Remotely triggered liposome release by near-infrared light absorption via hollow gold nanoshells

An elusive goal for systemic drug delivery is to provide both spatial and temporal control of drug realease. Liposomes have been evaluated as drug delivery vehicles for decades, but their clinical significance has been limited by slow relase or poor availability of the encapsulated drug. Here we show that near-complete liposome release can be intiated within seconds by irridiating hollow gold nanoshells (HGNs) with a near-infrared (NIR) pulsed laser. Our findings reveal that different coupling methods such as having the HGNs tethered to, encapuslated within, or suspended frelly outside the liposomes, all triggered liposome release but with different levels of efficiency. For the underlying content release mechanism, our experiments suggest that the mcirobubbe formation and collapse due to the rapid temperature increase of the HGN is responsible for liposome disruption, as evidenced by the formation of solid gold particles after the NIR irradiation and the conincidence of a laser power thershold for both triggered release.