Liquid Crystal Nanoparticles Research Articles

Recent Advances in Ocular Drug Delivery: Insights into Lyotropic Liquid Crystals.

Background/Objectives: This review examines the evolution of lyotropic liquid crystals (LLCs) in ocular drug delivery, focusing on their ability to address the challenges associated with traditional ophthalmic formulations. This study aims to underscore the enhanced bioavailability, prolonged retention, and controlled release properties of LLCs that significantly improve therapeutic outcomes. Methods: This review synthesizes data from various studies on both bulk-forming LLCs and liquid crystal nanoparticles (LCNPs). It also considers advanced analytical techniques, including the use of machine learning and AI-driven predictive modeling, to forecast the phase behavior and molecular structuring of LLC systems. Emerging technologies in biosensing and real-time diagnostics are discussed to illustrate the broader applicability of LLCs in ocular health. Results: LLCs are identified as pivotal in promoting targeted drug delivery across different regions of the eye, with specific emphasis on the tailored optimization of LCNPs. This review highlights principal categories of LLCs used in ocular applications, each facilitating unique interactions with physiological systems to enhance drug efficacy and safety. Additionally, novel applications in biosensing demonstrate LLCs' capacity to improve diagnostic processes. Conclusions: Lyotropic liquid crystals offer transformative potential in ocular drug delivery by overcoming significant limitations of conventional delivery methods. The integration of predictive technologies and biosensing applications further enriches the utility of LLCs, indicating a promising future for their use in clinical settings. This review points to continued advancements and encourages further research in LLC technology to maximize its therapeutic benefits.

Topological and Morphological Membrane Dynamics in Giant Lipid Vesicles Driven by Monoolein Cubosomes

Lipid nanoparticles have important applications as biomedical delivery platforms and broader engineering biology applications in artificial cell technologies. These emerging technologies often require changes in the shape and topology of biological or biomimetic membranes. Here we show that topologically‐active lyotropic liquid crystal nanoparticles (LCNPs) can trigger such transformations in the membranes of giant unilamellar vesicles (GUVs). Monoolein (MO) LCNPs, cubosomes with an internal nanostructure of space group Im3m incorporate into 1,2‐dioleoyl‐sn‐glycero‐3‐phosphocholine (DOPC) GUVs creating excess membrane area with stored curvature stress. Using time‐resolved fluorescence confocal and lattice light sheet microscopy, we observe and characterise various life‐like dynamic events in these GUVs, including growth, division, tubulation, membrane budding and fusion. Our results shed new light on the interactions of LCNPs with bilayer lipid membranes, providing insights relevant to how these nanoparticles might interact with cellular membranes during drug delivery and highlighting their potential as minimal triggers of topological transitions in artificial cells.

Topological and Morphological Membrane Dynamics in Giant Lipid Vesicles Driven by Monoolein Cubosomes.

Lipid nanoparticles have important applications as biomedical delivery platforms and broader engineering biology applications in artificial cell technologies. These emerging technologies often require changes in the shape and topology of biological or biomimetic membranes. Here we show that topologically-active lyotropic liquid crystal nanoparticles (LCNPs) can trigger such transformations in the membranes of giant unilamellar vesicles (GUVs). Monoolein (MO) LCNPs, cubosomes with an internal nanostructure of space group Im3m incorporate into 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) GUVs creating excess membrane area with stored curvature stress. Using time-resolved fluorescence confocal and lattice light sheet microscopy, we observe and characterise various life-like dynamic events in these GUVs, including growth, division, tubulation, membrane budding and fusion. Our results shed new light on the interactions of LCNPs with bilayer lipid membranes, providing insights relevant to how these nanoparticles might interact with cellular membranes during drug delivery and highlighting their potential as minimal triggers of topological transitions in artificial cells.

