丝素蛋白/羟基磷灰石复合物对磷酸钙骨水泥性能的影响

目的：磷酸钙骨水泥（Calcium phosphate cement，CPC）以其诸多优点正得到了越来越多的应用，但其较差的力学性能表现也限制了它的使用范围。本研究目的在于改善磷酸钙骨水泥的力学性能，同时评估改性后的磷酸钙骨水泥的其他性能。方法：通过丝素蛋白（Silk fibroin，SF）的矿化自组装方法制备丝素蛋白／羟基磷灰石复合物（silk fibroin/hydroxyapitite composite, SF/HA）。按照1％、2％、3％、4％的质量分数加入磷酸钙骨水泥中，与磷酸钙骨水泥组对比。比较内容包括力学强度、抗渍散性能及细胞毒性。结果：以丝素蛋白溶液为液相组的磷酸钙骨水泥强度大约为35MPa。随后随着添加丝素蛋白／羟基磷灰石复合物的质量分数从1％增至3％，磷酸钙骨水泥的强度逐渐增加（P〈0．05），最高约至45MPa。而当丝素蛋白／羟基磷灰石的质量分数达到4％时，磷酸钙骨水泥的强度较质量分数3％组小幅度下降至43MPa（P〈0．05）。以丝素蛋白溶液作为液相时，磷酸钙骨水泥的抗溃散能力也得到了加强。在MTT法测定细胞活力的对照实验中，无论是加入丝素蛋白溶液或丝素蛋白／羟基磷灰石复合物，都未观察到细胞毒性。结论：在磷酸钙骨水泥中加入3％质量分数的丝素蛋白／羟基磷灰石复合物，能显著提高磷酸钙骨水泥的抗压强度。而丝素蛋白溶液作为液相可改善磷酸钙骨水泥的抗溃散能力。同时，丝素蛋白和丝素蛋白／羟基磷灰石复合物都不表现出细胞毒性。更理想的力学强度和更强的抗溃散能力，大大扩展了磷酸钙骨水泥的应用范围。

Influence of Silk Fibroin/Hydroxyapitite Composite on the Properties of Calcium Phosphate Cement

Objective： Calcium phosphate bone cements are drawing more and more attention because of their advantages, but the main drawback of the poor mechanical performance also restrict its applications. The aim of this research is to improve the mechanical property of calcium phosphate cement, and to evaluate other properties of the modified cement. Methods： The silk fibroin/hydroxyapatite composite was fabricated by self-assembly of mineralized silk fibroin and added into calcium phosphate cements＇ powder phase at the weight fractions of 1%, 2 %, 3 % and 4 %. The compressive strength of all these cements were measured, the anti-washout property, cytotoxicity was observed, too. Results： The compressive strength of CPC applied silk fibroin solution as the liquid phase was about 35 MPa, and gradually increased to 45 MPa as the weight fraction of silk fibroin/hydroxyapitite composite increased fTom 1% to 3 % （P〈0.05）, and a decrease to about 43 MPa of compressive strength was observed when the weight fraction of silk fibroin/hydroxyapitite to 4 % （P〈0.05）. The capability of anti-washout was also enhanced when applied silk fibroin solution as liquid phase of cement. Meanwhile, in the control test of evaluat the cellular activity by MTT method, no cytotoxicity was observed neither silk fibroin or silk fibroin/hydroxyapitite composite was added into calcium phosphate cement. Conclusion： Adding 3 wt% Silk fibroin/hydroxyapitite into CPC has a strengthen effect in the mechanical property of CPC. And applying silk fibroin solution as the liquid phase of CPC can improve the anti-washout property. Meanwhile, no cytotoxicity was observed in cytotoxicity test. More ideal mechanical strength and better anti-washout property expanded the use of calcium phosphate cements.