Lipid bilayer permeabilities and antibiotic effects of tetramethylguanidinium and choline fatty acid ionic liquids

Ionic liquids (ILs) have been studied as potential components in antibiotic formulations based on their abilities to permeabilize and penetrate lipid bilayer, which correlate with their antibacterial effects. Fatty acid-based ILs (FAILs), in which the anion is a long-chain fatty acid, can permeabilize lipid membranes and have been used in biomedical applications since they have low human cell cytotoxicity. In this work we investigated the abilities of several different FAILs to permeabilize lipid bilayers and how that permeabilization correlates with antibacterial activity, cell membrane permeability, and cytotoxicity. The FAILs consisted of the cations tetramethylguanidinium (TMG) or choline combined with octanoate or decanoate. These FAILs were tested on model bilayer vesicles with three different lipid compositions for membrane permeabilization using a leakage assay. They were then tested for antibiotic and membrane permeabilization on bacterial and mammalian cells. The results show that while the octanoate-based FAILs do not form micelles and have low activities on vesicles and biological cells, the decanoate-based FAILs can permeabilize bilayers and have biological activities that correlate with the model vesicle results. The ILs with both cation and fatty-acid anion have strong activities while the decanoate alone has only minimal permeabilization and antibiotic activity. Membrane permeabilization occurs at FAIL concentrations below their CMC values which suggests that their mechanism of action may not involve micelle formation.

Polymerizable Cholinium-Based Antibiotics for Polymer Carriers: Systems with Combined Load of Cloxacillin and Ampicillin

Single and dual-drug delivery systems (DDSs) based on linear choline polymers were designed through the controlled polymerization of a pharmaceutically functionalized monomer, i.e., [2-(methacryloyloxy)ethyl]trimethylammonium, with counterions of cloxacillin (TMAMA/CLX), or its copolymerization with [2-(methacryloyloxy)ethyl]trimethylammonium with ampicillin (TMAMA/AMP), providing antibiotic properties. This strategy was effective in attaining well-defined linear copolymers with 38-93 mol. % of TMAMA content, which were regulated by the initial ratio of TMAMA to methyl methacrylate comonomer. The polymer compositions were controlled by the total monomer conversion (40-75%), resulting in a variable degree of polymerization (DPn = 160-300) and pharmaceutical anion contents (CLX- 51-80% and AMP- 78-87%). In aqueous solution, the polymers formed particles with sizes ranging between 274 and 380 nm for CLX- systems and 288-348 nm for CLX-/AMP- systems. In vitro drug release, driven by the exchange of pharmaceutical anions with phosphate ions in phosphate-buffered saline (PBS), imitating a physiological fluid, demonstrated release efficiencies of 58-76% for CLX- (10.5-13.6 µg/mL) in single systems, and 91-100% for CLX- (12.9-15.1 µg/mL) and 97-100% for AMP- (21.1-23.3 µg/mL) in dual systems. Compared to conventional systems delivering antibiotics without a polymer carrier, the choline-based polymer DDS attained satisfactory levels of drug loading content and (co-)release from the polymer carriers, offering a promising alternative for antibiotic delivery.

Utilizing ionic liquids as eco-friendly and sustainable carriers for delivering nucleic acids: A review on the revolutionary advancement in nano delivery systems

Ionic liquids (ILs) are an extremely versatile class of chemicals. It has been shown that they can effectively pass through many biological barriers in the human body to deliver medications. ILs are solvents noted for their ecological friendliness; they contain equal amounts of cations and anions and remain liquid at temperatures below 100 °C. Hence, these are ideal for biomedical applications owing to their advantageous properties such as biocompatibility, solubility, and adaptability. ILs are widely reported to improve the solubility and stability of nucleic acids (DNA and RNA) in aqueous conditions, allowing for more effective delivery. Certain ILs have shown the ability to enhance the absorption of nucleic acids into cells. In addition, ILs can also be used to create vectors for gene delivery, such as liposomes and nanoparticles, thereby improving the transfection efficiency of plasmid DNA and siRNA. Subsequently, the application of ILs for nucleic acid delivery has increased significantly in recent years. In this context, we believe that using ILs to enhance the transport of nucleic acids will have a considerable effect as a novel and crucial therapeutic method in the upcoming decades. The use of ILs as solvents to preserve the natural structure of DNA and RNA shows promise for a variety of biotechnological and medical applications. Notably, ILs may be utilized for a variety of functions, including extracting, concentrating, stabilizing, and spreading nucleic acids inside cells. Our review emphasizes the key findings of research works published in this domain, wherein outstanding effectiveness of delivering RNA to the desired areas was achieved, and was made possible through the utilization of ILs.

Novel reaction systems for catalytic synthesis of structured phospholipids

Phospholipids are distinctive, adaptable molecules that are crucial to numerous biological systems. Additionally, their various architectures and amphiphilic characteristics support their unrivaled crucial functions in scientific and industrial applications. Due to their enormous potential for use in the fields of medicine, food, cosmetics, and health, structured phospholipids, which are modified phospholipids, have garnered increased attention. Traditional extraction methods, however, are pricy, resource-intensive, and low-yielding. The process of enzyme-catalyzed conversion is effective for producing several types of structured phospholipase. However, most frequently employed catalytic procedures involve biphasic systems with organic solvents, which have a relatively large mass transfer resistance and are susceptible to solvent residues and environmental effects due to the hydrophobic nature of phospholipids. Therefore, the adoption of innovative, successful, and environmentally friendly enzyme-catalyzed conversion systems provides a new development route in the field of structured phospholipids processing. Several innovative catalytic reaction systems are discussed in this mini-review, including aqueous-solid system, mixed micelle system, water-in-oil microemulsion system, Pickering emulsion system, novel solvent system, three-liquid-phase system, and supercritical carbon dioxide solvent system. However, there is still a glaring need for a thorough examination of these systems for the enzymatic synthesis of structural phospholipids. In terms of the materials utilized, applicability, benefits and drawbacks, and comparative effectiveness of each system, this research establishes further conditions for the system's selection. To create more effective biocatalytic processes, it is still important to build green biocatalytic processes with improved performance. KEY POINTS: • The latest catalytic systems of phospholipase D are thoroughly summarized. • The various systems are contrasted, and their traits are enumerated. • Different catalytic systems' areas of applicability and limitations are discussed.

Design Principles and Applications of Ionic Liquids for Transdermal Drug Delivery

Ionic liquids (ILs) are salts with melting points typically <100 °C, composed of specific anions and cations. Recently, IL application has expanded into material engineering and biomedicine. Due to their unique properties, ILs have garnered significant interest in pharmacological research as solubilizers, transdermal absorption enhancers, antibacterial agents, and stabilizers of insoluble pharmaceutical active ingredients. The improvement of skin permeability by ILs is closely associated with their specific physicochemical characteristics, which are identified by their ionic composition. However, the existing literature on transdermal medication administration is insufficient in terms of a comprehensive knowledge base. This review provides a comprehensive assessment of the design principles involved in IL synthesis. Additionally, it discusses the methods utilized to assess skin permeability and provides a focused outline of IL application in transdermal drug administration.

