Synthesis and Characterization of a Biodegradable ABC Triblock Terpolymer as Co-Delivery Carrier of Doxorubicin and DNA

This study is aimed to develop a well-defined ABC triblock terpolymer, poly(ethylethylene phosphate)-blockpoly(epsilon-caprolactone)-block-poly[2-(dimethylamino) ethyl methacrylate] (PEEP-b-PCL-b-PDMAEMA), for co-encapsulating anticancer drug doxorubicin (DOX) and DNA to form polyplexes. The terpolymer is first synthesized via a combination of ring-opening polymerization and atom-transfer radical polymerization techniques, and characterized by H-1 NMR and gel permeation chromatography. Subsequently, the self-assembly behavior of the terpolymer and the micelles loaded with DOX or DNA are investigated by dynamic light scattering, zeta potential, transmission electron microscopy, and gel retardation assay, respectively. In vitro release study reveals that much more DOX is released at pH 5.0 than that at pH 7.4 in the same period. The simultaneous delivery of DOX and green fluorescent protein (GFP)-labeled DNA is studied by a fluorescence microscope and the results demonstrate that both drug and GFP-DNA can be efficiently delivered into HeLa cells. This system presents a practical and promising carrier for the co-delivery of drugs and genes. (c) 2014 Wiley Periodicals, Inc.