WS2 nanosheets were prepared by the solvent-thermal method in the presence of n-butyl lithium, then the exfoliation under the condition of ultrasound. The formed WS2 nanosheets were conjugated with thiol-modified polyethylene glycol(PEG-SH) to improve the biocompatibility. The nanosheets(WS2-PEG) were able to inhibit the growth of a model He La cancer cell line in vitro due to the high photothermal conversion efficiency of 35% irradiated by an 808 nm laser(1 W/cm2). As a proof of concept, WS2-PEG nanosheets with the better X-ray attenuation property than the clinical computed tomography(CT) contrast agent(Iohexol) could be performed for CT imaging of the lymph vessel.
Xiao-Zhen CuiZhi-Guo ZhouYan YangJie WeiJun WangMing-Wei WangHong YangYing-Jian ZhangShi-Ping Yang
背景与目的:由于肾细胞癌脂肪酸代谢异常升高,^(11)C-乙酸(^(11)C-acetate,^(11)C-AC)PET/CT显像已用于诊断肾细胞癌,能弥补^(18)F-FDG PET/CT显像在肾癌诊断方面的不足。然而,^(11)C的半衰期很短(t_(1/2)=20.4 min),极大地限制了^(11)C-AC PET/CT显像在临床诊断中的广泛应用。本实验旨在研究肾癌摄取^(18)F-氟乙酸盐(^(18)F-fluoroacetate,^(18)F-FAC)与脂肪酸合成酶(fatty acid synthase,FAS)的相关性,进而探讨^(18)F-FAC PET/CT分子影像是否能在体监测肾癌脂肪酸代谢的动态变化。方法:50只ACHN肾癌荷瘤裸小鼠分为3组,分别为^(18)F-FAC micro PET/CT显像组(n=6)、免疫组织化学组(n=24)和生存期观察组(n=20)。其中每组又分为2个亚组,即实验组(10 mg/kg,依维莫司)和对照组(0.9%Na Cl溶液),连续处理14 d。在处理前(第0天)和处理后第5、10和15天行小动物^(18)F-FAC PET/CT显像,定量分析肿瘤与对侧大腿肌肉每克组织放射性占注射量的百分比最大值(the maximum of the percent injected dose per gram tissue,%ID/g_(max)),并计算靶本比(T/M)。在上述相同时间点,分别随机处死3只荷瘤裸鼠,获取肿瘤组织,进行FAS免疫组织化学染色,并定量计算FAS表达水平。实验期间,每隔1天测量并记录荷瘤鼠肿瘤体积大小,观察荷瘤鼠死亡时间并绘制生存期曲线。结果:根据^(18)F-FAC PET/CT显像和定量分析,在第0、5、10和15天时实验组肾癌组织的^(18)F-FAC摄取值%ID/g_(max)分别为8.087±0.792、9.708±0.792、10.285±0.751和10.859±1.100,对照组分别为8.425±0.549、10.560±0.677、12.325±0.275和13.450±0.517,均有动态增加的变化趋势,但实验组明显低于对照组,并且差异有统计学意义。^(18)F-FAC T/M和FAS表达也有类似的动态变化,而且相关性分析发现,^(18)F-FAC摄取与FAS表达具有良好的正向相关性(P<0.001)。肿瘤体积变化和生存期实验表明,实验组肿瘤体积生长明显缓慢,荷瘤鼠中位生存期明显延长(35 d