Rationale: The synergism of new modalities alongside chemodynamic therapy into common chemotherapy has shown promising potential in clinical applications. This paper reports a tumor microenvironment-responsive nanosystem for chemodynamic/chemical synergistic therapy and magnetic resonance imaging (MRI). Methods: The biodegradable nanosystem is synthesized using a surface-modified chain transfer agent for surface-initiated living radical polymerization of the chemotherapeutic drug. Results: In this nanosystem, named CAMNSN@PSN38, the cycling time and solubility of the chemotherapeutic drug are improved. The nanoparticles delivered to tumor tissues gradually release the chemotherapeutic drug and Mn2+ through glutathione (GSH)-triggered biodegradation in the tumor microenvironment. SN38, the released chemotherapeutic drug, not only shows excellent chemical therapy effects but also improves the generation of H2O2. Furthermore, with the Fenton-like agent Mn2+, the generation of reactive oxygen species (ROS) is improved markedly. Finally, CAMNSN@PSN38 shows excellent inhibition of tumor growth in three colorectal cancer tumor models, with an improved accumulation of ROS and controlled release of SN38. Conclusions: The CAMNSN@PSN38-mediated chemodynamic/chemical synergistic therapy provides a promising paradigm for the treatment and MRI-guided therapy of colorectal cancer.

中文翻译：

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用于结直肠癌化学动力学/化学协同治疗诊断的肿瘤微环境响应纳米系统。

理由：新疗法与化学动力学疗法在普通化疗中的协同作用在临床应用中显示出巨大的潜力。本文报道了一种用于化学动力学/化学协同治疗和磁共振成像（MRI）的肿瘤微环境响应纳米系统。方法：使用表面改性链转移剂合成可生物降解的纳米系统，用于化疗药物的表面引发活性自由基聚合。结果：在这个名为 CAMNSN@PSN38 的纳米系统中，化疗药物的循环时间和溶解度得到了改善。递送到肿瘤组织的纳米粒子通过肿瘤微环境中谷胱甘肽（GSH）触发的生物降解逐渐释放化疗药物和Mn2+。已上市的化疗药物SN38不仅表现出优异的化疗效果，而且还提高了H2O2的生成。此外，使用类芬顿剂Mn2+，活性氧（ROS）的产生显着改善。最后，CAMSN@PSN38 在三种结直肠癌肿瘤模型中表现出出色的肿瘤生长抑制作用，并改善了 ROS 的积累和 SN38 的控制释放。结论：CAMSN@PSN38介导的化学动力学/化学协同疗法为结直肠癌的治疗和MRI引导治疗提供了一个有前景的范例。