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

Abstract

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 selforganized 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.

Reconfigurable scaffolds for adaptive tissue regeneration

“…66,67 LCEs, with stimuli-responsive shape-morphing properties, have demonstrated great promise for the applications of actuation, [68][69][70] soft robotics, [71][72][73] and controllable drug delivery. [74][75][76] In the field of tissue engineering and regenerative medicine, LCEs have also received intensive attention first because of their biomimetic architectures. 77 By engineering the orientations of LC moieties to resemble the anisotropic organizations between cells and extracellular matrix (ECM) fibrils in some biological tissues such as muscle, it could achieve directional alignments of cells on LCE-based scaffolds, [78][79][80] Diverse cellular functions (e.g., cellular function maturation 81 and stem cell differentiation 82 ) for facilitating tissue regeneration could be subsequently modulated.…”

Amplifying Molecular Scale Rotary Motion: The Marriage of Overcrowded Alkene Molecular Motor with Liquid Crystals

“…To explore the potential applications of the OAMM‐driven droplet, our group prepared light‐directed microcapsules composed of OAMM 11 ‐doped CLC core and gelatin shell ( Figure a,b). [ 90 ] It was found that there was only negligible leakage of LC when dispersing the microcapsules in aqueous solution due to the protection of the polymer shell. By UV irradiation, the texture of CLC core rotated (Figure 9c), at the meantime, the LC molecules escaped from the inner core, illustrating that the morphology change of CLC core could accelerate the leakage of container.…”

“…8CB and E7 represent commercial smectic LC with high viscosity and commercial nematic LC with low viscosity, respectively. a-e) Reproduced with permission [90]. Copyright 2021, American Chemical Society.…”

Thermochromic Cholesteric Liquid Crystal Microcapsules with Cellulose Nanocrystals and a Melamine Resin Hybrid Shell

“…The usual approach is to disperse the CLCs and then cover the resulting droplets with a shell. Various methods have been developed to fabricate the shells of CLC microcapsules using CLC emulsion microdroplets as templates, such as in situ polymerization, , interfacial polymerization, complex coacervation, , and sol–gel methods . Compared to surfactant-stabilized conventional emulsions, solid particle-stabilized Pickering emulsions show better stability and sustainability and have been demonstrated to be a promising template to fabricate microcapsules. ,,,− Cellulose nanocrystals (CNCs) are rod-like nanocelluloses and are normally extracted from wood pulp or cotton via acid hydrolysis. , CNCs display outstanding Pickering emulsifying ability due to their partial wettability with both oil and water phases.…”

“…The usual approach is to disperse the CLCs and then cover the resulting droplets with a shell. Various methods have been developed to fabricate the shells of CLC microcapsules using CLC emulsion microdroplets as templates, such as in situ polymerization, 31,32 interfacial polymerization, 33 complex coacervation, 34,35 and sol−gel methods. 36 Compared to surfactant-stabilized conventional emulsions, solid particle-stabilized Pickering emulsions show better stability and sustainability and have been demonstrated to be a promising template to fabricate microcapsules.…”