Publications by authors named "Mark Gumbleton"

The management of antibiotic-resistant, bacterial biofilm infections in chronic skin wounds is an increasing clinical challenge. Despite advances in diagnosis, many patients do not derive benefit from current anti-infective/antibiotic therapies. Here, we report a novel class of naturally occurring and semisynthetic epoxy-tiglianes, derived from the Queensland blushwood tree (, and demonstrate their antimicrobial activity (modifying bacterial growth and inducing biofilm disruption), with structure/activity relationships established against important human pathogens.

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Glioblastoma (GB) remains an aggressive malignancy with an extremely poor prognosis. Discovering new candidate drug targets for GB remains an unmet medical need. Caveolin-1 (Cav-1) has been shown to act variously as both a tumour suppressor and tumour promoter in many cancers.

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Glioblastoma (GBM) is the most aggressive malignant brain tumor and is associated with a very poor prognosis. The standard treatment for newly diagnosed patients involves total tumor surgical resection (if possible), plus irradiation and adjuvant chemotherapy. Despite treatment, the prognosis is still poor, and the tumor often recurs within two centimeters of the original tumor.

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Novel therapeutics designed to target the polymeric matrix of biofilms requires innovative techniques to accurately assess their efficacy. Here, multiple particle tracking (MPT) was developed to characterize the physical and mechanical properties of antimicrobial resistant (AMR) bacterial biofilms and to quantify the effects of antibiotic treatment. Studies employed nanoparticles (NPs) of varying charge and size (40-500 nm) in Pseudomonas aeruginosa PAO1 and methicillin-resistant Staphylococcus aureus (MRSA) biofilms and also in polymyxin B (PMB) treated Escherichia coli biofilms of PMB-sensitive (PMB) IR57 and PMB-resistant (PMB) PN47 strains.

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The current decline in antimalarial drug efficacy due to the evolution of resistant Plasmodium strains calls for new strategies capable of improving the bioavailability of antimalarials, especially of those whose lipophilic character imparts them a low solubility in biological fluids. Here we have designed, synthesized and characterized amphiphilic zwitterionic block copolymers forming nanoparticles capable of penetrating the intestinal epithelium that can be used for oral administration. Poly(butyl methacrylate-co-morpholinoethyl sulfobetaine methacrylate) (PBMA-MESBMA)-based nanoparticles exhibited a specific targeting to Plasmodium falciparum-infected vs.

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The coronavirus disease (COVID-19) outbreak has presented enormous challenges for healthcare, societal, and economic systems worldwide. There is an urgent global need for a universal vaccine to cover all SARS-CoV-2 mutant strains to stop the current COVID-19 pandemic and the threat of an inevitable second wave of coronavirus. Carbon dioxide is safe and superior antimicrobial, which suggests it should be effective against coronaviruses and mutants thereof.

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The secondary structures of Scherer commonly known as perineuronal and perivascular satellitosis have been identified as a histopathological hallmark of diffuse, invasive, high-grade gliomas. They are recognised as perineuronal satellitosis when clusters of neoplastic glial cells surround neurons cell bodies and perivascular satellitosis when such tumour cells surround blood vessels infiltrating Virchow-Robin spaces. In this review, we provide an overview of emerging knowledge regarding how interactions between neurons and glioma cells can modulate tumour evolution and how neurons play a key role in glioma growth and progression, as well as the role of perivascular satellitosis into mechanisms of glioma cells spread.

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Interleukin-13 (IL-13) drives cells of myeloid origin towards a more anti-inflammatory phenotype, but delivery to the brain remains problematic. Herein, we show that heparin-based cryogel microcarriers load high amounts of IL-13, releasing it slowly. Intra-striatal injection of loaded microcarriers caused local up-regulation of ARG1 in myeloid cells for pro-regenerative immunomodulation in the brain.

