Helen Hughes

• Waterford Institute of Technology

Recently, there has been emphasis on the need to shift away from the use of synthetic chemical herbicides to low risk alternatives derived from natural sources. This is aimed at lowering or averting the negative impact synthetic herbicides have on the environment and to deal with the emergence of weed species becoming resistant to these chemicals....

Despite much research over the last few decades, microneedle arrays for the transdermal delivery of drugs have failed to live up to their initial promise. This may be changing however as companies close in on the commercial delivery of vaccines via this technology. These breakthroughs will undoubtably increase the interest in the use of microneedle...

Synthetic chemical herbicides available to farmers and foresters are known to be hazardous, and their overuse, without possible alternatives, have resulted in some weed species developing resistance. Therefore, seaweed species were explored due to their known bioactive capability to see if they would potentially be effective as an alternative, nove...

Biopharmaceuticals are large, complex and labile therapeutic molecules prone to instability due to various factors during manufacturing. To ensure their safety, quality and efficacy, a wide range of critical quality attributes (CQAs) such as product concentration, aggregation, particle size, purity and turbidity have to be met. Size exclusion chrom...

A major cause of blindness worldwide is disease and damage in the posterior ocular segment. Due to poor penetration of therapeutic molecules, topical eye drops tend to be the least effective. We demonstrate a potential approach of penetration enhancement in topical drug formulations for such diseases using three penetration enhancing agents (PEAs)...

Sevelamer hydrochloride (SH) or Renagel® is an effective phosphate binder prescribed to prevent the absorption of phosphate in end stage renal disease (ESRD) patients. The relationship between SH structure and binding capacity and affinity is very important and can be used in characterising the sensitivity of the hydrogel to binding conditions. Thu...

Posterior segment eye diseases (PSEDs) including age macular degeneration (AMD) and diabetic retinopathy (DR) are amongst the major causes of irreversible blindness worldwide. Due to the numerous barriers encountered, highly invasive intravitreal (IVT) injections represent the primary route to deliver drugs to the posterior eye tissues. Thus, the p...

In the past two decades, biopharmaceuticals have been a breakthrough in improving the quality of lives of patients with various cancers, autoimmune, genetic disorders etc. With the growing demand of biopharmaceuticals, the need for reducing manufacturing costs is essential without compromising on the safety, quality, and efficacy of products. Batch...

There is an unmet clinical need for eye drop formulations to efficiently treat the diseases of the posterior ocular segment by non-invasive topical administration. Here, we systematically reviewed the literature on ocular penetration enhancers and their ability to transfer drugs to the posterior segment of the eye in experimental studies. Our aim w...

Poor aqueous solubility is a major challenge for formulation scientists as more than 40% of new chemical entities developed in the pharmaceutical industry are insoluble in water. The high energy amorphous form offers enhanced solubility and eventually the bioavailability of BCS class II drugs. Due to high thermodynamic properties, the amorphous for...

Biosecurity is emerging as one of the most important issues facing the agricultural and forestry communities, with the use of chemical pesticides being the main protocol for controlling plant pathogens. However, as a result of the emergence of resistance against these controls and the negative impact chemicals have on the environment, coupled with...

Antimicrobial resistant strains of infection are afflicting clinical settings, driving the search for novel antimicrobial compounds. Naturally sourced bioactives, for instance those from seaweeds, have the potential to ameliorate this issue. As such, solvent extracts from the edible Irish seaweeds Fucus serratus and Fucus vesiculosus were screened...

Chemical pesticides have a major impact on biological diversity, alongside habitat loss and climate change with the need to replace the use of these hazardous chemicals with ecologically sound alternatives. Four seaweed species collected along the southeast coast of Ireland were tested against nine plant pathogens using the disk diffusion assay. Th...

Microneedle technology offers a viable means of delivering biologically active pharmaceutical agents across the skin in a minimally invasive and virtually pain free manner. Previous work detailed the first successful transdermal delivery of a model peptide drug, polymyxin b, utilising a dissolving polymer-based microneedle system. The focus of this...

The highly effective barrier properties of the stratum corneum (SC) limit the application of transdermal delivery to relatively small, lipophilic molecules. Microneedles (MNs) however, offer a route to effectively deliver a wide range of pharmaceuticals through the skin, bypassing the SC in a non-invasive and pain-free manner. This study presents a...

Mucoadhesion is the process of binding a material to the mucosal layer of the body. Utilising both natural and synthetic polymers, mucoadhesive drug delivery is a method of controlled drug release which allows for intimate contact between the polymer and a target tissue. It has the potential to increase bioavailability, decrease potential side effe...

