Chemicals and Drugs Commons^™

Evaluation Of A Drug Delivery System Based On Cyclodextrins For Cancer Therapy, Caroline Mendes

Doctoral

Due to the side-effects caused by regular chemotherapy, the development of drug delivery systems that can specifically target cancer cells and deliver the therapeutic dose is required. In this study, a folate-derivative of β-cyclodextrin has been studied as a vehicle for targeting folate receptors (FR) and delivering the chemotherapeutic drug methotrexate (MTX). FRs can be considered key cell membrane targets since they are commonly over-expressed in cancer cells and play an important role in cancer development and progression. Cyclodextrins (CDs) are cyclic oligosaccharides with a unique structure that allows them to form inclusion complexes with guest molecules, increasing their aqueous …

A Rational Design Of A Selective Inhibitor For Kv1.1 Channels Prevalent In Demyelinated Nerves That Improves Their Impaired Axonal Conduction, Ahmed Al-Sabi, Declan Daly, Patrick Hoefer, Gemma K. Kinsella, Charles Metais, Mark Pickering, Caroline Herron, Seshu Kumar Kaza, Kieran Nolan, J. Oliver Dolly

Articles

K+ channels containing Kv1.1 α subunits, which become prevalent at internodes in demyelinated axons, may underlie their dysfunctional conduction akin to muscle weakness in multiple sclerosis. Small inhibitors were sought with selectivity for the culpable hyper-polarizing K+ currents. Modeling of interactions with the extracellular pore in a Kv1.1-deduced structure identified diaryldi(2-pyrrolyl)methane as a suitable scaffold with optimized alkyl ammonium side chains. The resultant synthesized candidate [2,2′-((5,5′(di-p-topyldiaryldi(2-pyrrolyl)methane)bis(2,2′carbonyl)bis(azanediyl)) diethaneamine·2HCl] (8) selectively blocked Kv1.1 channels (IC50 ≈ 15 μM) recombinantly expressed in mammalian cells, induced a positive shift in the voltage dependency of K+ current activation, and slowed its kinetics. It …

A Model For The Voltammetric Behaviour Of Tio2 Memristors, John Cassidy, Daryl Fox, Tony Betts

Articles

Abstract A model is solved based on the Nernst Planck equation to calculate the diffusion and migration currents for a species in a thin layer (about 200 nm) confined between two electrodes. This is proposed to account for the current voltage behaviour of a memristor constructed in a similar fashion. At the working electrode, an electroactive species is oxidised and at the counter electrode, the same species is reduced. Upon application of a simple voltammetric waveform, the migration current exhibits a resistance profile at slow scan rates and hysteresis at faster scan rates, indicative of memristor behavior.

Nitrogen And Phosphorus Availability From Various Composted Wastes For Use In Irish Agriculture And Horticulture, Alan Lee

Doctoral

Current environmental EU legislation promotes recycling and recovery from organic waste products. Compost has been identified as an alternative to inorganic fertilisers and animal slurries as a nutrient source for crop plants. This study aimed to investigate nitrogen (N) and phosphorus (P) availability from various composted waste through detailed characterisations, complemented by short term lab incubations and long term plant growth experiments. Twenty-five composts were selected and classified by their groups. The composts were characterised by multiple different analytical techniques. Two incubation studies were conducted. One investigating N and P mineralisation potential of the composts and the second on the …

Synthesis And Biochemical Evaluation Of 3-Phenoxy-1,4-Diarylazetidin-2-Ones As Tubulin-Targeting Antitumor Agents, Thomas F. Greene, Shu Wang, Lisa M. Greene, Seema M. Nathwani, Jade K. Pollock, Azizah M. Malebari, Thomas Mccabe, Brendan Twamley, Niamh O'Boyle, Daniela M. Zisterer, Mary J. Meegan

