Highly Effective Gene Transfection In Vivo by Alkylated Polyethylenimine
Figure 1
The effect of N-alkylation on the buffer capacity and DNA binding efficiency of linear PEI. (a) Acid titration profiles of aqueous solutions of the underivatized PEI (solid squares), methyl-PEI (open squares), ethyl-PEI (solid triangles), propyl-PEI (open triangles), butyl-PEI (solid circles), octyl-PEI (open circles), and NaCl as a control (× symbols). The corresponding 113 mM solutions were adjusted to pH 11.5 at room temperature and then titrated with 0.5 M HCl (0.04 M in the case of NaCl). (b) Displacement of the intercalated fluorophore EtBr from plasmid DNA by the underivatized PEI (solid squares), methyl-PEI (open squares), ethyl-PEI (solid triangles), propyl-PEI (open triangles), butyl-PEI (solid circles), and octyl-PEI (open circles). N/P ratio is that between the nitrogen atoms in the polycation and the phosphate groups of the bases in the plasmid.
