Photothermal agents with improved bioavailabilities can generate heat from near-infrared light, which has been efficiently used for in vivo photothermal therapy (PTT) for cancer, with minimum tissue invasion. Strategies for developing organic near-infrared-absorbing molecules for photothermal cancer therapy have drawn intensive attention among academic investigators. However, conventional organic near-infrared-absorbing molecules may not only have complex synthesis procedures, but also easily suffer from photobleaching under light irradiation. These drawbacks might lead to an increase in the synthesis cost, and elicit a risk of side effects in PTT. Thus, it is essential to devise an organic photothermal agent with stable photothermal capacity, which involves a facile synthesis process. In this study, incorporating a secondary amine group (donor) in the bay regions of perylenediimides (PDIs) could lead to a 150-nm bathochromic shift of the absorption maximum. Next, a modification of poly(ethylene glycol) (PEG) at the periphery of the chromophore renders the targeted macromolecule PDI-PEG highly water-soluble, and capable of intense absorption in the near-infrared region. The self-assembled PDI-based nanoparticles (PDI-NPs) have a size of 55 nm in aqueous solutions. PDI-NPs with excellent photostability possess a high photothermal conversion efficiency of up to 43% ± 2%. Finally, PDI-NPs allow for efficient in vitro and in vivo photothermal cancer therapy. Meanwhile, PDI-NPs exhibit quite low cytotoxicity and no biotoxicity on major organs in vivo. Thus, these easily-manufactured PDI-NPs can serve as extremely stable photothermal agents for efficient photothermal cancer therapy.

具有改进的生物利用度的光热剂可以从近红外光中产生热量，这已被有效地用于癌症的体内光热疗法（PTT），并且组织侵入最小。开发用于光热癌症治疗的有机近红外吸收分子的策略引起了学术研究人员的广泛关注。然而，传统的有机近红外吸收分子不仅合成过程复杂，而且在光照射下容易发生光漂白。这些缺点可能导致合成成本增加，并在 PTT 中引发副作用风险。因此，设计一种光热容量稳定、合成过程简单的有机光热剂是十分必要的。在这项研究中，在苝二酰亚胺 (PDI) 的湾区加入仲胺基团（供体）可能导致吸收最大值发生 150 nm 的红移。接下来，发色团外围聚乙二醇 (PEG) 的修饰使目标大分子 PDI-PEG 高度水溶，并且能够在近红外区域强烈吸收。自组装的基于 PDI 的纳米粒子 (PDI-NPs) 在水溶液中的尺寸为 55 nm。具有优异光稳定性的 PDI-NPs 具有高达 43% ± 2% 的高光热转换效率。最后，PDI-NPs 允许有效的体外和体内光热癌症治疗。同时，PDI-NPs 表现出相当低的细胞毒性，并且对体内主要器官没有生物毒性。因此，