Monosaccharide coating modulate the intracellular trafficking of gold nanoparticles in dendritic cells.

Dendritic cells (DCs) have emerged as a promising target for drug delivery and immune modulation due to their pivotal role in initiating the adaptive immune response. Gold nanoparticles (AuNPs) have garnered interest as a platform for targeted drug delivery due to their biocompatibility, low toxicity and precise control over size, morphology and surface functionalization. Our investigation aimed to elucidate the intracellular uptake and trafficking of AuNPs coated with different combinations of monosaccharides (mannose, galactose, and fucose) in DCs. We used 30 unique polymer-tethered monosaccharide combinations to coat 16 nm diameter spherical gold nanoparticles and investigated their effect on DCs phenotype, uptake, and intracellular trafficking. DCs internalized AuNPs coated with 100 % fucose, 100 % mannose, 90 % mannose +10 % galactose, and 80 % mannose +20 % galactose with highest efficiency. Flow cytometry analysis indicated that 100 % fucose-coated AuNPs showed increased lysosomal and endosomal contents compared to other conditions and uncoated AuNPs. Imaging flow cytometry further demonstrated that 100 % fucose-coated AuNPs had enhanced co-localization with lysosomes, while 100 % mannose-coated AuNPs exhibited higher co-localization with endosomes. Furthermore, our data showed that the uptake of carbohydrate-coated AuNPs predominantly occurred through receptor-mediated endocytosis, as evidenced by a marked reduction of uptake upon treatment of DCs with methyl-β-cyclodextrins, known to disrupt receptor-mediated endocytosis. These findings highlight the utility of carbohydrate coatings to enable more targeted delivery of nanoparticles and their payload to distinct intracellular compartments in immune cells with potential applications in drug delivery and immunotherapy.