defects, as well, the swelling, shrink and delamination of implants were not found for all animals.