Multiple stimuli-responsive polymeric micelles for controlled release

Multiple stimuli-responsive polymeric micelles that can respond to light, temperature and pH have been prepared by a novel polymer, pyrene-functionalized poly (dimethylaminoethyl methacrylate), where the pyrene-quaternized segments form a light-responsive shell and the unquaternized segments form a temperature/pH-responsive core. Under UV irradiation, the micelles could be dissociated; when the temperature increased above the lower critical solution temperature, the micelles shrunk. At pH 3, the micelles could be swelled/dissociated and at pH 10, the micelles could be collapsed to complex micelles. The controlled release of Nile Red from the micelle under stimuli was demonstrated. This novel multiple stimuli-responsive micelle shows potential as a new nanocarrier and delivery system.