Polyamidoamine Dendrimer-Modified Near Infrared-II Fluorescent Conjugated Polymer Brush for Photodynamic/Gas Therapy

The short lifespan of reactive oxygen species (ROS) and hypoxia nature of solid tumor severely impede the therapeutic efficacy of photodynamic therapy (PDT). To overcome this challenge, the light-triggered PDT/carbon monoxide (CO) gas therapy synergistic systems have received considerable attention. However, the development of single organic material-based multifunctional nanoplatforms for NIR-II fluorescence imaging (NIR-II FI) and synergistic PDT/CO gas therapy remains a challenge. Herein, a multifunctional NIR-II FI/PDT/CO gas therapy conjugated polymer brush (PBF-g-CO/PEG) was established by covalent conjugation of CO donors (CORM-401) onto a water-soluble polyamidoamine dendrimer-modified NIR-II fluorophore (PBF-AM3). The electron-rich polyamidoamine dendrimer-modified PBF-AM3 could be irradiated with 660 nm light to efficiently produce ROS and trigger CO release from CORM-401 inducing cancer cell apoptosis. Importantly, under the guidance of NIR-II FI, the PBF-g-CO/PEG polymer demonstrates superior in vivo anticancer efficacy by the combination of photodynamic and CO gas therapy. The remarkable anticancer efficacy and admirable biocompatibility endow PBF-g-CO/PEG with great potential for precision cancer therapy.