Water-Dispersible Plasmonic Gold Nanoparticle Vesicle as a Drug Delivery Carrier for Cancer Therapy

Fabrication of water-dispersible plasmonic gold nanoparticle vesicles (GNVs) by using small-molecule surface ligands for biological applications still remains a significant challenge. In this paper, we demonstrate that a tri(ethylene glycol) terminated octafluoro-4,4'-biphenol ligand (TrOFBL) can self-assemble with 5 or 10 nm gold nanoparticles into hollow-structured GNVs in tetrahydrofuran (THF). After the GNVs are transferred from THF to an aqueous solution, these single-layered plasmonic GNVs remain stable and dispersible. The precise control of the balance between hydrophilic and hydrophobic effects of the small-molecule ligand leads to the stabilization of the GNVs in water. The GNVs can encapsulate a hydrophobic anticancer drug in the interior with a high loading efficiency of 74%. Upon irradiation with a red laser (650 nm), the accumulative release of the drug can reach up to 99% due to the destruction of GNVs induced by local heating. Cellular assays confirm that the GNVs are efficiently internalized by cancer cells and release the drugs upon laser irradiation to induce cytotoxicity. <i>In vivo</i> anticancer result shows that the laser-triggered drug release effectively inhibits tumor growth after irradiation without noticeable systemic toxicity, making them suitable for <i>in vivo</i> tumor therapy.