All-aqueous liquid crystal emulsions for 4D laser-printing of dual-stimuli response porous 3D printlets with on-demand remote control of drug release

• An all-aqueous cholesteric bicontinuous liquid crystal is successfully stabilized by cellulose nanocrystal. • A dual stimulus response printlet is fabricated from w/w bicontinious liquid crystals. • The laser 3D printlets provided a sustained drug release profile at human body temperature. • The 3D printlets demonstrated a gated response in an aqueous environment in the realms of drug delivery systems. The integration of responsive materials with 3D printing can lead to fabrication of functional smart 4D structures for use in health, biofabrication, and biosensing. Here, we utilized an all-aqueous two-phase system made from chitosan and carrageenan to create a bioactive all-water emulsion encapsulating curcumin to develop 4D printed 'prinlets' for possible drug delivery. Specifically, we described the production of an original all-aqueous cholesteric bicontinuous liquid crystal (LC) emulsion, which was accomplished by homogenizing or sonicating a rod-like cellulose nanocrystal (CNC) with two thermodynamically immiscible, phase-separating carrageenan and chitosan dispersions. Stable water-in-water emulsions were effectively prepared by mixing or sonicating the respective CNC/biopolymer dispersions, resulting in micrometric CNC/chitosan dispersed droplets (loaded with curcumin) in a CNC/carrageenan continuous phase. The LC-based emulsion showed a confined 3D percolating bicontinuous network with cholesteric self-assembly of CNCs within the carrageenan phase, while the nanoparticles in the chitosan phase remain isotropic. After laser 3D printing of the freeze-dried LC-based emulsion, 3D macroporous “printlets” encapsulated with curcumin were produced exhibiting a dual-stimuli-responsive to temperature and redox. The curcumin-loaded 3D 'printlets' exhibited superior thermosensitive properties and maintained a sustained drug release profile, exhibiting much greater on-demand release mode at human body temperature. Notably, the 3D porous “printlets” demonstrated a gated response to the aqueous environment, showcasing potential advancements in the realms of supramolecular sensors and drug delivery systems.