Gold Nanoparticle-Loaded Stimuli-Sensitive Dendrimers with Peroxidase-Like Activity for Cancer Treatment

Gold nanoparticles (AuNPs) are unique in their optical properties and catalytic activities. Dendrimers are highly branched synthetic macromolecules that serve as nanotemplates for metal nanoparticles (NPs) as well as drug carriers. We previously synthesized carboxy-terminal phenylalanine (Phe)-modified polyamidoamine dendrimers to induce pH- and temperature-dependent coacervation. In this study, AuNPs were loaded into these dendrimers to produce a functional peroxidase (POD)-like nanozyme, whose activity was monitored using 3,3′,5,5′-tetramethylbenzidine and H2O2 under different pH and temperature conditions. The POD-like activity was changed by varying the temperature and pH, and the coacervation induced by the dendrimer suppressed the enzymatic activity. The POD-like activity of the AuNPs loaded in the dendrimers was higher than that of the AuNPs prepared by using citric acid and horseradish POD at high temperatures. Cancer cells were damaged after treatment with AuNP-loaded dendrimers in the presence of ascorbic acid. These results suggest that the AuNP-loaded dendrimers can function as POD-like nanozymes that are applicable to cancer treatment.