New biocompatible amphiphilic diblock copolymer based on dextran

A new biocompatible amphiphilic diblock copolymer was obtained by end-to-end coupling of amino terminated dextran with an oligoester based on lithocholic acid. The bile acid oligoester was synthesized by polycondensation reaction of 3-succinoyloxy-derivative of lithocholic acid with diethylene glycol. The compounds were characterized by H-1 NMR and Fourier transform infrared spectroscopy. Size exclusion chromatography, thermal studies and wide-angle X-ray diffraction technique were used for oligoester and diblock copolymer characterization. The hydrodynamic diameter, size distribution and morphology of diblock copolymer self-aggregates formed in aqueous media were studied by dynamic light scattering and transmission electron microscopy. The critical aggregation concentration value for dextran copolymer (0.028 mg/mL) in aqueous solution was determined by fluorescence probe technique and it was lower than that of low molecular weight surfactants. (C) 2015 Elsevier Ltd. All rights reserved.