While magnetic resonance imaging contrast agents have potential in noninvasive image‐guided tumor treatment, further developments are needed to increase contrast, biodegradability, and safety. Here, novel engineered manganese‐eumelanin coordination nanocomposites (MnEMNPs) are developed via a facile one‐pot intrapolymerization doping (IPD) approach in aqueous solution, through simple chemical oxidation–polymerization of the 3,4‐dihydroxy‐DL‐phenylalanine precursor with potassium permanganate serving as the Mn source and an oxidant. The resulting MnEMNPs possess ultrahigh longitudinal relaxivity (r₁ value up to 60.8 mM⁻¹ s⁻¹ at 1.5 T) attributed to the high manganese doping efficiency (>10%) and geometrically confined conformation. Due to their high manganese chelation stability, excellent biocompatibility, and strong near‐infrared absorption, high‐performance longitudinal‐transverse (T₁‐T₂) dual‐modal magnetic resonance/photoacoustic imaging and photothermal tumor ablation are achieved. Furthermore, the hydrogen peroxide‐triggered decomposition behavior of MnEMNPs circumvents the poor biodegradation issue of many nanomaterials. This facile, convenient, economical, and efficient IPD strategy will open up new avenues for the development of high‐performance multifunctional theranostic nanoplatforms in bionanomedicine.

中文翻译：

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具有超高弛豫性的新型内聚合掺杂锰-双胍配位纳米复合材料及其在肿瘤治疗中的应用

尽管磁共振成像造影剂在无创图像引导的肿瘤治疗中具有潜力，但仍需要进一步发展以提高对比度，可生物降解性和安全性。在这里，通过在水溶液中通过简单的化学氧化-3,4-二羟基-DL-苯丙氨酸前体与钾的简单化学氧化聚合反应，开发了一种新型的工程化锰-双锰配位纳米复合物（MnEMNPs）。高锰酸盐用作锰源和氧化剂。所得的MnEMNP具有超高的纵向弛豫性（r ₁值高达60.8 mM ^-1 s ^-1在1.5 T时）归因于高锰掺杂效率（> 10％）和几何约束构象。由于它们具有高的锰螯合稳定性，出色的生物相容性和强大的近红外吸收能力，因此可以实现高性能的纵向（T ₁ -T ₂）双模态磁共振/光声成像和光热肿瘤消融。此外，MnEMNPs的过氧化氢触发的分解行为避免了许多纳米材料的不良生物降解问题。这种简便，便捷，经济和有效的IPD策略将为生物纳米药物中高性能多功能治疗药物纳米平台的开发开辟新途径。