Single 808 nm near‐infrared‐triggered multifunctional upconverting phototheranostic nanocomposite for imaging‐guided high‐efficiency treatment of tumors

Abstract Multifunctional phototheranostic nanocomposites are promising for early diagnosis and precision therapy of cancer. Aim to enhance their accuracy and efficiency, in this study, we develop a single‐laser excited activatable phototheranostic nanocomposite (UCNPs‐D‐MQ): 808 nm‐excited upconverting nanoparticles (UCNPs) as the matrix programmed assembly with amphipathic compound DSPE‐PEG‐COOH, a near‐infrared absorbing polymer DPP and the pro‐photosensitizer MBQB. Upon endocytosed by cancer cells and excited by the 808 nm laser, UCNPs‐D‐MQ could produce high‐yield reactive oxygen species (ROS) as the results of singlet oxygen generation from transferring to methylene blue, GSH depletion and ROS generation from photoactivation. It was proven both in vitro and in vivo that the nanocomposites exhibits remarkable therapeutic efficacy as well as minimal photodamage to normal cells. These results reveal UCNPs‐D‐MQ as a robust theranostic agent for tumor phototherapy.