Experimental Study Of Vascular Tissue Engineering

Vascular disease, one of the most common diseases jeopardizing the health of the human being, is mainly treated by the vessel transplantation technique. Therefore the source of vascular grafts becomes the focus of the research. Currently there are three types of sources: autograft, allograft and artificial materials. Autografts have limited sources. Allografts are easy to get immune rejection. Artificial materials are not appropriate for vascular grafts of small caliber arteries.The development of tissue engineering provides a new approach for the source of vascular grafts. Vascular tissue engineering is classified as a field that applies the normal cells from the vascular wall and biologic degradable materials to produce, reconstruct and regenerate the vessel substitute, making it possible to reconstruct vascular model in vitro whose structure and function are the same as autogenous vessels.In this study, tissue engineered blood vessels (TEBV) were constructed in vitro and in vivo using rat vascular endothelial cells and smooth muscle cells as seed cells, gelatin-chitosan and fibrin gels as scaffolds. The purpose of our research is to explore the feasibility of vascular tissue engineering. This article is divided into three parts: Part 1 Seed cells for vascular tissue engineeringPurpose: To provide seed cells for the vascular tissue engineering research. Methods: Aortas of rats were exercised under general anesthesia, vascular endothelial cells and smooth muscle cells were cultured respectively by enzyme digestion and tissue explanation method, subcultured and identified by morphological characteristics and immunohistochemical staining.Results: The two kinds of cells were both successfully cultured and subcultured and their morpholoical characteristics were consistent with vascular endothelial and smooth muscle cells respectively, Immunohistochemical staining results showed that endothelial cells were Vffl factor positive and smooth muscle cells a-actin positive. Conclusion: Vascular endothelial cells and smooth muscle cells provide the seed cells for vascular tissue engineering.Part 2 Biocompatibility of the materials for vascular tissue engineering Purpose: To investigate the biocompatibility of gelatin-chitosan and the feasibility of its use as a scaffold material for the vascular tissue engineering. Methods: The vascular endothelial and smooth muscle cells were seeded on the gelatin-chitosan membrane. The porous gelatin-chitosan block was subcutaneously implanted into the rat. The cell growth condition was then observed under microscope. Results: On the gelatin-chitosan membrane, the rat vascular endothelial and smooth muscle cells displayed a good growth condition, and following the subcutaneous implantation of the porous gelatin-chitosan block, some subtle inflammatory reactions were observed, the material was gradually degraded. Conclusion: Gelatin-chitosan had a good biocompatibility and can be used as a scaffold. Part 3 Construction of TEBV in vitro and in vivo Purpose: To explore the construction of TEBV in vitro and in vivo. Methods: The vascular endothelial cells and smooth muscle cells were directly, or in combination with fibrin gels, seeded on different types of materials, respectively. Then the cell growth condition was observed under the microscope. The porous gelatin-chitosan scaffold with smooth muscle cells was subcutaneously implanted, followed by the observation of the cell growth ten days later. Results: All the cells directly seeded on membrane gelatin-chitosan scaffold material showed a single-layer cell growth. In the group of the smooth muscle cells seeded with fibrin gels, a good multi-layer...