Stimuli-responsive lipidic cubic phase: triggered release and sequestration of guest molecules

Abstract

New stimuli-responsive nanomaterials, made up of host-guest lipidic cubic phases (LCPs) are presented. These biocompatible, stable, transparent and water-insoluble LCPs are composed of monoolein (MO) as a neutral host, and small amounts of one of three judiciously designed and synthesized designer lipids as guest that preserve the structure and stability of LCPs, but render them specific functionalities. Efficient pH- and light-induced binding, release and sequestration of hydrophilic dyes are demonstrated. Significantly, these processes can be performed sequentially, thereby achieving both temporal and dosage control, opening up the possibility of using such LCPs as effective carriers to be used in drug delivery applications. Specifically, because of the inherent optical transparency and molecular isotropy of LCPs they can be envisaged as light-induced drug carriers in ophthalmology. The results presented here demonstrate the potential of molecular design in creating new functional materials with predicted operating mode.

Keywords: drug delivery; lipidic cubic phase; lipids; stimuli-responsive lipids; triggered release.