Articles

Structure-activity relationships for a series of 3-phenoxy-1,4-diarylazetidin-2-ones were investigated leading to the discovery of a number of potent antiproliferative compounds, including trans-4-(3-hydroxy-4-methoxyphenyl)-3-phenoxy-1-(3,4,5-trimethoxyphenyl)azetidin-2-one (78b) and trans-4-(3-amino-4-methoxyphenyl)-3-phenoxy-1-(3,4,5-trimethoxyphenyl)azetidin-2-one (90b). X-ray crystallography studies indicate the potential importance of the torsional angle between the 1-phenyl ‘A’ ring and 4-phenyl ‘B’ ring for potent antiproliferative activity, and that a trans configuration between the 3-phenoxy and 4-phenyl rings is generally optimal. These compounds displayed IC₅₀ values of 38 nM and 19 nM respectively in MCF-7 breast cancer cells, inhibited the polymerization of isolated tubulin in vitro, disrupted the microtubular …

Piperlongumine (Piplartine) And Analogues: Antiproliferative Microtubule-Destabilising Agents, Mary J. Meegan, Seema M. Nathwani, Brendan Twamley, Daniela M. Zisterer, Niamh O'Boyle

Articles

Piperlongumine (piplartine, 1) is a small molecule alkaloid that is receiving intense interest due to its antiproliferative and anticancer activities. We investigated the effects of 1 on tubulin and microtubules. Using both an isolated tubulin assay, and a combination of sedimentation and Western blotting, we demonstrated that 1 is a tubulin-destabilising agent. This result was confirmed by immunofluorescence and confocal microscopy, which showed that microtubules in MCF-7 breast cancer cells were depolymerised when treated with 1. We synthesised a number of analogues of 1 to explore structure-activity relationships. Compound 13 had the best cytotoxic profile of this series, …

Influence Of Ionic Liquids On The Selectivity Of Ion Exchange-Based Polymer Membrane Sensing Layers, Lukasz Mendecki, Nicole Callan, Meghan Ahern, Benjamin Schazmann, Aleksandar Radu

Articles

The applicability of ion exchange membranes is mainly defined by their permselectivity towards specific ions. For instance, the needed selectivity can be sought by modifying some of the components required for the preparation of such membranes. In this study, a new class of materials –trihexyl(tetradecyl)phosphonium based ionic liquids (ILs) were used to modify the properties of ion exchange membranes. We determined selectivity coefficients for iodide as model ion utilizing six phosphonium-based ILs and compared the selectivity with two classical plasticizers. The dielectric properties of membranes plasticized with ionic liquids and their response characteristics towards ten different anions were investigated using …

Artemisinin Production By Plant Hairy Root Cultures In Gas- And Liquid-Phase Bioreactors, Nivedita Patra, Ashok K. Srivastava

Articles

Key message

Alternative biotechnological protocol for large-scale artemisinin production was established. It featured enhanced growth and artemisinin production by cultivation of hairy roots in nutrient mist bioreactor (NMB) coupled with novel cultivation strategies.

Artemisinin is used for the treatment of cerebral malaria. Presently, its main source is from seasonal plant Artemisia annua. This study featured investigation of growth and artemisinin production by A. annua hairy roots (induced by Agrobacterium rhizogenes-mediated genetic transformation of explants) in three bioreactor configurations—bubble column reactor, NMB and modified NMB particularly to establish their suitability for commercial production. It was observed that cultivation of …

Raman Micro Spectroscopy For In Vitro Drug Screening: Subcellular Localisation And Interactions Of Doxorubicin, Zeineb Farhane, Franck Bonnier, Alan Casey, Hugh Byrne

Articles

Vibrational spectroscopy, including Raman spectroscopy, has been widely used over the last few years to explore potential biomedical applications. Indeed, Raman spectroscopy has been demonstrated to be a powerful non-invasive tool in cancer diagnosis and monitoring. In confocal microscopic mode, the technique is also a molecularly specific analytical tool with optical resolution which has potential applications in subcellular analysis of biochemical processes, and therefore as an in vitro screening tool of the efficacy and mode of action of, for example, chemotherapeutic agents.

