In this work, we report on biodegradable eumelanin–Fe₃O₄ hybrid nanoparticles (euMel–Fe₃O₄ NPs) for multiple imaging-assisted local photothermolysis. The euMel–Fe₃O₄ NPs are rationally prepared via a facile one-step co-precipitation method in the aqueous phase in the presence of eumelanin. The obtained NPs exhibited high stability and aqueous dispersity. euMel–Fe₃O₄ NPs could provide T₂-weighted magnetic resonance (MR) and photoacoustic (PA) imaging contrast enhancement prior to the treatment, due to their high r₂ relaxivity that was determined to be 245.88 mM⁻¹ s⁻¹ (a value higher than those for other commercially available iron oxide NPs) and good PA signal intensity. Besides, with effective NIR absorbance, the euMel–Fe₃O₄ NPs promoted an effective photothermolysis treatment in an experimental mouse model of cancer. Cytotoxicity and in vivo histological examination demonstrated no appreciable toxicity. Our work suggests that euMel–Fe₃O₄ NPs could be proposed as a potential class of theranostic nanoplatform with multiple imaging modalities for cancer therapy.

中文翻译：

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Eumelanin–Fe ₃ O ₄杂化纳米颗粒，用于增强MR / PA成像辅助的局部光热解消†

在这项工作中，我们报告了可生物降解的Eumelanin–Fe ₃ O ₄杂化纳米颗粒（euMel–Fe ₃ O ₄ NPs）用于多重成像辅助的局部光热解。euMel–Fe ₃ O ₄ NPs是通过一种简单的一步共沉淀方法在存在双氯乙烯的水相中合理制备的。所获得的NP显示出高稳定性和水分散性。euMel–Fe ₃ O ₄ NPs由于其较高的r _2值，可在治疗前增强T ₂加权磁共振（MR）和光声（PA）成像对比度确定为245.88 mM ^-1 s ^-1（比其他市售氧化铁NP高的值）和良好的PA信号强度。此外，通过有效的NIR吸收，euMel–Fe ₃ O ₄ NP在实验性癌症小鼠模型中促进了有效的光热解治疗。细胞毒性和体内组织学检查均未显示明显毒性。我们的工作表明，可以将euMel–Fe ₃ O ₄ NPs作为具有多种成像方式的恶性肿瘤治疗纳米平台的一种，用于癌症治疗。