Anionic liposomes for small interfering ribonucleic acid (siRNA) delivery to primary neuronal cells: Evaluation of alpha-synuclein knockdown efficacy

Alpha-synuclein (α-syn) deposition in Lewy bodies (LB) is one of the main \nneuropathological hallmarks of Parkinson's disease (PD). Of note, LB accumulation is \nconsidered as a causative factor for PD, thus suggesting that strategies aimed at \nreducing α-syn levels could be relevant for its treatment. \nIn the present study, we set up novel nanocarriers suitable for systemic delivery of \nsiRNA specifically designed to reduce neuronal α-syn by RNA interference. To this \npurpose, we prepared anionic liposomes, loaded with a complex of siRNA-protamine \nfor α-syn gene silencing and decorated with a rabies virus glycoprotein (RVG)-derived \npeptide as a targeting agent. The nanoparticles were characterized for their ability to \nload, protect and deliver the functional siRNA to mouse primary hippocampal and \ncortical neurons as well as for their efficiency to induce gene silencing in these cells. . \nMoreover, the deriving nanocarriers were tested to evaluate their stability in serum. Of \nnote, the RVG-decorated liposomes displayed suitable characteristics for future in vivo \napplications and were able to induce α-syn gene silencing in primary neurons, without \naltering cell viability. Collectively, our results indicate that RVG-decorated liposomes \nmay represent an ideal tool for further studies aimed at achieving efficient α-syn gene \nsilencing in vivo in mouse models of PD.