• QSAR-driven screening uncovers and designs novel pyrimidine-4,6-diamine derivatives as potent JAK3 inhibitors

      Faris, Abdelmoujoud; Ibrahim, Ibrahim M.; Alnajjar, Radwan; Hadni, Hanine; Bhat, Mashooq Ahmad; Yaseen, Muhammad; Chakraborty, Souvik; Alsakhen, Nada; Shamkh, Israa M.; Mabood, Fazal; et al. (Taylor & Francis, 2023-12-07)
      This study presents a robust and integrated methodology that harnesses a range of computational techniques to facilitate the design and prediction of new inhibitors targeting the JAK3/STAT pathway. This methodology encompasses several strategies, including QSAR analysis, pharmacophore modeling, ADMET prediction, covalent docking, molecular dynamics (MD) simulations, and the calculation of binding free energies (MM/GBSA). An efficacious QSAR model was meticulously crafted through the employment of multiple linear regression (MLR). The initial MLR model underwent further refinement employing an artificial neural network (ANN) methodology aimed at minimizing predictive errors. Notably, both MLR and ANN exhibited commendable performance, showcasing R2 values of 0.89 and 0.95, respectively. The model's precision was assessed via leave-one-out cross-validation (CV) yielding a Q2 value of 0.65, supplemented by rigorous Y-randomization. , The pharmacophore model effectively differentiated between active and inactive drugs, identifying potential JAK3 inhibitors, and demonstrated validity with an ROC value of 0.86. The newly discovered and designed inhibitors exhibited high inhibitory potency, ranging from 6 to 8, as accurately predicted by the QSAR models. Comparative analysis with FDA-approved Tofacitinib revealed that the new compounds exhibited promising ADMET properties and strong covalent docking (CovDock) interactions. The stability of the new discovered and designed inhibitors within the JAK3 binding site was confirmed through 500 ns MD simulations, while MM/GBSA calculations supported their binding affinity. Additionally, a retrosynthetic study was conducted to facilitate the synthesis of these potential JAK3/STAT inhibitors. The overall integrated approach demonstrates the feasibility of designing novel JAK3/STAT inhibitors with robust efficacy and excellent ADMET characteristics that surpass Tofacitinib by a significant margin.
    • Identification of Disalicyloyl Curcumin as a Potential DNA Polymerase Inhibitor for Marek’s Disease Herpesvirus: A Computational Study Using Virtual Screening and Molecular Dynamics Simulations

      Cherif, Aziza; Basharat, Zarrin; Yaseen, Muhammad; Bhat, Mashooq Ahmad; Uddin, Imad; Ziedan, Noha; Mabood, Fazal; Sadfi-Zouaoui, Najla; Messaoudi, Abdelmonaem; Université de Tunis-El Manar; Alpha Genomics, Islamabad; University of Swat; King Saud University; University of Chester; Jendouba University (MDPI, 2023-09-12)
      Marek’s disease virus (MDV) is a highly contagious and persistent virus that causes T-lymphoma in chickens, posing a significant threat to the poultry industry despite the availability of vaccines. The emergence of new virulent strains has further intensified the challenge of designing effective antiviral drugs for MDV. In this study, our main objective was to identify novel antiviral phytochemicals through in silico analysis. We employed Alphafold to construct a three-dimensional (3D) structure of the MDV DNA polymerase, a crucial enzyme involved in viral replication. To ensure the accuracy of the structural model, we validated it using tools available at the SAVES server. Subsequently, a diverse dataset containing thousands of compounds, primarily derived from plant sources, was subjected to molecular docking with the MDV DNA polymerase model, utilizing AutoDock software V 4.2. Through comprehensive analysis of the docking results, we identified Disalicyloyl curcumin as a promising drug candidate that exhibited remarkable binding affinity, with a minimum energy of −12.66 Kcal/mol, specifically targeting the DNA polymerase enzyme. To further assess its potential, we performed molecular dynamics simulations, which confirmed the stability of Disalicyloyl curcumin within the MDV system. Experimental validation of its inhibitory activity in vitro can provide substantial support for its effectiveness. The outcomes of our study hold significant implications for the poultry industry, as the discovery of efficient antiviral phytochemicals against MDV could substantially mitigate the economic losses associated with this devastating disease.
    • A measurement and modelling investigation of the indoor air chemistry following cooking activities

