甲氨蝶呤缓释植入剂延迟小鼠肉瘤复发的研究

Methotrexate sustained-release implants for delay of sarcoma recurrence in mice

目的:制备甲氨蝶呤缓释植入剂,检测其体外降解以及体外、内释放度。研究其延迟小鼠肉瘤局部复发的作用,探讨与传统给药方式相比的优势。方法:以PLGA和PEG4000为辅料,采用熔融挤出法制备甲氨蝶呤缓释植入剂。采用紫外光度法和高效液相色谱法分别检测其体外、体内释放度以及真实含药量。于昆明小白鼠腋下皮下注射Sarcoma 180细胞,模拟术后残留病灶,建立肉瘤术后辅助化疗模型,对甲氨蝶呤缓释植入剂延迟肉瘤复发作用做出评价。结果:采用熔融挤出法成功制备了甲氨蝶呤缓释植入剂,其实际含药量为(8.34±0.65)%,实际含量与理论含量呈一致性,在体外、内可分别达到7和15 d的长效释放。与传统给药方式相比甲氨蝶呤缓释植入剂能更有效地延迟肿瘤复发,同时延长了小鼠的生存期。结论:熔融挤出法可成功制备甲氨蝶呤缓释植入剂,将有利于延迟肿瘤局部复发的治疗效果。

Objective：In this study,methotrexate sustained-release implants were prepared and investigated for their potential usage for cancer treatment.The degradation ration and cumulative release in vitro and in vivo of the sustained-release implants were determined separately.The effect of methotrexate sustained-release implants on delayed sarcoma recurrence was explored.The methotrexate sustained-release implants made herein were compared with traditional delivery system to explore their clinical superiority and advantages.Methods：PLGA and PEG4000 were used as excipients and hot-melting extrusion method was applied to fabricate methotrexate sustained-release implants,whose cumulative release ratio in vitro and in vivo were measured by UV and HPLC,respectively.HPLC was also applied to determine the drug actual contents in the produced implants.KM mice were inoculated subcutaneously with Sarcoma 180 cells at the axillary region to simulate postoperative residual lesions.Adjuvant chemotherapy after radical operation model was fabricated and the effect of local administration of methotrexate sustained-release implants on delayed sarcoma recurrence was evaluated.Results：Yellow uniform methotrexate sustained-release implants with a diameter of 0.88 mm were successfully fabricated by hot-melting extrusion method.Further characterization results demonstrated that drug actual content was up to（8.34±0.65） %,which was consistent with theoretical content.Methotrexate sustained-release implants we made herein could maintain a sustained and controlled release up to 7 d in vitro release and 15 d in vivo release respectively.Compared withtraditional delivery system,methotrexate sustained-release implants prepared in this research were more effective in delaying tumor recurrence and prolonging the survival of mice and the implants could avoid some adverse effects.Conclusion：Hot-melting extrusion method can be applied successfully to fabricate methotrexate sustained-release implants,which have the advantages such as controlled slow-release and long-acting,and then can overcome some shortcomings and defects of the administration method of methotrexate,and might be a promising formulation for delaying local tumor recurrence.