[Chitosan-siRNA complex nanoparticles for gene silencing].

Small interference RNA (siRNA) induced RNA interference (RNAi) technology has shown high specificity and high efficiency of silencing target gene expression, and it is becoming a promising candidate drug for the therapy of cancer and viral infection diseases. At present, the lack of safe and effective carrier materials and delivery systems of siRNA through extracellular and intracellular barriers still hampers the clinical application. In order to overcome this difficulty, we proposed using chitosan, naturally occurring polycation, to form complex siRNA against green fluorescence protein (siRNA-eGFP). The spherical and stable chitosan-siRNA nanoparticles with 83%-94% siRNA complex efficiency can be formulated under mild electrostatic interaction. The size and Zeta potential of nanoparticles were within the range of 90-180 nm and 10-30 mV, respectively. 80% cell viability could be maintained inthe course of incubating with chitosan-siRNA nanoparticles. Moreover, nearly 80% gene silencing efficiency of chitosan-siRNA nanoparticles was realized.