Surface-modification With Chitosan And Gelatin And Their Composite Scaffold Construction

Tissue engineering combines the theories and methods of life sciences and engineering science, to develop new clinic substitute for human tissue and apparatus. Its typical method is seeding cells in the artificial extracellular matrix (ECMs) to form cells/artificial ECMs constructs. Here the manual ECMs are three dimensional biomaterial scaffolds with excellent biocompatibility. The functions of biomaterials scaffolds act as analogues to the natural ECMs found in tissue, which provide information for cells expressing their functions, e.g. adhesion, proliferation, differentiation etc. Therefore, the aim for biomaterial scaffolds design is to mimic the natural ECMs, from the compositions to microstructure.In the paper, the morphography of chitosan and gelatin film, as a composition of ECMs was analyzed, the chitosan / Bio-derived bone (BDB) and gelatin/BDB scaffolds were prepared, in which the bio-derived bones were surface-modified with chitosan and gelatin. The cell adhesion behavior and biocompatibility of the treated scaffolds were detected by inoculations of the bone marrow mesenchymal stem cells (MSCs) derived from New Zealand rabbits. The results show that gelatin is benefit for adhesion and the chitosan perhaps is as a framework. According to the result, the chitosan scaffold modified with gelatin was prepared. Results include:1 Morphography of chitosan and gelatin film and its biocompatibility: The films treated by different chitosan or gelatin solution concentrations were observed by AFM. It shows that the morphography of the chitosan film is hackle, as the concentration of chitosan solution decreases, roughness of the root-mean-square(RMS) for chitosan surface decreases accordingly, except for glass slide modified with 0.25%(w/v) chitosan solution, and as for the gelatin film, the morphography looks like protuberance, as the concentration of chitosan solution decreases, roughness of the root-mean-square(RMS) for chitosan surface decreases accordingly, but the roughness for the gelatin is more than that of the chitosan. The cell experiments have show that MSCs could expand and adhere on the gelatin film but the ones on the chitosan film appeared in a rodlike shape.2 The preparation of BDB modified with chitosan and gelatin and its biocompatibility: The chitosan and gelatin modified the surface physically by Raman spectrum analysis. The results showed that MSCs were prone to adhere and proliferate onto the bio-derived bone scaffold modified with gelatin. 3 The preparation of the gelatin/chitosan scaffold and its biocompatibility: The chitosan scaffolds were fabricated by lyophilization technique, and the scaffolds were surface-modified by the gelatin to biomimetitly construct a degradable composite for biomedical application. The results show that porosities of the prepared scaffolds are (86.85±2.42) % and (71.50±3.29) %, respectively, the pore size is 90～130μm, and the MSCs onto the treated surfaces present good adhesion and spreading ability. Therefore, it would be a promising scaffold for tissue engineering applications.