Mineralization Of SF/HA Regulated By Modified Silk Fibroin

Fibroin fibers from well-defiled silkworm silk, which have unique mechanical properties and excellent biocompatibility in vitro and in vivo, have been used as biomedical suture material. It is easy to induce inorganic mineral phase deposited in the simulated body fluid, such as calcium carbonate and calcium phosphate deposition. And the apatite is good bone repair materials. So it has been extent application in bone tissue transplantation.Hydroxyapatite has been received much attention because of its excellent biocompatibility, osteoconductivity and bioactivity, and the ability of promoting cell-material interaction. Unfortunately, its clinical application was limited as a loading-bearing implant due to the inherent poor fracture strength and toughness. Many researcher have been focused on the development of inorganic/organic hybrid composite materials to improve HA mechanical properties for better used in bone tissue transplantation.In this paper, the like-bone silk fibroin (SF)/hydroxyapatite (HA) biocomposite was prepared by biomineralization method with the modified template. We have investigated the influence of the ratio of modifier/SF, pre-mineralization temperature and modified time on the content of precipitation, calcium/phosphorous ratio and morphology.Firstly, the silk fibroin/hydroxyapatite on the DB-SF template was prepared by biomineralization method. We have investigated the influence of the ratio of DB/SF and premineralization temperature on the content of precipitation, calcium/phosphor-rous ratio and morphology. The morphology transform three-dimensional network from smooth spherical structures compared with the SF/HA. Secondly, the silk fibroin/hydroxyapatite on the IPDI-DMPA-SF template was prepared by biomine-ralization method. IPDI and DMPA have an important to the spherical particles and morphology. The structure and morphology of the apatite were investigated by FTIR, ICP, XRD and SEM. FTIR and ICP results show that the competent deposited on the SF surface was mainly hydroxyapatite; XRD and SEM show that the hydroxyapatite deposited on the SF template surface is low crystallinity. The results also show that the needle-like hydroxyapatite crystal grows along the c-axes with increase the time and the content of modifier. The morphology hydroxyapatite in the form self-assembled on the template surface transferred to three-dimensional network with increase the time in the IPDI and the ratio of mass of DMPA solution. The conclusion demonstrate that SF/HA composite via mineralization is similarly to the hydroxyl-apatite crystals in bone in the structure and morphology and crystallinity of the apatite.Calcium and phosphors have been deposited on the template of surface at the organic precise regulation in this paper. And nucleation and growth on the organic template surface, finally, like-bone silk fibroin/hydroxyapatite biocomposite were synthesized. Hydroxyapatite is low crystallinity and grows along aligned the c-axes. The structure and morphology and crystallinity of hydroxyapatite are consistent with the hydroxyapatite of like-bone, and it is a satisfactory material in the application of bone transplantation.In this thesis, we attempted a biomimetic method to obtained three-dimensional network bio-composite materials through introduced carboxyl groups by chemical modification, providing a new synthesis method for three-dimensional network bio-composite materials. The bioproperties of SF/HA needs further study by in vivo cells culture.