Chen Jian, Zhang Bei, Xia Fei, Xie Yunchang, Jiang Sifan, Su Rui, Lu Yi, Wu Wei
School of Pharmacy, Fudan University, Key Laboratory of Smart Drug Delivery of MOE and PLA, Shanghai 201203, China.
Nanoscale. 2016 Apr 7;8(13):7127-36. doi: 10.1039/c5nr06804e.
Breaking the natural barriers of cell membranes achieves fast entry of therapeutics, which leads to enhanced efficacy and helps overcome multiple drug resistance. Herein, transmembrane delivery of a series of small molecule anticancer drugs was achieved by the construction of artificial transmembrane nanochannels formed by self-assembly of cyclic peptide (cyclo[Gln-(d-Leu-Trp)4-d-Leu], CP) nanotubes (CPNTs) in the lipid bilayers. Our in vitro study in liposomes indicated that the transport of molecules with sizes smaller than 1.0 nm, which is the internal diameter of the CPNTs, could be significantly enhanced by CPNTs in a size-selective and dose-dependent manner. Facilitated uptake of 5-fluorouracil (5-FU) was also confirmed in the BEL7402 cell line. On the contrary, CPs could facilitate neither the transport across liposomal membranes nor the uptake by cell lines of cytarabine, a counterevidence drug with a size of 1.1 nm. CPs had a very weak anticancer efficacy, but could significantly reduce the IC50 of 5-FU in BEL7402, HeLa and S180 cell lines. Analysis by a q test revealed that a combination of 5-FU and CP had a synergistic effect in BEL7402 at all CP levels, in S180 at CP levels higher than 64 μg mL(-1), but not in HeLa, where an additive effect was observed. Temporarily, intratumoral injection is believed to be the best way for CP administration. In vivo imaging using (125)I radio-labelled CP confirmed that CPNPTs were completely localized in the tumor tissues, and translocation to other tissues was negligible. In vivo anticancer efficacy was studied in the grafted S180 solid tumor model in mice, and the results indicated that tumor growth was greatly inhibited by the combinatory use of 5-FU and CP, and a synergistic effect was observed at CP doses of 0.25 mg per kg bw. It is concluded that facilitated transmembrane delivery of anticancer drugs with sizes smaller than 1.0 nm was achieved, and the synergistic anticancer effect was confirmed both in cell lines and in vivo through the combinatory use of 5-FU and CP.
打破细胞膜的天然屏障可实现治疗药物的快速进入，这会提高疗效并有助于克服多重耐药性。在此，通过在脂质双层中自组装环肽（环[Gln-(d-Leu-Trp)4-d-Leu]，CP）纳米管（CPNTs）形成人工跨膜纳米通道，实现了一系列小分子抗癌药物的跨膜递送。我们在脂质体中的体外研究表明，尺寸小于CPNTs内径1.0 nm的分子的转运可被CPNTs以尺寸选择性和剂量依赖性方式显著增强。在BEL7402细胞系中也证实了5-氟尿嘧啶（5-FU）的摄取增加。相反，CPs既不能促进阿糖胞苷（一种尺寸为1.1 nm的对照药物）跨脂质体膜的转运，也不能促进其被细胞系摄取。CPs的抗癌疗效非常弱，但能显著降低BEL7402、HeLa和S180细胞系中5-FU的IC50。通过q检验分析发现，5-FU和CP的组合在所有CP水平下在BEL7402中具有协同作用，在CP水平高于64 μg mL(-1)时在S180中具有协同作用，但在HeLa中没有，在HeLa中观察到的是相加作用。暂时认为瘤内注射是CP给药的最佳方式。使用(125)I放射性标记的CP进行的体内成像证实，CPNPTs完全定位在肿瘤组织中，向其他组织的转运可忽略不计。在小鼠移植性S180实体瘤模型中研究了体内抗癌疗效，结果表明5-FU和CP联合使用可显著抑制肿瘤生长，在CP剂量为0.25 mg/kg bw时观察到协同作用。结论是实现了尺寸小于1.0 nm的抗癌药物的促进跨膜递送，并且通过5-FU和CP的联合使用在细胞系和体内均证实了协同抗癌作用。
