Triple stimuli-responsive polymers based on pyrene-functionalized poly(dimethylaminoethyl methacrylate): synthesis, self-assembled nanoparticles and controlled release.

A series of photo, temperature, and pH-responsive polymers have been synthesized by the quaternization of poly(dimethylaminoethyl methacrylate) (PDMAEMA) with 1-(bromomethyl)pyrene. Nanoparticles self-assembled from the pyrene-functionalized polymers in aqueous solution are demonstrated by transmission electron microscopy (TEM) and dynamic light scattering (DLS), the morphology of which can be changed under external stimulation by UV light, temperature, and pH. With the increase of the functionalization degree, the lower critical solution temperature (LCST) and the photo response of the pyrene-functionalized polymer increases, while the critical aggregation concentration (CAC) and the pH response decreases. The controlled release of encapsulated molecules such as Nile Red (NR)and anticancer drug doxorubicin (DOX) can be achieved under the triple stimulation from the self-assembled nanoparticles. [ABSTRACT FROM AUTHOR]