A novel biological antibacterial polyvinyl alcohol/polyionic liquid hydrogel for wound dressing

The release of antibiotics or anions by traditional bacteriostatic agents led to the development of bacterial drug resistance and environmental pollution. Ionic liquids (ILs) have become important choices for antibacterial agents because of their excellent physical, chemical and biological properties. In this paper, the bioactivities of 1-vinyl-3-butylimidazolium chloride ([VBIM]Cl, IL) and poly (1-vinyl-3-butylimidazolium chloride) (P[VBIM]Cl, PIL) were evaluated, and the potential antibacterial material was used to synthesize hydrogels. Using the colony formation assay and the Oxford cup method, antibacterial effect of IL and PIL were tested. Cell-Counting-Kit-8 (CCK-8) experiments were used to study the IC50 (half maximal inhibitory concentration) values of IL and showed 1.47 mg/mL, 0.35 mg/mL and 0.33 mg/mL at 24 h, 48 h and 72 h, respectively. The IC50 value of PIL were 12.15 μg/mL, 12.06 μg/mL and 11.76 μg/mL at 24 h, 48 h and 72 h, respectively. The PIL is further crosslinked with polyvinyl alcohol (PVA) to form a novel hydrogel through freeze-thaw cycles. The newly fabricated hydrogel exhibited a high water content, excellent water absorption properties and outstanding mechanical performance. Using the colony formation assay and the inhibition zone assay, the hydrogels exhibited favorable antibacterial effects (against E.coli and S.aureus) such that nearly 100% of the bacteria were killed in liquid medium while cultivating with H4 (synthesized by 0.5 g PIL and 1g PVA). In addition, the cytotoxicity of PIL was significantly reduced through hydrogen bond crosslinking. H4 showed the highest antibacterial activity and a good biocompatibility. The results indicated that the PVA&PIL hydrogels had great potential for wound dressing.

Ionic liquid-based aqueous biphasic system as an alternative tool for enhanced bacterial DNA extraction

BACKGROUND

Developing an alternative and benign method for DNA extraction is imperative due to the high cost and potential harms associated with conventional techniques. Investigation of Ionic liquid (IL) as a solvent for DNA storage and stability revealed the ability of IL to assist DNA processes. IL-based aqueous biphasic system emerges as a comprehensive extraction platform capitalizing on the task-specificity of ILs and the wide applicability of ABS for biomolecule extractions. Therefore, it is beneficial to optimize an IL-based ABS specifically for DNA extraction, taking into account the fundamental interactions between the IL and DNA.

RESULTS

The primary objective was to design ABS consisting of Ammonium based ILs, and Potassium phosphate buffer as the salting-out agent for the partitioning of salmon sperm DNA. The analysis focused on optimizing biocompatible anions for the extraction. Moreover, the stability of the DNA in the IL rich phases was analysed to validate the method. The proposed process was then employed for extracting plasmid DNA from bacteria, demonstrating results comparable to those obtained with a commercially available kit. Further validation using agarose gel electrophoresis and transformation of the extracted DNA into E.coli were conducted, producing promising outcomes. Although there is room for improvement in terms of recovery of DNA and reusability of ABS, the described approach is comparable with the conventional one while being cost-effective, and showcases a noticeable and convincing link to eco-friendly processes.

SIGNIFICANCE

There is limited literature on IL-based ABS for DNA extraction, and the existing studies predominantly concentrate on systems derived from Cholinium ILs. However, their high hydrophilicity limits the choice of the second-phase forming component to polymers for the formation of ABS. Ammonium ILs efficiently form biphasic systems with various available salting-out agents, and biocompatible anions are introduced to mitigate the toxicity of the ILs.

Simple strategy of the use of pharmaceutically functionalized ionic liquids in a new generation of polymer nanocarriers for the combined delivery of ionic p-aminosalicylate and ampicillin

Single and dual bioactive linear poly(ionic liquid)s (PIL) were synthesized for use as nanocarriers in drug delivery systems (DDS). These PILs were obtained through the (co)polymerization of the choline-based monomeric ionic liquids (MIL) with pharmaceutical anions possessing antibacterial properties, specifically [2-(methacryloyloxy)ethyl]trimethyl-ammonium with ampicillin and p-aminosalicylate (TMAMA/AMP and TMAMA/PAS). The copolymers exhibited varying chain lengths defined by a degree of polymerization (DPn = 122-370), and differing contents of ionic fraction and drugs (TMAMA 61-92 %, AMP 61-93 % and PAS 16-21 %). These parameters were adjustable by the monomer conversion (33-92 %) and the initial ratio of comonomers. In aqueous solution, the polymer particles reached nanosizes, i.e. 190-328 nm for AMP systems and 200-235 nm for AMP/PAS systems. In the release process, the pharmaceutical anions were released through exchange by phosphate anions in PBS at pH 7.4 at 37 °C. Depending on the copolymer composition the release of AMP was attained in 72-100 % (11.1-19.5 µg/mL) within 26 h by the single drug systems, while the dual drug systems released 61-100 % of AMP (14.8-24.7 µg/mL) and 82-100 % of PAS (3.1-4.8 µg/mL) within 72 h. The effectiveness in the drug delivery of the designed TMAMA polymers seems to be promising for future applications in antibiotic therapy and the combined therapy.

Scattering approaches to unravel protein solution behaviors in ionic liquids and deep eutectic solvents: From basic principles to recent developments

Proteins in ionic liquids (ILs) and deep eutectic solvents (DESs) have gained significant attention due to their potential applications in various fields, including biocatalysis, bioseparation, biomolecular delivery, and structural biology. Scattering approaches including dynamic light scattering (DLS) and small-angle X-ray and neutron scattering (SAXS and SANS) have been used to understand the solution behavior of proteins at the nanoscale and microscale. This review provides a thorough exploration of the application of these scattering techniques to elucidate protein properties in ILs and DESs. Specifically, the review begins with the theoretical foundations of the relevant scattering approaches and describes the essential solvent properties of ILs and DESs linked to scattering such as refractive index, scattering length density, ion-pairs, liquid nanostructure, solvent aggregation, and specific ion effects. Next, a detailed introduction is provided on protein properties such as type, concentration, size, flexibility and structure as observed through scattering methodologies. This is followed by a review of the literature on the use of scattering for proteins in ILs and DESs. It is highlighted that enhanced data analysis and modeling tools are necessary for assessing protein flexibility and structure, and for understanding protein hydration, aggregation and specific ion effects. It is also noted that complementary approaches are recommended for comprehensively understanding the behavior of proteins in solution due to the complex interplay of factors, including ion-binding, dynamic hydration, intermolecular interactions, and specific ion effects. Finally, the challenges and potential research directions for this field are proposed, including experimental design, data analysis approaches, and supporting methods to obtain fundamental understandings of complex protein behavior and protein systems in solution. We envisage that this review will support further studies of protein interface science, and in particular studies on solvent and ion effects on proteins.

Cytotoxicity and cell membrane interactions of choline-based ionic liquids: Comparing amino acids, acetate, and geranate anions

Ionic liquids (ILs) have found diverse applications in research and industry. Biocompatible ILs, a subset considered less toxic than traditional ILs, have expanded their applications into biomedical fields. However, there is limited understanding of the toxicity profiles, safe concentrations, and underlying factors driving their toxicity. In this study, we investigated the cytotoxicity of 13 choline-based ILs using four different cell lines: Human dermal fibroblasts (HDF), epidermoid carcinoma cells (A431), cervical cancer cells (HeLa), and gastric cancer cells (AGS). Additionally, we explored the haemolytic activity of these ILs. Our findings showed that the cytotoxic and haemolytic activities of ILs can be attributed to the hydrophobicity of the anions and the pH of the IL solutions. Furthermore, utilising quartz crystal microbalance with dissipation (QCM-D), we delved into the interaction of selected ILs, including choline acetate [Cho][Ac] and choline geranate [Cho][Ge], with model cell membranes composed of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC). The QCM-D data showed that ILs with higher toxicities exhibited more pronounced interactions with membranes. Increased variations in frequency and dissipation reflected substantial changes in membrane fluidity and mass following the addition of the more toxic ILs. Furthermore, total internal reflection fluorescence microscopy study revealed that [Cho][Ac] could cause lipid rearrangements and pore formation in the membrane, while [Cho][Ge] disrupted the bilayer packing. This study advances our understanding of the cellular toxicities associated with choline-based ILs and provides valuable insights into their mechanisms of action concerning IL-membrane interactions. These findings have significant implications for the safe and informed utilisation of biocompatible ILs in the realm of drug delivery and biotechnology.

