Recent advances in glyco-nanoparticles for probing the glyco-codes of cancer.

Aberrant glycosylation is a hallmark of cancer, producing tumor-associated carbohydrate antigens (TACAs) and altering cell-surface interactions that reshape adhesion, signaling, and immune recognition. These altered glycans, collectively referred to as the "cancer glyco-code", represent unique glycan expression patterns that create actionable targets for diagnosis and therapy. The glycan-binding proteins that recognize and interpret these structures, termed the "readers" of the glyco-code, include lectin families such as Siglecs, galectins, selectins, and cluster of differentiation 44 (CD44). Glyco-nanoparticles (GlycoNPs) are inspired by glyco-code and designed to probe these readers by multivalently presenting tumor-relevant glycans on engineered cores (gold, iron oxide, polymers), thereby boosting avidity and selectivity in cancer targeting. This review distills design principles for GlycoNPs' core selection, conjugation chemistry, glycan density/orientation, and multivalency control, and reviews applications in surface-enhanced Raman scattering (SERS), magnetic resonance imaging (MRI), high-throughput glycan binding screens, and targeted drug delivery. We highlight immune-modulatory strategies (e.g., Siglec decoying, galectin blockade, and glycan-guided macrophage reprogramming) that position GlycoNPs as "glycan immune checkpoints." We also examine translational bottlenecks: inter- and intra-tumoral glycan heterogeneity; manufacturing reproducibility (density/orientation/valency); colloidal and biological stability; pharmacokinetics; and regulatory expectations for characterization and immunogenicity. Finally, we outline emerging applications that may accelerate bench-to-bedside translation. Overall, GlycoNPs offer a modular, multiplexable path to precision oncology, enabling reader-guided tumor profiling, imaging, and intervention through the language of glycans.