A Ruthenium Nitrosyl-Functionalized Magnetic Nanoplatform with Near-Infrared Light-Controlled Nitric Oxide Delivery and Photothermal Effect for Enhanced Antitumor and Antibacterial Therapy.

Developing a spatiotemporal-controlled nitric oxide (NO) delivery nanoplatform is highly desirable for its biological applications as a tumor inhibitor and antibacterial agent. In this study, a novel multifunctional magnetic nanoplatform {FeO@PDA@Ru-NO@FA} () was developed for the near-infrared (NIR) light-controlled release of NO in which a ruthenium nitrosyl (Ru-NO) donor and a folic acid (FA)-directing group were covalently functionalized onto FeO@PDA. Nanoplatform preferentially accumulated in folate receptor-overexpressing cancer cell lines and magnetic field-guided tumor tissue, instantly released NO, and simultaneously produced a prominent photothermal effect upon 808 nm NIR light irradiation, leading to remarkable in vitro and in vivo antitumor efficacy. When nanoplatform was treated only once, the potential MRI contrast agent was sufficient to significantly inhibit or eliminate the tumor tissues in living mice, thus offering opportunities for future NO-involved multimodal cancer therapy. In addition, a NO delivery nanoplatform {FeO@PDA@Ru-NO} was imbedded in the matrix of a chitosan (CS)-poly(vinyl alcohol) (PVA) material to develop a hybrid thermosensitive CS-PVA/NO hydrogel. The CS-PVA/NO hydrogels demonstrated mild (<150 mW cm) NIR light-controlled NO delivery and thus produced an efficient antibacterial effect for both Gram-negative and Gram-positive . Therefore, these hydrogels have potential as antibacterial dressings for wound bacterial infection treatment.