DNA nanotechnology in ionic liquids and deep eutectic solvents

Nucleic acids have the ability to generate advanced nanostructures in a controlled manner and can interact with target sequences or molecules with high affinity and selectivity. For this reason, they have applications in a variety of nanotechnology applications, from highly specific sensors to smart nanomachines and even in other applications such as enantioselective catalysis or drug delivery systems. However, a common disadvantage is the use of water as the ubiquitous solvent. The use of nucleic acids in non-aqueous solvents offers the opportunity to create a completely new toolbox with unprecedented degrees of freedom. Ionic liquids (ILs) and deep eutectic solvents (DESs) are the most promising alternative solvents due to their unique electrolyte and solvent roles, as well as their ability to maintain the stability and functionality of nucleic acids. This review aims to be a comprehensive, critical, and accessible evaluation of how much this goal has been achieved and what are the most critical parameters for accomplishing a breakthrough.

Biocompatible Electronic Skins for Cardiovascular Health Monitoring

Cardiovascular diseases represent a significant threat to the overall well-being of the global population. Continuous monitoring of vital signs related to cardiovascular health is essential for improving daily health management. Currently, there has been remarkable proliferation of technology focused on collecting data related to cardiovascular diseases through daily electronic skin monitoring. However, concerns have arisen regarding potential skin irritation and inflammation due to the necessity for prolonged wear of wearable devices. To ensure comfortable and uninterrupted cardiovascular health monitoring, the concept of biocompatible electronic skin has gained substantial attention. In this review, biocompatible electronic skins for cardiovascular health monitoring are comprehensively summarized and discussed. The recent achievements of biocompatible electronic skin in cardiovascular health monitoring are introduced. Their working principles, fabrication processes, and performances in sensing technologies, materials, and integration systems are highlighted, and comparisons are made with other electronic skins used for cardiovascular monitoring. In addition, the significance of integrating sensing systems and the updating wireless communication for the development of the smart medical field is explored. Finally, the opportunities and challenges for wearable electronic skin are also examined.

Mechanisms of Biological Effects of Ionic Liquids: From Single Cells to Multicellular Organisms

The review presents a detailed discussion of the evolving field studying interactions between ionic liquids (ILs) and biological systems. Originating from molten salt electrolytes to present multiapplication substances, ILs have found usage across various fields due to their exceptional physicochemical properties, including excellent tunability. However, their interactions with biological systems and potential influence on living organisms remain largely unexplored. This review examines the cytotoxic effects of ILs on cell cultures, biomolecules, and vertebrate and invertebrate organisms. Our understanding of IL toxicity, while growing in recent years, is yet nascent. The established findings include correlations between harmful effects of ILs and their ability to disturb cellular membranes, their potential to trigger oxidative stress in cells, and their ability to cause cell death via apoptosis. Future research directions proposed in the review include studying the distribution of various ILs within cellular compartments and organelles, investigating metabolic transformations of ILs in cells and organisms, detailed analysis of IL effects on proteins involved in oxidative stress and apoptosis, correlation studies between IL doses, exposure times and resulting adverse effects, and examination of effects of subtoxic concentrations of ILs on various biological objects. This review aims to serve as a critical analysis of the current body of knowledge on IL-related toxicity mechanisms. Furthermore, it can guide researchers toward the design of less toxic ILs and the informed use of ILs in drug development and medicine.

Biophysical Characterization and Cryopreservation of Mammalian Cells Using Ionic Liquids

Ionic liquids (ILs) are a diverse class of solvents which can be selected for task-specific properties, making them attractive alternatives to traditional solvents. To tailor ILs for specific biological applications, it is necessary to understand the structure-property relationships of ILs and their interactions with cells. Here, a selection of carboxylate anion-based ILs were investigated as cryoprotectants, which are compounds added to cells before freezing to mitigate lethal freezing damage. The cytotoxicity, cell permeability, thermal behavior, and cryoprotective efficacy of the ILs were assessed with two model mammalian cell lines. We found that the biophysical interactions, including permeability of the ILs, were influenced by considering the IL pair together, rather than as single species acting independently. All of the ILs tested had high cytotoxicity, but ethylammonium acetate demonstrated good cryoprotective efficacy for both cell types tested. These results demonstrate that despite toxicity, ILs may be suitable for certain biological applications. It also demonstrates that more research is required to understand the contribution of ion pairs to structure-property relationships and that knowing the behavior of a single ionic species will not necessarily predict its behavior as part of an IL.

A green pathway for lignin valorization: Enzymatic lignin depolymerization in biocompatible ionic liquids and deep eutectic solvents

Lignin depolymerization, which enables the breakdown of a complex and heterogeneous aromatic polymer into relatively uniform derivatives, serves as a critical process in valorization of lignin. Enzymatic lignin depolymerization has become a promising biological strategy to overcome the heterogeneity of lignin, due to its mild reaction conditions and high specificity. However, the low solubility of lignin compounds in aqueous environments prevents efficient lignin depolymerization by lignin-degrading enzymes. The employment of biocompatible ionic liquids (ILs) and deep eutectic solvents (DESs) in lignin fractionation has created a promising pathway to enzymatically depolymerize lignin within these green solvents to increase lignin solubility. In this review, recent research progress on enzymatic lignin depolymerization, particularly in a consolidated process involving ILs/DESs is summarized. In addition, the interactions between lignin-degrading enzymes and solvent systems are explored, and potential protein engineering methodology to improve the performance of lignin-degrading enzymes is discussed. Consolidation of enzymatic lignin depolymerization and biocompatible ILs/DESs paves a sustainable, efficient, and synergistic way to convert lignin into value-added products.

Regulating the structural polymorphism and protein corona composition of phytantriol-based lipid nanoparticles using choline ionic liquids

Lipid-based lyotropic liquid crystalline nanoparticles (LCNPs) face stability challenges in biological fluids during clinical translation. Ionic Liquids (ILs) have emerged as effective solvent additives for tuning the structure of LCNP's and enhancing their stability. We investigated the effect of a library of 21 choline-based biocompatible ILs with 9 amino acid anions as well as 10 other organic/inorganic anions during the preparation of phytantriol (PHY)-based LCNPs, followed by incubation in human serum and serum proteins. Small angle X-ray scattering (SAXS) results show that the phase behaviour of the LCNPs depends on the IL concentration and anion structure. Incubation with human serum led to a phase transition from the inverse bicontinuous cubic (Q2) to the inverse hexagonal (H2) mesophase, influenced by the specific IL present. Liquid chromatography-mass spectrometry (LC-MS) and proteomics analysis of selected samples, including PHY control and those with choline glutamate, choline hexanoate, and choline geranate, identified abundant proteins in the protein corona, including albumin, apolipoproteins, and serotransferrin. The composition of the protein corona varied among samples, shedding light on the intricate interplay between ILs, internal structure and surface chemistry of LCNPs, and biological fluids.

Bioinspired Herbicides-Ionic Liquids or Liquid Cocrystals?

This research provides information about combinations of several amino acids, including l-proline (Pro), l-arginine (Arg), and l-histidine (His), with phenoxyacetic acid herbicides (MCPA and 2,4-D). Five amino acid ionic liquids (AAILs), one amino acid higher-melting salt (AAHMS), and two amino acid liquid cocrystals (AALCs) were obtained in high yields (>90%). The ionization of the six new structures was confirmed by NMR, IR, and molecular modeling. X-ray crystallography was used to definitively confirm the binding location of the mobile hydrogen. Furthermore, we propose a computational method for estimating the energy of specific hydrogen bond(s) in AAIL crystals based on the NBO and QTAIM hydrogen bond parameters obtained by model calculations. An in-depth analysis of the structures allowed to answer the question posed in the title, ionic liquids or liquid cocrystals? AAILs based on arginine and histidine were obtained. In contrast, combining proline with MCPA and 2,4-D led to AALCs. Finally, the compounds were analyzed to measure their herbicidal activity. These studies proved that the novel form of MCPA or 2,4-D improved its ability to control weeds compared to commercial formulations containing the same active ingredients.