Preparation of cubic liquid crystal nanoparticles of puerarin and its protective effect on ischemic stroke

The low oral bioavailability of puerarin (Pur) affects its efficacy. Preparation of puerarin cubic liquid crystal nanoparticles (Pur-Cub) enhances the protective effect of Pur against ischemic stroke (IS) by increasing its bioavailability. The average particle size, PDI, and zeta potential of Pur-Cub were 274.70 ± 16.20 nm, 0.24 ± 0.05 and −25.30 ± 2.34 mV, respectively. Polarized light microscopy (PLM) and Small angle X-ray diffraction (SAXS) identified Pur-Cub as a cubic phase (Pn3m). The in vitro release of Pur-Cub was fast and then slow, in accordance with the biphasic kinetic equation. Pur-Cub increased the penetration of Pur in the intestine (mainly the duodenum) and significantly improved the bioavailability of Pur in the blood (304.16 %) and its distribution in the brain (1.69-fold) compared to Pur suspension. Pur-Cub narrowed down cerebral infarcts and significantly reduced levels of TNF-α, IL-1β, and IL-6 in a rat model of middle cerebral artery occlusion (MCAO).

Therapeutic Potential of Molsidomine-Loaded Liquid Crystal Nanoparticles for the Treatment and Management of Niacin-Induced Varicose Veins: In Vitro and In Vivo Studies.

Varicose vein therapy has historically relied significantly on invasive surgical procedures, which frequently resulted in poor compliance among patients. The tendency could stem from the past use of abrasive surgical procedures and a lack of documented drug-induced animal models. To address this challenge, we envisaged an innovative approach for animal model development that uses niacin-induced recurrent flushing. And to further treat the condition, we used liquid crystal nanoparticles (LCNPs) as carriers for the antiangiogenic, cardio protective, and anti-inflammatory drug molsidomine. After the successful initiation of reticular perforant varicose veins, the animals were administered and treated with molsidomine-loaded liquid crystal nanoparticles (MD-LCNPs) that were simultaneously synthesized via a straightforward homogenization method. The preparation of MD-LCNPs involved inducing the disruption of a cubic-phase gel of glyceryl monostearate (GMS) by Milli-Q water in the presence of a Tween-80. Characterization of MD-LCNPs encompassed an assessment of their physicochemical properties. Microscopic studies revealed monodispersity with an average size of 195 ± 55.94 nm. In vitro evaluations demonstrated commendable antioxidant potential, excellent swelling behavior, and sustained release behavior of MD-LCNPs. Furthermore, MD-LCNPs exhibited nontoxicity toward cells, with minimal generation of reactive oxygen species (ROS) or nitric oxide (NO). Histopathological and hematological analysis indicated the efficacy of MD-LCNPs in ameliorating niacin-induced varicose veins, the absence of detrimental and toxic effects on blood cells and visceral organs, and safety for intravenous administration. Following the administration of nanoparticles, the formulation demonstrated appropriate levels of prostaglandins (PGDs), vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and vascular endothelial growth factor (VEGF). This substantiates the formulation's suitability for the treatment and management of varicose veins. In conclusion, our work shows an efficient method that induces varicose veins in rodents, and also a promising nanocarrier-based drug delivery approach using MD-LCNPs for effective and safe varicose vein therapy.

Liquid crystal nanoparticles for oral combination antibiotic therapies: A strategy towards protecting commensal gut bacteria during treatment

Antibiotics are essential for treating infections and reducing risks during medical interventions. However, many commonly used antibiotics lack the physiochemical properties for an efficient oral administration when treating systemic infection. Instead, we are reliant on intravenous delivery, which presents complications outside of clinical settings. Developing novel formulations for oral administration is a potential solution to this problem. We engineered hexosome and cubosome liquid crystal nanoparticles (LCNPs) characterized by small-angle X-ray scattering and cryogenic transmission electron microscopy, and could encapsulate the antibiotics vancomycin (VAN) and clarithromycin (CLA) with high loading efficiencies. By rationally choosing stable lipid building blocks, the loaded LCNPs demonstrated excellent resilience against enzymatic degradation in an in vitro gut model LCNP stability is crucial as premature antibiotic leakage can negatively impact the gut microbiota. In screens against the representative gut bacteria Enterococcus faecalis and Escherichia coli, our LCNPs provided a protective effect. Furthermore, we explored co-administration and dual loading strategies of VAN and CLA, and demonstrated effective loading, stability and protection for E. faecalis and E. coli. This work represents a proof of concept for the early-stage development of antibiotic-loaded LCNPs to treat systemic infection via oral administration, opening opportunities for combination antibiotic therapies.

