Hsin Tzu-Han, Dhenadhayalan Namasivayam, Lin King-Chuen
Department of Chemistry, National Taiwan University, and Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan.
ACS Appl Bio Mater. 2020 Dec 21;3(12):8786-8794. doi: 10.1021/acsabm.0c01151. Epub 2020 Nov 11.
herb-derived carbon dots (C-dots) were adopted as a drug carrier to deliver methotrexate (MTX). MTX is a folate antagonist drug for chemotherapy of cancer. The MTX was conjugated with C-dots to form the MTX/C-dot complex through non-covalent bonding. The efficiency of drug loading and release of MTX/C-dots was evaluated, showing a high drug loading (85.9%) capability of C-dots. The MTX/C-dots exhibited pH-dependent MTX release behavior in which high efficiency (∼69%) was obtained at pH 5.0 with respect to the value of ∼47% at pH 7.4. The cell viabilities of MTX/C-dots and bare C-dots were evaluated in HeLa and human normal fibroblasts (NHF) cells. The C-dots possess less toxicity, whereas MTX/C-dots showed high cytotoxicity compared to that of bare MTX in HeLa cells. The content of the folate receptor is higher (1.56 times) in HeLa cells than that of NHF cells such that a dense binding between the MTX and folate receptor reduces the cell viability. This finding confirms that the MTX/C-dots had a higher cellular uptake, signifying the excellent drug carrier property of C-dots. In addition, the fluorescence bioimaging measurements were examined in HeLa cells to demonstrate the drug delivery efficacy of MTX/C-dots by using confocal fluorescence microscopy. Accordingly, the MTX/C-dots demonstrate their potential in the bioimaging and drug delivery system resulting from fascinating features including photoluminescence, good biocompatibility, and proficient cellular uptake and drug release. It is believed that the MTX/C-dot nanocarrier might hold great potential for cancer chemotherapeutic applications.
源自草药的碳点（C点）被用作药物载体来递送甲氨蝶呤（MTX）。MTX是一种用于癌症化疗的叶酸拮抗剂药物。MTX与C点通过非共价键结合形成MTX/C点复合物。评估了MTX/C点的药物负载和释放效率，结果表明C点具有较高的药物负载能力（85.9%）。MTX/C点表现出pH依赖性的MTX释放行为，在pH 5.0时释放效率较高（约69%），而在pH 7.4时约为47%。在HeLa细胞和人正常成纤维细胞（NHF）中评估了MTX/C点和裸露C点的细胞活力。C点毒性较小，而在HeLa细胞中，与裸露的MTX相比，MTX/C点表现出较高的细胞毒性。HeLa细胞中叶酸受体的含量比NHF细胞高（1.56倍），因此MTX与叶酸受体之间的紧密结合降低了细胞活力。这一发现证实了MTX/C点具有更高的细胞摄取率，表明C点具有优异的药物载体特性。此外，在HeLa细胞中进行了荧光生物成像测量，以使用共聚焦荧光显微镜证明MTX/C点的药物递送效果。因此，MTX/C点因其包括光致发光、良好的生物相容性以及高效的细胞摄取和药物释放等迷人特性，在生物成像和药物递送系统中展现出潜力。据信，MTX/C点纳米载体在癌症化疗应用中可能具有巨大潜力。
