Miao Zhao-Hua, Li Kai, Liu Pei-Ying, Li Zhenglin, Yang Huanjie, Zhao Qingliang, Chang Manli, Yang Qingzhu, Zhen Liang, Xu Cheng-Yan
School of Materials Science and Engineering, Harbin Institute of Technology, Harbin, 150001, P. R. China.
MOE Key Laboratory of Micro-System and Micro-Structures Manufacturing, Harbin Institute of Technology, Harbin, 150080, P. R. China.
Adv Healthc Mater. 2018 Apr;7(7):e1701202. doi: 10.1002/adhm.201701202. Epub 2018 Jan 15.
Humic acids, a major constituent of natural organic carbon resources, are naturally formed through the microbial biodegradation of animal and plant residues. Due to numerous physiologically active groups (phenol, carboxyl, and quinone), the biomedical applications of humic acid have been already investigated across different cultures for several centuries or even longer. In this work, sodium humate, the sodium salt of humic acid, is explored as phototheranostic agent for light-induced photoacoustic imaging and photothermal therapy based on intrinsic absorption in the near-infrared region. The purified colloidal sodium humate exhibits a high photothermal conversion efficiency up to 76.3%, much higher than that of the majority of state-of-the-art photothermal agents including gold nanorods, Cu S nanoparticles, antimonene quantum dots, and black phosphorus quantum dots, leading to obvious photoacoustic enhancement in vitro and in vivo. Besides, highly effective photothermal ablation of HeLa tumor is achieved through intratumoral injection. Impressively, sodium humate reveals ultralow toxicity at the cellular and animal levels. This work promises the great potential of humic acids as light-mediated theranostic agents, thus expanding the application scope of traditional humic acids in biomedical field.
腐殖酸是天然有机碳资源的主要成分，通过动植物残体的微生物生物降解自然形成。由于含有众多生理活性基团（酚基、羧基和醌基），几个世纪甚至更长时间以来，腐殖酸在不同文化背景下的生物医学应用一直受到研究。在这项工作中，腐殖酸钠，即腐殖酸的钠盐，基于其在近红外区域的固有吸收，被探索用作光声成像和光热治疗的光诊疗剂。纯化后的胶体腐殖酸钠表现出高达76.3%的高光热转换效率，远高于包括金纳米棒、硫化铜纳米颗粒、锑烯量子点和黑磷量子点在内的大多数现有光热剂，在体外和体内均导致明显的光声增强。此外，通过瘤内注射实现了对HeLa肿瘤的高效光热消融。令人印象深刻的是，腐殖酸钠在细胞和动物水平上显示出超低毒性。这项工作预示着腐殖酸作为光介导诊疗剂具有巨大潜力，从而扩大了传统腐殖酸在生物医学领域的应用范围。
