Reversible Regulation of Drug Release from Chiral Liquid Crystalline Polymer Micelles without Leakage

Liquid crystalline polymers (LCPs) exhibit abrupt changes in their organized structures and mobilities at phase transition temperatures, which is reminiscent of the unique structures and properties of biological membranes. Despite the numerous potential applications of LCPs, no study of their medical use has been reported. In this study, we synthesized amphiphilic LCPs with chiral mesogens by introducing hydrophilic oligo­(ethylene glycol) (OEG), hydrophobic mesogens, and chiral mesogens into polysiloxane main chains. The resulting chiral LCP-g-OEG formed micelles with a highly ordered hydrophobic core and a hydrophilic OEG shell. While the release of a model drug from chiral LCP-g-OEG micelles was effectively suppressed at temperatures below the nematic–isotropic phase transition temperature (T NI), it was enhanced by an increase in the temperature above T NI. The reversible thermoresponsive ON–OFF regulation of drug release without leakage was achieved by using chiral LCP-g-OEG micelles. Interestingly, the chiral LCP-g-OEG micelles were preferentially internalized by cancer cells compared with normal cells.