共载多西他赛和维拉帕米脂质体逆转肿瘤耐药性的研究

The reversal of tumor drug resistance by liposomes containing docetaxel and verapamil

研究共载多西他赛(docetaxel, DTX)和维拉帕米(verapamil, VRP)组成的脂质体(DTX-VRP liposome,DTX-VRP LP)对人乳腺癌化疗多药耐药性的逆转作用。采用薄膜分散法制备DTX-VRP LP;用激光粒度仪考察了其粒径大小和zeta电位;用超滤法测定了载药量和包封率;动态透析法考察脂质体在pH值7.4和6.8的磷酸盐缓冲液(PBS)中体外累积释放率;以DTX诱导的多药耐药人源乳腺癌(MCF-7/DTX)细胞株研究脂质体的体内外药效学。动物实验获得上海交通大学动物伦理委员会批准(批准号:2019-06-172)。结果表明, DTX-VRP LP平均粒径约为140.9 nm, zeta电位约在-28.7 mV。DTX-VRP LP中DTX及VRP包封率和载药量分别是(81.7±3.9)%、(2.9±0.3)%和(59.6±0.6)%、(1.6±0.5)%;在pH 7.4和6.8 PBS中, 0~4 h内DTX-VRP LP组累积释放率分别约为40%和70%,相较于其他实验组, DTX-VRP LP组累积释放率稍慢些。体外药效学实验显示,在相同剂量下, DTX溶液组、DTX LP组及DTX-VRP LP组对MCF-7细胞的IC50值分别为3.19±0.6、1.46±0.48和1.12±0.33μmol·L^-1,对MCF-7细胞均具有很强的细胞毒性,各组结果相差不大。但在MCF-7/DTX细胞上,其他实验组的IC50均大于10μmol·L^-1,DTX-VRP LP组IC50值为7.4±2.86μmol·L^-1,显示出明显的细胞毒性,且随着浓度依赖性地逆转乳腺癌MCF-7/DTX细胞的多药耐药性(P<0.05),其他实验组均对MCF-7/DTX细胞无效。体内对MCF-7/DTX移植瘤的抑制作用与体外结果一致。综上, DTX-VRP LP可逆转MCF-7/DTX细胞多药耐药性。

To study the reversal effect of docetaxel(DTX) and verapamil(VRP) liposome(DTX-VRP LP) on multidrug resistance of human breast cancer chemotherapy, DTX-VRP LP was prepared by thin film dispersion method. The particle size and zeta potential were measured by laser particle sizer. The drug loading, entrapment efficiency and the cumulative release rate of liposomes in phosphate buffer saline solution(PBS) with pH 7.4 and6.8 were determined by ultrafiltration and dynamic dialysis, respectively. With DTX resistant human breast cancer cells(MCF-7/DTX) to study on the pharmacodynamics of liposomes in vitro and in vivo. The animal experiments were approved by the Animal Research Ethics Committee of School of Medicine of Shanghai Jiao Tong University(No. 2019-06-172). The average particle size and zeta potential of DTX-VRP LP were about 140.9 nm and-28.7 m V,respectively. The entrapment efficiency and drug loading of DTX and VRP in DTX-VRP LP were(81.7 ± 3.9)%,(2.9 ± 0.3)% and(59.6 ± 0.6)%,(1.6 ± 0.5)%, respectively. The cumulative release rate of the group of DTX-VRP LP was about 40% and 70% within 0-4 h in p H 7.4 and 6.8 PBS, respectively. It was slightly slower compared with other experimental groups. In vitro pharmacodynamics experiments, the value of IC50 of DTX solution, DTX LP and DTX-VRP LP were 3.19 ± 0.6, 1.46 ± 0.48 and 1.12 ± 0.33 μmol·L^-1 on human breast cancer cells(MCF-7),respectively. The results showed the data was not much difference between the other groups and all experimental groups had strong cytotoxicity on MCF-7. However, on the MCF-7/DTX, the IC50 values of the other groups were greater than 10 μmol·L^-1 while DTX-VRP LP group 7.4 ± 2.86 μmol·L^-1. The results showed DTX-VRP LP had obvious cytotoxicity with the concentration dependent reversal of multidrug resistance(MDR) of breast cancer MCF-7/DTX cells(P<0.05), the other experimental groups had no effect on MCF-7/DTX cells. The inhibitory effect of MCF-7/DTX in vivo is consistent with that in vitro. In conclusion, DTX-VRP LP could reverse the MDR of MCF-7/DTX cells.