Preparation And Biological Properties Of Hydrotalcite / Chitosan Three - Dimensional Porous Scaffolds

Three dimensional(3D) porous scaffolds are urgently developed to repair and regenerate large segmental bone defects suffering from trauma and surgery. As a good bone repair material for the implantation in the human body, it should not only have no toxicity to the human body system, but also promote the growth of the bone tissue within the porous scaffold. Chitosan and hydrotalcite-like compounds are good biocompatibility materials, chitosan can provide the body with higher density with large amounts of free NH2-cation surface, which can promote cell adhesion, thus promote cell migration, differentiation and reproduction. We combine coprecipitation method and freeze-drying to synthesize three different classes of cationic hydrotalcite(MgAl-LDH, MgFe-LDHs, MgSr Fe-LDHs) with three-dimensional porous. The morphologies, phases and pore structure of the powder were studied by means of SEM, TEM, EDS, XRD, FTIR, and so on. Ag-LDHs/CS have been successfully fabricated via a silver mirror reaction, Ag evently distribute on the surface of the scaffolds. The biocompatibility tests and osteoinductive tests by using human bone marrow stromal cells(hBMSCs) as cell models were used to investigate the in vitro biocompatibility and osteoinductive property of the LDHs/CS. Moreover, the antibacterial property was also studied by using Staphylococcus aureus as bacterium models.LDHs powder intercalated with three different classes of cationic were synthesized through coprecipitation, Both LDHs have characteristic of hydrotalcite structure and hexagonal flaky morphology, due to the radius of the added strontium ion and iron ion is bigger, making the LDHs has certain reunion. We combined coprecipitation method and freeze-drying to synthesize three different classes of cationic hydrotalcite with three-dimensional porous. The pore diameter was mainly distribute at 80-300μm, on the pore of the scaffolds evenly growing with hexagonal lamellar structure type of hydrotalcite, and the piece of LDHs combinationed closely with each other. Ag-LDHs/CS have been successfully fabricated via a silver mirror reaction, Ag evently distribute on the surface of the scaffolds. The hBMSCs biocompatibility tests indicate that all materials shows good biocompatibility, hBMSCs cell spreading well on the surface of the scaffolds. There are no obviously differences in biocompatibility of LDHs/CS before and after loaded with AgNPs. hBMSCs osteoinductive tests indicate that there are no obviously differences in osteoinductive property of LDHs/CS before and after loaded with AgNPs. The MgSrFe-LDHs/CS exhibit better osteoinductive property than other materials, and there is no abvious differences between MgAl-LDHs/CS and CS. The strontium ions in the MgSrFe-LDHs/CS play an important role in osteogenesis differentiation. Staphylococcus aureus antibacterial experiments show that the LDHs/CS have no antibacterial property, while the Ag-LDHs/CS have excellent antibacterial property.The excellent in vitro bioactivity, biocompatibility, antibacterial property, osteoinductive property of Ag-LDHs/CS suggest that they have great potential for bone inpalnts.