Dual-functional carbon dot-labeled heavy-chain ferritin for self-targeting bio-imaging and chemo-photodynamic therapy.

Image-guided cancer nanotheranostics with a simple nano-platform are seriously significant for nanomedicine. In this study, a novel design is described to achieve sensitive bio-imaging and effective treatment by utilizing heavy-chain ferritin (HFn) nanocages as a vector coupled with dual-functional carbon dots (CDs) on the surface of ferritin and encapsulating the chemotherapeutic drug doxorubicin (DOX). The CDs obtained herein emit bright fluorescence in the red region, which can be applied to bio-imaging in vivo. More significantly, the CDs can produce reactive oxygen species (ROS) under laser irradiation at 532 nm and cause damage to the DNA in the nucleus. These unique properties enabled CDs to act as a theranostic agent. Owing to the self-targeting ability of HFn, the final nanoparticles can internalize into cancer cells more efficiently. The nanoparticles can translocate into the nucleus after DNA damage resulting from the partial release of DOX into the cytoplasm, thereby increasing the nuclear delivery of the drug. The results of this study indicate that the multifunctional HFn(DOX)/CD nanoparticles have potential as a clinically available cancer theranostic agent to deliver diagnostic agents and therapeutic drugs into the cancer cells and thus provide a noninvasive, highly sensitive imaging approach and guidance to the chemo-photodynamic therapy simultaneously.