Spacer Twisting Strategy to Realize Ultrabright Near-Infrared II Polymer Nanoparticles for Fluorescence Imaging-Guided Tumor Phototheranostics

作者：Yifan Wu, Han Yu, Chunbin Li, Lingxiu Liu, Yue Zhang, Jianye Gong, Renmanduhu Sha, Lina Feng, He Yan, Guoyu Jiang, Jianguo Wang, Ben Zhong Tang · 发表于：ACS Nano · 年份：2024 · DOI：10.1021/acsnano.4c07896 · 被引用次数：23 · 研究领域：Nanoplatforms for cancer theranostics、Photoacoustic and Ultrasonic Imaging、Luminescence and Fluorescent Materials

Conjugated polymers are becoming popular near-infrared II (NIR-II) phototheranostic agents (PTAs) due to their numerous advantages, such as high photostability, large molar extinction coefficients, and excellent photothermal properties. However, the strong π-π interactions between the chains of the conjugated polymers resulted in their generally low NIR-II emission quantum yields (QY). Therefore, the synthesis of conjugated polymers with high QY is an interesting but challenging task. Herein, we proposed a spacer twisting strategy to realize ultrabright NIR-II polymer nanoparticles for fluorescence imaging-guided tumor phototheranostics. Theoretical calculations indicated that the polymer PY-IT has the largest dihedral angle between the largely π-conjugated skeleton and the spacer, which can effectively inhibit intermolecular π-π stacking, resulting in an improved QY as high as 16.5% in nanoparticles. In addition, PY-IT NPs can effectively perform NIR-II imaging and photothermal treatment of tumors. The work presents some valuable guides for achieving ultrabright NIR-II polymeric PTAs with high QY.