Synthesis and characterization of poly(ethylene glycol)-b-poly(ε-caprolactone)-b-poly(2-(2-aminoethyl amino)ethyl methacrylate) triblock copolymers as efficient gene delivery vectors

In this study, ABC‐type triblock copolymers, poly(ethylene glycol)‐b‐poly(ε‐caprolactone)‐b‐poly(2‐(2‐aminoethyl amino) ethyl methacrylate)s (PEG‐PCL‐PAEAEMAs), composed of novel poly(2‐(2‐aminoethyl amino) ethyl methacrylate) (PAEAEMA) that have a primary and a secondary amino group in each monomeric unit, were synthesized successfully. It was found that the length of PAEAEMA segments did not have obvious influence on the DNA‐binding capacity and other biophysical properties (size and zeta potential values of polymer/pDNA complexes) , but longer PAEAEMA chains led to a better buffering capacity. The triblock copolymers could mediate efficient gene expression that was similar to branched 25‐kDa polyethylenimine (25 kDa PEI) in the absence of serum and even superior to 25 kDa PEI in the presence of serum in COS‐7 cells. Low cytotoxicity of these polymers was also found in COS‐7 cells. As a result, PEG‐PCL‐PAEAEMAs are attractive candidates as serum‐tolerable gene carriers in biomedical field. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011