Authors: S.J. Leung, M. Romanowski
Affilation: University of Arizona, United States
Pages: 295 - 297
Keywords: nanostructures, plasmon resonance, self-assembly, liposomes, drug delivery
To address unmet medical needs in the area of controlled delivery, we recently presented liposome-supported plasmon resonant gold nanoshells. These composite structures are degradable into components of a size compatible with renal clearance, potentially enabling their use as multifunctional agents in imaging, diagnostic, therapeutic, and drug delivery applications. The liposome allows for encapsulation of substances, including diagnostic and therapeutic agents, while the plasmon resonant structure facilitates the rapid release of content upon laser illumination using a wavelength corresponding to the resonance band. The resonance of gold-coated liposomes is tunable in the near-infrared range. Using this tunability, we achieved spectrally-selective content release using two laser wavelengths, in which full content release occurs for liposomes spectrally matched with the illumination source and minimal release occurs for liposomes not matched with the source. Spectrally-selective release is accomplished through the use of multiple, low intensity laser pulses, ensuring that illumination affects only the gold-coated liposomes and avoids heating surrounding media; this observation is supported experimentally and through heat equation modeling. Within the context of biological and medical applications, gold-coated liposomes may enable the spectral, spatial, and temporal control of release of multiple agents from liposome carriers by means of a physiologically safe light-delivery method.