The applications of inorganic theranostic agents in clinical trials are generally limited to their innate non-biodegradability and potential long-term biotoxicity. To address this problem, herein via a straightforward and tailored space-confined on-substrate route, we obtained rhenium trioxide (ReO₃) nanocubes (NCs) that display a good biocompatibility and biosafety. Importantly, their aqueous dispersion has high localized surface plasmon resonance (LSPR) absorbance in near-infrared (NIR) region different from previous report, which possibly associates with the charge transfer and structural distortion in hydrogen rhenium bronze (H_xReO₃), as well as ReO₃'s cubic shape. Such a high LSPR absorbance in the NIR region endows them with photoacoustic (PA)/infrared (IR) thermal imaging, and high photothermal conversion efficiency (∼57.0%) for efficient ablation of cancer cells. Also, ReO₃ NCs show X-ray computed tomography (CT) imaging derived from the high-Z element Re. More attractively, those ReO₃ NCs, with pH-dependent oxidized degradation behaviors, are revealed to be relatively stable in hypoxic and weakly acidic microenvironment of tumor for imaging and treatment whilst degradable in normal physiological environments of organs to enable effective clearance. In spite of their degradability, ReO₃ NCs still possess tumor targeting capabilities. We thus develop a simple but powerful, safe and biodegradable inorganic theranostic platform to achieve PA/CT/IR imaging-guided cancer photothermal therapy (PTT) for improved therapeutic efficacy and decreased toxic side effects.

无机治疗药物在临床试验中的应用通常仅限于其固有的非生物降解性和潜在的长期生物毒性。为了解决这个问题，本文中通过直接且量身定制的在空间上受限的基板上路线，我们获得了显示出良好的生物相容性和生物安全性的三氧化Re（ReO ₃）纳米立方（NC）。重要的是，它们的水分散体在近红外（NIR）区域具有较高的局部表面等离振子共振（LSPR）吸光度，这与以前的报道不同，这可能与氢rh青铜（H _x ReO ₃）中的电荷转移和结构变形有关。以及ReO ₃的立方形状。NIR区域如此高的LSPR吸光度使它们具有光声（PA）/红外（IR）热成像功能，以及高的光热转换效率（〜57.0％），可有效消融癌细胞。同样，ReO ₃ NCs显示了来自高Z元素Re的X射线计算机断层扫描（CT）成像。更具吸引力的是，那些具有pH依赖性氧化降解行为的ReO ₃ NCs在低氧和弱酸性的肿瘤微环境中显像和治疗时相对稳定，而在正常的器官生理环境中可降解以实现有效清除。尽管具有降解性，但ReO ₃NCs仍然具有肿瘤靶向能力。因此，我们开发了一个简单但功能强大，安全且可生物降解的无机治疗平台，以实现PA / CT / IR成像引导的癌症光热疗法（PTT），以提高治疗效果并减少毒副作用。