Исследование теплового эффекта на основе наночастиц жидких кристаллов

Исследование теплового эффекта на основе наночастиц жидких кристаллов

On the effects of dispersing polar nanoparticles in liquid crystals

We have investigated the effect of adding polar rodlike nanoparticles (NPs) to a liquid crystal using Monte Carlo simulations. The mesogens (Ms) are represented with Gay–Berne elongated ellipsoids endowed with a central axial electric dipole. A NP is instead modelled by a overall rod-like set of rigidly assembled Lennard–Jones spherical beads (Orlandi et al. Phys. Chem. Chem. Phys. 18, 2428–2441 (2016). doi:10.1039/C5CP05754J) that are either non-polar or endowed with a central axial dipole of different strengths. We consider two cases: one of strong NP-M affinity and weak NP-NP interactions (case 1) and the opposite one of weak NP-M affinity and strong NP-NP interactions (case 2). We find that for case 1 adding polar NPs slightly lowers the nematic-isotropic transition temperature T NI which instead, for case 2, is essentially unaffected. Having strongly polar, instead of non-polar NPs reduces the T NI difference with the pristine one, while significantly increasing the dielectric anisotropy in the nematic phase, which could be useful in applications.

Optimization of the properties of nematic matrix suspended with subtle quantities of the nanoparticles for improved alignment and operating voltage

ABSTRACT The current study examines and reflects the effect of minute quantity of Diamond nanoparticles (DNPs) in the Nematic liquid crystal (NLC) matrix. A well structured and strategized study is performed in order to get a deep understanding about the interactions that might have taken place between the guests and the hosts. Our study professed a significant alteration in the number of parameters of guest-host system in comparison to the pure liquid crystal (LC) matrix that could be found extremely promising for the display devices and low-power switching machines. 0.05, 0.07 and 0.1 wt/wt% concentrations of the NPs incorporated in the LC matrix and the composites are prepared with the high precision weight measurement using electrical balance. Dielectric spectrum is catalogued for both the homogeneous and vertical alignments of sample cells. Threshold voltage and operating voltage are found to be significantly decreased for 0.05 wt/wt% composite. Response time for the prepared composites is profoundly abated which is a crucial factor for the fast response devices. Careful examination of pretilt angles is executed and an improvement in the alignment is found as one more perk of this study.

Synthesis of seawater-derived superhydrophobic calcium carbonate via CO2 mineralization by utilizing L-Arginine/L-Lysine oleate-based self-assembly structures

Superhydrophobic materials have been gaining popularity owing to their self-cleaning, anti-freezing, and anti-corrosion properties. This study presents an approach for the synthesis of superhydrophobic calcium carbonate via CO2 mineralization using carbon capture utilization (CCU) technology. By using biodegradable amino acids (L-arginine/L-lysine) and oleic acid, various biosurfactant self-assembly structures were formed as surface-modifying agents of calcium carbonate owing to the saponification and lyotropic phase transition. Moreover, calcium cations were recovered from salt-farm wastewater using pH-swing ion separation for sustainability and waste management. we presented various self-assembly structures depending on the ratio of amino acids to oleic acid, such as spherical micelles, liquid crystal nanoparticles, and vesicles for L-arginine oleate and spherical micelles, cylindrical micelles, and planar lamellar structures for L-lysine oleate. The synthesized calcium carbonates were 87.95 % purified scalenohedral calcite under micellar L-arginine oleate and 87.08 % purified spherical calcite under micellar L-lysine. Moreover, their surface areas were 28.85 m2/g for L-arginine and 13.46 m2/g for L-lysine. They were significantly improved and larger than that of commercial calcium carbonate (3.45 m2/g). In comparison, larger agglomerated calcite particles were produced under the other self-assembled structures. During mineralization, the amount of calcium oleate adsorbed on the surface of calcium carbonate played a crucial role in particle formation. Notably, superhydrophobic calcium carbonates were synthesized with a contact angle of 168.66° under spherical micelles of L-arginine oleate and 167.46° under spherical micelles of L-lysine oleate. The in-situ surface modification method utilizing biosurfactant self-assembled structures was expected to revitalize the carbon capture and utilization.

