12th International Conference of Pharmaceutical Sciences

Chitosan has received attention as a carrier for small interfering RNA molecules due to its capacity for complexation and intracellular release of these molecules. However, one of its limitation is the insolubility at neutral pH of its nanoparticles. In this study, amphipathic chitosans were synthesized by varying the degree of acetylation from ~20-30 mol %, and the grafting with diethylaminoethyl (DEAE) groups (15-25 %) and polyethylene glycol chains (PEG) (1.5%)(1). siRNA-containing nanoparticles of 100 to 150 nm were successful prepared with low polydispersities (0.15-0.2) and slightly positive zeta potentials (~+ 5 mV)(2). The cell uptake in Raw 264.7 macrophages was investigated using confocal microscopy. Fluorescence was observed within all areas of the cytoplasm (Fig. 1a). Nanoparticles showed reduced the in vitro TNF-α protein expression of lipopolysaccharide-stimulated macrophages (Fig. 1b). The amphiphilic derivatives displayed low toxicity making these derivatives potential candidates for the development of formulations and in vivo studies.