Study On Injectable Chitosan-based Biocomposite Materials

An injectable in-situ forming scaffold can be maintained sol state before beinginjected to deliver living cells, therapeutic agents and growth factors, etc. Thesesystems can turn into gels in situ by regulating conditions, e.g. temperature, pH, andionic strength. These compositions have many advantages, e.g. ease of operation andapplication, and little surgery wound. They can be used as drug delivery systems,filling materials, tissue substitutes and temporary scaffolds. Therefore, injectable in-situ forming compositions are believed to have extensive applications in the future.In this paper, the water-soluble chitosan hydrochloride was synthesized and itsmolecular structure was studied. Injectable compositions based on chitosanhydrochloride, β-glycerophosphate and β-tricalcium phosphate were prepared. Byadjusting pH, temperature and ratio of components, the compositions sol could turninto gel in physiological environment. The compositions had high water contents andporous structure, which was fit of cell adhering and proliferation.Icariin/Chitosan/Gelatin microspheres were achieved by emulsification and cross-linking methods. Physical and chemical characteristics were detected. A continualflowing system was used to determine releasing characteristics of microspheres andinfluencing factors. The physical and chemical characteristics of microspheres wereinfluenced by process conditions e.g. rate of mixing round, quantity of emulsificationand cross-linking agents. The in vitro release rate was negatively correlated withgranule diameters and crossing-linking extent, and positively correlated with drugcontents. The injectable compositions exhibit good biocompatibility and are a potentialscaffold in bone and cartilage tissue engineering. It is feasible for chitosan and gelatinmicrospheres to act as carriers of slow release of Chinese herber. Preparation processis simple and stable. The release rate of drug from microspheres is adjustable.