Ionic Liquid-Based Polymer Matrices for Single and Dual Drug Delivery: Impact of Structural Topology on Characteristics and In Vitro Delivery Efficiency

Previously reported amphiphilic linear and graft copolymers, derived from the ionic liquid [2-(methacryloyloxy)ethyl]trimethylammonium chloride (TMAMA_Cl‾), along with their conjugates obtained through modification either before or after polymerization with p-aminosalicylate anions (TMAMA_PAS‾), were employed as matrices in drug delivery systems (DDSs). Based on the counterion type in TMAMA units, they were categorized into single drug systems, manifesting as ionic polymers with chloride counterions and loaded isoniazid (ISO), and dual drug systems, featuring ISO loaded in self-assembled PAS conjugates. The amphiphilic nature of these copolymers was substantiated through the determination of the critical micelle concentration (CMC), revealing an increase in values post-ion exchange (from 0.011-0.063 mg/mL to 0.027-0.181 mg/mL). The self-assembling properties were favorable for ISO encapsulation, with drug loading content (DLC) ranging between 15 and 85% in both single and dual systems. In vitro studies indicated ISO release percentages between 16 and 61% and PAS release percentages between 20 and 98%. Basic cytotoxicity assessments using the 2,5-diphenyl-2H-tetrazolium bromide (MTT) test affirmed the non-toxicity of the studied systems toward human non-tumorigenic lung epithelial cell line (BEAS-2B) cell lines, particularly in the case of dual systems bearing both ISO and PAS simultaneously. These results confirmed the effectiveness of polymeric carriers in drug delivery, demonstrating their potential for co-delivery in combination therapy.

On the Key Influence of Amino Acid Ionic Liquid Anions on CO2 Capture

Amino acid ionic liquids (AAILs) are promising green materials for CO2 capture and conversion due to their large chemical structural tunability. However, the structural understanding of the AAILs underlying the CO2 reaction dynamics remains uncertain. Herein, we examine the steric effects of AAIL anions with various chemical structures on CO2 capture behavior. Based on ab initio free-energy sampling, we assess reaction mechanisms for carbamate formation via a two-step reaction pathway with a zwitterion intermediate undergoing dynamic proton transfer. Our results show that free-energy barriers for carbamate formation can be significantly reduced as the degree of steric hindrance of the anions decreases. Further analyses reveal that reduced steric hindrance of anions causes markedly stronger intermolecular interactions between zwitterion and anions, leading to an increased kinetically favorable intermolecular proton transfer for carbamate production. We also describe the correlation strength between intramolecular interactions within the zwitterion and intermolecular interactions between the zwitterion and anions. We conclude that the favored structural flexibility due to the less steric hindrance of the zwitterion leads to enhanced intermolecular interactions, facilitating proton transfer to nearby AAIL anions for carbamate formation. Our study provides invaluable insight into the influence of various degrees of steric hindrance of the AAIL anions governing CO2 chemisorption. These findings may aid in the design of optimal AAIL solvents for the CO2 capture process.

Preparation and characterization of chemically modified tapioca starch-ionic liquid antibacterial films

The plasticizing and antibacterial effects of ionic liquids (ILs) in the preparation of tapioca starch-IL films were studied for the first time. 1-Ethyl-3-methylimidazolium acetate ([Emim][OAc]) caused complete disruption of starch crystallites during thermal compression, while some crystallites remained after the plasticization of starch with choline acetate ([Ch][OAc]). Compared to native tapioca starch (NTS), the plasticization of acetylated tapioca starch (ATS) and cross-linked tapioca (CTS) was slightly promoted and inhibited, respectively. Starch-[Emim][OAc] films exhibited higher hydrophobicity and mechanical properties but lower antibacterial activity than starch-[Ch][OAc] films. CTS-[Ch][OAc] films presented higher mechanical strength and antibacterial activity than NTS-[Ch][OAc] and ATS-[Ch][OAc] films. From this study, we conclude that ILs can be used in the preparation of antibacterial starch films to play the roles of plasticization and antibacterial activity. The antibacterial activity of starch films depends on types of ILs and their interactions with starch during film preparation.

Ionogels for flexible conductive substrates and their application in biosensing

Ionogels are highly conductive gels made from ionic liquids dispersed in a matrix made of organic or inorganic materials. Ionogels are known for high ionic conductivity, flexibility, high thermal and electrochemical stability. These characteristics make them suitable for sensing and biosensing applications. This review discusses about the two main constituents, ionic liquids and matrix, used to make ionogels and effect of these materials on the characteristics of ionogels. Here, the material properties like mechanical, electrochemical and stability are discussed for both polymer matrix and ionic liquid. We have briefly described about the fabrication methods like 3D printing, sol-gel, blade coating, spin coating, aerosol jet printing etc., used to make films or coating of these ionogels. The advantages and disadvantages of each method are also briefly summarized. Finally, the last section provides a few examples of application of flexible ionogels in areas like wearables, human-machine interface, electronic skin and detection of biological molecules.

3D bioactive ionic liquid-based architectures: An anti-inflammatory approach for early-stage osteoarthritis

3D bioprinting enables the fabrication of biomimetic cell-laden constructs for cartilage regeneration, offering exclusive strategies for precise pharmacological screenings in osteoarthritis (OA). Synovial inflammation plays a crucial role in OA's early stage and progression, characterized by the increased of the synovial pro-inflammatory mediators and cytokines and chondrocyte apoptosis. Therefore, there is an urgent need to develop solutions for effectively managing the primary events associated with OA. To address these issues, a phenolic-based biocompatible ionic liquid approach, combining alginate (ALG), acemannan (ACE), and cholinium caffeate (Ch[Caffeate]), was used to produce easily printable bioinks. Through the use of this strategy 3D constructs with good printing resolution and high structural integrity were obtained. The encapsulation of chondrocytes like ATDC5 cells provided structures with good cell distribution, viability, and growth, for up to 14 days. The co-culture of the constructs with THP-1 macrophages proved their ability to block pro-inflammatory cytokines (TNF-α and IL-6) and mediators (GM-CSF), released by the cultured cells. Moreover, incorporating the biocompatible ionic liquid into the system significantly improved its bioactive performance without compromising its physicochemical features. These findings demonstrate that ALG/ACE/Ch[Caffeate] bioinks have great potential for bioengineering cartilage tissue analogs. Besides, the developed ALG/ACE/Ch[Caffeate] bioinks protected encapsulated chondrocyte-like cells from the effect of the inflammation, assessed by a co-culture system with THP-1 macrophages. These results support the increasing use of Bio-ILs in the biomedical field, particularly for developing 3D bioprinting-based constructs to manage inflammatory-based changes in OA. STATEMENT OF SIGNIFICANCE: Combining natural resources with active biocompatible ionic liquids (Bio-IL) for 3D printing is herein presented as an approach for the development of tools to manage inflammatory osteoarthritis (OA). We propose combining alginate (ALG), acemannan (ACE), and cholinium caffeate (Ch[Caffeate]), a phenolic-based Bio-IL with anti-inflammatory and antioxidant features, to produce bioinks that allow to obtain 3D constructs with good printing resolution, structural integrity, and that provide encapsulated chondrocyte-like cells good viability. The establishment of a co-culture system using the printed constructs and THP-1-activated macrophages allowed us to study the encapsulated chondrocyte-like cells behaviour within an inflammatory scenario, a typical event in early-stage OA. The obtained outcomes support the beneficial use of Bio-ILs in the biomedical field, particularly for the development of 3D bioprinting-based models that allow the monitoring of inflammatory-based events in OA.