      Davies, Helen L.; O'Leary, Catherine; Dillon, Terry; Shaw, David R.; Shaw, Marvin; Mehra, Archit; Phillips, Gavin J.; Carslaw, Nicola (The Royal Society of Chemistry, 2023-08-14)
      Domestic cooking is a source of indoor air pollutants, including volatile organic compounds (VOCs), which can impact on indoor air quality. However, the real-time VOC emissions from cooking are not well characterised, and similarly, the resulting secondary chemistry is poorly understood. Here, selected-ion flow-tube mass spectrometry (SIFT-MS) was used to monitor the real-time VOC emissions during the cooking of a scripted chicken and vegetable stir-fry meal, in a room scale, semi-realistic environment. The VOC emissions were dominated by alcohols (70% of total emission), but also contained a range of aldehydes (14%) and terpenes (5%), largely attributable to the heating of oil and the preparation and heating of spices, respectively. The direct cooking-related VOC emissions were then simulated using the Indoor Chemical Model in Python (INCHEM-Py), to investigate the resulting secondary chemistry. Modelling revealed that VOC concentrations were dominated by direct emissions, with only a small contribution from secondary products, though the secondary species were longer lived than the directly emitted species. Following cooking, hydroxyl radical concentrations reduced by 86%, while organic peroxy radical levels increased by over 700%, later forming secondary organic nitrates, peroxyacylnitrates (PANs) and formaldehyde. Monoterpene emissions were shown to drive the formation of secondary formaldehyde, albeit to produce relatively modest concentrations (average of 60 ppt). Sensitivity analysis of the simulation conditions revealed that increasing the outdoor concentrations of ozone and NOx species (2.9× and 9×, respectively) resulted in the greatest increase in secondary product formation indoors (≈400%, 200% and 600% increase in organic nitrates, PANs and formaldehyde production, respectively). Given the fact that climate change is likely to result in increased ozone concentrations in the future, and that increased window-opening in response to rising temperatures is also likely, higher concentrations of indoor oxidants are likely in homes in the future. This work, therefore, suggests that cooking could be a more important source of secondary pollutants indoors in the future.
    • Ultrasound-guided day-case wide-bore percutaneous mucin aspiration in advanced pseudomyxoma peritonei

      Borg, Philip; Ng, Helen Hoi-Lam; Mullan, Damian; Aziz, Omer; Laasch, Hans-Ulrich; The Christie NHS Foundation Trust; University of Leeds; University of Manchester; University of Chester (Elsevier, 2023-02-16)
      To evaluate percutaneous ultrasound-guided day-case mucin aspiration in advanced pseudomyxoma peritonei (PMP) using a wide-bore drain with regards to its safety and efficacy. All patients who underwent percutaneous mucin aspiration for PMP between 2019-2021 at a single national peritoneal tumour service were included in this study. Under local anaesthesia, a suction-enabled 28-32 F catheter was used for drainage following wire-guided track dilatation. The volume drained and difference in abdominal girth pre- and post-procedure were measured. Patients graded difficulty in breathing and abdominal discomfort pre- and post-procedure. Histology reports were reviewed. Sixteen patients received 56 percutaneous mucin aspirations between 2019-2021. The aetiology was a low-grade appendiceal mucinous neoplasm (LAMN) in 50% of patients. The mean amount of mucin drained was 7,320 ± 3,000ml (range 300-13,500 ml). The mean reduction in abdominal girth post-procedure was 12.2 ± 5 cm (range 0-27 cm). Only grade 1 complications were observed. Percutaneous ultrasound-guided day-case aspiration of mucin for advanced and recurrent PMP using a wide-bore drain is a safe and effective procedure. It may be used in the palliative setting or as a bridge to surgery in the very symptomatic patient or if there is a reversible contraindication to surgery. [Abstract copyright: Copyright © 2023. Published by Elsevier Ltd.]
    • Pyrolysis activation energy of cellulosic fibres investigated by a method derived from the first order global model

