Biological Study Of Seed Cells And Scaffold Materials In Skin Tissue Engineering

Tissue engineering utilizes the principles and methods of life science and engineering science, researching and developing new clinic substitute for human tissue and apparatus.Its typical method is seeding cells in the three-dimensional biomaterial scaffolds with excellent biocompatibility to form artificial tissue constructs after isolating and proliferating seed-cells in vitro. Thereinto, seed-cells and scaffold materials are two basal elements in tissue engineering. Planting the seed-cells into scaffolds to construct artificial tissue is tissue engineering technology's core and even more the key to successful construction.According to tissue engineering's principles and methods, we isolated dermal fibroblasts(Fbs) with stable biological character from SD rat skin and fabricated collagen-chitosan sponge scaffolds which were suitable for tissue engineering skin construction, then transplanted the Fbs on the sponge scaffolds. We studied the two elements' biological characters'changes in the process of tissue construction in order to provide theory data for the tissue engineering technology's improvement and perfection. The main results of the research are as follows:1. We successfully isolated SD rat's skin Fbs by using Dispase II- type I collagenase digestion. The Fbs are suitable for tissue engineering skin construction research for their strong proliferation ability and stable biological characteristic.2. The collagen-chitosan sponge scaffolds were fabricated with type I collagen and chitosan by freeze-drying and then cross-linked with glutaraldehyde(GA). The scaffolds have interconnected pore structure, suitable pore sizes and good mechanical property. The cell compatibility experiments indicated that the scaffolds had no cytotoxicity and showed good cell adhesion property.3. We transplanted the Fbs on the collagen-chitosan scaffolds and studied the seed-cells' proliferation and biological activity. MTT test and flow cytometry indicated that cells on the scaffolds proliferated slowly and steadily. IL-6 concentration measurement by ELISA test indicated that the scaffolds could promote Fbs' cytokines secretion.In summary, Fbs and the 3D-scaffolds interacted with each other in the process of tissue construction. This process was similar with dynamic effection of cells and extracellularmatrix (ECM) in vivo. These experiment data are important for scaffold materials' improvement and artificial tissues' construction in vitro.