The iron-based Fenton-type reaction has drawn tremendous attention in cancer therapy. Compared with oxidized iron, Fe(0) possesses high catalytic activity but unstable for biomedical application. Here, we report a new strategy to stabilize Fe(0) via a porous yolk shell nanostructure of Fe/Fe₃O₄ (PYSNPs) in normal physiological condition, and to control the release of Fe(0) in tumor microenvironment for enhanced cancer therapy. These PYSNPs display superior tumor inhibition with the IC₅₀ down to 20 μg/mL (over 1 mg/mL for iron oxide nanoparticles as control) for HepG2 cell. A single intravenous injection of as low as 1 mg/kg dosage is effective to suppress tumor growth in vivo. Moreover, the disintegration of PYSNPs in the acidic tumor microenvironment could cause significant change in MRI signal for contrast-enhanced diagnosis. Of note, the resulting Fe₃O₄ fragments are renal clearable with minimized side effect. In all, this work represented a nanoplatform to stabilize and selectively deliver Fe(0) for highly effective cancer therapy.

铁基芬顿型反应在癌症治疗中引起了极大的关注。与氧化铁相比，Fe（0）具有较高的催化活性，但对生物医学应用不稳定。在这里，我们报告了一种新的策略，通过正常生理条件下的Fe / Fe ₃ O ₄（PYSNPs）的卵黄壳纳米结构稳定Fe（0），并控制肿瘤微环境中Fe（0）的释放，以增强癌症治疗。这些PYSNP对HepG2细胞显示出优异的肿瘤抑制性，IC ₅₀降至20μg/ mL（作为对照的氧化铁纳米颗粒为1 mg / mL以上）。低至1 mg / kg剂量的单次静脉注射可有效抑制体内肿瘤生长。此外，酸性肿瘤微环境中PYSNPs的分解可能会导致MRI信号的显着变化，从而增强造影剂的诊断能力。值得注意的是，所得的Fe ₃ O ₄片段可通过肾脏清除，且副作用最小。总而言之，这项工作代表了一种纳米平台，可以稳定并选择性地递送Fe（0）用于高效的癌症治疗。