Key Laboratory for Organic Electronics and Information Displays & Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM) , Nanjing University of Posts & Telecommunications , 9 Wen yuan Road , Nanjing 210023 , China.
Shaanxi Institute of Flexible Electronics (SIFE) , Northwestern Polytechnical University (NPU) , Xi'an 710072 , P. R. China.
ACS Appl Mater Interfaces. 2018 May 16;10(19):16299-16307. doi: 10.1021/acsami.8b03568. Epub 2018 May 1.
Photothermal therapy (PTT) as a kind of noninvasive tumor treatment has attracted increasing research interest. However, the efficiency of existing PTT agents in the near-infrared (NIR) region is the major problem that has hindered further development of PTT. Herein, we present an effective strategy to construct the efficient photothermal agent by utilizing an intramolecular photoinduced electron transfer (PeT) mechanism, which is able to dramatically improve photothermal conversion efficiency in the NIR region. Specifically, an NIR dye (A1) constructed with dimethylamine moiety as the electron donor and the aza-BODIPY core as the electron acceptor is designed and synthesized, which can be used as a class of imaging-guided PTT agents via intramolecular PeT. After encapsulation with biodegradable polymer DSPE-mPEG, nanophotothermal agents with a small size exhibit excellent water solubility, photostability, and long-time retention in tumor. Importantly, such nanoparticles exhibit excellent photothermal conversion efficiency of ∼35.0%, and the PTT effect in vivo still remains very well even with a low dosage of 0.05 mg kg upon 808 nm NIR laser irradiation (0.5 W cm). Therefore, this reasonable design via intramolecular PeT offers guidance to construct excellent photothermal agents and subsequently may provide a novel opportunity for future clinical cancer treatment.
光热疗法（PTT）作为一种非侵入性的肿瘤治疗方法，引起了越来越多的研究兴趣。然而，现有近红外（NIR）区域 PTT 试剂的效率是阻碍 PTT 进一步发展的主要问题。在此，我们提出了一种利用分子内光诱导电子转移（PeT）机制构建高效光热剂的有效策略，该策略能够显著提高 NIR 区域的光热转换效率。具体而言，设计并合成了一种带有二甲胺部分作为电子给体和aza-BODIPY 核作为电子受体的 NIR 染料（A1），可通过分子内 PeT 用作一类成像引导的 PTT 试剂。用可生物降解的聚合物 DSPE-mPEG 包封后，纳米光热剂具有较小的尺寸，表现出优异的水溶性、光稳定性和在肿瘤中的长时间保留性。重要的是，这些纳米粒子表现出优异的光热转换效率约为 35.0%，并且即使在 808nmNIR 激光照射（0.5Wcm）下以 0.05mgkg 的低剂量进行治疗，体内的 PTT 效果仍然非常好。因此，这种通过分子内 PeT 的合理设计为构建优异的光热试剂提供了指导，并为未来的临床癌症治疗提供了新的机会。
