Optimization of Lipofectamine-2000/siRNALipoplexLoaded PLGANanoparticles for Efficient EGFR Gene Silencing: An in Vitro Study

In this study, a novel small interfering RNA (siRNA) delivery system based on encapsulation of lipolexes was introduced. A Lipofectamine-2000– siRNA complex was encapsulated in particles of poly (D,L-lactic-co-glycolic acid; PLGA) by double micro-emulsion. Parameters such as surfactant concentration, the volume of the inner water phase and the outer water phase were evaluated to achieve high loading efficiency, small particle size and low polydispersity. The ratio of the internal to the external phase has a significant effect on the particle size and encapsulation efficiency. The various concentration of surfactant has a different effect on the particle size. In order to achieve optimum conditions for siRNA delivery, the luciferase siRNA was used as a reporter gene. The prepared formulations have a particle sizes in the range of 222 ± 5.2 nm to 900 ± 20 nm and loading efficiency in the range of 4% to 29%. lipoplex loaded PLGA particles (LPPs) had a zeta potential values ranging from −23±2.5 to −29±1.5 mV. S1 and S3 formulations showed greater efficiency compared to the lipoplexes. The gene silencing pattern of LPPs was different from lipoplex. The cytotoxicity of lipoplex loaded PLGA particles (LPPs) was lower than lipoplexes in H1299 cell line. LPPs showed better stability and higher level transfection in the presence of heparin than lipoplexes. The EGFR silencing of S1 formulation was greater than other formulation in A431 cell line. All together these properties suggest that lipoplex loaded PLGA particles have strong potential as a gene carrier for in vivo silencing angiogenesis and treatment of cancer.