Assembling AgAuSe Quantum Dots with Peptidoglycan and Neutrophils to Realize Enhanced Tumor Targeting, NIR (II) Imaging, and Sonodynamic Therapy.

Significant progress is made in drug delivery systems, but they still face problems such as poor stability in vivo, off-target drugs, and difficulty in crossing biological barriers. It is urgent to realize efficient targeted delivery and precisely controlled sustained release of drugs by using the integrated nanoplatform. Theranostic nanoplatform is a new biomedical technology that combines diagnosis or monitoring of diseases with treatment. Here, an integrated strategy of diagnosis and treatment is reported for delivering NIR-II imaged and therapeutic AgAuSe quantum dots (QDs) carried by peptidoglycan multilayer networks of bacteria to hitchhike circulating neutrophils for targeting the tumor. The assembled nanomaterials have good stability, which can not only initiate endogenous cells for drug delivery and achieve efficient targeting, but also guide drug imaging with excellent fluorescence property. Meanwhile, the elimination of established solid tumor is achieved with the administration of sonodynamic therapy without recurrence. This drug system expands the application of endogenous cell to participate in drug delivery system. Thus, the assembly strategy demonstrates the potential of endogenous neutrophils in functioning as natural drug vehicles and the application of NIR-II fluorescent QDs in biomedical engineering.