Gold Nanostars as Multifunctional Platforms in Cancer Imaging and Therapy: Toward Radiotheranostic Applications.

Gold nanostars (AuNSs) have emerged as promising platforms for cancer theranostics due to their distinctive optical and physicochemical properties, including strong plasmon resonance, tunable structure, and high photothermal conversion efficiency. These features support their use in various imaging modalities such as surface-enhanced Raman scattering (SERS), fluorescence, computed tomography (CT), magnetic resonance imaging (MRI), and photoacoustic imaging as well as in therapies like photothermal, photodynamic, and radiotheranostic treatments. The ability of GNS-based systems to integrate diagnostic and therapeutic functions in a single way facilitate real-time treatment monitoring and improves therapeutic accuracy. Furthermore, surface functionalization and the development of hybrid nanostructures can enhance tumor-targeting capability, biocompatibility, and performance in biological environments. However, several challenges such as limited tumor specificity, potential toxicity, complex interactions in biological systems, and difficulties in large-scale synthesis remain and limit their preclinical translation. Therefore, future efforts on optimizing nanoparticle stability, biodistribution, and safety while incorporating advanced strategies would support their preclinical and anticipated clinical application. In this review, we focus on the design, functionalization, and biomedical applications of gold nanostars in cancer imaging and therapy with future perspective in radiotheranostic strategies.