      Liang, Yunhao; Hine, Peter; Ries, Michael; University of Leeds (Elsevier, 2022-12-30)
      The pyrolysis kinetics of cellulosic fibres, a natural cotton yarn (NCY) and a mercerized cotton yarn (MCY), has been explored with a modified first order global analysis method (FOG), via a series of non-isothermal experiments, using thermogravimetric analysis (TGA). The modified FOG analysis routine was developed to overcome discrepancy in heating rate and the difference between exact results and approximations in integrals. The intrinsic pyrolysis activation energy, with temperature range tending to zero, was found to be independent of heating rate and approximation used, giving average values of 153 ± 2 kJ/mol for NCY and 192 ± 7 kJ/mol for MCY. This proves the applicability of the reported analysis routine under the conducted TGA measurements. The reasons for different values were hypothesized to be the difference in chemical composition and crystalline structure. The findings provide a new approach in the investigation on pyrolysis kinetics of biomass and factors impacting their pyrolytic behaviour.
    • A stable platinum porphyrin-based photocatalyst for hydrogen production under visible light in water

      Orfanos, Emmanouil; Ladomenou, Kalliopi; Angaridis, Panagiots; Papadopoulos, Theodoros A.; Charalambidis, Georgios; Vasilopoulou, Maria; Coutsolelos, Athanassios G.; University of Crete; University of Chester (Royal Society of Chemistry, 2022-10-07)
      A stable system containing a Pt metallated porphyrin as a molecular solid photocatalyst in acidic aqueous solution is able to produce hydrogen efficiently, under visible light irradiation. The system shows an average H2 evolution of 467.3 μmol g-1 h-1.
    • Three methods to measure the dissolution activation energy of cellulosic fibres using time-temperature superposition

      Liang, Yunhao; Ries, Michael; Hine, Peter; University of Leeds (Elsevier, 2022-04-28)
      Three methods are established to explore the dissolution kinetics of cellulosic fibres in the ionic liquid 1-ethyl-3-methyl-imidazolium acetate ([C2mim][OAc]), based on optical microscopic images of processed dried cellulose and cellulose hydrogels. The dissolution process for different times at various temperatures was analysed using time-temperature superposition, and from this the dissolution was found to follow an Arrhenius behaviour. Three values for the activation energy of dissolution were obtained from three different quantifying methods; these were found to agree, giving an average value of 73 ± 2 kJ/mol. A new method is developed to determine the swelling ratio of different regions of the processed cellulose samples, along with the different water volume fractions contained therein. The findings will be of interest to researchers making all cellulose composites and those studying the dissolution of cellulose by ionic liquids.
    • 2D‐Hexagonal Boron Nitride Screen‐Printed Bulk‐Modified Electrochemical Platforms Explored towards Oxygen Reduction Reactions

      Khan, Aamar F.; Ferrari, Alejandro Garcia-Miranda; Hughes, Jack; Smith, Graham C.; Banks, Craig E.; Rowley-Neale, Samuel J.; Manchester Metropolitan University; University of Chester (MDPI, 2022-04-26)
      A low‐cost, scalable and reproducible approach for the mass production of screen‐printed electrode (SPE) platforms that have varying percentage mass incorporations of 2D hexagonal boron nitride (2D‐hBN) (2D‐hBN/SPEs) is demonstrated herein. These novel 2D‐hBN/SPEs are explored as a potential metal‐free electrocatalysts towards oxygen reduction reactions (ORRs) within acidic media where their performance is evaluated. A 5% mass incorporation of 2D‐hBN into the SPEs resulted in the most beneficial ORR catalysis, reducing the ORR onset potential by ca. 200 mV in comparison to bare/unmodified SPEs. Furthermore, an increase in the achievable current of 83% is also exhibited upon the utilisation of a 2D‐hBN/SPE in comparison to its unmodified equivalent. The screen‐printed fabrication approach replaces the less‐reproducible and time‐consuming dropcasting technique of 2D‐hBN and provides an alternative approach for the large‐scale manufacture of novel electrode platforms that can be utilised in a variety of applications
    • Structural speciation in chemical reactivity profiling of binary-ternary systems of Ni(II) with iminodialcohol and aromatic chelators

