Department of Pharmacy, School of Chemical Sciences and Pharmacy, Central University of Rajasthan, Bandar Sindri, Dist., Ajmer, Rajasthan, 305817, India.
Division of Pharmaceutics, University Institute of Pharmaceutical Sciences, Centre of Advanced Studies, Panjab University, Chandigarh, 160014, India.
AAPS PharmSciTech. 2018 Apr;19(3):1084-1092. doi: 10.1208/s12249-017-0920-0. Epub 2017 Nov 20.
Derivatization of fullerenes to polyhydroxylated fullerenes, i.e., fullerenols (FLU), dramatically decreases their toxicity and has been reported to enhance the solubility as well as cellular permeability. In this paper, we report synthesis of FLU as nanocarrier and subsequent chemical conjugation of Methotrexate (MTX) to FLU with a serum-stable and intracellularly hydrolysable ester bond between FLU and MTX. The conjugate was characterized for physiochemical attributes, micromeritics, drug-loading, and drug-release and evaluated for cancer cell-toxicity, cellular-uptake, hemocompatibility, protein binding, and pharmacokinetics. The developed hemocompatible FL-MTX offered lower protein binding vis-à-vis naïve drug and substantially higher drug loading. The conjugate offered pH-dependent release of 38.20 ± 1.19% at systemic pH and 85.67 ± 3.39% at the cancer cell pH. FLU-MTX-treated cells showed significant reduction in IC value vis-à-vis the cells treated with pure MTX. Analogously, the results from confocal scanning laser microscopy also confirmed the easy access of the dye-tagged FLU-MTX conjugate to the cell interiors. In pharmacokinetics, the AUC of MTX was enhanced by approx. 6.15 times and plasma half-life was enhanced by 2.45 times, after parenteral administration of single equivalent dose in rodents. FLU-MTX offered enhanced availability of drug to the biological system, meanwhile improved the cancer-cell cytotoxicity, sustained the effective plasma drug concentrations, and offered substantial compatibility to erythrocytes.
富勒烯衍生物多羟基化富勒烯，即富勒醇（FLU），可显著降低其毒性，并已被报道可提高其溶解度和细胞通透性。在本文中，我们报告了 FLU 作为纳米载体的合成，以及随后将甲氨蝶呤（MTX）通过血清稳定且在 FLU 和 MTX 之间可在细胞内水解的酯键化学偶联到 FLU 上。该缀合物的理化特性、微粉学特性、载药量和药物释放进行了表征，并对其进行了抗癌细胞毒性、细胞摄取、血液相容性、蛋白质结合和药代动力学评价。开发的血液相容性 FL-MTX 与天然药物相比，具有较低的蛋白质结合率和更高的载药量。该缀合物在全身 pH 值下可实现 38.20±1.19%的 pH 依赖性释放，在癌细胞 pH 值下可实现 85.67±3.39%的释放。与用纯 MTX 处理的细胞相比，用 FLU-MTX 处理的细胞的 IC 值明显降低。类似地，共聚焦扫描激光显微镜的结果也证实了染料标记的 FLU-MTX 缀合物很容易进入细胞内部。在药代动力学中，在啮齿动物中给予单倍等效剂量后，MTX 的 AUC 增强了约 6.15 倍，血浆半衰期延长了 2.45 倍。FLU-MTX 使药物更有效地到达生物系统，同时提高了癌细胞的细胞毒性，维持了有效的血浆药物浓度，并与红细胞具有很大的相容性。
