Preparation of Poly(ethylene glycol)-Modified Poly(amido amine)\nDendrimers Encapsulating Gold Nanoparticles and Their\nHeat-Generating Ability

Abstract

Loading of HAuCl₄ in poly(amido amine) G4 dendrimers having poly(ethylene glycol) (PEG) grafts at all chain\nends and subsequent reduction with NaBH₄ yielded PEG-modified dendrimers encapsulating gold nanoparticles (Au\nNPs) of ca. 2 nm diameter. The Au NPs held in the dendrimers were stable in aqueous solutions and dissolved readily,\neven after freeze-drying. Despite their small particle size, the heat-generating ability of Au NPs held in the dendrimer\nwas comparable to that of widely used Au NPs with ca. 11 nm diameter under visible light irradiation. The observed\nexcellent colloidal stability, high heat-generating ability and their biocompatible surface confirm that the PEG-modified dendrimers encapsulating Au NPs are a promising tool for photothermal therapy and imaging.