Natural proteins have been greatly explored to address unmet medical needs. However, few work has treated proteins as natural pH-sensitive nanoplatforms that make use of the inherent pH gradient of pathogenic sites. Here, hemoglobin is employed as a smart pH-sensitive nanocarrier for near-infrared dye IR780, which disperses well at normal tissue pH and exhibits aggregation at tumor acidic milieu. The pH-sensitive hemoglobin loaded with IR780 shows higher uptake by cancer cells at tumor acidic pH 6.5 than normal tissue pH 7.4. In vivo and ex vivo studies reveal that the hemoglobin nanocarrier exhibits distinct retention kinetics with remarkably prolonged residence time in tumor. Hemoglobin is then proved to be a potent pH-sensitive nanocarrier for cancer diagnosis and treatment.

中文翻译：

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血红蛋白作为一种智能的pH敏感纳米载体，可实现聚集增强的肿瘤保留

天然蛋白质已被广泛研究以解决未满足的医学需求。然而，很少有工作将蛋白质视为利用病原体固有的pH梯度的天然pH敏感纳米平台。在这里，血红蛋白被用作近红外染料IR780的智能pH敏感纳米载体，它在正常组织pH值下很好地分散并且在肿瘤酸性环境中表现出聚集。载有IR780的对pH敏感的血红蛋白在癌细胞的酸性pH 6.5下显示比正常组织pH 7.4更高的癌细胞摄取。体内和离体研究表明，血红蛋白纳米载体表现出独特的保留动力学，在肿瘤中的停留时间显着延长。然后证明血红蛋白是一种有效的pH敏感的纳米载体，可用于癌症的诊断和治疗。