A Comprehensive Review on Imperative Role of Ionic Liquids in Pharmaceutical Sciences

Ionic liquids (ILs) are poorly-coordinated ionic salts that can exist as a liquid at room temperatures (or <100 °C). ILs are also referred to as "designer solvents" because so many of them have been created to solve particular synthetic issues. ILs are regarded as "green solvents" because they have several distinctive qualities, including better ionic conduction, recyclability, improved solvation ability, low volatility, and thermal stability. These have been at the forefront of the most innovative fields of science and technology during the past few years. ILs may be employed in new drug formulation development and drug design in the field of pharmacy for various functions such as improvement of solubility, targeted drug delivery, stabilizer, permeability enhancer, or improvement of bioavailability in the development of pharmaceutical or vaccine dosage formulations. Ionic liquids have become a key component in various areas such as synthetic and catalytic chemistry, extraction, analytics, biotechnology, etc., due to their superior abilities along with highly modifiable potential. This study concentrates on the usage of ILs in various pharmaceutical applications enlisting their numerous purposes from the delivery of drugs to pharmaceutical synthesis. To better comprehend cuttingedge technologies in IL-based drug delivery systems, highly focused mechanistic studies regarding the synthesis/preparation of ILs and their biocompatibility along with the ecotoxicological and biological effects need to be studied. The use of IL techniques can address key issues regarding pharmaceutical preparations such as lower solubility and bioavailability which plays a key role in the lack of effectiveness of significant commercially available drugs.

The ratio of choline lysine ionic liquid determines the structure and digestion of starch-oleic acid complex

Fully green choline lysine ([Cho][Lys]) ionic liquid (IL) was explored as the solvent to prepare starch-fatty acid complex, and the regulation of water: [Cho][Lys] (W:IL) ratio on the structure and digestion of starch-oleic acid (OA) complex was illuminated. Compared with pure water (W:IL-10:0), high (W:IL-0:10) or low concentration (W:IL-8:2, 6:4) of [Cho][Lys] IL would inhibit the disaggregation behaviors of starch. This inhibition led to the preservation of more original ordered multi-structures of starch (indicated as more double helix, type A crystalline structures, denser aggregate structure and ΔH values of gelatinization peak) and less complexion of starch with OA (indicated as less single helix, type V crystalline structures). While in W:IL-4:6, 2:8 mixtures, the disaggregation behaviors of starch were much promoted, and the original multi-structures of starch were much destroyed, which would enhance the complexion of starch with OA to form higher contents of single helix and type II V crystalline structures. As results, the anti-digestibility of starch-OA complexes prepared in W:IL-4:6, 2:8 mixtures were much improved in paste form. These results provide a new way of using [Cho][Lys] solvents to improve the complexion of starch with fatty acid and to create starch-based functional foods.

Porous Ionic Liquids Go Green

This Perspective points toward pathways to prepare porous ionic liquids using easily accessible materials, aiming for reduced environmental impact. We demonstrate that suspensions of porous solids are stable in eutectic mixtures, underscoring their potential for the preparation of porous ionic liquids. Porous ionic liquids retain the wide electrochemical window observed in their precursor pure ionic liquids, rendering them well-suited for green electrochemical reactions, particularly those involving gases whose solubility is enhanced in the porous suspensions. Moreover, their capacity as gas-rich media points to sustainable biomedical and pharmaceutical applications, provided nontoxic, biocompatible ionic liquids and porous solids are utilized.

Self-Assembling Polymers with p-Aminosalicylate Anions Supported by Encapsulation of p-Aminosalicylate for the Improvement of Drug Content and Release Efficiency

Bioactive linear choline-based copolymers were developed as micellar carriers for drug delivery systems (DDSs). The polymethacrylates containing trimethylammonium groups with p-aminosalicylate anions (PAS-based copolymers: series 1) or chloride anions (Cl-based copolymers: series 2) differing in ionic content and chain length were selected for drug loading. The diverse structures of amphiphilic copolymers made it possible to adjust the encapsulation efficiency of a well-known antibiotic, i.e., p-aminosalicylate in the form of sodium salt (PASNa) or acid (PASA), providing single drug systems. Goniometry was applied to verify the self-assembly capacity of the copolymers using the critical micelle concentration (CMC = 0.03-0.18 mg/mL) and the hydrophilicity level quantifying the surface wettability of polymer film using the water contact angle (WCA = 30-53°). Both parameters were regulated by the copolymer composition, indicating that the increase in ionic content caused higher CMC and lower WCA, but the latter was also modified to a less hydrophilic surface by drug encapsulation. The drug content (DC) in the PAS-based polymers was increased twice by encapsulation of PASNa and PASA (47-96% and 86-104%), whereas in the chloride-based polymer systems, the drug was loaded in 43-96% and 73-100%, respectively. Efficient drug release was detected for PASNa (80-100% series 1; 50-100% series 2) and PASA as complete in both series. The strategy of loading extra drug by encapsulation, which enhances the drug content in the copolymers containing anions of the same pharmaceutics, provided promising characteristics, which highlight the potential of PAS-loaded micellar copolymers for drug delivery.

Ionic liquids revolutionizing biomedicine: recent advances and emerging opportunities

Ionic liquids (ILs), due to their inherent structural tunability, outstanding miscibility behavior, and excellent electrochemical properties, have attracted significant research attention in the biomedical field. As the application of ILs in biomedicine is a rapidly emerging field, there is still a need for systematic analyses and summaries to further advance their development. This review presents a comprehensive survey on the utilization of ILs in the biomedical field. It specifically emphasizes the diverse structures and properties of ILs with their relevance in various biomedical applications. Subsequently, we summarize the mechanisms of ILs as potential drug candidates, exploring their effects on various organisms ranging from cell membranes to organelles, proteins, and nucleic acids. Furthermore, the application of ILs as extractants and catalysts in pharmaceutical engineering is introduced. In addition, we thoroughly review and analyze the applications of ILs in disease diagnosis and delivery systems. By offering an extensive analysis of recent research, our objective is to inspire new ideas and pathways for the design of innovative biomedical technologies based on ILs.

Cellulose-Based Ionic Conductor: An Emerging Material toward Sustainable Devices

Ionic conductors (ICs) find widespread applications across different fields, such as smart electronic, ionotronic, sensor, biomedical, and energy harvesting/storage devices, and largely determine the function and performance of these devices. In the pursuit of developing ICs required for better performing and sustainable devices, cellulose appears as an attractive and promising building block due to its high abundance, renewability, striking mechanical strength, and other functional features. In this review, we provide a comprehensive summary regarding ICs fabricated from cellulose and cellulose-derived materials in terms of fundamental structural features of cellulose, the materials design and fabrication techniques for engineering, main properties and characterization, and diverse applications. Next, the potential of cellulose-based ICs to relieve the increasing concern about electronic waste within the frame of circularity and environmental sustainability and the future directions to be explored for advancing this field are discussed. Overall, we hope this review can provide a comprehensive summary and unique perspectives on the design and application of advanced cellulose-based ICs and thereby encourage the utilization of cellulosic materials toward sustainable devices.

