PH- and thermo-sensitive co-polymers based on a hyperbranched polymers core as encapsulation and release carriers for guest molecules

Abstract

Hyperbranched poly(3-ethyl-3-(hydroxymethyl)oxetane) (HPBO), modified by S-1-dodecyl-S′-(α, α-dimethyl-α′′-acetic acid) trithiocarbonate (DMP) to form a RAFT macroinitiator, and then two monomers, 2-(dimethylamino)ethyl-methacrylate (DMAEMA) and acrylic acid (AA), were polymerized to obtain novel pH- and thermo-sensitive polymers with a hyperbranched polymer core. These polymers exhibited phase transitions in response to pH and temperature. They were possible to harvest a bioactive molecule, indometacin, from solution using the phase transition of these pH- and thermo-sensitive polymers. Various parameters, such as percent loading of drugs, pH, temperature and nature of the release media on the release profiles, were investigated. The resultant polymer carriers can potentially be used for the controlled release of the anti-inflammatory drug indometacin. © 2010 Koninklijke Brill NV, Leiden.