• A novel approach to crystallisation of nanodispersible microparticles by spray drying for improved tabletability

      Paluch, Krzysztof J.; Tajber, L.; Adamczyk, B.; Corrigan, O.I.; Healy, A.M. (2012-10-15)
      High-dose API powders which are to be tableted by direct compression should have high compactibility and compressibility. This note reports on a novel approach to the manufacture of crystalline powders intended for direct compaction with improved compactibility and compressibility properties. The poorly compactable API, chlorothiazide, was spray dried from a water/acetone solvent mix producing additive-free nanocrystalline microparticles (NCMPs) of median particle size 3.5 μm. Tablets compacted from NCMPs had tensile strengths ranging from 0.5 to 4.6 MPa (compared to 0.6–0.9 MPa for tablets of micronised CTZ) at compression forces ranging from 6 kN to 13 kN. NCMP tablets also had high porosities (34–20%) and large specific surface areas (4.4–4.8 m2/g). The time taken for tablets made of NCMPs to erode was not statistically longer (p > 0.05) than for tablets made of micronised CTZ. Fragmentation of NCMPs on compression was observed. The volume fraction of particles below 1 μm present in the suspension recovered after erosion of NCMP tablets was 34.8 ± 3.43%, while no nanosized particles were detected in the slurry after erosion of compacted micronised CTZ.
    • Novel Aspects of the Conduction Mechanisms of Electrolytes Containing Tetrahedral Moieties

      Kendrick, E.; Kendrick, John; Orera, A.; Panchmatia, P.; Islam, M.S.; Slater, P.R. (2010-04)
      Traditionally materials with the fluorite and perovskite structures have dominated the research in the area of oxide ion/proton conducting solid electrolytes. In such cases, the key defects are oxide ion vacancies, and conduction proceeds via a simple vacancy hopping mechanism. In recent years, there has been growing interest in alternative structure types, many of which contain tetrahedral moieties. For these new systems, an understanding of the accommodation of defects and the nature of the conduction mechanism is important for the optimisation of their conductivities, as well as to help target related structures that may display high oxide ion/proton conduction. Computer modelling studies on a range of systems containing tetrahedral moieties are presented, including apatite-type La9.33+xGe6O26+3x/2, cuspidine-type La4Ga2¿xTixO9+x/2 and La1¿xBa1+xGaO4¿x/2. The type of anion defect (vacancy or interstitial), their location and the factors affecting their incorporation are discussed. In addition, modelling data to help to understand their conduction mechanisms are presented, showing novel aspects including the important role of the tetrahedral moieties in the conduction processes
    • Novel Aspects of the Conduction Mechanisms of Electrolytes Containing Tetrahedral Moieties

      Kendrick, E.; Kendrick, John; Orera, A.; Panchmatia, P.; Islam, M.S.; Slater, P.R. (2010-09)
      Traditionally materials with the fluorite and perovskite structures have dominated the research in the area of oxide ion/proton conducting solid electrolytes. In such cases, the key defects are oxide ion vacancies, and conduction proceeds via a simple vacancy hopping mechanism. In recent years, there has been growing interest in alternative structure types, many of which contain tetrahedral moieties. For these new systems, an understanding of the accommodation of defects and the nature of the conduction mechanism is important for the optimisation of their conductivities, as well as to help target related structures that may display high oxide ion/proton conduction. Computer modelling studies on a range of systems containing tetrahedral moieties are presented, including apatite-type La9.33+xGe6O26+3x/2, cuspidine-type La4Ga2-xTixO9+x/2 and La1-xBa1+xGaO4-x/2. The type of anion defect (vacancy or interstitial), their location and the factors affecting their incorporation are discussed. In addition, modelling data to help to understand their conduction mechanisms are presented, showing novel aspects including the important role of the tetrahedral moieties in the conduction processes.
    • Novel Coronin7 interactions with Cdc42 and N-WASP regulate actin organization and Golgi morphology

