Preparation of Super-Stable Gold Nanorods via Encapsulation into Block Copolymer Micelles.
ABSTRACT Gold nanorods (GNRs) have the potential to be used as imaging and hyperthermia agents for cancer theranostics. Clinical applications of as-synthesized GNRs (i.e., cetyl trimethylammonium bromide (CTAB)-coated GNRs) are currently limited by their cytotoxicity and insufficient colloidal stability. With an aim to address these problems, we developed a self-assembly processing technique for encapsulating GNRs in poly(ethylene oxide)-poly(n-butyl acrylate) (PEO-PnBA) block copolymer (BCP) micelles. This technique uses simple steps of solvent exchange processes, based on the known principles of block copolymer self-assembly. The resultant BCP-encapsulated GNRs were found to be stable against aggregation under physiological salt conditions for indefinite periods of time, which has rarely previously been achieved by other means of encapsulation.