In order to demonstrate and explore the potential in this field, established, model chemotherapeutic agents can be valuable. …

In Vitro Evaluation Of The Cytotoxicity Of A Folate-Modified Β-Cyclodextrin As A New Anti-Cancer Drug Delivery System, Zlata Tofzikovskaya, Alan Casey, Orla L. Howe, Christine O'Connor, Mary Mcnamara

Articles

Many chemotherapeutic drugs are therapeutically non-selective and do not distinguish between healthy cells and tumour cells which can result in severe side effects and toxicity. Drug delivery systems can be used to target specific cells and therefore may eliminate many of the side effects, increasing drug efficiency and efficacy, and controlling drug release. One possible strategy for targeted drug delivery is to use unique molecular markers such as folate receptors in cancer cells. In this work the cytotoxicity of a novel cyclodextrin-folate conjugate, 6-deoxy-6-[(1-(-2amino)ethylamino)folate-β-cyclodextrin (CDEnFA) was studied using the MTT assay and the MCF-7 (Breast), HeLa (Cervical), A549 (Lung cancer) …

Nanotechnology Solutions For Global Water Challenges, Aine Whelan, Niall B. Mcguinness, Mary Garvey, Honey John, Chun Zao, Geshan Zhang, Dionysios D. Dionysiou, J. Anthony Byrne, Suresh C. Pillai

Books/Book chapters

The lack of clean and safe drinking water is responsible for more deaths than war, terrorism and weapons of mass destruction combined. This suggests contaminated water poses a significant threat to human health and welfare. In addition, standard water disinfection approaches such as sedimentation, filtration, and chemical or biological degradation are not fully capable of destroying emerging contaminants (e.g. pesticides, pharmaceutical waste products) or certain types of bacteria (e.g. Cryptosporidium parvum). Nanomaterials and nanotechnology based devices can potentially be employed to solve the challenges posed by various contaminants and microorganisms. Nanomaterials of different shapes, namely nanoparticles, nanotubes, nanowires and fibers …

Β-Lactam Estrogen Receptor Antagonists And A Dual-Targeting Estrogen Receptor/Tubulin Ligand, Niamh O'Boyle, Jade K. Pollock, Miriam Carr, Andrew Js Knox, Seema M. Nathwani, Shu Wang, Laura Caboni, Daniela M. Zisterer, Mary Meegan

Articles

Twelve novel β-lactams were synthesised and their antiproliferative effects and binding affinity for the predominant isoforms of the estrogen receptor (ER), ERα and ERβ, were determined. β-Lactams 23 and 26 had the strongest binding affinities for ERα (IC₅₀ values: 40 and 8 nM respectively) and ERβ (IC₅₀ values: 19 and 15 nM). β-Lactam 26 was the most potent in antiproliferative assays using MCF-7 breast cancer cells, and further biochemical analysis showed that it caused accumulation of cells in G₂/M phase (mitotic blockade) and depolymerisation of tubulin in MCF-7 cells. Compound 26 also induced apoptosis and downregulation …

Vibrational Spectroscopy: Disease Diagnostics And Beyond, Hugh Byrne, Kamila Ostrowska, Haq Nawaz, Jennifer Dorney, Aidan Meade, Franck Bonnier, Fiona Lyng

Books/Book Chapters

Summary

This chapter outlines some developments in the applications of vibrational spectroscopy for disease diagnostics and demonstrates how the applications of the spectroscopic techniques can be extended to the analysis and evaluation of disease aetiology and the mechanisms of interaction and the cellular and subcellular responses to, for example chemotherapeutic agents and nanoparticles. The primary emphasis is on Raman spectroscopy, although some examples are based on infrared absorption spectroscopy. The studies presented are chosen to illustrate how a range of multivariate analytical techniques can be employed to maximize the potential benefits of the complex spectral information obtained from tissue or …

Novel Cis-Restricted Β-Lactam Combretastatin A-4 Analogues Display Anti-Vascular And Anti-Metastatic Properties In Vitro, Seema M. Nathwani, Lisa M. Greene, Linda Hughes, Miriam Carr, Niamh O'Boyle, Susan Mcdonnell, Mary J. Meegan, Daniela M. Zisterer

Articles

No abstract provided.

