Alginate Hydrogel Scaffolds Fabricated By Dynamic Self-assembly And Its Applications In Cartilage Tissue Engineering

Cartilage damage or loss of functionality is a common clinical orthopedic diseases, due to thedifficulty of cartilage regeneration, how to treat such diseases is still a tough problem in front ofbone and joint surgeons and orthopedic researchers. The establishment and development of tissueengineering provides a new therapeutic approach for cartilage repair. Hydrogel is an ideal cartilagetissue repair material which can provide a micro-environment that close to the of the naturalcartilage extracellular matrix. In this way, the hyrogel material is able to facilitate cell proliferationand differentiation, during the process of repair and regeneration of cartilage tissue,.In this thesis, we introduced methods to prepare two different kinds of hydrogel for cartilagetissue engineering use and discussed some of their basic performance. Firstly, we fabricatedmultilayer alginate hydrogel which have the "onion-like" structure through self-assembling method.The addition of drug-loaded PLLA microspheres not only increased the compression strength ofhydrogel, but also made the hydrogel become a dual controlled-release system which can carry boththe hydrophilic and hydrophobic drug at the same time. Secondly, alginate hydrogel with tube-likepores was prepared by the method of ion diffusion crosslinking. The study indicated that as theconcentration of alginate solution increased the pore size of the hydrogel reduced gradually, whilethe pore density increased; The pores of alginate hydrogel was mineralized by Na2HPO4solutionwith different concentration and the of composite of mineral was analyzed by XRD, FT-IR and TG.The results confirmed that the mineral consisted of hydroxyapatite and other phosphate and with theincrease of concentration of Na2HPO4solution, the content of hydroxyapatite increased as well.In addition to the research on the basic physical and chemical properties of these hydrogelmaterial, we also investigated the biocompatibility of the material and the growth of the cells inthem as well. This work provides new ideas and methods of fabricating hydrogel for cartilage tissueengineering use.