外磁场协同卟啉-葡聚糖磁性纳米微粒的光动力学对人膀胱癌细胞的杀伤作用

目的:探讨外磁场协同卟啉-葡聚糖磁性纳米微粒(porphyrin-dextran magnetic nanoparticles,PDMN)的光动力学作用对人膀胱癌细胞杀伤作用的影响。方法:用化学共沉淀和氧化还原法制备PDMN,并检测其理化性质。采用四甲基偶氮唑蓝(methyl thiazolyl tetrazolium,MTT)法、流式细胞术分别观察脉冲电磁场协同PDMN的光动力学作用对人膀胱癌BIU-87细胞的杀伤作用。结果:PDMN的直径、比饱和磁化强度(saturation magnetization,Ms)分别为10～15 nm、0.20 emu/g,有效粒径为94.8 nm。PDMN光动力学作用可显著抑制BIU-87细胞增值,抑制率达(17.61±2.73)%,并诱导BIU-87细胞发生明显的凋亡,凋亡率为(24.53±5.74)%。脉冲外电磁场(5 mT)也可抑制BIU-87细胞增殖和诱导发生凋亡,且协同PDMN的光动力学作用对BIU-87细胞的生长抑制和诱导肿瘤细胞凋亡的效应均显著增强,抑制率和凋亡率分别为(28.11±4.25)%、(24.53±5.74)%,明显高于其他各组(P﹤0.01)。结论:化学修饰后的PDMN的光动力学作用能有效地抑制人膀胱癌BIU-87细胞的增殖并诱导其凋亡,与恒定外磁场协同作用对BIU-87细胞的杀伤作用更强。

Synergetic killing effects of external magnetic fields combined with porphyrin-dextran magnetic nanoparticles on the human bladder cancer cells

Objective:To study the synergetic killing effects of external magnetic fields combined with the photodynamic action of porphyrin-dextran iron oxide magnetic nanoparticles(PDMN) on human bladder cancer cells in vitro.Methods: The PDMN were produced by using the chemical co-precipitation and redox process and the physicochemical properties were characterized.Methyl thiazolyl tetrazolium(MTT) and flow cytometry were used to determine the effects of photodynamic therapy of PDMN combined with external pulsed electromagnetic fields(5 mT) on killing human bladder cancer BIU-87 cells respectively.Results: The diameters of PDMN were 10-15 nm and the saturation magnetization was 0.20 emu/g.Effective diameter of PDMN was 94.8 nm.PDMN could remarkably inhibit the proliferation and induce the obvious apoptosis of BIU-87 cells,and the rates of growth inhibition and apoptosis were(17.61±2.73)% and(24.53±5.74)% respectively.Moreover,external pulsed electromagnetic fields(5 mT) could also suppress the proliferation and induce apoptosis of BIU-87 cells.Furthermore,the photodyna-mic action of PDMN combined with external magnetic fields significantly inhibited the proliferation and promote apoptosis of BIU-87 cells,and the rates of growth inhibition and apoptosis was(28.11±4.25)% and(24.53±5.74)%,respectively,which were significantly higher than those of other groups(P<0.01).Conclusion: The chemical modified photodynamic action of PDMN could effectively inhibit proliferation and induce apoptosis of BIU-87 cells.Moreover,these effects on BIU-87 cells could be strengthened by the combination with external magnetic fields.