Cheng Quan, Tian Youliang, Dang Huiping, Teng Changchang, Xie Kai, Yin Dalong, Yan Lifeng
Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei, 230026, China.
Department of Hepatobiliary Surgery, The First Affiliated Hospital, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230036, China.
Adv Healthc Mater. 2022 Jan;11(1):e2101697. doi: 10.1002/adhm.202101697. Epub 2021 Oct 8.
Most NIR-II fluorescent dyes, especially polymethine cyanine, face the inevitable self-quenching phenomenon in an aqueous solution. This unacceptable property has severely limited their application in high-resolution biological imaging. Here, a NIR-II macromolecular probe (MPAE) is synthesized through the structure modification of molecule probe and the covalent coupling of an amphiphilic polypeptide, which presents considerable biocompatibility and negligible systemic side effect. The molecule probe's stereo structure and the polymer's conjugation could effectively prevent the π-π stacking, thereby exhibiting excellent quenching resistance in aqueous solutions (absolute QY = 0.178%). This remarkable feature endows it with deeper tissue penetration than the clinically used indocyanine green (ICG) and high contrast brightness at the tumor site for the NIR-II fluorescence imaging. Based on the effective accumulation of tumor sites and considerable photothermal conversion efficiency (40.07%), the MPAE-NPS presents superior antitumor efficiency on breast tumor-bearing mice under the 1064 nm irradiation without rebound or recurrence. All these outstanding performances reveal the great promise of MPAE-NPS in Nano-drug delivery and imaging-assisted photothermal therapy in the NIR-II window.
大多数近红外二区（NIR-II）荧光染料，尤其是聚甲炔菁染料，在水溶液中会不可避免地出现自猝灭现象。这种难以接受的特性严重限制了它们在高分辨率生物成像中的应用。在此，通过分子探针的结构修饰和两亲性多肽的共价偶联合成了一种近红外二区大分子探针（MPAE），其具有相当好的生物相容性且全身副作用可忽略不计。分子探针的立体结构和聚合物的共轭作用能够有效防止π-π堆积，从而在水溶液中表现出优异的抗猝灭性能（绝对量子产率 = 0.178%）。这一显著特性使其在近红外二区荧光成像中比临床使用的吲哚菁绿（ICG）具有更深的组织穿透能力以及在肿瘤部位具有高对比度亮度。基于肿瘤部位的有效富集和可观的光热转换效率（40.07%），MPAE-NPS在1064 nm激光照射下对荷乳腺肿瘤小鼠表现出卓越的抗肿瘤效果，且无反弹或复发。所有这些优异性能揭示了MPAE-NPS在近红外二区窗口的纳米药物递送和成像辅助光热治疗方面具有巨大潜力。
