Facile fabrication and application of near-IR light-responsive drug release system based on gold nanorods and phase change material.

Near-IR (NIR)-responsive drug delivery systems have received enormous attention because of their good biocompatibility and the high biological penetration of NIR. This work describes the facile fabrication and anticancer effect of a NIR-responsive drug delivery system based on the nano-assembly of mesoporous silica-coated gold nanorods (AuNR@mSiO) and a phase change material (PCM). The core gold nanorods in AuNR@mSiO provided excellent NIR sensitivity, and the mesoporous silica shell provided an increased reservoir of loaded drug. The PCM was applied as both a thermosensitive gatekeeper and a medium for a hydrophobic anticancer drug. The photothermal effect of the AuNRs under NIR irradiation facilitated a rapid release of the drug through the temperature-sensitive phase transition of PCM at just above body temperature. An enhanced anticancer effect was observed against various cell lines, and intracellular release of the drug was easily monitored by live cell imaging. Our system does not require any complicated synthetic methods for fabrication, and PCM is easily capable of solubilizing various hydrophobic drugs. Therefore, this system has significant potential for broad application in the biomedical field as a delivery system for hydrophobic drugs with NIR-responsive behavior.