Application of Hydrogel in the Capture and Detection of Circulating Tumor Cells.

Circulating tumor cells (CTCs) represent critical biomarkers for liquid biopsy, and their efficient capture and accurate detection hold profound clinical significance for early cancer diagnosis, real-time monitoring of metastasis, and the implementation of personalized therapeutic strategies. As an advanced functional material, hydrogels offer distinctive advantages for CTC capture: their three-dimensional porous architecture facilitates deep cell infiltration and effective physical entrapment; their exceptional biocompatibility preserves CTC viability and functionality; and their tunable physicochemical properties combined with versatile functionalization modalities enable highly specific, affinity-driven targeting. Furthermore, integration of hydrogels with optical or electrochemical transducers allows the development of unified, multifunctional platforms capable of sequential CTC capture, in-situ detection, controlled release, and downstream analysis. This review comprehensively summarizes recent advances in hydrogel-based CTC capture and detection technologies, critically examines key challenges currently impeding clinical translation, and finally outlines future research directions. Synergistic multifunctional integration, stimuli-responsive behavior, standardized and scalable fabrication protocols, and rigorous clinical validation will constitute pivotal pathways toward realizing the practical clinical utility of hydrogel-based CTC capture and detection technologies.