pH sensitive vinyl copolymers as vectors for gene therapy

A series of pH-sensitive vinyl (co)polymers was synthesised to investigativ e whether the buffering capacity is a crucial factor in determining the tra nsfection efficiency of synthetic vectors in gene therapy. The polymers con taining side groups with different pKa were prepared by radical polymerizat ion. All cationic polymers were able to condense DNA, yielding rather small and homogeneous particles, as determined by dynamic light scattering. The effect of pH, temperature and serum albumin on complex formation was also i nvestigated. The results from the titration studies showed that copolymers of (2-dimethylaminoethyl) methacrylate and 4-methyl-5-imidazoyl methyl meth acrylate or methacrylic acid have a buffering effect over a broader pH rang e compared to poly(2-dimethylaminoethyl methacrylate). Introduction of N-(2 -hydroxyethyl) nicotinamide methacrylate had no significant, effect on the buffering range.