      Bhattacharya, K.; Swaminathan, Karthic; Peche, V.S.; Clemen, C.S.; Knyphausen, P.; Lammers, M.; Noegel, A.A.; Rastetter, R.H. (2016-05)
      The contribution of the actin cytoskeleton to the unique architecture of the Golgi complex is manifold. An important player in this process is Coronin7 (CRN7), a Golgi-resident protein that stabilizes F-actin assembly at the trans-Golgi network (TGN) thereby facilitating anterograde trafficking. Here, we establish that CRN7-mediated association of F-actin with the Golgi apparatus is distinctly modulated via the small Rho GTPase Cdc42 and N-WASP. We identify N-WASP as a novel interaction partner of CRN7 and demonstrate that CRN7 restricts spurious F-actin reorganizations by repressing N-WASP ‘hyperactivity’ upon constitutive Cdc42 activation. Loss of CRN7 leads to increased cellular F-actin content and causes a concomitant disruption of the Golgi structure. CRN7 harbours a Cdc42- and Rac-interactive binding (CRIB) motif in its tandem β-propellers and binds selectively to GDP-bound Cdc42N17 mutant. We speculate that CRN7 can act as a cofactor for active Cdc42 generation. Mutation of CRIB motif residues that abrogate Cdc42 binding to CRN7 also fail to rescue the cellular defects in fibroblasts derived from CRN7 KO mice. Cdc42N17 overexpression partially rescued the KO phenotypes whereas N-WASP overexpression failed to do so. We conclude that CRN7 spatiotemporally influences F-actin organization and Golgi integrity in a Cdc42- and N-WASP-dependent manner.
    • Novel formation of [2M-H](+) species in positive electrospray mass spectra of indoles

      Saidykhan, Amie; Ayrton, Stephen T.; Gallagher, R.T.; Martin, William H.C.; Bowen, Richard D. (2014)
      When subjected to positive ion electrospray ionisation (ESI+) mass spectrometry (MS), indoles with a 3-alkyl substituent show a propensity to form novel [2M-H](+) 'covalently bound dimers'. This process, which appears to be initiated in the nebuliser of the instrument, is mechanistically interesting, analytically useful and potentially significant in organic synthesis. A selection of 2- and 3-substituted indoles have been synthesised and analysed by ESI-MS. The formation of the 'homo' and 'hetero' dimers of these compounds has been investigated using ESI+ mode. The mechanism of formation of the observed 'dimeric' species has been probed by synthesising authentic samples of the dimeric compounds. 'Dimeric' species corresponding to [2M-H](+) have been observed for all 3-substituted indoles studied, but not for indoles substituted in just the 2-position. By infusing equimolar mixtures of labelled and unlabelled indoles through the instrument, the expected approximately statistical mixture of homo- and heterodimeric species has been observed. Further experiments have established that this novel dimerisation occurs in the droplets formed in the nebuliser of the instrument. It has been shown that 3-substituted indoles form [2M-H](+) dimers in high abundance in the spray obtained from the nebiliser of an ESI+ instrument. The mechanism for the dimerisation does not involve the known 2M dimeric species that is readily formed in the solution-phase chemistry of indoles.
    • Novel muscle imaging in inflammatory rheumatic diseases — a focus on ultrasound shear wave elastography and quantitative MRI

      Farrow, Matthew; Biglands, J.; Alfuraih, A.M.; Wakefield, R.J.; Tan, A.L. (2020-08)
      In recent years, imaging has played an increasing role in the clinical management of patients with rheumatic diseases with respect to aiding diagnosis, guiding therapy and monitoring disease progression. These roles have been underpinned by research which has enhanced our understanding of disease pathogenesis and pathophysiology of rheumatology conditions, in addition to their key role in outcome measurement in clinical trials. However, compared to joints, imaging research of muscles is less established, despite the fact that muscle symptoms are very common and debilitating in many rheumatic diseases. Recently, it has been shown that even though patients with rheumatoid arthritis may achieve clinical remission, defined by asymptomatic joints, many remain affected by lingering constitutional systemic symptoms like fatigue, tiredness, weakness and myalgia, which may be attributed to changes in the muscles. Recent improvements in imaging technology, coupled with an increasing clinical interest, has started to ignite new interest in the area. This perspective discusses the rationale for using imaging, particularly ultrasound and MRI, for investigating muscle pathology involved in common inflammatory rheumatic diseases. The muscles associated with rheumatic diseases can be affected in many ways, including myositis—an inflammatory muscle condition, and myopathy secondary to medications, such as glucocorticoids. In addition to non-invasive visual assessment of muscles in these conditions, novel imaging techniques like shear wave elastography and quantitative MRI can provide further useful information regarding the physiological and biomechanical status of the muscle.
    • Novel nicotinamide skin-adhesive hot melt extrudates for treatment of acne

