Redox-Controlled Voltage Responsive Micelles Assembled by Noncovalently Grafted Polymers for Controlled Drug Release

Voltage responsive micelles prepared from noncovalently grafted amphiphilic polymers were reported. The noncovalent amphiphilic polymers were prepared through the host-guest interaction between beta-cyclodextrin (beta-CD) grafted dextran (Dex-CD) and ferrocene (Fc) terminated poly(epsilon-caprolactone) (PCL-Fc). Because of the presence of Fc groups, the inclusion complex between Fc and beta-CD can be reversibly controlled by an external stimulating voltage, leading to reversible formation and disassembly of the micelles. The occurrence of the inclusion complex between Fc and beta-CD was confirmed by cyclic voltammetry (CV) and the 2D NOESY spectrum. Furthermore, meloxicam was selected as a model drug to test the controlled release performance of these voltage responsive micelles. It was found that the release rate and the final cumulative release amount of meloxicam can be effectively controlled by the external voltage, which may be of use in controlled drug delivery.