DMSA@γ-Fe_2O_3纳米磁流体联合卡氮芥在交变磁场下对人胶质瘤细胞U251的影响

The effects of magnetic fluid hyperthermia induced by an alternative magnetic field combining with BCNU on human glioma cell line U251 in vitro

目的研究在一定强度交变磁场下DMSA@γ-Fe2O3纳米磁流体热疗联合化疗药物卡氮芥对人胶质瘤细胞U251的影响。方法对Fe2O3纳米材料进行体外升温实验,以期找到热疗(43℃)所需的最佳浓度。MTT法评价Fe2O3纳米材料对人胶质瘤细胞U251的毒性作用,并确定卡氮芥对该细胞的工作浓度。将人胶质瘤细胞U251分为对照组、磁纳米热疗组、化疗组、磁纳米热疗联合化疗组(简称热化疗组),对照组更换培养液后继续培养,磁纳米热疗组加入适当浓度的Fe2O3浸提液置于磁场下43℃热疗2h,化疗组加入工作浓度的卡氮芥后继续培养24h,热化疗组加入上述浓度的卡氮芥后置于于磁场下43℃热疗2h,采用流式细胞仪观察各组细胞的凋亡情况。结果Fe2O3纳米材料升温效应良好,当Fe2O3浓度≥8g·L-1时,温度可达43℃以上。Fe2O3纳米材料对U251细胞毒性为0～1级,均属对细胞无毒性范畴。以24h时IC10～IC25的药物浓度作为实验的工作浓度,确定卡氮芥的工作浓度为0.02g·L-1;43℃单独热疗和单独化疗均对胶质瘤细胞有抑制和杀伤作用(P<0.05),而在此温度下磁纳米热疗与药物联合抑制作用均明显强于单独热疗和单独化疗(P<0.05);流式细胞仪结果显示,对照组、磁纳米热疗组、化疗组、热化疗组细胞凋亡率分别为2.58%、13.75%、17.60%和35.27%。结论交变磁场作用下,磁纳米热疗(43℃)可以明显增强化疗药物卡氮芥对人胶质瘤细胞U251的抑制作用。

Objective To investigate the influence of magnetic fluid hyperthermia induced by an alternating magnetic field（AMF） combining with 1,3-bis（zchboroethl）-1-nitrosourea （BCNU） on human glioma cell line U251 in vitro.Methods The experiment of Fe2O3 temperature rising was made to find the best concentration（the working temperature was 43℃）.MTT assay was used to evaluate the cytotoxicity of this material in vitro and determine the working concentration of BCNU against U251.Gliom cells were randomly divided into four groups（control group：cells without warming or medicating;hyperthermia group：cells with hyperthermia induced by AMF at 43℃ for 2 h;chemotherapy group：cells affected by BCNU at working concentration for 24 h;hyperthermia and chemotherapy group：cells affected by BCNU at working concentration for 24 h and then with hyperthermia induced by AMF at 43 ℃ for 2 h）.After managed with hyperthermia in alternating magnetic field at 43 ℃ for 2 h,BCNU for 24 h or both of two sides,The assessment of apoptosis rates were analysed by flow cytometry （FCM）.Results With the concentration of Fe2O3 increasing,it showed good effects on the temperature rising;above 43 ℃ was got as the concentration of Fe2O3≥8 g·L-1.MTT assay indicated that the toxicity of the material on human glioma cell line U251 was between 0-1 degree which belonged to no cytotoxicity.The working concentration was defined as that of IC10-IC25 at 24h,it turned out to be 0.02g·L-1.Single 43℃ hyperthermia in alternating magnetic field and single chemotherapy could suppressed the proliferation of U251 cells（all P〈0.05）.Combination of 43℃ hyperthermia and chemotherapy could suppressed cells proliferation and killed more cells than those in hyperthermia group and chemotherapy group（all P〈0.05）.Flow cytometry demonstrated that the apoptosis rates of the four groups were 2.58%,13.75%,17.60%,35.27% respectively.Conclusion Ferromagnetic fluid hyperthermia induced by AMF could obviously enhance the inhibitive effects of BCNU on human glioma cell line U251.