Biodegradable micelles/polymersomes from fumaric/sebacic acids and poly(ethylene glycol).

Linear unsaturated oligo-anhydrides containing terminal acylchloride groups have been synthesized by polycondensation of fumaric or sebacic acid with either fumaryl chloride or sebacoyl chloride. Reaction of these oligo-anhydrides with poly(ethylene glycol) produce di- and tri-block copolymers. The oligo-anhydrides and block copolymers have been characterized by gel permeation chromatography (GPC), NMR and FT-IR spectroscopies. The tri-block copolymers composed of two PEG end blocks and an oligo-anhydride center block have been used in encapsulation of calcein (encapsulation efficiency up to 40%). Encapsulation and release profile of calcein (as a model hydrophilic drug) from the di-block copolymers (micelles) and tri-block copolymer vesicles (polymersomes) as well as their in-vitro hydrolytic degradation (pH=7.4 degrees C, 37 degrees C) are reported.