      Salifoglou, Athanasios; Papadopoulos, Theodoros A.; Reimann, M. K.; Pöttgen, R.; Matsia, S.; Kaoulla, A.; Menelaou, M.; Hatzidimitriou, Antonios; Aristotle University of Thessaloniki; University of Chester; Universität Münster; Cyprus University of Technology (Elsevier, 2021-11-10)
      The importance of structural speciation in the control of chemical reactivity in Ni(II) binary-ternary systems, involving (O,O,N)-containing substrates (1,1’-iminodi-2-propanol), and aromatic chelators (2,2’-bipyridine, 1,10-phenanthroline), prompted the systematic synthesis of new crystalline materials characterized by elemental analysis, FT-IR, UV-Visible, Luminescence, TGA, magnetic susceptibility, and X-ray crystallography. The structures contain mononuclear octahedral assemblies, the lattice architecture of which exemplifies reaction conditions under which conformational variants and solvent-associated lattice-imposed complexes are assembled. Transformations between complex species denote their association with reactivity pathways, suggesting alternate synthetic methodologies for their isolation. Theoretical work (Hirshfeld, Electrostatic Potential, DFT) signifies the impact of crystal structure on energy profiles of the generated species. The arisen physicochemical profiles of all compounds portray a well-configured interwoven network of pathways, projecting strong connection between structural speciation and Ni(II) reactivity patterns in organic-solvent media. The collective results provide well-defined parameterized profiles, poised to influence the synthesis of new Ni(II)-iminodialcohol materials with specified structural-magneto-optical properties.
    • ERRATUM: Versailles project on advanced materials and standards interlaboratory study on intensity calibration for x-ray photoelectron spectroscopy instruments using low-density polyethylene

      Reed, Benjamen; Cant, David; Spencer, Steve; Carmona-Carmona, Abraham; Bushell, Adam; Herrera-Gómez, Alberto; Kurokawa, Akira; Thissen, Andreas; Thomas, Andrew; Britton, Andrew; et al. (American Vacuum Society, 2021-01-25)
    • Versailles Project on Advanced Materials and Standards interlaboratory study on intensity calibration for x-ray photoelectron spectroscopy instruments using low-density polyethylene

      Reed, Benjamen; Cant, David; Spencer, Steve; Carmona-Carmona, Abraham; Bushell, Adam; Herrera-Gomez, Alberto; Kurokawa, Akira; Thissen, Andreas; Thomas, Andrew; Britton, Andrew; et al. (American Vacuum Society, 2020-11-23)
      We report the results of a Versailles Project on Advanced Materials and Standards interlaboratory study on the intensity scale calibration of x-ray photoelectron spectrometers using low-density polyethylene (LDPE) as an alternative material to gold, silver, and copper. An improved set of LDPE reference spectra, corrected for different instrument geometries using a quartz-monochromated Al Kα x-ray source, was developed using data provided by participants in this study. Using these new reference spectra, a transmission function was calculated for each dataset that participants provided. When compared to a similar calibration procedure using the NPL reference spectra for gold, the LDPE intensity calibration method achieves an absolute offset of ∼3.0% and a systematic deviation of ±6.5% on average across all participants. For spectra recorded at high pass energies (≥90 eV), values of absolute offset and systematic deviation are ∼5.8% and ±5.7%, respectively, whereas for spectra collected at lower pass energies (<90 eV), values of absolute offset and systematic deviation are ∼4.9% and ±8.8%, respectively; low pass energy spectra perform worse than the global average, in terms of systematic deviations, due to diminished count rates and signal-to-noise ratio. Differences in absolute offset are attributed to the surface roughness of the LDPE induced by sample preparation. We further assess the usability of LDPE as a secondary reference material and comment on its performance in the presence of issues such as variable dark noise, x-ray warm up times, inaccuracy at low count rates, and underlying spectrometer problems. In response to participant feedback and the results of the study, we provide an updated LDPE intensity calibration protocol to address the issues highlighted in the interlaboratory study. We also comment on the lack of implementation of a consistent and traceable intensity calibration method across the community of x-ray photoelectron spectroscopy (XPS) users and, therefore, propose a route to achieving this with the assistance of instrument manufacturers, metrology laboratories, and experts leading to an international standard for XPS intensity scale calibration.
    • Modified magnetic core-shell mesoporous silica nano-formulations with encapsulated quercetin exhibit anti-amyloid and antioxidant activity

