丝素蛋白的磷酸化及其仿生矿化膜的制备

为制备功能性丝素基仿生矿化材料，将丝素蛋白通过三聚磷酸钠（STP）磷酸化，从而在仿生矿化过程中促进钙离子吸附，利于更多的钙磷酸盐的形成和沉积。探究了体系中pH 值和三聚磷酸钠用量对丝素磷酸化的影响，分析了磷酸化对丝素蛋白二级结构、热性能、粒径及膜力学性能的影响；以磷酸化丝素为原料制备冻干丝素膜，采用交替矿化法，在其表面沉积形成羟基磷灰石（HA）；借助扫描电子显微镜和能量色散X 射线光谱仪，评价了矿化膜表面结构形态和钙、磷元素含量变化。结果表明：在pH 值为10 和 STP 质量为0.24 g 条件下，磷转移量达到67.1%，且磷酸化丝素膜对阳离子有较好的吸附效果，力学性能较空白样略有下降；经交替仿生矿化处理后，磷酸化丝素膜表面沉积的羟基磷灰石较空白样结构更规整。

Phosphorylation of silk fibroin and preparation of biomimetic mineralization membrane thereof

In order toprepare 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 theformation 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 microscopyand energy dispersive spectrometer. The results show that the phosphorylated conditionsis pH 10 and the0.24 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.