      Nasr, M.; Karandikar, H.; Abdel-Aziz, R.T.A.; Moftah, N.; Paradkar, Anant R. (Taylor and Francis, 2018-11-15)
      Hot melt extrusion is a continuous process with wide industrial applicability. Till current date, there have been no reports on the formulation of extrudates for topical treatment of dermatological diseases. The aim of the present work was to prepare and characterize medicated hot melt extrudates based on Soluplus polymer and nicotinamide, and to explore their applicability in acne treatment. The extrudates were characterized using DSC, FTIR, XRD, and DVS. The extrudates were also tested for their skin adhesion potential, ability to deposit nicotinamide in different skin layers, and their clinical efficacy in acne patients. The 10% nicotinamide extrudates exhibited amorphous nature which was reserved during storage, with no chemical interaction between nicotinamide and Soluplus. Upon contrasting the skin adhesion and drug deposition of extrudates and nicotinamide gel, it was evident that the extrudates displayed significantly higher adhesion and drug deposition reaching 4.8 folds, 5.3 folds, and 4.3 folds more in the stratum corneum, epidermis and dermis, respectively. Furthermore, the extrudates significantly reduced the total number of acne lesions in patients by 61.3% compared to 42.14% with the nicotinamide gel. Soluplus extrudates are promising topical drug delivery means for the treatment of dermatological diseases.
    • Novel Ran-RCC1 inhibitory peptide-loaded nanoparticles have anti-cancer efficacy in vitro and in vivo

      Haggag, Y.A.; Matchett, K.B.; Falconer, Robert A.; Isreb, Mohammad; Jones, Jason; Faheem, A.; McCarron, P.; El-Tanani, Mohamed (2019-02)
      The delivery of anticancer agents to their subcellular sites of action is a significant challenge for effective cancer therapy. Peptides, which are integral to several oncogenic pathways, have significant potential to be utilised as cancer therapeutics due to their selectivity, high potency and lack of normal cell toxicity. Novel Ras protein-Regulator of chromosome condensation 1 (Ran-RCC1) inhibitory peptides designed to interact with Ran, a novel therapeutic target in breast cancer, were delivered by entrapment into polyethylene glycol-poly (lactic-co-glycolic acid) PEG-PLGA polymeric nanoparticles (NPs). A modified double emulsion solvent evaporation technique was used to optimise the physicochemical properties of these peptide-loaded biodegradable NPs. The anti-cancer activity of peptide-loaded NPs was studied in vitro using Ran-expressing metastatic breast (MDA-MB-231) and lung cancer (A549) cell lines, and in vivo using Solid Ehrlich Carcinoma-bearing mice. The anti-metastatic activity of peptide-loaded NPs was investigated using migration, invasion and colony formation assays in vitro. A PEG-PLGA-nanoparticle encapsulating N-terminal peptide showed a pronounced antitumor and anti-metastatic action in lung and breast cancer cells in vitro and caused a significant reduction of tumor volume and associated tumor growth inhibition of breast cancer model in vivo. These findings suggest that the novel inhibitory peptides encapsulated into PEGylated PLGA NPs are delivered effectively to interact and deactivate Ran. This novel Ran-targeting peptide construct shows significant potential for therapy of breast cancer and other cancers mediated by Ran overexpression.
    • Novel strategies for the synthesis of unsymmetrical glycosyl disulfides

      Ribeiro Morais, Goreti; Springett, Bradley R.; Pauze, Martin; Schröder, Lisa; Northrop, Matthew; Falconer, Robert A. (2016-03)
      Novel strategies for the efficient synthesis of unsymmetrical glycosyl disulfides are reported. Glycosyl disulfides are increasingly important as glycomimetics and molecular probes in glycobiology. Sialosyl disulfides are synthesised directly from the chlorosialoside Neu5Ac2Cl, proceeding via a thiol-disulfide exchange reaction between the sialosyl thiolate and symmetrical disulfides. This methodology was adapted and found to be successfully applicable to the synthesis of unsymmetrical glucosyl disulfides under mild conditions.
    • A novel strategy for NQO1 (NAD(P)H:quinone oxidoreductase, EC 1.6.99.2) mediated therapy of bladder cancer based on the pharmacological properties of EO9.

