中文摘要：

为了探讨SiO2包裹层对纳米磁性微粒的细胞毒性和磁热效应的影响,采用柠檬酸盐自燃烧法制备用于肿瘤磁热疗的纳米MnZn铁氧体微粒,应用ATP细胞活力测试和磁热量测定等方法,对其生物相容性和磁热效应进行测试。在60kHz交变磁场作用下,重量为10mg的包有SiO2的纳米磁性微粒在25min内可以使1mL去离子水温度升高26.5℃;未包裹SiO2的样品浸泡于37℃的生理模拟液（SBF溶液）中有微量的Zn^2＋、Fe^3＋、Mn^2＋离子溶出,但在剂量小于20mg时,其细胞毒性较小,而包裹了SiO2的样品则无论在剂量和时程上对细胞都没有影响。SiO2的包裹有利于提高纳米磁性微粒的生物相容性和细胞安全性,而且经过SiO2包裹的纳米磁性微粒的发热量仍能完全满足肿瘤磁热治疗的要求,其在肿瘤磁热治疗方面具有良好的应用前景。

英文摘要：

In order to study the biocompatibility and thermomagnetic effect of MnZn ferrite nanoparticles prepared by citrate auto-combustion method for cancer treatment, ATP ceil viability assay and thermomagnetic measurements were applied and the effect of silica coating on cell cytotoxicity and thermomagnetic effect was discussed. 10mg silica-coated MnZn ferrite nanoparticles led the lmL deionized water to increase by 26.5℃ under a 60kHz alternating magnetic field in 25min. A dram of Mn^2＋ , Zn^2＋, Fe3^2＋ were released when the non-coated MnZn ferrite nanoparticles soaked in SBF solution, and the particles were mildly cytotoxic when the dosage was less than 20mg. However, silica-coated ferrite nanoparticles had no effects on cells by either dosage or time. The results revealed that the silica coating could enhance the biocompatibility and cell safety of the ferrite particles. Furthermore, the silica-coated MnZn ferrite nanoparticles could fully meet the requirements of magnetic hyperthermia.