Amphiphilic random polycarbonate self-assemble into GSH/pH dual responsive micelle-like aggregates in water

Responsive polymers have been playing an increasingly important role in a wide variety of applications, such as biomedical materials and biosensors. Herein, we reported a dual-responsive polycarbonate (poly (MN-co-MSS)) based on the macrocyclic Sulfur/Nitrogen-substituted carbonate monomer (MSS/MN) via an enzyme-catalyzed ring-opening copolymerization and Lipase CA Novozym-435 as catalyst, with the disulfide and tertiary amine groups situated on the backbone. The structure of the random copolymers was confirmed by NMR and FTIR. In addition, size exclusion chromatography (SEC) results indicated that the copolymer had a symmetric peak and a relatively narrow polydispersity. Also, the random copolymers can self-assemble into micelle-like aggregates in water due to the hydrophilicity endowed by the amino groups, and the aggregates exhibited rich pH and GSH responsive behavior, which was verified by zeta masters instrument and dynamic light scattering (DLS). Moreover, transmission electron microscopy (TEM) demonstrated the morphology of the micellar aggregates and the variation subjected to the lower pH and GSH, and the responsive mechanism was elaborated. Therefore, these results highlighted a facile synthesis of the environment-responsive polymers and provided a novel GSH/pH responsive material platform for further application.