Controlled ROMP Synthesis of Ferrocene-Containing Amphiphilic Dendronized Diblock Copolymers as Redox-Controlled Polymer Carriers

摘要

Novel well-defined redox-responsive Ferrocene (Fc)-containing amphiphilic dendronized diblock copolymers are synthesized by the ring-opening metathesis polymerization technique using Grubbs' third-generation olefin metathesis catalyst as the initiator. These dendronized block copolymers can self-assemble into spherical micelles in aqueous solution. The size of selfassembled micelles can be modulated by the composition (namely, the ratio of hydrophobic and hydrophilic segments) and concentration of the dendronized copolymers. The obtained micelles show reversible redox-controlled self-assembly behaviors using FeCl_3 as oxidant and glutathione as reductant. Furthermore, the model molecule Rhodamine B is successfully loaded in these micelles, and the oxidation-triggered controllable release is achieved by changing the type of oxidants (FeCl_3 and H_2O_2) and their concentrations. This is the first example of redox-responsive micelles self-assembled by novel amphiphilic dendronized Fc-containing block copolymers, and the present micelles are visualized to be potential candidates in many fields, especially in stimuli-responsive drug delivery systems.