Synthesis And Biochemical Activities Of Antiproliferative Amino Acid And Phosphate Derivatives Of Microtubule-Disrupting Beta-Lactam Combretastatins, Niamh M. O'Boyle, Lisa M. Greene, Niall O. Keely, Shu Wang, Tadhg S. Cotter, Daniela M. Zisterer, Mary J. Meegan

Articles

The synthesis and biochemical activities of novel water-soluble β-lactam analogues of combretastatin A-4 are described. The first series of compounds investigated, β-lactam phosphate esters 7a, 8a and 9a, exhibited potent antiproliferative activity and caused microtubule disruption in human breast carcinoma-derived MCF-7 cells. They did not inhibit tubulin polymerisation in vitro, indicating that biotransformation was necessary for their antiproliferative and tubulin binding effects in MCF-7 cells. The second series of compounds, β-lactam amino acid amides (including 10k and 11l) displayed potent antiproliferative activity in MCF-7 cells, disrupted microtubules in MCF-7 cells and also inhibited the polymerisation of …

Raman Micro Spectroscopy Study Of The Interaction Of Vincristine With A549 Cells Supported By Expression Analysis Of Bcl-2 Protein, Haq Nawaz, Amaya Garcia, Aidan Meade, Fiona Lyng, Hugh Byrne

Articles

Understanding the interaction of anticancer drugs with model cell lines is important to elucidate the mode of action of these drugs as well as to develop cost effective and rapid screening methods. Raman spectroscopy has been demonstrated to be a valuable technique for high throughput, noninvasive analysis. The interaction of vincristine with a human lung adenocarcinoma cell line (A549)was investigated using Raman micro spectroscopy. The results were correlated with parallel measurements from the MTT cytotoxicity assay, which yielded an IC₅₀ value of 0.10 ± 0.03 μM. The Raman spectral data acquired from vincristine treated A549 cells was analysed to …

Analogues Of The Epoxy Resin Monomer Diglycidyl Ether Of Bisphenol F: Effects On Contact Allergenic Potency And Cytotoxicity, Niamh O'Boyle, Tamara Delaine, Kristina Luthman, Andreas Natsch, Ann-Therese Karlberg

Articles

Diglycidyl ethers of bisphenol A (DGEBA) and bisphenol F (DGEBF) are widely used as components in epoxy resin thermosetting products. They are known to cause occupational and non-occupational allergic contact dermatitis. The aim of this study is to investigate analogues of DGEBF with regard to contact allergy and cytotoxicity. A comprehensive knowledge of the structural features that contribute to the allergenic and cytotoxic effects of DGEBF will guide the development of future novel epoxy resin systems with reduced health hazards for those coming into contact with them. It was found that the allergenic effects of DGEBF were dependent on its …

Antiviral Trims: Friend Or Foe In Autoimmune And Autoinflammatory Disease?, Caroline A. Jefferies, Claire Wynne, Rowan Higgs

Articles

The concept that viral sensing systems, via their ability to drive pro-inflammatory cytokine and interferon production, contribute to the development of autoimmune and autoinflammatory disease is supported by a wide range of clinical and experimental observations. Recently, the tripartite motif-containing proteins (TRIMs) have emerged as having key roles in antiviral immunity — either as viral restriction factors or as regulators of pathways downstream of viral RNA and DNA sensors, and the inflammasome. Given their involvement in these pathways, we propose that TRIM proteins contribute to the development and pathology of autoimmune and autoinflammatory conditions, thus making them potential novel targets …

Lead Identification Of Β-Lactam And Related Imine Inhibitors Of The Molecular Caperone Heat Shock Protein 90, Niamh O'Boyle, Andrew Js Knox, Trevor P. Price, D. Clive Williams, Daniela M. Zisterer, David G. Lloyd, Mary J. Meegan

Articles

Heat shock protein 90 is an emerging target for oncology therapeutics. Inhibitors of this molecular chaperone, which is responsible for the maintenance of a number of oncogenic proteins, have shown promise in clinical trials and represent a new and exciting area in the treatment of cancer. Heat shock protein 90 inhibitors have huge structural diversity, and here we present the identification of inhibitors based on β-lactam and imine templates. β-Lactam 5 and imines 12 and 18 exhibit binding to heat shock protein 90-α with IC₅₀ values of 5.6 μM, 14.5 μM and 22.1 μM respectively. The binding affinity displayed …

