Polysaccharide-coated polypeptidic micelles for drug delivery

Polypeptides and block copolypeptides prepared by ring opening polymerization of Ncaboxyanhydrides of protected aminoacids have attracted great research interest due to their broad structural and chemical diversity, their self-assembling properties and their intrinsic biocompatibility. In this contribution we present a carrier for drug delivery based on micelles formed by block copolypeptides of benzyloxycarbonyl lysine and glutamic acid. Upon tuning of the structure, highly reproducible and homogeneous micelles can be produced. We have improved the stability of the system by coating the particles with polysaccharides. Our methodology has permitted the encapsulation of a hydrophobic antimicrobial drug, which reinforces the micelle formation. Drug release experiments reveal an improved performance for coated micelles in different media and indicate the system might be appropriate for oral drug delivery. Our studies with M. tuberculosis bacteria in vitro show a promising decrease in the minimum inhibitory concentration compared to the controls.