Department of Hematology and Research Laboratory of Hematology, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, and Collaborative Innovation Center, Chengdu 610041, PR China.
Department of Hematology and Research Laboratory of Hematology, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, and Collaborative Innovation Center, Chengdu 610041, PR China.
Int J Pharm. 2019 Feb 25;557:74-85. doi: 10.1016/j.ijpharm.2018.12.025. Epub 2018 Dec 15.
Drug resistance and recurrence are the main clinical challenges in chemotherapy of lymphoma. Methotrexate (MTX), especially high dose MTX (HD MTX), is extensively used to treat some aggressive subtypes of lymphoma, such as Burkitt's lymphoma, in order to overcome drug resistance. But poor solubility of the free drug and severe side effects of HD MTX limit its clinical application. Polymeric micelle, as an ideal nano delivery system, provides effective solutions to these problems. In this work, monomethyl poly (ethylene glycol)-poly (ε-caprolactone) (MPEG-PCL) was employed to load MTX through a one-step solid dispersion method. MTX loaded micelles had a small particle size of 25.64 ± 0.99 nm and polydisperse index (PDI) of 0.176 ± 0.05. Drug loading and encapsulation efficiency of MTX loaded micelles were 5.57 ± 0.14% and 92.46 ± 2.38%. Compared with free MTX, MTX loaded micelles demonstrated a much slower and sustained release behavior in vitro. MTT assay and cell apoptosis study suggested that MTX loaded micelles were more effective in inhibiting proliferation and inducing apoptosis on Raji lymphoma cells than MTX injection, which was especially distinct in high dose groups. Cellular uptake study indicated that MPEG-PCL micelle had a 1.5 times higher uptake rate in Raji cells. As for in vivo studies, MTX loaded micelles were more competent to suppress tumor growth and prolong survival time than MTX injection in the subcutaneous Raji lymphoma model. Notably, the high dose group of micelle formulation exhibited the strongest anti-tumor effect without additional toxicity. Furthermore, immunofluorescent and immunohistochemical studies showed that tumors of MPEG-PCL-MTX treated mice had more apoptotic cells and fewer proliferative cells. In conclusion, MPEG-PCL-MTX micelle is an excellent intravenously injectable formulation of MTX with both good solubility and enhanced anti-tumor activity, which perfectly meets clinical demands, especially for administration of HD MTX.
耐药性和复发是淋巴瘤化疗的主要临床挑战。甲氨蝶呤（MTX），特别是大剂量甲氨蝶呤（HD-MTX），被广泛用于治疗伯基特淋巴瘤等侵袭性淋巴瘤亚型，以克服耐药性。但游离药物的溶解度差和 HD-MTX 的严重副作用限制了其临床应用。聚合物胶束作为一种理想的纳米递药系统，为解决这些问题提供了有效的解决方案。在这项工作中，采用单甲氧基聚乙二醇-聚（ε-己内酯）（MPEG-PCL）通过一步固相分散法载药 MTX。MTX 载药胶束的粒径为 25.64±0.99nm，多分散指数（PDI）为 0.176±0.05。MTX 载药胶束的载药量和包封率分别为 5.57±0.14%和 92.46±2.38%。与游离 MTX 相比，MTX 载药胶束在体外具有更慢和更持续的释放行为。MTT 法和细胞凋亡研究表明，MTX 载药胶束对 Raji 淋巴瘤细胞的增殖抑制和诱导凋亡作用明显优于 MTX 注射液，尤其是在高剂量组更为明显。细胞摄取研究表明，MPEG-PCL 胶束在 Raji 细胞中的摄取率提高了 1.5 倍。体内研究表明，MTX 载药胶束在 Raji 淋巴瘤皮下模型中比 MTX 注射液更能抑制肿瘤生长和延长生存时间。值得注意的是，载药胶束高剂量组表现出最强的抗肿瘤作用，而无额外毒性。此外，免疫荧光和免疫组织化学研究表明，MPEG-PCL-MTX 治疗小鼠的肿瘤中凋亡细胞增多，增殖细胞减少。综上所述，MPEG-PCL-MTX 胶束是一种具有良好溶解度和增强抗肿瘤活性的 MTX 优秀静脉注射制剂，完全满足临床需求，特别是用于 HD-MTX 的给药。
