Nanotechnology in medicine has greatly expanded the therapeutic strategy that may be explored for cancer treatment by exploiting the specific tumor microenvironment such as mild acidity, high glutathione (GSH) concentration and overproduced hydrogen peroxide (H2O2). Among them, tumor microenvironment responsive chemodynamic therapy (CDT) utilized the Fenton or Fenton-like reaction to produce excess hydroxyl radical (·OH) for the destruction of tumor cells. However, the produced ·OH is easily depleted by the excess GSH in tumors, which would undoubtedly impair the CDT’s efficiency. To overcome this obstacle and enhance the treatment efficiency, we design the nanoplatforms for magnetic resonance imaging (MRI)-guided CDT. In this study, we applied the bovine serum albumin (BSA)-templated CuS:Gd nanoparticles (CuS:Gd NPs) for MRI-guided CDT. The Cu2+ in the CuS:Gd NPs could be reduced to Cu+ by GSH in tumors, which further reacted with H2O2 and triggered Fenton-like reaction to simultaneously generate abundant ·OH and deplete GSH for tumor enhanced CDT. Besides, the Gd3+ in CuS:Gd NPs endowed them with excellent MRI capability, which could be used to locate the tumor site and monitor the therapy process preliminarily. The designed nanoplatforms offer a major step forward in CDT for effective treatment of tumors guided by MRI.

中文翻译：

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用于磁共振成像引导化学动力学治疗的牛血清白蛋白模板纳米平台

医学中的纳米技术通过利用特定的肿瘤微环境，如温和的酸性、高谷胱甘肽（GSH）浓度和过量产生的过氧化氢（H2O2），极大地扩展了可探索的癌症治疗策略。其中，肿瘤微环境响应化学动力学疗法（CDT）利用芬顿或类芬顿反应产生过量的羟自由基（·OH）来破坏肿瘤细胞。然而，产生的·OH很容易被肿瘤中过量的GSH耗尽，这无疑会损害CDT的效率。为了克服这一障碍并提高治疗效率，我们设计了用于磁共振成像（MRI）引导的 CDT 的纳米平台。在这项研究中，我们应用牛血清白蛋白 (BSA) 模板的 CuS:Gd 纳米颗粒 (CuS:​​Gd NPs) 进行 MRI 引导的 CDT。CuS:Gd NPs 中的 Cu2+ 可以被肿瘤中的 GSH 还原为 Cu+，进一步与 H2O2 反应并引发类 Fenton 反应，同时产生丰富的·OH 并消耗 GSH，从而增强肿瘤的 CDT。此外，CuS:Gd NPs中的Gd3+赋予它们优异的MRI能力，可用于定位肿瘤部位并初步监测治疗过程。设计的纳米平台在 MRI 引导下的 CDT 有效治疗肿瘤方面向前迈出了重要一步。