Self-assembly of near-monodisperse redox-sensitive micelles from cholesterol-conjugated biomimetic copolymers

Poly(D,L-lactide)-SS-poly(2-methacryloyloxyethyl phosphorylcholine) block copolymers conjugated with cholesterol are synthesized by ROP and ATRP using a novel kind of double-dead initiator. This facile strategy not only can endue block copolymers with disulfide bonds, but can also overcome the disadvantages inherent in the synthesis procedure for the copolymers. The resultant biomimetic copolymers can self-assemble into near-monodisperse micelles. Subsequently, they are used as a carrier to encapsulate a hydrophobic dye, and the release can be triggered by a redox reagent, dithiothreitol. MTT study shows that the as-prepared micelles has good biocompatibility to both normal and cancer cells. These properties indicate that these micelles may be used as promising drug delivery vehicles.