Engineered Exosome-Mediated Near-Infrared-II Region VC Quantum Dot Delivery for Nucleus-Target Low-Temperature Photothermal Therapy.

The limited penetration depth of photothermal agents (PTAs) active in the NIR-I biowindow and the thermoresistance caused by heat shock protein (HSP) significantly limit the therapeutic efficiency of photothermal therapy (PTT). To address the problem, we introduce a strategy of low-temperature nucleus-targeted PTT in the NIR-II region achieving effective tumor killing by combining the vanadium carbide quantum dots (VC QDs) PTA and an engineered exosomes (Ex) vector. The small fluorescent VC QDs with good photothermal effect in the NIR-II region were modified with TAT peptides and packaged into Ex with RGD modification (VC-TAT@Ex-RGD). The resulting nanoparticles (NPs) exhibited good biocompatibility, long circulation time, and endosomal escape ability, and they could target the cell and enter into the nucleus to realize low-temperature PTT with advanced tumor destruction efficiency. The fluorescent imaging, photoacoustic imaging (PAI), and magnetic resonance imaging (MRI) capability of the NPs were also revealed. The low-temperature nucleus-targeted PTT in the NIR-II region provides more possibilities toward successful clinical application of PTT.