Cellular Uptake of siRNA Nanoparticles for Drug Delivery in Whole Blood and Lymphocytes

The newest frontier of drug delivery and disease treatment is nanotechnology utilizing therapeutic nucleic acids, which are proving to be fully customizable, programmable and can carry multiple functionalities. Nucleic acid based nanoparticles functionalized with multiple short interference RNAs (siRNAs), or other therapeutic oligonucleotides and formulated with lipid-like carriers for efficient intracellular delivery can act as an active pharmaceutical ingredient. Due to the route of administration, it is important to study how this new therapeutic technology interacts with blood and lymphocytes to elucidate possible undesirable side-effects.

This investigation examines the cellular uptake by whole blood and by lymphocyte isolations from human donors of several fluorescently tagged functional RNA nanoparticles selected from the laboratory library. Lymphocytes are isolated from each whole blood sample and the siRNA nanoparticles formulated with polycationic carriers are introduced to both the whole blood and lymphocyte isolation. Fluorescence changes indicating the relative uptake of nano-formulations by blood cells are measured via flow cytometry and further analyzed. Experimentation has thus far shown a marked difference in nanoparticle uptake when the formulation is introduced after the samples are serially diluted as opposed to introduction to undiluted human blood samples. This may indicate that the currently used experimental protocol may affect apoptosis and cell morphology of lymphocytes thus promoting their interaction with nanoparticles. Further experimentation aims to examine which constructs and cells have the most efficient cellular uptake by blood cells, which lipid-like carrier works best for uptake and mechanisms for cellular entry.