Transformative R01 Program
ORAL DELIVERY VEHICLES FOR RNAI THERAPIES
Schematic depiction of Glucan-encapsulated siRNA particle (GeRP) structure (top). GeRps added to cultured macrophages are taken up by phagocytosis depicted in immunofluorescence microscopy images (bottom) in which fluorescein labeled glucan shells (green) are visible within cells labeled with a macrophage specific marker (blue). Glucan-encapsulated siRNA particles (GeRPs) consist of a porous, 2-4 micron glucan shell derived from baker’s yeast cell walls. Within this shell a core consisting of tRNA is coated with a layer of a cationic polymer, PEI. SiRNA is added, which binds to the PEI layer, and is then coated with a second PEI layer. These GeRPs carrying siRNAs designed to silence specific genes can be added to macrophages in culture. The macrophages take up the GeRPs by phagocytosis, and after a short time, the GeRPs (labeled in this case with a greef fluorescent molecule) can be seen in microscopic images to be within the macrophages (visualized with blue fluorescence).