Photoactive Oligomer with an Acceptor–Donor–Acceptor-Conjugated Structure for Single Near-Infrared Light-Triggered Photothermal/Photodynamic Synergistic Therapy of Tumors

Phototherapy is attracting increasing attention as a noninvasive, safe, and effective therapeutic modality for tumors. Especially, it is expected to achieve better therapeutic efficacy, fewer side effect, and deeper tissue penetration by the combination of photothermal (PTT) and photodynamic (PDT) under single near-infrared (NIR) light irradiation. For this purpose, herein, we develop a photoactive acceptor (A)–donor (D)–acceptor (A)-type conjugated oligomer (UF-TTOEH-2Cl). A NIR light-responsive nanoplatform (UTNPs) was fabricated based on UF-TTOEH-2Cl, and a folic acid-functionalized amphiphilic block copolymer (FA-PEG-PBLA10) was prepared as the polymer matrix through a nanoprecipitation method, which showed a high photothermal conversion efficiency (42%) and singlet oxygen (1O2) quantum yield (ΦΔ = 17.2%) under 880 nm laser irradiation. Furthermore, efficient UTNPs-based PDT/PTT synergistic therapy of tumors was demonstrated utilizing HeLa and SiHa cells as the models in vitro.