Multiresponsive properties of triple-shell architectures with poly(N,N-diethylaminoethyl methac rylate), poly(N-vinylcaprolactam), and poly(N,N-dimethylaminoethyl methac rylate) as building blocks

Triple-shell architectures, consisting of poly[(N,N-diethylaminoethyl methacrylate)-block-(N-vinylcaprolactam)-block-(N,N-dimethylaminoethyl methacrylate)] triblock copolymers, are obtained by sequential reversible addition-fragmentation chain transfer polymerizations, using a terminal-modified hyperbranched poly(β-cyclodextrin) core as a macro chain transfer agent. UV-vis spectroscopy results indicate that the triple-shell architectures possess one pH response at pH 12.5 in aqueous solution at room temperature, followed by double-temperature-responsiveness between 33 °C and 36 °C. The special multire-sponsive properties are further confirmed by investigating the controlled release behavior of the resulting polymers using metronidazole as a model drug.