Preparation Of Natural Polymer Porous Scaffolds For Tissue Engineering

Chitosan,collagen and gelatin are important natural polymer materials in tissue engineering field. Freeze drying process of natural polymer porous scaffolds is researched in this paper based on phase separation. Upper limit of freeze drying temperature is determined according to the solidification and remelting temperature of the chitosan solution. The freeze drying process is optimized in order to decrease the drying time. Neutralization of remained acetic acid and crosslinking by glutaraldehyde processes are improved, which shortens the processing time evidently. The effects of contents of polymer solution, freeze temperature, and freeze manner on the characteristics of scaffolds, such as pore structure, pore's diameter, porosity, water absorption, and hydrophilicity are investigated. Results indicate that the scaffolds have opening pores and the pore's diameter increases with the freezing temperature rising; The porosity increases with increasing concentration of solution usually, it's also affected by thickness of scaffolds; All scaffolds have the good water absorption and storage ability, though there are some differences caused by different materials or structures. The scaffolds have high hydrophilic surfaces as the contact angles are all smaller than 90°.Furthermore, the dipping-deposition process to fabricate the chitosan porous scaffolds is explored. The scaffolds have double layer pore structure. The method can simplify the preparing process of porous scaffolds, but the brittleness is greater, and the thickness is limited to 2mm.Preparation and performances of the composite scaffolds are researched. The structures of the scaffolds are related to composition and the properties of the scaffolds are improved to a certain degree. In addition, the possibility of porous chitosan membrane compounded with antibacterial nano-materials is researched and the composite membrane may be possesses the potential to be a new wound dressing.