Synthesis and Self-Assembly of Stimuli-Responsive Poly(2-(dimethylamino) ethyl methacrylate)-block-fullerene (PDMAEMA-b-C60) and the Demicellization Induced by Free PDMAEMA Chains

Well-defined poly(2-(dimethylamino) ethyl methacrylate)-block-fullerene [60] ((PDMAEMA)-b-C-60) with a galactose targeting moiety was prepared by atom-transfer radical polymerization (ATRP). This copolymer was designed for possible use as a targeted drug carrier. The chemical composition and the self-assembly behavior were characterized using different techniques, including GPC, NMR, UV, and DLS. The self-assembly of the galactose-functionalized PDMAEMA-b-C-60 structure in aqueous solutions was investigated using dynamic light scattering (DLS) under different pH conditions. At pH 3 and 10, the DLS results showed the presence of both polymeric micelles and unimers. However, a smaller R-h was observed at pH 10 than at pH 3 because of electrostatic repulsion at low pH values. In addition, free PDMAEMA chains induced the demicellization of self-assembled nanostructures caused by the formation of a charge-transfer complex between PDMAEMA and C-60. This phenomenon offers possible applications for free-polymer-triggered drug release.