J Biomed Nanotechnol. 2014 Jun;10(6):1016-29. doi: 10.1166/jbn.2014.1782.
Many health benefits have been associated with tea consumption. In an effort to elucidate the source of these health benefits, numerous phytochemicals have been extracted from tea infusions, some of which have demonstrated promise as clinical therapeutics for cancer therapy. Considering the advantageous properties of organic nanoparticles, the purpose of this study is to develop a method for isolating nanoparticles from tea leaves, and explore potential biomedical applications for these nanoparticles. First, an infusion-dialysis procedure for isolating tea nanoparticles (TNPs) from green tea infusions is developed. Second, atomic force microscopy and scanning electron microscopy reveal that the TNPs are spherical with diameters of 100-300 nm. Third, electrophoretic light scattering is used to determine that the TNPs have a zeta potential of -26.52 mV at pH 7.0. Finally, chemical analysis demonstrates that (-) Epigallocatechin gallate, caffeine, and theobromine are not found in the TNPs. Interestingly, the TNPs do enhance the in vitro secretion of cytokines IL-6, TNF-alpha, and G-CSF, as well as the chemokines RANTES, IP-10, MDC from mouse macrophages RAW264.7, indicating an immunostimulatory effect. As a nanocarrier, the TNPs are able to form complexes with doxorubicin (DOX) and have the potential for applications in drug delivery. Further the DOX-loaded TNPs increase the cellular DOX uptake, compared to free DOX, leading to higher cytotoxicity in the A549 human lung cancer and MCF-7 breast cancer cells. More importantly, the DOX-loaded TNPs significantly increase the DOX uptake and cytotoxicity in MCF-7/ADR multidrug resistant breast cancer cells. In this work, an infusion-dialysis procedure is developed for isolation of the TNPs from green tea, and the potential of these nanoparticles as a multifunctional nanocarrier for cancer therapy in vitro is explored.
饮茶有益健康，这一点已得到广泛证实。为了阐明这些健康益处的来源，人们从茶提取物中提取了许多植物化学物质，其中一些已被证明具有作为癌症治疗临床治疗剂的潜力。考虑到有机纳米粒子的有利特性，本研究旨在开发一种从茶叶中分离纳米粒子的方法，并探索这些纳米粒子在生物医学中的潜在应用。首先，开发了一种从绿茶浸出液中分离茶纳米粒子（TNPs）的浸出液透析法。其次，原子力显微镜和扫描电子显微镜显示，TNPs 呈球形，直径为 100-300nm。第三，电泳光散射法测定 TNPs 在 pH7.0 时的zeta 电位为-26.52mV。最后，化学分析表明，TNPs 中不含有表没食子儿茶素没食子酸酯、咖啡因和可可碱。有趣的是，TNPs 确实能增强小鼠巨噬细胞 RAW264.7 体外分泌细胞因子 IL-6、TNF-α和 G-CSF 以及趋化因子 RANTES、IP-10 和 MDC，表明具有免疫刺激作用。作为纳米载体，TNPs 能够与阿霉素（DOX）形成复合物，并具有应用于药物传递的潜力。进一步研究表明，负载 DOX 的 TNPs 比游离 DOX 能增加细胞内 DOX 的摄取，从而导致 A549 人肺癌和 MCF-7 乳腺癌细胞的细胞毒性更高。更重要的是，负载 DOX 的 TNPs 能显著增加 MCF-7/ADR 多药耐药乳腺癌细胞对 DOX 的摄取和细胞毒性。本研究开发了一种从绿茶中分离 TNPs 的浸出液透析法，并探讨了这些纳米粒子作为一种多功能纳米载体在体外癌症治疗中的应用潜力。
