Glycans as Biofunctional Ligands for Gold Nanorods: Stability and Targeting in Protein-Rich Media

Poly(ethylene glycol) (PEG) has become the gold standard for stabilization of plasmonic nanoparticles (NPs) in biofluids, because it prevents aggregation while minimizing unspecific interactions with proteins. Application of Au NPs in biological environments requires the use of ligands that can target selected receptors, even in the presence of protein-rich media. We demonstrate here the stabilizing effect of low-molecular-weight glycans on both spherical and rod-like plasmonic NPs under physiological conditions, as bench-marked against the well-established PEG ligands. Glycan-coated NPs are resistant to adsorption of proteins from serum-containing media and avoid phagocytosis by macrophage-like cells, but retain selectivity toward carbohydrate-binding proteins in protein-rich biological media. These results open the way toward the design of efficient therapeutic/diagnostic glycan-decorated plasmonic nanotools for specific biological applications.The proteomic analysis was performed in the proteomics platform at CIC bioGUNE that belongs to ProteoRed, PRB2- ISCIII, supported by grant PT13/0001. This work has been supported by the Spanish MINECO (CT2011-27268 and MAT2013-46101-R) and the Basque Department of Economical Development and Competitiveness (ETORTEK IE13- 371)