Superior photoluminescence of quantum dot displays via organic-inorganic composite scatterers

High color purity of quantum dot organic light-emitting diodes (QD-OLEDs) can be achieved by blue OLED light to stimulate pixelized green and red QDs within a color conversion layer, providing high color conversion efficiency in commercialized displays. However, enhancing external quantum efficiency (EQE) and minimizing blue light leakage remain significant challenges. To resolve these issues, we have developed an organic-inorganic composite system comprising quantum dots (QDs), liquid crystal (LC), polymer, and inorganic nanoparticles, like titanium dioxide (TiO2). The best EQE was enhanced by ∼81.9% when TiO2 of 6 wt%. More importantly, the EQE was enhanced by ∼58.6% when TiO2 of 3 wt% while TiO2 nanoparticles were well-dispersed and stable without aggregation for more than 3 days, which is crucial for preventing nozzle blockages during inkjet printing in manufacturing processes. We believe our innovative approach is promising for boosting color conversion efficiency by exciting highly concentrated green and red QDs with blue light while also overcoming inherent fabrication hurdles associated with high concentrations of inorganic scatterers.

Lipid Nanocarriers-Enabled Delivery of Antibiotics and Antimicrobial Adjuvants to Overcome Bacterial Biofilms.

The opportunistic bacteria growing in biofilms play a decisive role in the pathogenesis of chronic infectious diseases. Biofilm-dwelling bacteria behave differently than planktonic bacteria and are likely to increase resistance and tolerance to antimicrobial therapeutics. Antimicrobial adjuvants have emerged as a promising strategy to combat antimicrobial resistance (AMR) and restore the efficacy of existing antibiotics. A combination of antibiotics and potential antimicrobial adjuvants, (e.g., extracellular polymeric substance (EPS)-degrading enzymes and quorum sensing inhibitors (QSI) can improve the effects of antibiotics and potentially reduce bacterial resistance). In addition, encapsulation of antimicrobials within nanoparticulate systems can improve their stability and their delivery into biofilms. Lipid nanocarriers (LNCs) have been established as having the potential to improve the efficacy of existing antibiotics in combination with antimicrobial adjuvants. Among them, liquid crystal nanoparticles (LCNPs), liposomes, solid lipid nanoparticles (SLNs), and nanostructured lipid carriers (NLCs) are promising due to their superior properties compared to traditional formulations, including their greater biocompatibility, higher drug loading capacity, drug protection from chemical or enzymatic degradation, controlled drug release, targeted delivery, ease of preparation, and scale-up feasibility. This article reviews the recent advances in developing various LNCs to co-deliver some well-studied antimicrobial adjuvants combined with antibiotics from different classes. The efficacy of various combination treatments is compared against bacterial biofilms, and synergistic therapeutics that deserve further investigation are also highlighted. This review identifies promising LNCs for the delivery of combination therapies that are in recent development. It discusses how LNC-enabled co-delivery of antibiotics and adjuvants can advance current clinical antimicrobial treatments, leading to innovative products, enabling the reuse of antibiotics, and providing opportunities for saving millions of lives from bacterial infections.

Enhancing Liquid Crystal Properties through Nanoparticle Doping: A Mini Review

Liquid crystals doped with nanoscale particles have recently acquired popularity, improving their capabilities and applications. The impact of doping metallic and metal-oxide nanoparticles as well as other nanoparticles in liquid crystals is presented in this brief review. Silver nanoparticles (Ag NPs) have an effect on phase transitions, molecular alignment and electrical properties such as threshold voltage and response time. The optical tilt and electro-optical characteristics of gold nanoparticles (Au NPs) are improved. Metal-oxide nanoparticles such as MgO, ZnO, Al2O3, CuO and SiO2 enhance dielectric properties, mitigate screening effects, increase birefringence, and reduce light leakage. Doping carbon nanotubes (CNTs) influences impedance, optical transmittance and electro-optical properties. The review aims to study the effects of nanoparticle doping on liquid crystal features such as phase transitions, molecular alignment, electrical and optical properties, dielectric behavior, and impedance. A better understanding of these modifications can lead to more applications for liquid crystal in areas such as sensors, displays, optoelectronics, and photovoltaics.

Exploiting Molecular Orders at the Interface of Microdroplets for Intelligent Materials.