      Choudry, Guzanfar A.; Hamilton Stewart, P.A.; Double, John A.; Krul, M.R.L.; Naylor, Brian; Flannigan, G. Michael; Shah, Tariq K.; Phillips, Roger M. (2001)
      The indolequinone EO9 demonstrated good preclinical activity but failed to show clinical efficacy against a range of tumours following intravenous drug administration. A significant factor in EO9's failure in the clinic has been attributed to its rapid pharmacokinetic elimination resulting in poor drug delivery to tumours. Intravesical administration of EO9 would circumvent the problem of drug delivery to tumours and the principal objective of this study is to determine whether or not bladder tumours have elevated levels of the enzyme NQO1 (NAD(P)H:quinone oxidoreductase) which plays a key role in activating EO9 under aerobic conditions. Elevated NQO1 levels in human bladder tumour tissue exist in a subset of patients as measured by both immunohistochemical and enzymatic assays. In a panel of human tumour cell lines, EO9 is selectively toxic towards NQO1 rich cell lines under aerobic conditions and potency can be enhanced by reducing extracellular pH. These studies suggest that a subset of bladder cancer patients exist whose tumours possess the appropriate biochemical machinery required to activate EO9. Administration of EO9 in an acidic vehicle could be employed to reduce possible systemic toxicity as any drug absorbed into the blood stream would become relatively inactive due to an increase in pH.
    • A novel theranostic strategy for MMP-14 expressing glioblastomas impacts survival

      Mohanty, S.; Chen, Z.; Li, K.; Ribeiro Morais, Goreti; Klockow, J.; Yerneni, K.; Pasani, L.; Chin, F.T.; Mitra, S.; Cheshier, S.; et al. (2017-06)
      Glioblastoma (GBM) has a dismal prognosis. Evidence from preclinical tumor models and human trials indicates the role of GBM initiating cells (GIC) in GBM drug resistance. Here, we propose a new treatment option with tumor enzyme-activatable, combined therapeutic and diagnostic (theranostic) nanoparticles, which caused specific toxicity against GBM tumor cells and GICs. The theranostic cross-linked iron oxide nanoparticles (CLIO) were conjugated to a highly potent vascular disrupting agent (ICT) and secured with a matrix-metalloproteinase (MMP-14) cleavable peptide. Treatment with CLIO-ICT disrupted tumor vasculature of MMP-14 expressing GBM, induced GIC apoptosis and significantly impaired tumor growth. In addition, the iron core of CLIO-ICT enabled in vivo drug tracking with MR imaging. Treatment with CLIO-ICT plus temozolomide achieved tumor remission and significantly increased survival of human GBM bearing mice by more than 2 fold compared to treatment with temozolomide alone. Thus, we present a novel therapeutic strategy with significant impact on survival and great potential for clinical translation.
    • A novel transflectance near infrared spectroscopy technique for monitoring hot melt extrusion

      Kelly, Adrian L.; Halsey, S.A.; Bottom, R.A.; Korde, Sachin A.; Gough, Timothy D.; Paradkar, Anant R. (2015-12-30)
      A transflectance near infra red (NIR) spectroscopy approach has been used to simultaneously measure drug and plasticiser content of polymer melts with varying opacity during hot melt extrusion. A high temperature reflectance NIR probe was mounted in the extruder die directly opposed to a highly reflective surface. Carbamazepine (CBZ) was used as a model drug, with polyvinyl pyrollidone-vinyl acetate co-polymer (PVP-VA) as a matrix and polyethylene glycol (PEG) as a plasticiser. The opacity of the molten extrudate varied from transparent at low CBZ loading to opaque at high CBZ loading. Particulate amorphous API and voids formed around these particles were found to cause the opacity. The extrusion process was monitored in real time using transflectance NIR; calibration and validation runs were performed using a wide range of drug and plasticiser loadings. Once calibrated, the technique was used to simultaneously track drug and plasticiser content during applied step changes in feedstock material. Rheological and thermal characterisations were used to help understand the morphology of extruded material. The study has shown that it is possible to use a single NIR spectroscopy technique to monitor opaque and transparent melts during HME, and to simultaneously monitor two distinct components within a formulation.
    • Novel ways to regulate T-type Ca2+ channels

      Peers, C.; Elies, Jacobo; Gamper, N. (2015)
    • Novel, High-yielding Synthesis of meso-Substituted Porphyrins via the Direct Arylation of Porphine.

