Voltage-responsive micelles based on the assembly of two biocompatible homopolymers†
Voltage stimulus is considered as a clean and simple method in the field of stimuli-responsive polymer systems, in which the system based on β-cyclodextrin (β-CD) and ferrocene (Fc) has attracted considerable attention. Herein, we report voltage-responsive micelles based on the assembly of two biocompatible homopolymers, namely, the poly(ethylene glycol) homopolymer modified with β-CD (PEG–β-CD) and the poly(L-lactide) homopolymer modified with Fc (PLLA–Fc). Through host–guest interactions between β-CD and Fc, the two homopolymers connect together, forming a non-covalent supramolecular block copolymer PLLA–Fc/PEG–β-CD. PLLA–Fc/PEG–β-CD can further self-assemble to form stable micelles in aqueous solution. Through electrochemical control, a reversible assembly–disassembly transition of this micellar system was realized. Voltage-controlled drug release based on this system was also conducted successfully.