RuNO-Thnl-loaded nanoplatform excited by 808 nm near-infrared light for gas release

Förster energy resonance transfer (FRET) refers to a type of non-radiative energy transfer between two chromophores. In addition to the distance between the donor and acceptor, it depends on the extent of overlap between the fluorescence spectrum of the donor and the absorption spectrum of the acceptor. Based on the principle of FRET, in this study, NIR-responsive nanoplatforms comprising up-conversion nanoparticles (UCNPs)@mSiO2&RuNO-Thnl were designed for the targeted and controllable release of NO. First, core–shell UCNPs were prepared by the thermal decomposition method and then coated with a mesoporous silica layer by surface modification. The prepared [email protected]2 was excited by NIR at 808 nm, which avoided the overheating of Yb3+ and increased the penetration depth; in addition, it imparted drug-loading capability and biocompatibility to the UCNPs. Subsequently, RuNO-Thnl and [email protected]2 were combined using van der Waals forces. Furthermore, [email protected]2 converted 808 nm NIR laser irradiation into ultraviolet light or visible light, thereby exciting RuNO-Thnl for the effective local release of NO. The results showed that this NO release platform can release 0.0012–0.0037 μmol/mL of NO gas when the concentration of the solution containing the nanoplatform is in the range of 0.15–0.8 mg/mL, allowing for concentration-controlled NO release on demand. Importantly, the temperature changes generated during the conversion process were not harmful to cells and tissues. This targeted and controlled release approach has broad application prospects in NO-based medical therapy.