A Dual-Functional Theranostic Perovskite-Nitro Ruthenium(II) Complex Nanoplatform for X-Ray-Triggered ROS Generation and NO Release

X-ray-induced photodynamic therapy (X-PDT) has emerged as a promising strategy for treating deep-seated tumors. In this work, we present a dual-functional nanoplatform consisting of a CsPbBr₃ perovskite scintillator embedded in mesoporous silica (SiO₂@CsPbBr₃) and covalently functionalized with a nitro ruthenium(II) complex (SiO₂−NH₂−RuNO₂@CsPbBr₃), combining improved biocompatibility and stability with controlled nitric oxide (NO) release under light and X-ray irradiation. The nanoplatform retained photoluminescence and radioluminescence at 515 nm in aqueous media. XRD confirmed cubic CsPbBr₃, while TEM revealed spherical silica nanoparticles containing the perovskite. APTES functionalization was verified by the zeta potential shift, and NTA showed a mean diameter of 148.8 nm for NO₂-conjugated nanoplatform. Under X-ray irradiation, SiO₂@CsPbBr₃ generated singlet oxygen, while SiO₂−NH₂−RuNO₂@CsPbBr₃ released NO. Confocal microscopy confirmed cellular uptake in A549 cells. The NO-containing nanoplatform showed ~30% dark cytotoxicity, whereas the aqua analogue was non-cytotoxic. Future X-ray studies will evaluate therapeutic efficacy and the contribution of X-ray-triggered NO release.