Twofold Light and Magnetic Responsive Behavior in Nanoparticle–Lyotropic Liquid Crystal Systems

Abstract

We demonstrate the dual magnetic and light responsive nature of hybrid mesophases constituted by Fe(3)O(4) nanoparticles dispersed in lipid-based lyotropic liquid crystals (LC). When subjected to an external magnetic field in the mesophase isotropic state, the nanoparticles aggregate and orient along the magnetic field direction, and upon cooling the system through the disorder-order transition the aggregates drive the orientation of the mesophase via heterogeneous nucleation; furthermore, order-disorder transitions in the lipidic mesophase can be triggered by Fe(3)O(4)-induced photothermal effect under visible light exposure. Both the orientational order and the photothermal effect of the hybrid mesophase can be tuned by the nanoparticle content, offering a general route for controlled assembly of complex fluids with combined magnetic and light responsiveness.

Lamellar Lα Mesophases Doped with Inorganic Nanoparticles

“…Then, the lamellar phase melts and all birefringence is lost. [86] Thus, such systems are both light-and magnetic-field-responsive and might therefore find biomedical applications. Optical microscopy textures (top) and SAXS signal (bottom) of the nematic phase of goethite, at a concentration fg=8 vol %, in water (left) and contained within the lamellar La phase (right).…”

Dual‐Responsive Viscoelastic Lyotropic Liquid Crystal Fluids to Control the Diffusion of Hydrophilic and Hydrophobic Molecules

“…Third, the microstructures and properties (e.g., rheological properties and stability) of LLC systems can be well modulated by adjusting either the solution environment or the molecule structures. As a result, these systems are usually used as controlled drug‐delivery systems …”

“…As ar esult,t hese systems are usually used as controlled drugdelivery systems. [9][10][11][12][13][14] Stimuli-responsive LLC drug-delivery systems show special behavior in response to variationsi np H, temperature, light, magnetic field,i onic strength,t he presence and type of metal cations,a nd oxidation-reduction reactions. Of these external stimuli,l ight has attracted particulara ttention because it provides ab road range of tunable parameters (e.g.,w avelength, intensity,a nd duration)t om anipulate the rheological properties of photoresponsive systems.…”

Understanding the photothermal heating effect in non-lamellar liquid crystalline systems, and the design of new mixed lipid systems for photothermal on-demand drug delivery

“…14 Functionalised nanostructured materials, like self-assembled liquid crystalline matrices, are of particular interest for many bioapplications including the optimisation of pharmaceutical and diagnostic therapies. 22,23 The reversible phase transitions in the proposed stimuli responsive liquid crystalline drug delivery systems were in the direction from the fast releasing V 2D phase to the slower releasing H 2 structure in the PHYT and GMO matrices, which is the opposite of that which would be ideal for pulsatile release matrices. The interest in these materials stems from their biocompatibility, the ability to solubilise hydrophobic and hydrophilic active drugs, 4 thermodynamic stability in excess water which allows for dispersion of lipids into nanoparticles which retain the internal nanostructure, 15 and most importantly, a Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical the potential to control the release of active drugs through control of the nanostructure.…”