ConspectusThe intrinsic molecular order of liquid crystals (LCs) and liquid crystalline elastomers (LCEs) is the origin of their stimuli-responsive properties. The programmable responsiveness and functionality, such as shape morphing and color change under external stimuli, are the key features that attract interest in designing LC- and LCE-based intelligent material platforms. Methods such as mechanical stretching and shearing, surface alignment, and field-assisted alignment have been exploited to program the order of LC molecules for the desired responsiveness. However, the huge size mismatch between the nanometer-sized LC mesogens and the targeted macroscopic objects calls for questions about how to delicately control molecular order for desired performance. Microparticles that can be synthesized with intrinsic molecular order precisely controlled to micrometer size can be used as building blocks for bulk materials, thus offering opportunities to bridge the gap and transcend molecular orders across scales. By taking advantage of the interfacial anchoring effects, we can control and engineer the molecular orders inside the microdroplets, allowing for the realization of various responsive behaviors. Furthermore, designer LC microparticles with multiple responsiveness can be assembled and confined within a matrix, opening a new pathway to engineering LC-enabled intelligent materials.In this Account, we present our recent work on exploiting the molecular order inside microdroplets for the construction of intelligent materials. We briefly introduce the typical chemicals used in the synthesis and the methods developed to control LC molecular alignment within a microdroplets. We then present examples of microparticles synthesized from microdroplets that can transform into complex morphologies upon cooling from the isotropic to nematic phase or due to phase separation within the droplets coupled with the segregation of LC oligomers (LCOs) with polydisperse chain lengths. Furthermore, we show the synthesis of elliptical LCE microparticles and exploit their thermal and magnetic responsiveness to program shape-morphing behaviors and microarrays with switchable optical polarization. By mixing magnetic nanoparticles in cholesteric liquid crystals (CLCs) and silicone oils, we created Janus microparticles capable of color switching for camouflage and information encryption. Moreover, we can engineer complex molecular orders in LCE microparticles by mixing different surfactants, yielding microparticles of diverse anisotropic, temperature-responsive shapes after photopolymerization and extraction of the template LC molecules with different solvents. We conclude the Account with an outlook on the design of intelligent material systems via the design of unprecedented molecular ordering within the microparticles and their coupling with bulk materials.

Niacin-Loaded Liquid Crystal Nanoparticles Ameliorate Prostaglandin D2-Mediated Niacin-Induced Flushing and Hepatotoxicity

Niacin-Loaded Liquid Crystal Nanoparticles Ameliorate Prostaglandin D2-Mediated Niacin-Induced Flushing and Hepatotoxicity

Preparation and characterization of macrophage membrane camouflaged cubosomes as a stabilized and immune evasive biomimetic nano-DDS.

This study aims to develop a biomimetic nano-drug delivery system (nano-DDS) by employing a macrophage cell membrane camouflaging strategy to modify lyotropic liquid crystal nanoparticles (LLC-NPs). The cubic-structured LLC-NPs (Cubosomes, CBs) were prepared via a top-down approach (ultra-sonification) using monoolein (MO) and doped with the cationic lipid, DOTAP. The cell membrane camouflaging procedure induced changes in the cubic lipid phase from primitive cubic phase (QIIP) to a coexistence of QIIP and diamond cubic phase (QIID). The macrophage membrane camouflaging strategy protected CB cores from the destabilization by blood plasma and enhanced the stability of CBs. The in vitro experiment results revealed that the macrophage cell membrane coating significantly reduced macrophage uptake efficacy within 8 h of incubation compared to the non-camouflaged CBs, while it had minimal impact on cancer cell uptake efficacy. The macrophage membrane coated CBs showed lower accumulation in the heart, kidney and lungs in vivo. This study demonstrated the feasibility of employing cell membrane camouflaging on CBs and confirmed that the bio-functionalities of the CBs-based biomimetic nano-DDS were retained from the membrane source cells, and opened up promising possibilities for developing an efficient and safe drug delivery system based on the biomimetic approach.

