Remotely Controlling Drug Release by Light-Responsive Cholesteric Liquid Crystal Microcapsules Triggered by Molecular Motors.

Stimuli-responsive smart nanocarriers are an emerging class of materials applicable in fields including drug delivery and tissue engineering. Instead of constructing responsive polymer shells to control the release and delivery of drugs, in this work, we put forward a novel strategy to endow the internal drugs with light responsivity. The microcapsule consisted of molecular motor (MM)-doped cholesteric liquid crystals (CLCs) and drugs. The drug in gelatin-gum arabic microcapsules can protect the carried drugs for a long time with a low release speed totally resulting from drug diffusion. Under UV light, the MM isomerizes and the chirality changes, inducing the alteration of the superstructure of the CLCs. In this process, the cooperative molecular disturbance accelerates the diffusion of the drugs from the microcapsule core to the outside. As a result, thanks to the cooperative effect of liquid crystalline mesogens, molecular-scale geometric changes of motors could be amplified to the microscale disturbance of the self-organized superstructure of the CLCs, resulting in the acceleration of the drug release. This method is hoped to provide opportunities in the design and fabrication of novel functional drug delivery systems.