Aerosol-based fabrication of modified chitosans and their application for gene transfection

J.H. Byeon, J.T. Roberts
Purdue University, US

Keywords: aerosol, modified chitosan, gene transfection


Droplets containing modified chitosans were formed by collison atomization, dried to form solid particles, and collected and studied for potential use as nanocarriers (Figure 1). Modified chitosans consisted of a chitosan backbone and an additional component [with cholesterol, poly(L-lysine) (PLL), PEI, or poly(ethylene glycol) (PEG)]. Agarose gel retardation assays confirmed that modified chitosans could associate with plasmid DNA. Even though the cell viability of cholesterol-chitosan (Ch-Cs) showed a slight higher cytotoxicity (~90% in cell viability) than that for unmodified chitosan (Cs, ~95%), transfection [>7.5 × 105 in relative light units (RLU) mg-1] was more effective than it was for Cs (~7.6 × 104 RLU mg-1). The addition of PEI onto Cs (i.e. Cs/PEI) enhanced the transfection efficiency (~1.3 × 106 RLU mg-1) more than did the addition of PLL (i.e. Cs/PLL, ~9.3 × 105 RLU mg-1). However it resulted in higher cytotoxicity (~86% in cell viability for Cs/PEI vs ~94% for Cs/PLL). The cell viability (~92%) and transfection efficiency (~1.9 × 106 RLU mg-1) were complemented by further adding PEG on Cs/PEI (i.e. Cs/PEI-PEG). This work concludes that gene transfection of Cs can be significantly enhanced by adding cationic polymers during aerosol fabrication without wet chemical modification processes of Cs.