(526c) Plasmon Resonant Nanoparticles for Lipid-Based Drug Delivery

Optimal drug carriers for intravenous drug delivery of chemotherapeutic drugs need to have the following properties: (1) good retention; (2) specific targeting; and (3) spatially and temporally controlled release. Vesosomes are multi-compartment lipid-based nanoparticles consisting of multiple smaller liposomes encapsulated within bigger liposomes. Due to the double-bagged structure, vesosomes have superior drug retention and stability. We used small angle x-ray scattering to characterize the lipid bilayer phase transformations among interdigitated phase, gel-phase, and fluid-phase. With thorough understanding of the vesosome formation, we successfully incorporated tri-block copolymers into vesosomes to shrink the nanoparticle size to minimize immunogenicity and prevent non-specific adsorption of proteins and peptides on the vesosome surface.

Plasmon resonant particles with strong optical absorption at the near-infrared (NIR) light enable development of novel biomedical application. They can act as molecular contrast agents and their localized heating enables thermal ablation. Recently, we showed Plasmon resonant gold nanoshells can generate transient cavitations if irradiated with fs-NIR laser. This allows their novel application in targeting and controlled release from lipid-based drug carriers where the optically triggered cavitations can temporarily rupture lipid membranes with a mechanism similar to that of ultrasound which is known to induced controlled drug delivery.