Department of Pharmaceutical Sciences and Experimental Therapeutics, College of Pharmacy, The University of Iowa, Iowa City, Iowa 52242, United States.
Department of Surgery, University of Iowa, Iowa City, Iowa 52242, United States.
ACS Biomater Sci Eng. 2020 May 11;6(5):2659-2667. doi: 10.1021/acsbiomaterials.9b01108. Epub 2019 Dec 20.
Doxorubicin (DOX) has been widely used for the treatment of various cancers, however, the use of soluble DOX is limited by its low therapeutic index and improved formulations are therefore sought. Aside from its tumoricidal properties, DOX has also been shown to cause an immunogenic form of cell death, however, it is becoming abundantly clear that in situ immune stimulation alone is insufficient to cause significant immune based antitumor activity and that immune checkpoint modulation is also required. In this study, DOX-loaded nanoparticles were made by nanoprecipitation of DOX with a PEGylated poly(lactide--glycolide) copolymer (DOX-PLGA-PEG NPs) and were then tested in combination with immune checkpoint blockade (antiprogrammed death (anti-PD-1)) in a murine melanoma model to enhance antitumor effectiveness. Results showed the prepared particles to be approximately 134 nm in diameter (zeta potential -22 mV) with a loading of 1.75 μg DOX/mg NPs. In vitro release studies (of DOX) revealed the NPs to exhibit a 12 h burst release phase, followed by a slower release phase for up to 200 h. Survival studies of mice challenged with B16.F10 melanoma cells, revealed 60% of mice treated with the combination of DOX-PLGA-PEG NPs plus anti-PD-1 were tumor-free at the completion of the study. This combination therapy demonstrated higher antitumor efficacy in vivo compared to control, soluble DOX, and monotherapy of DOX-PLGA-PEG NPs or anti-PD-1 solution ( < 0.05). Moreover, in vivo safety studies (mouse weight/histopathological/toxicity) were investigated and results suggested that the combination therapy was safe. In conclusion, this study demonstrates the successful fabrication of DOX-loaded NPs by a nanoprecipitation method, and when combined with checkpoint inhibition could provide significant therapy in a murine melanoma model, suggesting that the DOX-PLGA-PEG NPs may be generating immune stimulation in situ and that benefit from this combination may be obtained in a clinical setting in the future.
阿霉素（DOX）已被广泛用于治疗各种癌症，然而，可溶性 DOX 的使用受到其治疗指数低的限制，因此寻求改进的制剂。除了其杀肿瘤特性外，DOX 还被证明会引起免疫原性细胞死亡形式，但是，越来越明显的是，单独原位免疫刺激不足以引起明显的基于免疫的抗肿瘤活性，还需要免疫检查点调节。在这项研究中，通过 DOX 与聚乙二醇化聚（乳酸-共-乙醇酸）共聚物（DOX-PLGA-PEG NPs）的纳米沉淀制备了 DOX 负载的纳米颗粒，然后在小鼠黑色素瘤模型中与免疫检查点阻断（抗程序性死亡（抗 PD-1））联合测试，以增强抗肿瘤效果。结果表明，所制备的颗粒直径约为 134nm（ζ电位-22mV），载药量为 1.75μg DOX/mg NPs。体外释放研究（DOX）表明，纳米颗粒表现出 12 小时的突释相，随后在长达 200 小时内释放缓慢。用 B16.F10 黑色素瘤细胞挑战的小鼠的存活研究表明，在研究结束时，接受 DOX-PLGA-PEG NPs 加抗 PD-1 联合治疗的 60%的小鼠无肿瘤。与对照、可溶性 DOX 以及 DOX-PLGA-PEG NPs 或抗 PD-1 溶液的单一疗法相比，这种联合疗法在体内显示出更高的抗肿瘤疗效（<0.05）。此外，还进行了体内安全性研究（小鼠体重/组织病理学/毒性），结果表明联合治疗是安全的。总之，本研究通过纳米沉淀法成功制备了 DOX 负载的纳米颗粒，当与检查点抑制联合使用时，可为小鼠黑色素瘤模型提供显著的治疗效果，这表明 DOX-PLGA-PEG NPs 可能在原位产生免疫刺激，并且未来在临床环境中可能会从中受益。
