177Lu-FA-DOTA-PEG-PLGA靶向可降解纳米粒子腹腔灌注治疗小鼠卵巢癌伴腹膜转移的实验研究

目的 观察放射性核素¹⁷⁷Lu标记的叶酸-二乙烯三胺五乙酸-聚乙二醇-聚乳酸共聚物(¹⁷⁷Lu-FA-DOTA-PEG-PLGA)纳米粒子的体内靶向分布,评价腹腔灌注纳米粒子治疗小鼠卵巢癌腹膜转移瘤及腹水疗效。方法 制备¹⁷⁷Lu-FA-DOTA-PEG-PLGA纳米粒子,向人卵巢癌移植瘤荷瘤小鼠尾静脉注射纳米粒子后4、24、72 h和7 d,行微型单光子发射计算机断层显像仪(micro-SPECT/CT)显像,观察纳米粒子体内分布情况。将12只人卵巢癌腹腔转移瘤裸鼠模型按随机抽签法分为阴性对照组(生理盐水)、化疗组(顺铂3 mg/kg,2次/周)和粒子组(¹⁷⁷Lu-FA-DOTA-PEG-PLGA粒子18.5 MBq),每组4只,腹腔灌注给药。7 d后行活体荧光成像评价腹腔肿瘤生长情况,计算相对抑瘤率,TUNEL法检测肿瘤细胞凋亡率,免疫组织化学法检测肿瘤Ki67增殖活性,比较治疗后各组腹水体积。结果 micro-SPECT/CT显像显示,移植瘤放射性浓聚,24 h肿瘤肌肉摄取比值(T/M)最高,为2.81±0.49。活体荧光成像显示,腹腔给药治疗后,粒子组、化疗组和阴性对照组的腹腔肿瘤荧光强度分别为(1.45±0.19)×10¹⁰、(2.21±0.36)×10¹⁰和(2.63±0.79)×10¹⁰,差异有统计学意义(F=6.09,P=0.029);粒子组和化疗组的相对肿瘤抑制率(TGI)分别为35.6%和18.6%。粒子组和化疗组的肿瘤细胞凋亡率(AI)均高于阴性对照组(F=9.96,P=0.009),粒子组和化疗组的Ki67指数均低于阴性对照组(F=9.93,P=0.013),粒子组和化疗组腹水体积均小于阴性对照组(F=13.43,P=0.006)。结论 ¹⁷⁷Lu-FA-DOTA-PEG-PLGA纳米粒子可行小鼠卵巢癌靶向显像,腹腔灌注后局部滞留和降解吸收,抑制卵巢癌腹膜转移瘤和腹水生长,为晚期卵巢癌伴腹膜转移患者诊疗提供新思路。

The experimental study on intraperitoneal injection of targeted degradable nanoparticles 177Lu-FA-DOTA-PEG-PLGA in the treatment of ovarian cancer peritoneal metastases and ascites

Objective To observe the distribution of ¹⁷⁷Lu-FA-DOTA-PEG-PLGA nanoparticles in vivo,and evaluate the therapeutic effect of nanoparticles intraperitoneal injection on ovarian cancer peritoneal metastases and ascites.Methods Nanoparticles were prepared and injected into human ovarian cancer xenograft nude mice model by tail vein.Micro-SPECT/CT imaging was performed at different times (4,24,72 h and 7 d) after injection to observe the distribution of nanoparticles in vivo.Nude mouse models of intraperitoneal metastases of human ovarian cancer were randomly divided into negative control group (normal saline),chemotherapy group (cisplatin 3 mg/kg,twice a week) and nanoparticle group (18.5 MBq),with 4 mice in each group.After 7 days,intraperitoneal tumor growth was evaluated by in vivo fluorescence imaging.The relative tumor inhibition rate was counted.Tumor cell apoptosis rate was detected by TUNEL method,and the proliferation activity tumor Ki67 was detected by immunohistochemical method.The ascites volume of each group was compared after treatment.Results Micro-SPECT/CT imaging showed the radioactive uptake of the transplanted tumor,and the 24 h tumor muscle uptake ratio (T/M) was the highest,about 2.81±0.49.Intravital fluorescence imaging showed that,after intraperitoneal administration,the fluorescence intensity of abdominal tumor in particle group,chemotherapy group and control group was (1.45±0.19)×10¹⁰,(2.21±0.36)×10¹⁰ and (2.63±0.79)×10¹⁰(F=6.09,P=0.029),respectively.The relative tumor growth inhibition (TGI) of the particle group and the chemotherapy group were 35.6% and 18.6%,respectively.The tumor cell apoptosis rates in particle group and chemotherapy group were higher than those in control group (F=9.96,P=0.009).Ki67 indexes in particle group and chemotherapy group were lower than those in control group (F=9.93,P=0.013).The ascites volume in particle group and chemotherapy group were both smaller than those in control group (F=13.43,P=0.006).Conclusions ¹⁷⁷Lu-FA-DOTA-PEG-PLGA nanoparticles can be used for the targeted imaging of ovarian cancer.After intraperitoneal injection,nanoparticles show local retention,degradation and absorption and thus inhibit the growth of peritoneal metastases and ascites of ovarian cancer,which provides a new idea for the diagnosis and treatment of advanced ovarian cancer with peritoneal metastasis.