      Halevas, Eleftherios; Mavroidi, Barbara; Nday, Christiane; Tang, Jianhua; Smith, Graham; Boukos, Nikos; Litsardakis, George; Pelecanou, Maria; Salifoglou, Athanasios; NCSR "Demokritos" Athens (Halevas, Mavroidi, Pelecanou), University of Chester (Tang, Smith), Aristotle University of Thessalonika (Litsardakis, Nday) (Elsevier, 2020-10-06)
      Targeted tissue drug delivery is a challenge in contemporary nanotechnologically driven therapeutic approaches, with the interplay interactions between nanohost and encapsulated drug shaping the ultimate properties of transport, release and efficacy of the drug at its destination. Prompted by the need to pursue the synthesis of such hybrid systems, a family of modified magnetic core-shell mesoporous silica nano-formulations was synthesized with encapsulated quercetin, a natural flavonoid with proven bioactivity. The new nanocarriers were produced via the sol-gel process, using tetraethoxysilane as a precursor and bearing a magnetic core of surface-modified monodispersed magnetite colloidal superparamagnetic nanoparticles, subsequently surface-modified with polyethylene glycol 3000 (PEG3k). The arising nano-formulations were evaluated for their textural and structural properties, exhibiting enhanced solubility and stability in physiological media, as evidenced by the loading capacity, entrapment efficiency results and in vitro release studies of their load. Guided by the increased bioavailability of quercetin in its encapsulated form, further evaluation of the biological activity of the magnetic as well as non-magnetic core-shell nanoparticles, pertaining to their anti-amyloid and antioxidant potential, revealed interference with the aggregation of β-amyloid peptide (Aβ) in Alzheimer’s disease, reduction of Aβ cellular toxicity and minimization of Aβ-induced Reactive Oxygen Species (ROS) generation. The data indicate that the biological properties of released quercetin are maintained in the presence of the host nanocarriers. Collectively, the findings suggest that the emerging hybrid nano-formulations can function as efficient nanocarriers of hydrophobic natural flavonoids in the development of multifunctional nanomaterials toward therapeutic applications.
    • ‘Radial force’ of colonic stents: A parameter without consistency, definition or standard

      Laasch, Hans-Ulrich; Milward, Graham D.; Edwards, Derek W. (Society of Gastrointestinal Intervention, 2020-07-31)
    • Optimization of anti-wear and anti-bacterial properties of beta TiNb alloy via controlling duty cycle in open-air laser nitriding

      Chang, Xianwen; Smith, Graham; Quinn, James; Carson, Louise; Chan, Chi-Wai; Lee, Seunghwan; Technical University of Denmark; University of Chester; Queens University Belfast (Elsevier, 2020-07-09)
      A multifunctional beta TiNb surface, featuring wear-resistant and antibacterial properties, was successfully created by means of open-air fibre laser nitriding. Beta TiNb alloy was selected in this study as it has low Young’s modulus, is highly biocompatible, and thus can be a promising prosthetic joint material. It is, however, necessary to overcome intrinsically weak mechanical properties and poor wear resistance of beta TiNb in order to cover the range of applications to loadbearing and/or shearing parts. To this end, open-air laser nitriding technique was employed. A control of single processing parameter, namely duty cycle (between 5% and 100%), led to substantially different structural and functional properties of the processed beta TiNb surfaces as analyzed by an array of analytical tools. The TiNb samples nitrided at the DC condition of 60% showed a most enhanced performance in terms of improving surface hardness, anti-friction, antiwear and anti-bacterial properties in comparison with other conditions. These findings are expected to be highly important and useful when TiNb alloys are considered as materials for hip/knee articular joint implants
    • The past, present and future of indoor air chemistry

