Cationization of Ganoderma lucidum polysaccharides in concentrated alkaline solutions as gene carriers

Quaternized Ganoderma lucidum glucans (QGs) were synthesized using 3-chloro-2-hydroxypropyltrimethylammonium chloride (CHPTAC) as the cationic reagent in 1 M NaOH aqueous solution at 60 °C. The chemical structure and solution properties of QGs were characterized by using elemental analysis, FTIR, 13C NMR, laser light scattering, ζ-potential measurement and viscometry. The QG solutions in pure water exhibited a typical polyelectrolyte behavior, and normal viscosity behavior in 0.9% NaCl. Moreover, two QG samples with relatively high degree of substitution (DS = 0.43 and 0.51) were selected and studied as gene carriers. The results of gel retardation assay suggested that QGs could condense DNA efficiently. QGs displayed relatively lower cytotoxicity as compared with PEI, and QG/DNA complexes exhibited effective transfection compared to the naked DNA in 293T cells. The quaternized glucan derivatives prepared in NaOH aqueous solutions could be considered as promising non-viral gene carriers.