金属医用材料表面微磁场改善的血液相容性

摘要 背景：在316L不锈钢、NiTi合金的表面用溶胶凝胶法制备含SrFe12O19磁性粉末的TiO2薄膜，磁化后在材料表面形成微磁场，可以延长其动态凝血时间，降低其溶血率，改善材料的血液相容性。 目的：讨论材料表面微磁场与血液相互作用的机制。 方法：用柠檬酸法制备SrFe12O19粉末，用X射线衍射仪(XRD)、扫描电镜(SEM)等分析了磁性粉末的成分及形貌，用磁强计检测了SrFe12O19粉末的磁性能；用溶胶凝胶法在316 L不锈钢、NiTi合金的表面制备含SrFe12O19磁性粉末的TiO2薄膜，并用X射线衍射仪分析了薄膜成分；通过动态凝血时间和溶血率的测定结果分析材料表面微磁场与血液相容性的关系。 结果与结论：材料表面产生的磁场阻碍了血液中Ca2+、和纤维蛋白原、血小板及红细胞等分子在材料表面上的黏附，从而抑制了凝血反应的进行，因而具有抗血栓的作用，提高了材料与血液之间的相容性。

Blood compatibility of micromagnetic field on surface of biomedical metallic materials

Abstract BACKGROUND: TiO2 film containing SrFe12O19 magnetic powder is coated on the surface of NiTi alloy and 316L stainless with sol-gel method. After magnetization, micromagnetic field is established on it. Dynamic clotting time of 316L stainless steel and NiTi alloy can be increased with TiO2 film containing SrFe12O19, and hemolysis rate is decreased, which indicate the improved blood compatibility of TiO2 film contained SrFe12O19. OBJECTIVE: To discuss mechanism of the interaction between micromagnetic field and blood. METHODS: SrFe12O19 nano-powder was prepared by the method of harnessing the citric acid, its morphology and size were studied by using X-ray diffraction and scanning electron microscopy. The magnetic properties were detected by using a magnetometer. The sol-gel method was used to prepare the TiO2 film containing SrFe12O19 powder, and the coating film component was then characterized by X-ray diffraction. The relations between the micro-magnetic field surface and the blood compatibility of materials were evaluated by dynamic clotting time and hemolysis rate. RESULTS AND CONCLUSION: Adsorptions of Ca2+, fibrinogen, platelets and erythrocytes in blood on material surface were prevented because of their diamagnetism. So the process of clotting was restrained, which indicated an antithrombotic effect and the improved blood compatibility of materials.