Preparation of hydroxyapatite nanofibers by using ionic liquids as template and application in enhancing hydrogel performance

Introduction: Hydroxyapatite (HAP or HA) nanofibers are very attractive in the field of biomedical engineering. However, templates used for preparing HAP nanofibers are usually hydrophobic molecules, like fatty acids and/or surfactants, which are difficult to remove and potentially toxic. Therefore, it is important to develop a green approach to prepare HAP nanofibers. Methods: Imidazolium-based ionic liquids (ILs) were used as templates to control the crystallization of HAP. The obtained HAP nanofibers were composited into polyvinyl alcohol-sodium alginate (PVA-Alg) hydrogel (HAP@H). The rheological performance, stretching, and compression properties were tested. Scanning electron microscope (SEM), high resolution transmission electron microscope (HRTEM), X-ray diffraction (XRD), Fourier-transform infrared (FT-IR), and differential scanning calorimetry (DSC) were adopted to characterize the morphology, size, crystallographic orientations, and phase of HAP@H. Results: HAP nanofibers with a length of ∼50 μm were harvested. The DSC results proved that water loss temperature increased from 98°C (for pure hydrogel) to 107°C (for HAP@H). Also, HAP@H hydrogel presented much better porous structure, tensile performance, and compressive performance than that of pure hydrogel. Discussion: The morphology, size, and growth direction of HAP could be modulated easily by altering the alkyl chain length of ILs' cations. This is possibly due to face-specific adsorption of imidazolium moieties on HAP nanocrystals. The enhancing performance of HAP@H is probably due to the composited highly oriented HAP nanofibers.

Microstructures of Choline Amino Acid based Biocompatible Ionic Liquids

Bio-compatible ionic liquids (Bio-ILs) represent a class of solvents with peculiar properties and exhibit huge potential for their applications in different fields of chemistry. Ever since they were discovered, researchers have used bio-ILs in diverse fields such as biomass dissolution, CO2 sequestration, and biodegradation of pesticides. This review highlights the ongoing research studies focused on elucidating the microscopic structure of bio-ILs based on cholinium cation ([Ch]+ ) and amino acid ([AA]- ) anions using the state-of-the-arta b i n i t i o ${ab\hskip0.25eminitio}$ and classical molecular dynamics (MD) simulations. The microscopic structure associated with these green ILs guides their suitability for specific applications. ILs of this class differ in the side chain of the amino acid anions, and varying the side chain significantly affects the structure of these ILs and thus helps in tuning the efficiency of biomass dissolution. This review demonstrates the central role of the side chain on the morphology of choline amino acid ([Ch][AA]) bio-ILs. The seemingly matured field of bio-ILs and their employment in various applications still holds significant potential, and the insights on their microscopic structure would steer the field of target specific application of these green ILs.

Cholinium-Based Ionic Liquids as Promising Antimicrobial Agents in Pharmaceutical Applications: Surface Activity, Antibacterial Activity and Ecotoxicological Profile

Cholinium-based ionic liquids are compounds increasingly studied in pharmaceutics and biomedicine to enhance bioavailability in drug delivery systems and as bioactive ingredients in pharmaceutical formulations. However, their potential as antimicrobial agents has scarcely been investigated. Herein, we explored the antimicrobial activity of a series of surface-active cholinium-based ionic liquids (Chol-ILs). For this purpose, Chol-ILs with alkyl chains of 10-16 carbon atoms were synthesized and their self-assembly in aqueous medium was investigated. Subsequently, their antimicrobial activity against a panel of clinically relevant bacteria and their ability to eradicate MRSA and P. aeruginosa PAO1 biofilms was evaluated. Finally, we analyzed the ecotoxicological profile of Chol-ILs in terms of susceptibility to aerobic biodegradation and acute aquatic toxicity against D. magna and V. fisheri. Our results reveal that cholinium-based ILs with alkyl chain lengths ≥12 C show a broad spectrum of antibacterial activity. Their antimicrobial efficacy depends on their hydrophobicity, with the C₁₄-C₁₆ homologs being the most effective compounds. These ILs exhibit antimicrobial activity similar to that of imidazolium ILs and quaternary ammonium antiseptics. Moreover, the longer alkyl chain Chol-ILs are able to eradicate established biofilms at concentrations as low as 16-32 µg/mL. The biodegradation rate of cholinium-based ILs decreases with alkyl chain elongation. Our results reinforce the suitability of Chol-ILs as promising multifunctional compounds for application in pharmaceutical and biomedical formulation.

Alginate/acemannan-based beads loaded with a biocompatible ionic liquid as a bioactive delivery system

Combining biomacromolecules with green chemistry principles and clean technologies has proven to be an effective approach for drug delivery, providing a prolonged and sustained release of the encapsulated material. The current study investigates the potential of cholinium caffeate (Ch[Caffeate]), a phenolic-based biocompatible ionic liquid (Bio-IL) entrapped in alginate/acemannan beads, as a drug delivery system able to reduce local joint inflammation on osteoarthritis (OA) treatment. The synthesized Bio-IL has antioxidant and anti-inflammatory actions that, combined with biopolymers as 3D architectures, promote the entrapment and sustainable release of the bioactive molecules over time. The physicochemical and morphological characterization of the beads (ALC, ALAC0,5, ALAC1, and ALAC3, containing 0, 0.5, 1, and 3 %(w/v) of Ch[Caffeate], respectively) revealed a porous and interconnected structure, with medium pore sizes ranging from 209.16 to 221.30 μm, with a high swelling ability (up 2400 %). Ch[Caffeate] significantly improved the antioxidant activities of the constructs by 95 % and 97 % for ALAC1 and ALAC3, respectively, when compared to ALA (56 %). Besides, the structures provided the environment for ATDC5 cell proliferation, and cartilage-like ECM formation, supported by the increased GAGs in ALAC1 and ALAC3 formulations after 21 days. Further, the ability to block the secretion of pro-inflammatory cytokines (TNF-α and IL-6), from differentiated THP-1 was evidenced by ChAL-Ch[Caffeate] beads. These outcomes suggest that the established strategy based on using natural and bioactive macromolecules to develop 3D constructs has great potential to be used as therapeutic tools for patients with OA.

Molecular Insights into the Binding Behavior of Imidazolium Ionic Liquids to the Receptor Binding Domain of the SARS-CoV-2 Spike Protein

The receptor-binding domain (RBD) of the SARS-CoV-2 spike protein is considered as a key target for the design and development of COVID-19 drugs and inhibitors. Due to their unique structure and properties, ionic liquids (ILs) have many special interactions with proteins, showing great potential in biomedicine. Nevertheless, few research studies have been carried out on ILs and the spike RBD protein. Here, we explore the interaction of ILs and the RBD protein through large-scale molecular dynamics simulations (4 μs in total). It was found that IL cations with long alkyl chain lengths (nchain) could spontaneously bind to the cavity region of the RBD protein. The longer the alkyl chain is, the stabler the cations bind to the protein. The binding free energy (ΔG) had the same trend, peaking at nchain = 12 with -101.19 kJ/mol. The cationic chain lengths and their fit to the pocket are decisive factors that influence the binding strength of cations and proteins. The cationic imidazole ring has a high contact frequency with phenylalanine and tryptophan, and the hydrophobic residues phenylalanine, valine, leucine, and isoleucine are the most interacting residues with side chains of cations. Meanwhile, through analysis of the interaction energy, the hydrophobic and π-π interactions are the main contributors to the high affinity between cations and the RBD protein. In addition, the long-chain ILs would also act on the protein through clustering. These studies not only provide insights into the molecular interaction between ILs and the RBD of SARS-CoV-2 but also contribute to the rational design of IL-based drugs, drug carriers, and selective inhibitors as a therapeutic for SARS-CoV-2.