Synthesis, Biochemical And Molecular Modelling Studies Of Antiproliferative Azetidinones Causing Microtubule Disruption And Mitotic Catastrophe, Niamh O'Boyle, Miriam Carr, Lisa M. Greene, Niall O. Keely, Andrew Js Knox, Thomas Mccabe, David G. Lloyd, Daniela M. Zisterer, Mary J. Meegan

Articles

The structure-activity relationships of antiproliferative β-lactams, focusing on modifications at the 4-position of the β-lactam ring, is described. Synthesis of this series of compounds was achieved utilizing the Staudinger and Reformatsky reactions. The antiproliferative activity was assessed in MCF-7 cells, where the 4-(4-ethoxy)phenyl substituted compound 26 displayed the most potent activity with an IC₅₀ value of 0.22 μM. The mechanism of action was demonstrated to be by inhibition of tubulin. Cell exposure to combretastatin A-4 and 26 led to arrest of MCF-7 cells in the G2/M phase of the cell cycle and induction of apoptosis. Additionally, mitotic catastrophe for …

Development And Validation Of A Rapid Multi-Class Method For The Confirmation Of Fourteen Prohibited Medicinal Additives In Pig And Poultry Compound Feed By Liquid Chromatography Tandem Mass Spectrometry, Mark Cronly, Patrice Behan, Barry Foley, Liam Regan, Marella Gallagher, Sean Earley, Paula Shearan, Edward Malone

Articles

A confirmatory method has been developed to allow for the analysis of fourteen prohibited medicinal additives in pig and poultry compound feed. These compounds are prohibited for use as feed additives although some are still authorised for use in medicated feed. Feed samples are extracted by acetonitrile with addition of sodium sulphate. The extracts undergo a hexane wash to aid with sample purification. The extracts are then evaporated to dryness and reconstituted in initial mobile phase. The samples undergo an ultracentrifugation step prior to injection onto the LC-MS/MS system and are analysed in a run time of 26 minutes. The …

Reactive Oxygen Species Induced Cytokine Production And Cytotoxicity Of Pamam Dendrimers In J774a.1 Cells, Pratap Naha, Maria Davoren, Fiona Lyng, Hugh Byrne

Articles

The immunotoxicity of three generations of polyamidoamine (PAMAM) dendrimers (G-4, G-5 and G-6) was evaluated in mouse macrophage cells in vitro. Using the Alamar blue and MTT assays, a generation dependent cytotoxicity of the PAMAM dendrimers was found whereby G-6 > G-5 > G-4. The toxic response of the PAMAM dendrimers correlated well with the number of surface primary amino groups, with increasing number resulting in an increase in toxic response. An assessment of intracellular ROS generation by the PAMAM dendrimers was performed by measuring the increased fluorescence as a result of intracellular oxidation of Carboxy H2DCFDA to DCF both quantitatively using …

Differential Control Of Tgm2 Expression By Oestrogen Receptor/Serms., Damian Lally

Masters

Breast cancer is a malignancy of the epithelial cells comprising the mammary gland. As the ER is necessary for the growth of pproximately 70% of breast cancers, pharmaceutical efforts have focused on uncovering modulators of the ERα such as antiestrogens and Selective Oestrogen Receptor Modulator (SERMs). SERMs differ from pure ER antagonists in their capacity to display tissue-selective and C promoter dependent agonist-antagonist activities. Tamoxifen (TAM) is a SERM that is used in the treatment of hormonally responsive breast cancer. TAM is the most commonly used treatment for patients with ERα positive breast cancer. In this study we examined the …

Pk/Pd Modelling Of Comb-Shaped Pegylated Salmon Calcitonin Conjugates Of Differing Molecular Weights, Sinead Ryan, Jesus Maria Frias, David H. Haddleton, David J. Brayden

