Gharebaghi Farhad, Dalali Naser, Ahmadi Ebrahim, Danafar Hossein
1 Faculty of Science, Phase Separation & FIA Lab., Department of Chemistry, University of Zanjan, Zanjan, Iran.
2 Department of Chemistry, University of Zanjan, Zanjan, Iran.
J Biomater Appl. 2017 Apr;31(9):1305-1316. doi: 10.1177/0885328217698063. Epub 2017 Mar 24.
Methotrexate is one of the most effective drugs that is commonly used in the treatment of cancer. However, its application is limited due to low solubility, high toxicity and rapid metabolism. Therefore, in the present study, worm-like polymeric nanoparticles as carrier of methotrexate were prepared using biodegradable copolymers (mPEG-PCL). The impact of nanoparticles' geometry on the loading, delivery and drug's anti-cancer activity was investigated. The di-block copolymer mPEG-PCL was being synthesized by a ring opening polymerization of ɛ-caprolactone in the presence of mPEG as the initiator and Sn(oct) as the catalyst. It was used for the preparation of worm-like micelles and coated with silica, so that their structures are stable after drying. The synthesized copolymers and nanoparticles were characterized by FTIR, HNMR, GPC, XRD, TGA, DLS, and FE-SEM analyses. The efficiencies of drug loading and release of nanoparticles as in vitro, was studied by high performance liquid chromatography. The MTT method was used to estimate the toxicity on MCF-7 cell category. The obtained results showed that the nanoparticles were worm-like particles with less than 150 nm diameter and about 1 µm length. The loading and encapsulation efficiencies of drug by the worm-like nanoparticles were 3.5 ± 0.14% and 65.6 ± 0.12%, respectively, while they were obtained as 2.1 ± 0.08% and 26 ± 0.10%, respectively, for spherical nanoparticles. The methotrexate diffusional behavior of worm-like nanoparticles was compared with that of the spherical ones. On the other hand, the anti-cancer activity of MTX-loaded nanoparticles was more than the free drug. The results of the MTT assay showed strong and dose-dependent inhibition of cell (MCF-7 category) growth by the nanoparticles compared with MTX. The inhibitory concentrations (IC i.e. reduction viability of cell to 50%) obtained for worm-like, spherical nanoparticles and free drug (incubation times 72 h) were 8.25 ± 0.20, 9.15 ± 0.17, 12.28 ± 0.15 µg/mL, respectively. It can be concluded that application of non-spherical nanoparticles is a better and more effective strategy for controlled and slow release of methotrexate in the treatment of cancer.
甲氨蝶呤是治疗癌症常用的最有效药物之一。然而，由于其低溶解度、高毒性和快速代谢，其应用受到限制。因此，在本研究中，使用可生物降解共聚物（mPEG-PCL）制备了类蠕虫状聚合物纳米颗粒作为甲氨蝶呤的载体。研究了纳米颗粒的几何形状对药物负载、递送及抗癌活性的影响。双嵌段共聚物mPEG-PCL是在mPEG作为引发剂和Sn（辛酸盐）作为催化剂的存在下，通过ε-己内酯的开环聚合反应合成的。它用于制备类蠕虫状胶束并包覆二氧化硅，使其在干燥后结构稳定。通过傅里叶变换红外光谱（FTIR）、核磁共振氢谱（HNMR）、凝胶渗透色谱（GPC）、X射线衍射（XRD）、热重分析（TGA）、动态光散射（DLS）和场发射扫描电子显微镜（FE-SEM）分析对合成的共聚物和纳米颗粒进行了表征。通过高效液相色谱法研究了纳米颗粒在体外的药物负载和释放效率。采用MTT法评估对MCF-7细胞系的毒性。所得结果表明，纳米颗粒为类蠕虫状颗粒，直径小于150 nm，长度约为1 µm。类蠕虫状纳米颗粒对药物的负载率和包封率分别为3.5±0.14%和65.6±0.12%，而球形纳米颗粒的负载率和包封率分别为2.1±0.08%和26±0.10%。比较了类蠕虫状纳米颗粒和球形纳米颗粒中甲氨蝶呤的扩散行为。另一方面，负载甲氨蝶呤的纳米颗粒的抗癌活性高于游离药物。MTT分析结果表明，与甲氨蝶呤相比，纳米颗粒对细胞（MCF-7细胞系）生长具有强烈的剂量依赖性抑制作用。类蠕虫状纳米颗粒、球形纳米颗粒和游离药物（孵育时间72小时）的抑制浓度（即细胞活力降低至50%）分别为8.25±0.20、9.15±0.17、12.28±0.15 µg/mL。可以得出结论，应用非球形纳米颗粒是在癌症治疗中控制甲氨蝶呤缓释的一种更好且更有效的策略。
