Preparation and characterization of neutrally-buoyant oleosin-rich synthetic lipid droplets

Lipid droplets also known as oil bodies are found in a variety of organisms and function as stores of high-energy metabolites. Recently, there has been interest in using lipid droplets for protein production and drug delivery. Artificial lipid droplets have been previously prepared, but their short lifetime in solution and inhomogeneity has severely limited their applicability. Herein we report an improved methodology for the production of synthetic lipid droplets that overcomes the aforementioned limitations. These advancements include: 1) development of a methodology for the expression and purification of high-levels of oleosin, a crucial lipid droplet component, 2) preparation of neutrally-buoyant synthetic lipid droplets, and 3) production of synthetic lipid droplets of a specific size. Together, these important enhancements will facilitate the advancement of lipid droplet science and its application in biotechnology.