Articles

Salmon calcitonin (sCT) was conjugated via cysteine-1 to novel combed-shaped end-functionalised poly(PEG) methyl ether methacrylate) (sCT-P) comb-shaped polymers, to yield conjugates of total molecular weights (MW) inclusive of sCT: 6.5, 9.5, 23 and 40 kDa. The conjugates were characterised by HPLC and their in vitro and in vivo bioactivity was measured by cAMP assay on human T47D cells and following intravenous (i.v.) injection to rats, respectively. Stability against endopeptidases, rat serum and liver homogenates was assessed. There were linear and exponential relationships between conjugate MW with potency and efficacy respectively, however the largest MW conjugate still retained 70% of E …

Antitumour And Antimalarial Activity Of Artemisinin–Acridine Hybrids, Michael Jones, Amy Mercer, Paul Stocks, Louise La Pensee, Rick Cosstick, B. Kevin Park, Miriam Kennedy, Ivo Piantanida, Stephen Ward, Jill Davies, Patrick Bray, Sarah Rawe, Jonathon Baird, Tafadzwa Charidza, Omar Janneh, Paul O'Neill

Articles

Artemisinin–acridine hybrids were prepared and evaluated for their in vitro activity against tumour cell lines and a chloroquine sensitive strain of Plasmodium falciparum. They showed a 2–4-fold increase in activity against HL60, MDA-MB-231 and MCF-7 cells in comparison with dihydroartemisinin (DHA) and moderate antimalarial activity. Strong evidence that the compounds induce apoptosis in HL60 cells was obtained by flow cytometry, which indicated accumulation of cells in the G1 phase of the cell cycle.

Ecotoxicological Investigations Of Pharmaceutical Compounds On A Battery Of Freshwater Test Species., Elaine Minagh

Masters

Currently interest in pharmaceuticals as potential environmental contaminants has increases significantly. This is due to the awareness of the possible adverse effects to human health and the environment caused by such contaminants. Within the past few years, the highly prescribed antidepressants, selective serotonin reuptake inhibitors (SSRI), have received attention as their occurrence in the environment has been recently documented. Prior to this, there was very little known about the ecotoxicity of SSRIs, and in particular sertraline hydrochloride. Similarly the cholesterol-lowering drugs, known as statins are among the most frequently prescribed agents in Ireland and worldwide for the treatment of coronary …

The Occipital And Sacral Pressures Experienced By Healthy Volunteers Under Spinal Immobilization: A Trial Of Three Surfaces, Ruairí De Fréin, Fintan Sheerin

Articles

The development of a pressure ulcer is of great significance to the life-long rehabilitative management of the person with a spinal cord injury, and may indeed delay and repeatedly interfere with that process. That the period preceding admission to the specialized spinal injury unit is crucial with regard to pressure ulcer development is evident in the professional literature. Both anecdotal and empirical evidence indicates that a significant number of pressure ulcers occur as a result of management provided prior to admission, and that such ulcers are more likely to occur in those patients who have undergone a transfer process from …

Newly Identified Vitamin K-Producing Bacteria Isolated From The Neonatal Faecal Flora, Gordon Cooke, John Behan, Mary Costello

Articles

Fat-soluble vitamin K is an essential component of the blood clotting process. Menaquinones are the naturally occurring form of vitamin K identified in bacteria. Lipid extracts were made from three bacteria originally isolated from the human neonatal gut and identified as Enterobacter agglomerans, Serratia marcescens and Enterococcus faecium. Following preparative thin layer chromatography (TLC), the lipid extracts were subjected to liquid chromatography-mass spectrometry (LC-MS) analysis. Peak analysis of the LC-MS data showed that the three bacteria produce various forms of menaquinone.

Phenmedipham Process Development, Maura Byrne

Masters

The objective of this work was to investigate the process for the production of an organic herbicide, phenmedipham, utilising isobutylacetate as solvent and to scale up the reaction to one litre. This was carried out according to a technical bulletin received from Barclay Plant Protection Ltd. Difficulties were encountered in isolating the product, methyl N-(3-hydroxyphenyl) carbamate, from stage 1 with isobutylacetate as solvent. An investigation of the use of other solvents for the reaction process led to the use of ethyl acetate, in a modified version of the method used by Schering A-G, and resulted in a 93% yield of …