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Glioblastoma multiforme (GBM) is the most aggressive type of malignant brain tumour, which is associated with a poor two-year survival rate and a high rate of fatal recurrence near the original tumour. Focal/local drug delivery devices hold promise for improving therapeutic outcomes for GBM by increasing drug concentrations locally at the tumour site, or by facilitating the use of potent anti-cancer drugs that are poorly permeable across the blood brain barrier (BBB). For inoperable tumours, stereotactic delivery to the tumour necessitates the development of nanoscale/microscale injectable drug delivery devices.

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The epithelial permeation of water-soluble fluorescent PAMAM dendrons based on 7H-benz[de] benzimidazo [2,1-a] isoquinoline-7-one as a fluorescent core across epithelial cell models MDCK I and MDCK II has been quantified. Hydrodynamic radii have been derived from self-diffusion coefficients obtained via pulsed-gradient spin-echo Nuclear Magnetic Resonance (PGSE-NMR). Results indicate that these dendritic molecules are molecularly disperse, non-aggregating, and only slightly larger than their parent homologues.

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Despite the importance of the tumor microenvironment in regulating tumor progression, few in vitro models have been developed to understand the effects of non-neoplastic cells and extracellular matrix (ECM) on drug resistance in glioblastoma (GBM) cells. Using CellTrace-labeled human GBM and microglial (MG) cells, we established a 2D co-culture including various ratios of the two cell types. Viability, proliferation, migration, and drug response assays were carried out to assess the role of MG.

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Enterotoxigenic Escherichia coli (ETEC) strains are a major cause of illness and death in neonatal and recently weaned pigs. The immune protection of the piglets derives from maternal colostrum, since this species does not receive maternal antibodies through the placenta. In the present study, outer membrane vesicles (OMVs) obtained from main ETEC strains involved in piglet infection (F4 and F18 serotypes), encapsulated into zein nanoparticles coated with Gantrez AN-mannosamine conjugate, were used to orally immunize mice and pregnant sows.

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The aim of this work was to evaluate the mucus-permeating properties of nanocarriers using zein nanoparticles (NPZ) coated with a Gantrez® AN-thiamine conjugate (GT). NPZ were coated by incubation at different GT-to-zein ratios: 2.5% coating with GT (GT-NPZ1), 5% (GT-NPZ2) and 10% (GT-NPZ3).

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Mucus is a dynamic barrier which covers and protects the underlying mucosal epithelial membrane against bacteria and foreign particles. This protection mechanism extends to include therapeutic macromolecules and nanoparticles (NPs) through trapping of these particles. Mucus is not only a physical barrier that limiting particles movements based on their sizes but it selectively binds with particles through both hydrophilic and lipophilic interactions.

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Peanut allergy is one of the most prevalent and severe of food allergies with no available cure. The aim of this work was to evaluate the potential of an oral immunotherapy based on the use of a roasted peanut extract encapsulated in nanoparticles with immunoadjuvant properties. For this, a polymer conjugate formed by the covalent binding of mannosamine to the copolymer of methyl vinyl ether and maleic anhydride was first synthetized and characterized.

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Unlabelled: Bailey, Damian Miles, Benjamin S. Stacey, and Mark Gumbleton. A systematic review and meta-analysis reveals altered drug pharmacokinetics in humans during acute exposure to terrestrial high altitude-clinical justification for dose adjustment? High Alt Med Biol.

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Background: The aim of the study was to develop an oral self-emulsifying drug delivery system (SEDDS) for exenatide and to evaluate its in vivo efficacy.

Methods: Exenatide was lipidised via hydrophobic ion pairing with sodium docusate (DOC) and incorporated in SEDDS consisting of 35% Cremophor EL, 25% Labrafil 1944, 30% Capmul-PG 8 and 10% propylene glycol. Exenatide/DOC was characterized in terms of lipophilicity evaluating the octanol/water phase distribution (logP).

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Unlabelled: The objective of this study was to investigate the impact of different hydrophobic ion pairs (HIP) on the oral bioavailability of the model drug octreotide in pigs. Octreotide was ion paired with the anionic surfactants deoxycholate, decanoate and docusate differing in lipophilicity. These hydrophobic ion pairs were incorporated in self-emulsifying drug delivery systems (SEDDS) based on BrijO10, octyldodecanol, propylene glycol and ethanol in a concentration of 5mg/ml.

