Molecular glycoengineering of carbohydrate-functionalized nanocarriers for receptor-mediated targeted drug delivery...

Carbohydrate-functionalized nanocarriers have moved from a decorative surface-modification concept to a molecular drug-delivery strategy in which glycan ligands, polysaccharide shells and synthetic glycopolymers are engineered to negotiate tumor recognition, receptor clustering, endocytosis, intracellular trafficking and stimulus-triggered release. The field is scientifically attractive because cancer cells and tumor-associated stromal cells remodel their glycocalyx, overexpress selected carbohydrate-recognizing receptors and display altered metabolic demand; however, the translation of glycoengineered nanomedicine remains limited by low tumor delivery efficiency, heterogeneous receptor density, competitive off-target uptake by liver and macrophages, batch-to-batch variation in ligand density and insufficient quantitative reporting. This review re-frames carbohydrate-mediated cancer drug delivery as an evidence-weighted design problem. It integrates receptor-density data, particle-size boundaries, ligand-density ranges, release-rate targets, in vitro uptake metrics, pharmacokinetic endpoints and preclinical efficacy readouts into a quantitative framework. Special attention is given to hyaluronic acid-CD44, galactose/GalNAc-ASGPR, mannose-CD206, sialylated glycan-siglec/selectin, beta-galactoside-galectin and glucose/GLUT-related approaches, with emphasis on what the available data can and cannot prove. The central conclusion is that molecular glycoengineering is most defensible when carbohydrate chemistry is linked to measurable receptor engagement, competitive inhibition, uptake kinetics, intracellular drug exposure and statistically stronger antitumor benefit rather than to generic claims of active targeting. The framework explicitly links anomeric configuration, glycosidic linkage, branching, sulfation/acetylation, epitope display and glycan-protein hydration to receptor-specific pharmacological outcomes, thereby shifting the emphasis from general nanomedicine performance to carbohydrate structure-activity relationships required for a carbohydrate-chemistry readership.