      Wheelhouse, Richard T.; Shi, D-F. (2002)
      A new method for the synthesis of meso-substituted porphyrins is described: reaction of 5,10,15,20-tetrabromoporphine magnesium complex with aryl or heteroaryl boronic acids in the presence of Pd(PPh3)4 gave meso-substituted porphyrins in yields up to 70%.
    • Nuclear factor kappa B is involved in lipopolysaccharide- stimulated induction of interferon regulatory factor-1 and GAS/GAF DNA-binding in human umbilical vein endothelial cells.

      Graham, Anne M.; Bryant, C.; Liu, L.; Plevin, R.; Andrew, P.; Mackenzie, C. (2001)
      1 In this study we examined the signalling events that regulate lipopolysaccharide (LPS)-stimulated induction of interferon regulatory factor (IRF)-1 in human umbilical vein endothelial cells (HUVECS). 2 LPS stimulated a time- and concentration-dependent increase in IRF-1 protein expression, an effect that was mimicked by the cytokine, tumour necrosis factor (TNF)-¿. 3 LPS stimulated a rapid increase in nuclear factor kappa B (NFKB) DNA-binding activity. Preincubation with the NFKB pathway inhibitors, N-¿-tosyl-L-lysine chloromethyl ketone (TLCK) or pyrrolidine dithiocarbamate (PDTC), or infection with adenovirus encoding IKB¿, blocked both IRF-1 induction and NFKB DNA-binding activity. 4 LPS and TNF¿ also stimulated a rapid activation of gamma interferon activation site/gamma interferon activation factor (GAS/GAF) DNA-binding in HUVECs. Preincubation with the Janus kinase (JAK)-2 inhibitor, AG490 blocked LPS-stimulated IRF-I induction but did not affect GAS/ GAF DNA-binding. 5 Preincubation with TLCK, PDTC or infection with I¿Ba adenovirus abolished LPS-stimulated GAS/GAF DNA-binding. 6 Incubation of nuclear extracts with antibodies to RelA/p50 supershifted GAS/GAF DNA-binding demonstrating the involvement of NF¿B isoforms in the formation of the GAS/GAF complex. 7 These studies show that NF¿B plays an important role in the regulation of IRF-1 induction in HUVECs. This is in part due to the interaction of NF¿B isoforms with the GAS/GAF complex either directly or via an intermediate protein.
    • Nuclear targeting of dystroglycan promotes the expression of androgen regulated transcription factors in prostate cancer

      Mathew, G.; Mitchell, Andrew; Down, J.M.; Jacobs, L.A.; Hamdy, F.C.; Eaton, C.; Rosario, D.J.; Cross, S.S.; Winder, S.J. (2013)
      Dystroglycan is frequently lost in adenocarcinoma, but the mechanisms and consequences are poorly understood. We report an analysis of beta-dystroglycan in prostate cancer in human tissue samples and in LNCaP cells in vitro. There is progressive loss of beta-dystroglycan immunoreactivity from basal and lateral surfaces of prostate epithelia which correlates significantly with increasing Gleason grade. In about half of matched bone metastases there is significant dystroglycan re-expression. In tumour tissue and in LNCaP cells there is also a tyrosine phosphorylation-dependent translocation of beta-dystroglycan to the nucleus. Analysis of gene expression data by microarray, reveals that nuclear targeting of beta-dystroglycan in LNCaP cells alters the transcription of relatively few genes, the most unregulated being the transcription factor ETV1. These data suggest that proteolysis, tyrosine phosphorylation and translocation of dystroglycan to the nucleus resulting in altered gene transcription could be important mechanisms in the progression of prostate cancer.
    • Nucleosides Rescue Replication-Mediated Genome Instability of Human Pluripotent Stem Cells

