Photothermally Responsive Conjugated Polymeric Singlet Oxygen Carrier for Phase Change-Controlled and Sustainable Phototherapy for Hypoxic Tumor
Li Guo, Ruyi Zhou, Weili Zhao, Bo Yu, Jie Zhou, Shujuan Liu, Wei Huang, Qiang Zhao
Abstract
Hypoxia significantly compromises the therapeutic performance of photodynamic therapy (PDT) owing to the oxygen level which plays a key role in the production of singlet oxygen ( 1 O 2 ). Herein, the photothermally responsive phase change materials (PCM) are used to encapsulate 1,4-dimethylnaphthalene-functionalized platinum(II)-acetylide conjugated polymer (CP1) with intense near-infrared (NIR) absorption to prepare new 1 O 2 nanocarriers (CP1-NCs). The 1,4-dimethylnaphthalene moieties in CP1-NCs can trap the 1 O 2 produced from CP1 under irradiation and form a stable endoperoxide. Then, the endoperoxide undergoes cycloreversion to controllably release 1 O 2 via the NIR light-triggered photothermal effect of CP1 and controllable phase change of PCM, which can be used for oxygen-independent PDT for hypoxic tumor. Furthermore, the in vivo luminescence imaging-guided synergistic PDT and photothermal therapy showed better efficiency in tumor ablation. The smart design shows the potent promise of CP1-NCs in PCM-controlled and sustainable phototherapy under tumor hypoxic microenvironment, providing new insights for constructing oxygen-independent precise cancer phototherapeutic platform.