One-pot synthesis of sugar-decorated gold nanoparticles with reduced cytotoxicity and enhanced cellular uptake

The unique properties of gold nanoparticles (AuNPs) enable their use for instance in medical diagnostics and therapeutic applications. The straightforward applicability of AuNPs requires accordingly the development of facile synthesis approaches towards the manufacturing of ready-to-use biomedical devices. Additionally, the behavior of nano-sized gold colloids in contact with living systems needs further and deeper investigations since nanoparticle-cell interactions, cellular uptake and cytotoxicity, particularly with regard to surface chemistry effects, are still poorly understood. Taken it into account, we herein demonstrate a facile one-pot synthesis of polymer-stabilized gold nanoparticles (AuNPs) using branched polyethyleneimine (BPEI) with primary amine groups substituted by lactose residues. The polymer chains are simultaneously responsible for the Au3+ reduction and stabilization of the produced metallic colloids. The approach enables the manufacturing of highly stable similar to 20 nm AuNPs with the surface decorated by sugar moieties. The use of sugar substituted polymer chains leads to gold nanocolloids with reduced cytotoxicity and enhanced cellular uptake compared to those stabilized by unmodified polymer chains. These findings can lead to significant advances towards the application of AuNPs-based therapies, diagnostics and imaging.