Nanosistemas de baja toxicidad para la entrega de siRNA

ANA PAULA PEREZ; EDER LILIA ROMERO; MARÍA JOSÉ MORILLA

Mar del Plata

Congreso; XLIII Reunión anual Sociedad Argentina de investigación Bioquímica y Biología Molecular; 2007

Sociedad Argentina de investigación Bioquímica y Biología Molecular

PAMAM dendrimers could be potential nano-Controlled Release System (nano-CRS) for nucleic acids because of their nearly perfect monodispersity and controlled size in the nanorange. In this work, complexes were prepared by combining generation 4 (G4) PAMAM dendrimers with anti-green fluorescein protein (GFP) siRNA. Interaction between G4 and siRNA was determined by measuring the ability of G4 to displace the intercalating dye ethidium bromide from siRNA. Analysis of the formation of complexes was made evident by detecting retarded migration of siRNA in a polyacrilamide 20% gel electrophoresis, as the stability of the complex in the presence of RNAsa and human serum. Cytotoxicity after 24 hs incubation of the complexes G4-siRNAand lipofectamine (L-siRNA), at different concentrations, was determined by methyl thiazolyl tetrazolium (MTT) assay, on Vero cells (endocytic fibroblast) and J774 cells (macrophages). Viability of both cell lines decresed only in the presence of the higher concentration of G4 and siRNA. On the contrary, L-siRNAcomplex d e c r e a s e d v i a b i l i t y a t m i n o r c o n c e n t r a t i o n s . Finally, the efficiency of gene silencing was analyzed for G4-siRNA complexes, that showed to be more efficient for silencing GFP than the commercial reagent Lipofectamine 2000.