Synthesis, characterization and study of electrochemical applicability of novel asymmetrically substituted 1,3-dialkyl-1,2,3-benzotriazolium salts for supercapacitor fabrication

Here we report the successful synthesis, fabrication, and testing of novel asymmetrically substituted 1,3-dialkyl-1,2,3-benzotriazolium-based ionic liquids. Their applicability in energy storage is tested as gel polymer electrolytes (ILGPE) immobilized in poly(vinylidene fluoride-co-hexa-fluoropropylene) (PVDF-HFP) copolymer as a solid-state electrolyte in electric double layer capacitors (EDLC). Asymmetrically substituted 1,3-dialkyl-1,2,3-benzotriazolium salts of tetrafluoroborates (BF₄^-) and hexafluorophosphates (PF₆^-) are synthesized by anion exchange metathesis reaction using 1,3-dialkyl-1,2,3-benzotriazolium bromide salts. N-Alkylation followed by quaternization reaction results in dialkyl substitution on 1,2,3-benzotriazole. The synthesized ionic liquids were characterized with ¹H-NMR, ¹³C-NMR, and FTIR spectroscopy. Their electrochemical and thermal properties were studied using cyclic voltammetry, impedance spectroscopy, thermogravimetric analysis, and differential scanning calorimetry. The 4.0 V potential windows obtained for asymmetrically substituted 1,3-dialkyl-1,2,3-benzotriazolium salts of BF₄^- and PF₆^- are promising electrolytes for energy storage. ILGPE tested with symmetrical EDLC with a wide operating window from 0-6.0 V gave an effective specific capacitance of 8.85 F g^-1 at a lower scan rate of 2 mV s^-1, the energy density of 2.9 μW h and 11.2 mW g^-1 power density. The fabricated supercapacitor was employed for lighting red LED (2 V, 20 mA).

Oral Ionic Liquid for Transdermal Delivery and Obesity Treatment

Obesity is currently a prerequisite for more than 70% of adults, including chronic obesity and long-term obesity. With the increase of diabetes patients in the world, it is urgent to develop effective oral drugs to replace insulin. However, the gastrointestinal tract is a main obstacle to oral drug preparations. Here, a highly effective oral drug was developed, mainly formulated as an ionic liquid (IL) prepared by l-(-)-carnitine and geranic acid. Density functional theory (DFT) calculations showed that l-(-)-carnitine and geranic acid can exist stably through hydrogen bonding. IL can significantly enhance the transdermal transport of drugs. In vitro study of intestinal permeability showed that particles formed by IL can prevent the absorption of intestinal fat. Compared with the control group, oral administration of IL (10 mL kg^-1) significantly reduced blood glucose, white adipose tissue in the liver and epididymis, and the expression of SREBP-1c and ACC in IL. Therefore, these results and high-throughput sequencing analysis showed that IL can effectively reduce the intestinal absorption of adipose tissue to reduce blood glucose. IL has good biocompatibility and stability. Therefore, IL has a certain application value in the field of oral drug-delivery carriers, which provides an effective means for the treatment of diabetes and is a potential tool to solve the epidemic of obesity.

Recent Advances in Biocompatible Ionic Liquids in Drug Formulation and Delivery

The development of effective drug formulations and delivery systems for newly developed or marketed drug molecules remains a significant challenge. These drugs can exhibit polymorphic conversion, poor bioavailability, and systemic toxicity, and can be difficult to formulate with traditional organic solvents due to acute toxicity. Ionic liquids (ILs) are recognized as solvents that can improve the pharmacokinetic and pharmacodynamic properties of drugs. ILs can address the operational/functional challenges associated with traditional organic solvents. However, many ILs are non-biodegradable and inherently toxic, which is the most significant challenge in developing IL-based drug formulations and delivery systems. Biocompatible ILs comprising biocompatible cations and anions mainly derived from bio-renewable sources are considered a green alternative to both conventional ILs and organic/inorganic solvents. This review covers the technologies and strategies developed to design biocompatible ILs, focusing on the design of biocompatible IL-based drug formulations and delivery systems, and discusses the advantages of these ILs in pharmaceutical and biomedical applications. Furthermore, this review will provide guidance on transitioning to biocompatible ILs rather than commonly used toxic ILs and organic solvents in fields ranging from chemical synthesis to pharmaceutics.

Design and synthesis of novel bis-pyridinium based-ionic liquids as potent antiparasitic agents

Focused bis-pyridinium based-ionic liquids were successfully synthesized through the quaternization of the selected 1,2-di(pyridin-4-yl)ethane followed by metathetical anion exchange. The synthesized pyridinium derivatives were fully characterized using various NMR-spectroscopic techniques including ¹H, ¹³C, ¹¹B, ³¹P and ¹⁹F NMR. The synthesized compounds were tested for their potential effect against Toxoplasma gondii. It was revealed that compound 5 had higher antiparasitic activity compared to other compounds. Parasitic reduction percentage reached 38, 50, 77 and 79 for groups III, IV, V and VI respectively in the liver with noticed distortion and deformation in tachyzoites' shape. Surprisingly there was no statistically significant difference between the synthesized compound 5 and the known anti-toxoplasmosis drug pyrimethamine. Histopathological study proved the effectiveness of the synthesized compound 5 on liver, spleen and brain tissues with observed better histological features compared to pyrimethamine treated group. The present investigation may pave the way to the possible use of compound 5 to replace the known drug pyrimethamine with better antiparasitic profile and fewer side effects.

Choline ester based ionic liquid: A multi-functional system to enhance nucleic acid stability, drug solubilization and cell penetration

Ionic liquids (ILs) are emerging systems with applications in varying areas of biomedical research. This study aims at developing a biocompatible, dual function choline ester-based IL with chloride as anion ([Ch] IL) for stabilizing nucleic acids (DNA) and enhancing cellular uptake of drugs. The ability of IL to complex with DNA was characterized using electrophoresis, dye displacement and UV absorbance. The effect of pH on complex stability and protection of DNA from nuclease were also studied. Even though [Ch] IL had positive zeta potential and showed effective complex formation, at physiological pH the zeta potential of the complex decreased and became negative, thereby, destabilizing the complex. To address this, citric acid (CA) was added to [Ch] IL which facilitated strong complexation. Further, DNA could be retrieved from these complexes without compromising its purity and integrity. Additionally, [Ch] IL was found to improve the cellular uptake of doxorubicin by improving its solubility in water. Thus, we demonstrate that the [Ch] IL developed here can enhance nucleic acid stability, drug solubilization and cell penetration. Our results show that the developed [Ch] IL can be used for long term storage of nucleic acids as well as for enhancing permeation of drugs in vivo.

Ionogels: recent advances in design, material properties and emerging biomedical applications

Ionic liquid (IL)-based gels (ionogels) have received considerable attention due to their unique advantages in ionic conductivity and their biphasic liquid-solid phase property. In ionogels, the negligibly volatile ionic liquid is retained in the interconnected 3D pore structure. On the basis of these physical features as well as the chemical properties of well-chosen ILs, there is emerging interest in the anti-bacterial and biocompatibility aspects. In this review, the recent achievements of ionogels for biomedical applications are summarized and discussed. Following a brief introduction of the various types of ILs and their key physicochemical and biological properties, the design strategies and fabrication methods of ionogels are presented by means of different confining networks. These sophisticated ionogels with diverse functions, aimed at biomedical applications, are further classified into several active domains, including wearable strain sensors, therapeutic delivery systems, wound healing and biochemical detections. Finally, the challenges and possible strategies for the design of future ionogels by integrating materials science with a biological interface are proposed.

Nitric oxide-releasing poly(ionic liquid)-based microneedle for subcutaneous fungal infection treatment

Poor permeation of therapeutic agents and similar eukaryotic cell metabolic and physiological properties of fungi and human cells are two major challenges that lead to the failure of current therapy for fungi-induced skin and soft tissue infections. Herein, a nitric oxide (NO)-releasing poly(ionic liquid)-based microneedle (PILMN-NO) with the capacity of deep persistent NO toward subcutaneous fungal bed is presented as a synergistic antifungal treatment strategy to treat subcutaneous fungal infection. Upon the insertion of PILMN-NO into skin, the contact fungicidal activities induced by electrostatic and hydrophobic effects of poly(ionic liquid) and the released NO sterilization resulting from the peroxidation and nitrification effect of NO achieved enhanced antifungal efficacy against fungi (Candida albicans) both in vitro and in vivo. Simultaneously, PILMN-NO showed biofilm ablation ability and efficiently eliminated mature biofilms. In vivo fungal-induced subcutaneous abscess studies revealed that PILMN-NO could effectively sterilize fungi while suppressing the inflammatory reaction, facilitating collagen deposition and angiogenesis, and promoting wound healing. This work provides a new strategy to overcome the difficulties in deep skin fungal infection treatment and has potential for further exploitation of NO-releasing microbicidal therapy.