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The aim of this work was to evaluate the potential application of an original oral immunotherapy, based on the use of nanoparticles, against an experimentally induced peanut allergy. In this context, a roasted peanut extract, containing the main allergenic proteins, were encapsulated into poly(anhydride) nanoparticles. The resulting peanut-loaded nanoparticles (PE-NP) displayed a mean size of about 150nm and a significantly lower surface hydrophobicity than empty nanoparticles (NP).

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Time-series image capture of in vitro 3D spheroidal cancer models embedded within an extracellular matrix affords examination of spheroid growth and cancer cell invasion. However, a customizable, comprehensive and open source solution for the quantitative analysis of such spheroid images is lacking. Here, the authors describe INSIDIA (INvasion SpheroID ImageJ Analysis), an open-source macro implemented as a customizable software algorithm running on the FIJI platform, that enables high-throughput high-content quantitative analysis of spheroid images (both bright-field gray and fluorescent images) with the output of a range of parameters defining the spheroid "tumor" core and its invasive characteristics.

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Purpose: To examine if pulmonary P-glycoprotein (P-gp) is functional in an intact lung; impeding the pulmonary absorption and increasing lung retention of P-gp substrates administered into the airways. Using calculated physico-chemical properties alone build a predictive Quantitative Structure-Activity Relationship (QSAR) model distinguishing whether a substrate's pulmonary absorption would be limited by P-gp or not.

Methods: A panel of 18 P-gp substrates were administered into the airways of an isolated perfused mouse lung (IPML) model derived from Mdr1a/Mdr1b knockout mice.

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Purpose: Polyamidoamine (PAMAM) dendrimers are a promising class of nanocarrier with applications in both small and large molecule drug delivery. Here we report a comprehensive evaluation of the uptake and transport pathways that contribute to the lung disposition of dendrimers.

Methods: Anionic PAMAM dendrimers and control dextran probes were applied to an isolated perfused rat lung (IPRL) model and lung epithelial monolayers.

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The School of Pharmacy and Pharmaceutical Sciences at Trinity College Dublin hosted the "1 Workshop on Drug Transporters in the Lungs" in September 2016 to discuss the impact of transporters on pulmonary drug disposition and their roles as drug targets in lung disease. The workshop brought together about 30 scientists from academia and pharmaceutical industry from Europe and Japan and addressed the primary questions: What do we know today, and what do we need to know tomorrow about transporters in the lung? The 3 themes of the workshop were: (1) techniques to study drug transporter expression and actions in the lungs; (2) drug transporter effects on pulmonary pharmacokinetics-case studies; and (3) transporters as drug targets in lung disease. Some of the conclusions of the workshop were: suitable experimental models that allow studies of transporter effects are available; data from these models convincingly show a contribution of both uptake and efflux transporters on pulmonary drug disposition; the effects of transporters on drug lung PK is now better conceptualized; some transporters are associated with lung diseases.

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We have previously examined the mechanism of antimicrobial peptides on the outer membrane of vaccinia virus. We show here that the formulation of peptides LL37 and magainin-2B amide in polysorbate 20 (Tween 20) results in greater reductions in virus titer than formulation without detergent, and the effect is replicated by substitution of polysorbate 20 with high-ionic-strength buffer. In contrast, formulation with polysorbate 20 or high-ionic-strength buffer has the opposite effect on bactericidal activity of both peptides, resulting in lesser reductions in titer for both Gram-positive and Gram-negative bacteria.

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Clear cell renal cell carcinoma (ccRCC), the most aggressive and lethal form of renal cell carcinoma accounts for over 90% of metastasis that occur following curative surgery for clinically confined disease. High relapse rates have prompted the evaluation of targeted therapies for the prevention or delay of metastatic disease in high-risk patients, with biomarkers offering significant potential to guide and improve patient management in this setting. In this current study we examined the value of the 4E-BP1/eIF4E axis for prognostic significance and risk stratification in patients with clinically confined ccRCC.

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