Poly(DMAEMA-co-PPGMA): Dual-responsive reversible micelles

A series of copolymers with poly(dimethylaminoethyl methacrylate) (P(DMAEMA)), and poly(propylene glycol methacrylate) (PPGMA) segments were synthesized by atom transfer radical polymerization (ATRP) technique. The composition and structural information of the copolymers were studied by gel permeation chromatography (GPC), 1H-NMR, and TGA. The critical micellization concentrations (CMCs), as well as thermodynamic parameters for micelle formation, of these water-soluble copolymers were determined at different temperatures. The micelles formed were temperature and pH responsive as determined by lower critical solution temperature (LCST) measurements at different pH environments. At elevated temperatures and low pH, micelles will form with the hydrophobic P(PPGMA) core and the hydrophilic P(DMAEMA) corona. When the temperature is lowered and the pH raised, the morphology of the micelles are reversed. In this situation, micelles will form with the hydrophobic P(DMAEMA) core and the hydrophilic P(PPGMA) corona. Preliminary cytotoxicity studies were carried out and showed that these copolymers were nontoxic to cells. These copolymers thus show significant promise for use as a multiresponsive carrier vehicle for the delivery of drugs and other therapeutics to the body. (C) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013