Synthesis of an Amphiphilic Multiarm Star Polymer as Encapsulation and Release Carrier for Guest Molecules

A multiarm star amphiphilic polymer with a three-dimensional structure was synthesized via melt polycondensation and atom transfer radical polymerization (ATRP). The polymer, consisting of a hydrophobic hyperbranched polyester (HPE) inner core and hydrophilic poly(2-dimethylaminoethyl methacrylate) (PDMAEMA) multiarm shell, was used as the host for molecular encapsulation, and water-soluble dye (Congo Red) was selected as the corresponding guest molecule. Due to the hyperbranched structure and inner polar core, the synthesized polymer was used as load carrier for encapsulation and release of Congo Red. The skeleton of these polymers played an important role in the procedure of guest-encapsulation. The influences of controlled pH on encapsulation and release behaviors were investigated and examined in vitro in simulated synthetic body fluid. This co-polymer system should be an attractive candidate for drug delivery in aqueous media and could provide the phase-transfer carriers between water and organic media. (C) Koninklijke Brill NV, Leiden, 2010