Delivery of Antiviral siRNA with Gold Nanoparticle Against Dengue Virus

The goal of this study was to use specific small-interfering RNA (siRNA) sequences to target the E gene of the Dengue virus serotype 2 (DENV-2). It was predicted that this targeted binding of siRNA would prevent subsequent translation of the E gene protein, as well as virion production in infected cells. Due to the instability of the antiviral siRNA, the siRNA was conjugated to gold nano-particles (AuNP) in order to provide stability during delivery to the infected Vero cells. Cells were transfected with siRNA-AuNP complexes prior to DENV-2 infection. The siRNA-AuNP complexes tested included two different siRNA sequences (at varying concentrations) paired with positively, negatively, or neutrally charged nano-particles. In one experiment, the effectiveness of these complexes were tested in cells that were incubated for 48 hours post-infection, while in another experiment the cells were incubated for 72 hours post-infection. The inhibition of viral propagation in infected cells was analyzed using the quantitative polymerase chain reaction (QPCR). The QPCR results obtained were used to calculate the DENV-2 E gene to β-actin housekeeping gene ratio in order to determine effective viral inhibition in the infected cells. The results of the experiment showed decrease in viral propagation in infected cells with the use of the positively charged AuNP. There was consistent viral inhibition in both types of siRNA tested, especially within cell samples that were incubated for 72 hours post-infection (as compared to a 48-hour post-infection incubation). However, further experiments must be conducted in order to confirm efficacy of the anti-viral siRNA