脂蟾毒配基PLGA-TPGS纳米粒对小鼠肝癌异位移植瘤抑制作用的研究

Study the inhibition of Resibufogenin-loaded PLGA-TPGS Nanoparticles on the hepatocarcinoma ectopic transplantation tumor-bearing mice

目的:考察脂蟾毒配基乙交酯丙交酯共聚物-维生素E聚乙二醇1000琥珀酸酯(PLGA-TPGS)纳米粒(RPTN)在体内对荷腹水型肝癌高淋巴道转移细胞HCa-F小鼠异位移植实体瘤的抑制作用。方法:为保证体内给药的安全性和确定给药剂量,考察RPTN和脂蟾毒配基溶液(RS)在小鼠体内静脉给药途径的半数致死量(LD50)。建立荷HCa-F细胞小鼠肝癌异位移植实体瘤模型后分为6组,分别为空白对照组、空白纳米粒组、5-氟尿嘧啶溶液(FS)组、RS组、脂蟾毒配基乙交酯丙交酯共聚物(PLGA)纳米粒(RPN)组、RPTN组,尾静脉给药,每天1次,连续给药7 d;在停药次日,处死小鼠后剥离实体瘤,称重并测量实体瘤体积,根据公式计算实体瘤体积增长量和抑瘤率;将实体瘤固定后进行常规石蜡切片包埋,苏木素&曙红(H&E)染色观察,全面评价RPTN在小鼠体内的抑瘤效果。结果:RPTN和RS小鼠静脉给药LD50分别为38.2 mg·kg-1和18.9 mg·kg-1,表明RPTN在一定程度上可减轻RBG在小鼠体内的毒性作用,相比RS更安全。小鼠体内抗肿瘤试验中给药7 d后,FS组、RPN组、RPTN组的实体瘤体积增长量与空白对照组相比明显减小(P<0.05或P<0.01),RPTN组抑瘤率为64.93%,明显高于RPN组(51.64%)、FS组(37.19%)、RS组(31.60%)的抑瘤率。H&E染色后镜下观察的结果也表明RPTN组对荷HCa-F细胞小鼠肝癌异位实体瘤抑制作用效果最好。结论:与RPN、RS和FS相比,在抑制荷HCa-F细胞小鼠肝癌异位移植实体瘤试验中RPTN具有良好的抗肿瘤作用。

OBJECTIVE To investigate the inhibition of Resibufogenin（RBG）-loaded poly1actide-co-glycolide tocopherol polyethylene glycol 1000 succinate（PLGA-TPGS）nanoparticles（RPTN）in vivo on the model of ectopic transplantation solid tumors using ascitic hepatocarcinoma cell strain with high metastasis potential in lymphatic system（HCa-F cells）-bearing mice.METHODS Median lethal dose（LD50）values of Resibufogenin solutions（RS）and RPTN suspensions were determined in mice through intravenous injection via tail vein in order to guarantee the safety and determine dosage of drug administration in vivo.The model of hepatocarcinoma ectopic transplantation solid tumor-bearing mice was established and the mice were randomly divided into six groups：the blank control group,empty PLGA-TPGS nanoparticles（EPTN）group,5-Fluorouracil solutions（FS）group,RS group,RBG-loaded poly1actide-co-glycolide nanoparticles（RPN）group and RPTN group.The mice in all groups received respectively administration via tail vein once a day for 7 d.After 7 days of administration,all mice were sacrificed,the tumors of which were removed and weighed.The increment tumor volumes and tumor growth inhibition rate were calculated according to the correlative formulas.Then,the tumor specimens were prepared to be formalin-fixed,paraffin-embedded sections for hematoxylin and eosin（HE）staining and observed under the microscope.Thus,tumor inhibition effect of RPTN was evaluated comprehensively in mice.RESULTS LD50 values of RS and RPTN were found to be 18.9 mg·kg-1 and 38.2 mg·kg-1,respectively,i.v.in mice,which revealed that nanoparticles reduced the toxicity of the drug and could be a safer dosage formin vivo.The results illustrated that after 7 days of administration,the increment tumor volumes of mice in the FS,RPN,and RPTN groups were significantly（P0.05 or P0.01）smaller than that in the blank control group.The tumor growth inhibition rate of RPTN group was 64.93%,which was much higher than 51.64% for RPN group,37.19% for FS group and31.60%for RS group.Conditions of cell growth and apoptosis of solid tumors in various groups were observed by HE staining on tumor sections,which also indicating that RPTN showed effective inhibition against the growth of tumor cells.CONCLUSION RPTN group had a better therapeutic effect on the model of hepatocarcinoma ectopic transplantation solid tumor using HCa-F cells-bearing mice than RPN,RS,and FS groups.