“…In particular, the nanosized polyplexes composed of negatively charged condensed DNA and cationic polymers (DNA-polycation polyplex) have been intensely investigated mainly for their roles as excellent nonimmunogenic biocompatible carriers for DNA delivery. − Importantly, the rapid biodegradation of DNA-polycation polyplexes into nontoxic monomers under physiological conditions minimizes the possible cellular toxicity stemming from the cationic surface properties. , In addition to the biomedical applications, DNA-polycation polyplexes are highly attractive from the viewpoint of synthesis, because their size and surface charge can be easily controlled by changing their molecular weight or composition . Overall, the DNA-polycation polyplexes have potential advantages as biodegradable organic building blocks for the synthesis of functional nanomaterials, as demonstrated with other organic and inorganic nanoparticles. − Unfortunately, however, the polyplexes can be easily destabilized or irreversibly aggregated even under common reaction conditions, such as high ionic strength, high temperature, and mechanical stress, all of which are a vast hurdle for their chemical modification. − For the stabilization of polyplexes, molecular crosslinkers, , PEGylated cationic polymers, , and annealing method have been mainly employed. Additionally, gold nanoparticles (AuNPs) have been intensely investigated as stabilizing agents for soft nanoparticles, such as microbubbles, liposomes, and micelles. − Despite their efficiency and convenience, however, no studies have taken advantage of AuNPs to stabilize DNA polyplexes for their further nanofabrication as organic building blocks to date.…”