Near-Infrared Luminescent Nanoparticles Enable Olaparib Delivery for Radiosensitized Image-Guided Theranostics

High Resolution Image Download MS PowerPoint Slide This work presents the design of near-infrared (NIR) luminescent nanoparticles codoped with rare-earth and transition-metal ions as a multifunctional materials platform for imaging-guided cancer therapy and radiological treatment assistance. Germanium oxide-based nanoparticles codoped with La 3+ and Cr 3+ (GeO 2:La 3+, Cr 3+; GOLC) were engineered to generate long-lasting NIR emission through a stable oxide host lattice and Cr 3+ -mediated charge-trapping states. The resulting NIR luminescence enables high-contrast, background-suppressed optical imaging without continuous external excitation, addressing key challenges associated with tissue autofluorescence and photobleaching in biological environments. To integrate therapeutic functionality, GOLC nanoparticles were loaded with the poly(ADP-ribose) polymerase (PARP) inhibitor olaparib, yielding GOLC@OLA nanostructures. These nanostructures effectively suppress oral cancer cell proliferation and induce apoptosis, combining optical tracking capability with drug delivery within a single materials system. Beyond chemical delivery, the high atomic number (high- Z ) the GOLC carrier confers an inherent radiosensitizing effect, significantly enhancing the efficacy of radiotherapy (RT) by increasing local photoelectric absorption. From a radiological perspective, La 3+ was incorporated primarily as a structural and electronic modulator rather than a conventional high- Z radiosensitizer. Although La 3+ does not strongly enhance photoelectric absorption, its incorporation may indirectly influence radiation responses through lattice defect modulation, defect-assisted charge dynamics, and radiation-induced apoptosis. This integration enables precise spatial correlation among nanoparticle localization, imaging readout, and therapeutic payload delivery, thereby supporting image-guided chemo-radiotherapy strategies in oral cancer models. Overall, this study establishes a versatile NIR luminescent nanoparticle framework that bridges optical imaging, drug delivery system, and imaging-guided radiological therapy, providing a materials-centric foundation for advanced oncological nanomedicine research.