Hydrogel-Integrated Nanotheranostic Platforms for Localized Diagnosis and Therapy

Nanotheranostic platforms integrating diagnostic and therapeutic functions within a single system have attracted significant attention in precision medicine. However, conventional nanotheranostics based on systemic administration often suffer from off-target accumulation, limited retention at disease sites, and dose-limiting toxicity. To address these limitations, hydrogel-integrated nanotheranostic systems have emerged as a promising strategy for achieving localized diagnosis and therapy with improved spatial control and safety. This review provides a comprehensive overview of recent advances in hydrogel–nanomaterial nanotheranostic platforms, focusing on their design principles, diagnostic capabilities, and therapeutic applications. We discuss the complementary roles of hydrogels and nanomaterials, where hydrogels function as localized reservoirs and tissue interfaces, and nanomaterials provide imaging and therapeutic functionalities. Key integration strategies including physical encapsulation, chemical conjugation, and in situ nanoparticle formation are systematically compared. We further summarize localized diagnostic modalities such as real-time imaging and therapy monitoring, and highlight research-driven applications in cancer treatment, inflammation and infection management, and tissue regeneration. Finally, major translational challenges and future perspectives toward personalized, image-guided local theranostics are discussed. Overall, hydrogel-based nanotheranostic platforms represent a versatile approach for next-generation localized precision medicine.