Glyco-gold nanoparticles as smart tools in nanomedicine: synthesis and biodistribution in healthy mice

Gold nanoparticles are a platform of interest with a broad range of applications and they are emerging as a powerful tool in nanomedicine. The surface chemistry based on the soft-soft interaction among gold and sulfur allows a reliable coating of the nanoparticles, paving the way to numbers of bio-applications. In particular, the multivalent presentation of carbohydrates can trigger a cluster effect which can overcome the low affinity of the individual ligands towards their receptors. Moreover, the glycans surface modification can improve the gold nanoparticle circulation time in blood, tuning the formation of the “bio-corona” and therefore preserving their active targeting. In the last years, great efforts have been addressed to the synthesis and characterization of glyco-coated gold nanoparticles, in order to develop reliable and robust nanosystems which can be employed in many fields, from drug delivery to diagnosis.
Herein, we propose two different procedures to obtain a library of ultra-small glyco-gold nanoparticles: 1) A modified Brust-Schiffrin method developed in a bench-top reactor followed by a post-functionalization step to introduce glycans; 2) A new photo-induced one-pot synthesis based on a microfluidic approach: ultra-small gold nanoparticles were synthesized without the addition of template or reducing agents, affording size-controlled functionalized nanoparticles. Glyco-gold nanoparticles were fully analyzed by dynamic light scattering and transmission electron microscopy to determine their size and morphology. Moreover, in order to evaluate their in vivo behavior, mannose-decorated gold nanoparticles have been exploited to perform a pharmacokinetics and biodistribution (PKBD) study in healthy mice.