      Ivana, Barbaric,; Peter W, Andrews,; Halliwell, J.A.; Frith, T.J.R.; Laing, O.; Price, C.J.; Bower, O.J.; Stavish, T.; Gokhale, P.J.; Hewitt, Z.; et al. (2020-06-09)
      Human pluripotent stem cells (PSCs) are subject to the appearance of recurrent genetic variants on prolonged culture. We have now found that, compared with isogenic differentiated cells, PSCs exhibit evidence of considerably more DNA damage during the S phase of the cell cycle, apparently as a consequence of DNA replication stress marked by slower progression of DNA replication, activation of latent origins of replication, and collapse of replication forks. As in many cancers, which, like PSCs, exhibit a shortened G1 phase and DNA replication stress, the resulting DNA damage may underlie the higher incidence of abnormal and abortive mitoses in PSCs, resulting in chromosomal non-dysjunction or cell death. However, we have found that the extent of DNA replication stress, DNA damage, and consequent aberrant mitoses can be substantially reduced by culturing PSCs in the presence of exogenous nucleosides, resulting in improved survival, clonogenicity, and population growth.
    • Nulling the motion aftereffect with dynamic random-dot stimuli: limitations and implications.

      Keeble, David R.T.; Castet, E.; Verstraten, F. (2002)
      We used biased random-dot dynamic test stimuli to measure the strength of the motion aftereffect (MAE) to evaluate the usefulness of this technique as a measure of motion adaptation strength. The stimuli consisted of noise dots whose individual directions were random and of signal dots moving in a unique direction. All dots moved at the same speed. For each condition, the nulling percentage (percentage of signal dots needed to perceptually null the MAE) was scaled with respect to the coherence threshold (percentage needed to perceive the coherent motion of signal dots without prior adaptation). The increase of these scaled values with the density of dots in the test stimulus suggests that MAE strength is underestimated when measured with low densities. We show that previous reports of high nulling percentages at slow speeds do not reflect strong MAEs, but are actually due to spatio-temporal aliasing, which dramatically increases coherence thresholds. We further show that MAE strength at slow speed increases with eccentricity. These findings are consistent with the idea that using this dynamic test stimulus preferentially reveals the adaptation of a population of high-speed motion units whose activity is independent of adapted low-speed motion units.
    • Object size determines the spatial spread of visual time

      Fulcher, Corinne; McGraw, Paul V.; Roach, N.W.; Whitaker, David J.; Heron, James (2016-07-27)
      A key question for temporal processing research is how the nervous system extracts event duration, despite a notable lack of neural structures dedicated to duration encoding. This is in stark contrast with the orderly arrangement of neurons tasked with spatial processing. In this study, we examine the linkage between the spatial and temporal domains. We use sensory adaptation techniques to generate after-effects where perceived duration is either compressed or expanded in the opposite direction to the adapting stimulus’ duration. Our results indicate that these after-effects are broadly tuned, extending over an area approximately five times the size of the stimulus. This region is directly related to the size of the adapting stimulus—the larger the adapting stimulus the greater the spatial spread of the aftereffect. We construct a simple model to test predictions based on overlapping adapted versus non-adapted neuronal populations and show that our effects cannot be explained by any single, fixed-scale neural filtering. Rather, our effects are best explained by a self-scaled mechanism underpinned by duration selective neurons that also pool spatial information across earlier stages of visual processing.
    • Observation of highly decoupled conductivity in protic ionic conductors

      Wojnarowska, Z.; Wang, Y.; Paluch, Krzysztof J.; Sokolov, A.P.; Paluch, M. (2014-03)
      Ionic liquids (ILs) are key materials for the development of a wide range of emerging technologies. Protic ionic liquids, an important class of ILs, have long been envisioned as promising anhydrous electrolytes for fuel cells. It is well known that in comparison to all other cations, protons exhibit abnormally high conductivity in water. Such superprotonic dynamics was expected in protic ionic conductors as well. However, many years of extensive studies led to the disappointing conclusion that this is not the case and most protic ionic liquids display subionic behavior. Therefore, the relatively low conductivity seems to be the main obstacle for the application of protic ionic liquids in fuel cells. Using dielectric spectroscopy, herein we report the observation of highly decoupled conductivity in a newly synthesized protic ionic conductor. We show that its proton transport is strongly decoupled from the structural relaxation, in terms of both temperature dependence and characteristic rates. This finding offers a fresh look on the charge transport mechanism in PILs and also provides new ideas for design of anhydrous materials with exceptionally high proton conductivity.