Conductive and self-healing hydrogel for flexible electrochemiluminescence sensor

A flexible electrochemiluminescence (ECL) hydrogel sensor exhibiting good self-healing was constructed. A transparent self-healing oxidized sodium alginate/hydrazide polyethylene glycol (OSA/PEG-DH) hydrogel was prepared by crosslinking dynamic covalent acylhydrazone bond. The introduction of 4-amino-DL-phenylalanine, a catalyst with good biocompatibility, allows rapid gelation and self-healing of hydrogel under mild conditions. Using the hydrogel as the sensing substrate, the ionic liquid (IL) 2-hydroxy-N,N,N-trimethylethanaminium chloride and the luminescent reagent N-(aminobutyl)-N-(ethylisoluminol) (ABEI) were simultaneously immobilized in the OSA/PEG-DH hydrogel to obtain the ABEI/IL/OSA/PEG-DH hydrogel. The ABEI/IL/OSA/PEG-DH hydrogel can be directly used as a semi-solid electrolyte for constructing a flexible ECL hydrogel sensor for the detection of H₂O₂, which acted as a coreactant of ABEI. The prepared flexible ECL sensor showed good self-healing performance, can restore ECL signal intensity within 20 min after physical damage, and showed high accuracy in the analysis of complex serum samples. This research shed new light on the development of flexible ECL sensor for bioanalytical applications.

Advances in green solvents for production of polysaccharide-based packaging films: Insights of ionic liquids and deep eutectic solvents

The problems with plastic materials and the good film-forming properties of polysaccharides motivated research in the development of polysaccharide-based films. In the last 5 years, there has been an explosion of publications on using green solvents, including ionic liquids (ILs), and deep eutectic solvents (DESs) as candidates to substitute the conventional solvents/plasticizers for preparations of desired polysaccharide-based films. This review summarizes related properties and recovery of ILs and DESs, a series of green preparation strategies (including pretreatment solvents/reaction media, ILs/DESs as components, extraction solvents of bioactive compounds added into films), and inherent properties of polysaccharide-based films with/without ILs and DESs. Major reported advantages of these new solvents are high dissolving capacity of certain ILs/DESs for polysaccharides (i.e., up to 30 wt% for cellulose) and better plasticizing ability than traditional plasticizers. In addition, they frequently display intrinsic antioxidant and antibacterial activities that facilitate ILs/DESs applications in the processing of polysaccharide-based films (especially active food packaging films). ILs/DESs in the film could also be further recycled by water or ethanol/methanol treatment followed by drying/evaporation. One particularly promising approach is to use bioactive cholinium-based ILs and DESs with good safety and plasticizing ability to improve the functional properties of prepared films. Whole extracts by ILs/DESs from various byproducts can also be directly used in films without separation/polishing of compounds from the extracting agents. Scaling-up, including costs and environmental footprint, as well as the safety and applications in real foods of polysaccharide-based film with ILs/DESs (extracts) deserves more studies.

Recent Advances in the Preparation of Delivery Systems for the Controlled Release of Scents

Scents are volatile compounds highly employed in a wide range of manufactured items, such as fine perfumery, household products, and functional foods. One of the main directions of the research in this area aims to enhance the longevity of scents by designing efficient delivery systems to control the release rate of these volatile molecules and also increase their stability. Several approaches to release scents in a controlled manner have been developed in recent years. Thus, different controlled release systems have been prepared, including polymers, metal-organic frameworks and mechanically interlocked systems, among others. This review is focused on the preparation of different scaffolds to accomplish a slow release of scents, by pointing out examples reported in the last five years. In addition to discuss selected examples, a critical perspective on the state of the art of this research field is provided, comparing the different types of scent delivery systems.

Advances of Imidazolium Ionic Liquids for the Extraction of Phytochemicals from Plants

In this review, we present the research from 2013 to 2022 about the character of ionic liquids, the categories of phytochemicals, and the reasons for selecting imidazolium ionic liquids for phytochemical extraction. Then we introduce the structural formulae of the imidazolium ionic liquids commonly used in the extraction of phytochemicals, the methods used to prepare imidazolium ionic liquids, and a comprehensive introduction of how imidazolium ionic liquids are applied to extract phytochemicals from plants. Importantly, we discuss the strategies for studying the extraction mechanisms of imidazolium ionic liquids to extract phytochemicals, and the recovery methods regarding imidazolium ionic liquids and their recyclability are analyzed. Then the toxicity in imidazolium ionic liquids is pointed out. Finally, the challenges and prospects of extracting phytochemicals by imidazolium ionic liquids are summarized, and they are expected to provide some references for researchers.

Favourable Interfacial Characteristics of A2 Milk Protein Monolayer

Shielding of the specific body organ using the biocompatible material helps preventing direct exposure of that part to the foreign entities responsible for infections. Here we show the potential of the A2 milk protein recovered from the milk of cow from Indian origin for possible prevention of the direct exposure to other foreign molecules. We measured the surface pressure of the monolayers of different types of protein samples using Langmuir isotherm experiments. The surface pressure measurements for the monolayer of four types of protein macromolecules have been carried out using the Wilhelmy plate micro pressure sensor. We studied the self-organization of different protein macromolecules and their monolayer compression characteristics. The electrochemical behaviour is studied using electrochemical impedance spectroscopy. We found the highest surface pressure for the monolayer of A2 protein. Further, it is also found that A2 protein exhibited the highest surface activity amongst the other proteins. This property can be effectively used for making the envelope of the A2 protein surrounding the targeted entity.

Recent advances in bio-inspired ionic liquid-based interfacial materials from preparation to application

Natural creatures always display unique and charming functions, such as the adhesion of mussels and the lubrication of Nepenthes, to maintain their life activities. Bio-inspired interfacial materials infused with liquid, especially for ionic liquids (ILs), have been designed and prepared to meet the emerging and rising needs of human beings. In this review, we first summarize the recent development of bio-inspired IL-based interfacial materials (BILIMs), ranging from the synthesis strategy to the design principle. Then, we discuss the advanced applications of BILIMs from anti-adhesive aspects (e.g., anti-biofouling, anti-liquid fouling, and anti-solid fouling) to adhesive aspects (e.g., biological sensor, adhesive tape, and wound dressing). Finally, the current limitations and future prospects of BILIMs are provided to feed the actual needs.

Applications of biomass-derived solvents in biomass pretreatment - Strategies, challenges, and prospects

Biomass pretreatment is considered a key step in the 2nd generation biofuel production from lignocellulosic biomass. Research on conventional biomass pretreatment solvents has mainly been focused on carbohydrate conversion efficiency, while their hazardousness and/or carbon intensity were not comprehensively considered. Recent sustainability issues request further consideration for eco-friendly and sustainable alternatives like biomass-derived solvents. Carbohydrate and lignin-derived solvents have been proposed and investigated as green alternatives in many biomass processes. In this review, the applications of different types of biomass pretreatment solvents, including organic, ionic liquid, and deep eutectic solvents, are thoroughly discussed. The role of water as a co-solvent in these pretreatment processes is also reviewed. Finally, current research challenges and prospects of utilizing biomass-derived pretreatment solvents for pretreatment are discussed. Given bioethanol's market potential and increasing public awareness about environmental concerns, it will be a priority adopting sustainable and green biomass pretreatment solvents in biorefinery.