| RNA interference (RNAi) has emerged as a novel therapeutic pathway by which harmful genes can be "silenced" by complementary short interfering RNA (siRNA) in target cells. siRNA delivery facilitated by polymers, although very promising, suffers from many of the same limitations as DNA delivery. Poly (D,L-lactide-co-glycolide) (PLGA), due to its biodegradable properties, and Polytheylinimine, due to its proton sponge effect to facilitate endosomal escape, were chosen to prepare non-viral nanoparticle carrier system to deliver siRNA oligos with desired physicochemical properties.;The siRNA loaded and PEI modified PLGA nanoparticles were prepared by single emulsion solvent evaporation technique. The particle size and zeta potential of nanoparticles were characterized by laser diffraction particle sizer.;The siRNA loaded nanoparticles were transfected into HEK293T cells. After siRNA transfection, reduction of the marker green fluorescence protein (GFP) was monitored by fluorescence microscopy and flow cytometry (FACS).;Both positive and negative controls were used to compare with new siRNA nanoparticle delivery system. Cytotoxicity of nanoparticles was evaluated by means of the XTT assay. It was found that nanoparticles offered both effective delivery of siRNA and prominent GFP gene silencing effect. Compared to conventional viral based carrier system, polymeric nanoparticle system offers improved formulation stability and safety which are practically beneficial and may be evaluated for in vitro studies in future. |
