Abstract:

In order to prepare the silk fibroin-based bionic mineralization materials, silk fibroin (SF) was phosphorylated by sodium tripolyphosphate (STP), which can promote the adsorption of calcium ions, and facilitates the formation and deposition of calcium phosphate. The effects of two factors on the phosphorylated silk fibroin by controlling pH and the amount of sodium tripolyphosphate. The secondary structure, thermal stability, particle size, mechanical properties were analyzed. Phosphorylated silk fibroin was freeze-dried to form membrane, hydroxyapatite(HA) was formed on the surface by alternating mineralization method, and the surface morphology and content of calcium and phosphorus were evaluated by scanning electron microscopy and energy dispersive spectrometer. The results show that the phosphorylated conditions is pH 10 and the 0.24 g of STP, phosphorus transfer rate reaches 67.1%, and adsorption capacity of cationic dyes on the phosphorylated silk fibroin is better, and mechanical properties is slightly lower than the blank . Hydroxyapatite deposited on the surface of the phosphorylated silk fibroin membrane is more regular than the blank sample after alternating bionic mineralization.

Key words: silk fibroin, mineralization membrane, phosphorylation, hydroxyapatite, biomimetic mineralization