Hydrogel-Driven Construction of Integrated Cancer Theranostic Platforms: From Diagnosis to Therapy

Current cancer treatment still relies largely on stage-specific diagnosis and relatively fixed therapeutic regimens, with diagnostic information, therapeutic intervention, and efficacy feedback often separated into different time windows, making it increasingly difficult to meet the demands of precision and individualized therapy. Theranostic platforms can organically integrate disease diagnosis with therapeutic decision-making. They can simultaneously provide feedback on or predict therapeutic efficacy during treatment, thereby enabling continuous evaluation throughout the entire treatment course. Hydrogels, as a class of soft materials with tissue-like three-dimensional networks, can stably load imaging probes and therapeutic agents by virtue of their unique biological characteristics, while also enabling controlled release, signal activation, and therapeutic monitoring at lesion sites, thus providing an ideal material basis for the construction of integrated cancer theranostic platforms. This review systematically summarizes hydrogel construction strategies for different diagnostic and therapeutic scenarios, with particular emphasis on the practical impact of distinct matrix compositions, crosslinking modes, and emerging materials on hydrogel-based theranostic platforms. We further highlight recent advances over the past three years in precision oncology and, on this basis, discuss in depth the key applications of hydrogels in tumor biomarker recognition and enrichment, visual imaging, therapeutic payload delivery, and multifunctional integration. Finally, we analyze the challenges facing practical implementation in this field and outline future directions involving organoids, spatial omics, artificial intelligence, and bioelectronic interfaces, with the aim of providing a systematic reference for the design of next-generation hydrogel-based cancer theranostic platforms that are personalized, monitorable, and clinically translatable.