Rheological Properties Study of Polymer Dispersed Liquid Crystals Doped by SiO2 Nanoparticles

The present report discusses the development of a novel nano-composite using a polymer dispersed liquid crystal (PDLC) and inorganic silicon dioxide (SiO2) nanoparticles. The aim of this work was to investigate the effect of the SiO2 nanoparticles on the rheological properties of the PDLC films. In our research described in this paper SiO2 nanoparticle-doped polymer dispersed liquid crystal films were made from a mixture of ethylene glycol phenyl ether methacrylate (EGPEMA) pre-polymer, 4-Cyano-4′-pentylbiphenyl (5CB) liquid crystals (LC) and SiO2 nanoparticles by the polymerization induced phase separation (PIPS) process. Doping the PDLC systems with SiO2 improved the rheological properties of these materials; the percolation (network formation) observed reflected the good interfacial adhesion between the nanoparticles, the polymer matrix and the LC. On the other hand, a decrease in the storage modulus (G′) and loss modulus (G″) of the PDLC systems after addition of the SiO2 nanoparticles confirmed their high flexibility and low crystallinity. A slight increase in G′ at 0.05 wt.% SiO2 resulted in the good mechanical strength of the doped PDLC. The viscoelastic behavior of the doped and undoped PDLC systems was confirmed at high frequencies. Thermal characterization by differential scanning calorimetry (DSC) showed a decrease in the glass transition temperature (Tg) of the PDLC with 0.05 wt.% of SiO2 nanoparticles, which showed that we had a more flexible material.

Cubosomes as versatile lipid nanocarriers for neurological disorder therapeutics: a comprehensive review.

Cubosomes are novel vesicular drug delivery systems with lipidic liquid crystal nanoparticles formed of predetermined proportions of amphiphilic lipids. They have a honeycomb-like structure and are thermodynamically stable. These bicontinuous lipid layers are separated into two water-based channels internally that can be used by various bioactive substances, including drugs, proteins, and peptides. This complex structure is responsible for its high drug-loading capacity. Cubosomes are thought to be promising vehicles for various routes of administration because of their extraordinary characteristics, including bioadhesion, the capacity to encapsulate hydrophilic, and hydrophobic, as well as amphiphilic substances, high resistance to environmental stress, and their ability to achieve controlled release through modification. One of the essential elements for improving patient compliance is the ability of these well-defined nano-drug delivery systems to boost the effectiveness of targeting while lowering the side effects/toxicities of payloads. The large internal surface area, a sufficiently uncomplicated fabrication procedure, and biodegradability make it an attractive nano lipid carrier for drug delivery. This review outlines the recent advancement of cubosomes for managing various neurological disorders, highlighting their potential in this field.

Theoretical study of the nematic to isotropic phase transition in the mixtures of nematic liquid crystal and quantum dots nanoparticles

ABSTRACTThe nematic to isotropic phase transition in the mixtures of nematic liquid crystal and quantum dots nanoparticles has been studied. Flory Huggins theory of isotropic mixing and Landau-de Gennes theory have been used to study the nematic to isotropic phase transition. The effects of quantum dots nanoparticles on the nematic order parameter, transition temperature, and splay elastic constant have been discussed. The decrease of nematic order parameter, transition temperature, and splay elastic constant with the increase in volume fraction of quantum dots nanoparticles has been observed.

Polarization Z-Scan Studies Revealing Plasmon Coupling Enhancement Due to Dimer Formation of Gold Nanoparticles in Nematic Liquid Crystals.

We investigate the plasmon coupling of gold nanoparticle (AuNP) dimers dispersed in a nematic liquid crystal matrix using the polarization z-scan technique. Our experimental setup includes the precise control of incident light polarization through polarization angles of 0°, 45°, and 90°. Two distinct cell orientations are examined: parallel and twisted nematic cells. In parallel-oriented cells, where liquid crystal molecules and AuNPs align with the rubbing direction, we observe a remarkable 2-3-fold increase in the nonlinear absorption coefficient when the polarization of the incident light is parallel to the rubbing direction. Additionally, a linear decrease in the third-order nonlinear absorption coefficient is noted as the polarization angle varies from 0° to 90°. In the case of twisted nematic cells, the NPs do not have any preferred orientation, and the enhancement remains consistent across all polarization angles. These findings conclusively establish that the observed enhancement in the nonlinear absorption coefficient is a direct consequence of plasmon coupling, shedding light on the intricate interplay between plasmonic nanostructures and liquid crystal matrices.