Photothermal agents with good biocompatibility, high tumor accumulation efficiency, large-scale production ability, and low cost are crucial for potential photothermal treatment in clinic. Herein, we proposed a green and highly efficient strategy to fabricate a kilogram-scale alginate-Ca²⁺-Fe powder hydrogel (ALG-Ca²⁺-Fe) by turning commercial Fe powder into hydrogel for enhanced photothermal therapy. The ALG-Ca²⁺-Fe was formed by simply dispersing commercial Fe powder into the preformed alginate-Ca²⁺ hydrogel in a green and energy-/time-saving way. The hydrogel exhibited the advantages of ultrahigh loading capacity of Fe powder (>100 mg mL^–1), excellent large-scale production capacity (>1 kg in lab synthesis), low cost (<1.7 $/kg), and good injectability. More importantly, large size and hydrophobicity endowed Fe powder with excellent tumor retention effect and minimal diffusion to surrounding tissues, greatly benefiting improving treatment efficiency and reducing side effects. In vivo and in vitro studies both proved that the large-scale produced ALG-Ca²⁺-Fe can be used for highly efficient and biosafe tumor treatment in vivo by simple noninvasive injection. The developed ALG-Ca²⁺-Fe with multiple superiors opens up a novel green way to develop efficient and safe photothermal therapeutic agents with great clinic transformation potential.

中文翻译：

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绿色和千克级合成铁水凝胶用于体内光热疗法的肿瘤治疗

具有良好的生物相容性，高的肿瘤蓄积效率，大规模的生产能力和低成本的光热剂对于临床上潜在的光热治疗至关重要。在此，我们提出了一种绿色高效的策略，通过将商用铁粉制成水凝胶以增强光热疗法，来制造千克级藻酸盐-Ca ²⁺ -Fe粉末水凝胶（ALG-Ca ²⁺ -Fe）。ALG-Ca ²⁺ -Fe是通过以绿色且节能/省时的方式将市售Fe粉简单地分散到预制的藻酸盐-Ca ²⁺水凝胶中而形成的。水凝胶显示出超高的铁粉载量（> 100 mg mL ^{–1）的优势}），出色的大规模生产能力（实验室合成中大于1千克），低成本（<1.7美元/千克）和良好的可注射性。更重要的是，大尺寸和疏水性赋予了铁粉优异的肿瘤保留效果和最小的向周围组织的扩散，极大地提高了治疗效率并减少了副作用。体内和体外研究均证明，大规模生产的ALG-Ca ²⁺ -Fe可通过简单的非侵入性注射用于体内高效且生物安全的肿瘤治疗。具有多个上级的已开发ALG-Ca ²⁺ -Fe开辟了一种新颖的绿色途径，以开发具有巨大临床转化潜力的高效，安全的光热治疗剂。