      Bekö, Gabriel; Carslaw, Nicola; Fauser, Patrick; Kauneliene, Violeta; Nehr, Sascha; Phillips, Gavin J.; Saraga, Dikaia; Schoemaecker, Coralie; Wierzbicka, Aneta; Querol, Xavier; et al. (Wiley, 2020-04-25)
      This is an editorial contribution to the Journal Indoor Air on the future direction of indoor air chemistry research.
    • Graphene Oxide Bulk Modified Screen-Printed Electrodes Provide Beneficial Electroanalytical Sensing Capabilities

      Rowley-Neale, Samuel J.; Brownson, Dale A. C.; Smith, Graham; Banks, Craig E.; Manchester Metropolitan University; University of Chester (MDPI, 2020-03-19)
      We demonstrate a facile methodology for the mass production of graphene oxide (GO) bulk modified screen-printed electrodes (GO-SPEs) that are economical, highly reproducible and provide analytically useful outputs. Through fabricating GO-SPEs with varying percentage mass incorporations (2.5, 5, 7.5 and 10%) of GO, an electrocatalytic effect towards the chosen electroanalytical probes is observed, that increases with greater GO incorporated compared to bare/ graphite SPEs. The optimum mass ratio of 10% GO to 90% carbon ink displays an electroanalytical signal towards dopamine (DA) and uric acid (UA), which is ca. ×10 greater in magnitude than that achievable at a bare/unmodified graphite SPE. Furthermore, 10% GO-SPEs exhibit a competitively low limit of detection (3σ) towards DA at ca. 81 nM, which is superior to that of a bare/unmodified graphite SPE at ca. 780 nM. The improved analytical response is attributed to the large number of oxygenated species inhabiting the edge and defect sites of the GO nanosheets, which are available to exhibit electrocatalytic responses towards inner-sphere electrochemical analytes. Our reported methodology is simple, scalable, and cost effective for the fabrication of GO-SPEs, that display highly competitive LODs, and is of significant interest for use in commercial and medicinal applications
    • Additively Manufactured Graphitic Electrochemical Sensing Platforms

      Foster, Christopher W.; El Bardisy, Hadil M.; Down, Michael P.; Keefe, Edmund M.; Smith, Graham C.; Banks, Craig E.; Manchester Metropolitan University; University of Chester (Elsevier, 2020-02-01)
      Additive manufacturing (AM)/3D printing technology provides a novel platform for the rapid prototyping of low cost 3D platforms. Herein, we report for the first time, the fabrication, characterisation (physicochemical and electrochemical) and application (electrochemical sensing) of bespoke nanographite (NG)-loaded (25 wt. %) AM printable (via fused deposition modelling) NG/PLA filaments. We have optimised and tailored a variety of NG-loaded filaments and their AM counterparts in order to achieve optimal printability and electrochemical behaviour. Two AM platforms, namely AM macroelectrodes (AMEs) and AM 3D honeycomb (macroporous) structures are benchmarked against a range of redox probes and the simultaneous detection of lead (II) and cadmium (II). This proof-of-concept demonstrates the impact that AM can have within the area of electroanalytical sensors.
    • A single parameter approach to enhance the microstructural and mechanical properties of beta Ti-Nb alloy via open-air fiber laser nitriding

      Chan, Chi-Wai; Chang, Xianwen; Bozorgzadeh, Mohammad Amin; Smith, Graham C.; Lee, Seunghwan; Queen's University Belfast, Technical University of Denmark, University of Chester (Elsevier, 2019-12-13)
      In this study, the idea of applying open-air laser nitriding to improve the microstructural and mechanical properties of beta Ti-45 at.% Nb alloy was demonstrated. Surface cracking after laser nitriding is one of the main reasons impeding direct translation of the laser nitriding technique from the laboratories to industries as cracks can be the weak points to initiate mechanical and corrosion failures in long-term usage. With proper selection of duty cycle (DC) between 40% (modulated mode) and 100% (continuous wave, CW mode) to control the laser energy input and laser-material-gas interaction time, the cracking problems of laser nitriding can be alleviated and even solved. A crack-free and uniformly gold-coloured nitrided surface was successfully obtained at the DC of 40% in this study. The morphology, microstructure, composition and mechanical properties of the nitrided samples were studied and analysed by optical microscopy (OM), scanning electron microscopy (SEM), SEM-energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and Vickers micro-hardness tests. The OM results indicated that minimum overlapping between the laser tracks would give desirable results to obtain the crack-free surface. The measurements from the SEM micrographs indicated the depth of the laser-nitrided areas ranged between 22 and 43 µm. The XRD findings showed that a clear conversion of the TiNb surface to a nitride as a result of laser nitriding was observed. The maximum hardness, as measured by the Vickers method in cross-sections, lay in the range of 780 to 870 HV after laser nitriding. To summarise, control of DC to obtain a crack free and quality surface via fiber laser nitriding in open air is a simpler and quicker approach in comparison with the conventional substrate preheating and nitrogen (N) dilution approaches. The single-parameter approach is more efficient than parameter optimisation via design of experiments (DOE) employed in conventional methods.
    • Self-assembled nanostructures in ionic liquids facilitate charge storage at electrified interfaces

