Improving gold nanorod delivery to the central nervous system by conjugation to the shuttle Angiopep-2

To improve the delivery of gold nanorods (GNRs) to the central nervous system of rats, these gold nanoparticles were conjugated to Angiopep-2, a shuttle peptide that can cross the blood-brain barrier. GNRs were synthesized and modified using polyethylene glycol and Angiopep-2 (GNR-PEG-Angiopep-2). The physicochemical properties, cytotoxicity and biodistribution of the conjugate were examined. GNR-PEG-Angiopep-2 was stable over the following days, and the different concentrations that were tested did not affect the viability of microvascular endothelial cells. The conjugation of Angiopep-2 to GNRs enhanced the endocytosis of these particles ( ) and the accumulation in brains ( ), when compared with GNRs modified only with PEG. This study provides evidence that Angiopep-2 improves the delivery of GNRs to the brain parenchyma. This property is highly relevant for future applications of GNRs as platforms for photothermal and theranostic purposes.