Diverse biomedical applications of lipid-coated particles

Lipids are extremely versatile biomolecules capable of encapsulating particles composed of a gas, liquid, or solid. In this talk I will present three particles that have been developed for various projects in the biomedical sciences. First, I will review the development and utility of pressure-sensitive nanoemulsions (PSNE), which can be vaporized with high amplitude acoustic pulses. Vaporization produces microbubbles that can be driven to collapse energetically, generating intense stresses capable of permeabilizing cell membranes and homogenizing solid tumors. In a second project, we encapsulated the optical imaging tracer indocyanine green (ICG) into liposomes designed to remain in circulation for hours. This enabled two-photon (2P) imaging at multiple depths that required at least an hour of light exposure, which was not possible with unencapsulated ICG. Third, I will describe the generation and characterization of ICG J-aggregates packaged within lipid vesicles. ICG J-aggregates absorb more photons at longer wavelengths than soluble ICG, which is advantageous for in vivo multispectral photoacoustic imaging as well as photothermal therapy at deeper locations in tissue. The versatility of lipid-coated particles makes the technology accessible to scientists and students from various disciplines, which can lead to many fruitful multidisciplinary projects.