      Mao, Xianwen; Brown, Paul; Cervinka, Citrad; Hazell, Gavin; Li, Hua; Ren, Yinying; Chen, Di; Atkin, Rob; Eastoe, Julian; Grillo, Isabelle; et al. (Nature Research, 2019-08-12)
      Driven by the potential applications of ionic liquids (ILs) in many emerging electrochemical technologies, recent research efforts have been directed at understanding the complex ion ordering in these systems, to uncover novel energy storage mechanisms at IL–electrode interfaces. Here, we discover that surface-active ILs (SAILs), which contain amphiphilic structures inducing self-assembly, exhibit enhanced charge storage performance at electrified surfaces. Unlike conventional non amphiphilic ILs, for which ion distribution is dominated by Coulombic interactions, SAILs exhibit significant and competing van der Waals interactions owing to the non-polar surfactant tails, leading to unusual interfacial ion distributions. We reveal that, at an intermediate degree of electrode polarization, SAILs display optimum performance, because the low-charge-density alkyl tails are effectively excluded from the electrode surfaces, whereas the formation of non-polar domains along the surface suppresses undesired overscreening effects. This work represents a crucial step towards understanding the unique interfacial behaviour and electrochemical properties of amphiphilic liquid systems showing long-range ordering, and offers insights into the design principles for high-energy-density electrolytes based on spontaneous self-assembly behaviour.
    • Magnetic cationic liposomal nanocarriers for the efficient drug delivery of a curcumin-based vanadium complex with anticancer potential

      Halevas, Eleftherios; Mavroidi, Barbara; Moschona, Alexandra; Hadjispyrou, Spyros; Salifoglou, Athanasios; Pelecanou, Maria; Litsardakis, George; Pantazaki, Anastasia; Swanson, Claudia H.; Smith, Graham C.; et al. (Elsevier, 2019-07-15)
      In this work novel magnetic cationic liposomal nanoformulations were synthesized for the encapsulation of a crystallographically defined ternary V(IV)-curcumin-bipyridine (VCur) complex with proven bioactivity, as potential anticancer agents. The liposomal vesicles were produced via the thin film hydration method employing N-[1-(2,3-dioleoyloxy)propyl]-N,N,N-trimethylammonium (DOTAP) and egg phosphatidylcholine lipids and were magnetized through the addition of citric acid surface-modified monodispersed magnetite colloidal magnetic nanoparticles. The obtained nanoformulations were evaluated for their structural and textural properties and shown to have exceptional stability and enhanced solubility in physiological media, demonstrated by the entrapment efficiency and loading capacity results and the in vitro release studies of their cargo. Furthermore, the generated liposomal formulations preserved the superparamagnetic behavior of the employed magnetic core maintaining the physicochemical and morphological requirements for targeted drug delivery applications. The novel nanomaterials were further biologically evaluated for their DNA interaction potential and were found to act as intercalators. The findings suggest that the positively charged magnetic liposomal nanoformulations can generate increased concentration of their cargo at the DNA site, offering a further dimension in the importance of cationic liposomes as nanocarriers of hydrophobic anticancer metal ion complexes for the development of new multifunctional pharmaceutical nanomaterials with enhanced bioavailability and targeted antitumor activity.