Carboxylated hydroxyethyl starch: a novel polysaccharide for the delivery of doxorubicin.

Hydroxyethyl starch (HES) was interacted with succinic anhydride affording a carboxylated derivative which has proved to be a promising polymeric drug delivery system. Specifically, this polymer is conveniently prepared, is biodegradable, non-immunogenic, and can encapsulate doxorubicin due to the protonation of the primary amino group of doxorubicin by the carboxylic group located on the branched scaffold of the polysaccharide. In addition, due to the polyhydroxylated character of the polysaccharide, the latter can act as a protective coating in an analogous manner to the PEG-chains ensuring prolonged circulation in vivo. In vitro experiments showed controlled release of doxorubicin to the nuclei of DU145 prostate cancer cells when the anticancer drug is incorporated in the carboxylated hydroxyethyl starch.