Synthesis and Encapsulation-Release Property of Unimolecular Inversed Micelle having Hyperbranched Polysaccharide Core

摘要

Amphiphilic macromolecules have attracted growing interest with respect to biotechnological and pharmaceutical applications. In particular, amphiphilic three-dimensional macromolecular architectures, which have hydrophobic and hydrophilic regions in one molecule, have a stable micelle-type structure, therefore, that they are suitable for the noncovalent encapsulation of guest molecules. Recently, we reported that hyperbranched polysaccharides were synthesized by the thermally induced cationic polymerization of 1,6-anhydrohexopyranoses. Thus, of great interest is to study the synthesis of amphiphilic hyperbranched polysaccharides along with their amphiphilic property, e.g., the encapsulation-release property of hydrophilic guest molecules. In this study, we report the reaction of a hyperbranched polysaccharide (1) using N-carbonyl L-leucine ethyl ester (2) leading to a novel amphiphilic polymer consisting of the hyperbranched polysaccharide as the core (3), as shown in Scheme 1. In addition, the encapsulation-release property of 3 toward water-soluble dyes, rose bengal, is discussed on the basis of UV-Vis and CD measurements.