The thiolation of polyallylamine (PAAm) for use in mucoadhesive drug delivery has been achieved. PAAm was reacted with different ratios of Traut's reagent, yielding products with thiol contents ranging from 134–487 μmol/g. Full mucoadhesive characterisation of the thiolated PAAm samples was conducted using swelling studies, mucoadhesive testing on...

Synthetic polymers, polyacrylic acid (PAA) and polyallylamine (PAAm), were thiolated using different methods of thiolation. Both polymers resulted in comparable thiol contents, thus allowing for the direct comparison of mucoadhesive and cohesive properties between the well-established thiolated PAA and the more novel thiolated PAAm. Thiolation of b...

Using a novel two-step approach, the thiolation of gelatin for mucoadhesive drug delivery has been achieved. The initial step involved the amination of native gelatin via an amine to carboxylic acid coupling reaction with ethylene diamine, followed by thiolation with Traut’s reagent. The resulting thiolated product showed an increase in thiol conte...

Six antimicrobial-producing seaweed-derived Bacillus strains were evaluated in vitro as animal probiotics, in comparison to two Bacillus from an EU-authorized animal probiotic product. Antimicrobial activity was demonstrated on solid media against porcine Salmonella and E. coli. The marine isolates were most active against the latter, had better ac...

Forty eight individual pigs (8.7±0.26 kg) weaned at 28±1 d of age were used in a 22-d study to evaluate the effect of oral administration of a Bacillus pumilus spore suspension on growth performance and health indicators. Treatments (n = 16) were: (1) non-medicated diet; (2) medicated diet with apramycin (200 mg/kg) and pharmacological levels of zi...

Seaweeds are known to contain a range of bioactive compounds, including ones with antimicrobial activity. Some studies have succeeded in isolating, purifying, and identifying seaweed-derived antimicrobial compounds. Although this is a challenging process, it is crucial if a compound is to be exploited commercially. This chapter reviews the differen...

The objective of this study was to develop a novel antimicrobial seaweed wound dressing. The seaweed extract was active against nine clinically-relevant wound pathogens. A hydrogel formulation was prepared using polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP), followed by addition of 1% seaweed extract. The antimicrobial properties of the no...

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The objectives of this study were (1) to assess the bacteriocinogenic potential of bacteria derived mainly from seaweed, but also sand and seawater, (2) to identify at least some of the bacteriocins produced, if any and (3) to determine if they are unique to the marine environment and/or novel. Fifteen Bacillus licheniformis or pumilus isolates wit...

Sevelamer carbonate, a polymeric drug, adsorbs phosphate ions from the gastro intestine of patients suffering from chronic kidney disease. Polymer chain mobility becomes critical during its manufacture and storage. How the polymer chain mobility in sevelamer carbonate is quantitatively controlled by small molecular species, in this case by water mo...

A facile, robust and cost-effective suspension polymerisation methodology for the generation of ibuprofen molecularly imprinted polymers in bead formats was evaluated. Mineral oil was employed as the continuous phase whereby microdroplets of the pre-polymerisation mixture were formed through vigorous agitation, followed by photo-polymerisation resu...

A novel non-stabilised aqueous suspension polymerisation methodology for the preparation of spherical molecularly imprinted polymers is described with chlorpheniramine (CP), d-chlorpheniramine (d-CP), brompheniramine (BP) and d-brompheniramine (d-BP) as the templates, respectively. Using this rapid and simple technique, controlled polymer beads in...

This study aimed to optimize an extraction and separation procedure to obtain a concentrated fraction with antibacterial activity from the macroalga Ulva lactuca. Antibacterial compounds were extracted using eight solvents, and consistent activity against Staphylococcus aureus, Bacillus subtilis and methicillin-resistant (MR) S. aureus was observed...

Isoflavone metal chelates are of interest as isoflavones act as oestrogen mimics. Metal interactions may enhance isoflavones biological properties so understanding isoflavone metal chelation is important for the commercial application of isoflavones. This work aimed to determine if isoflavones, daidzein (4',7-dihydroxyisoflavone) and genistein (4',...

Photochemically-induced ligand rearrangements for the N2 and N4 coordination isomers of the complex [Ru(bpy)(2)(Hpztr)](2+) and its deprotonated analogue [Ru(bpy)(2)(pztr)](+), where bpy is 2,2'-bipyridyl and Hpztr is pyrazine-1,2,4-triazole ligand, are reported. (1)H NMR spectroscopic and HPLC studies indicate that in acetone and acetonitrile the...

The marine environment is an untapped source of bioactive compounds. Specifically, marine macroalgae (seaweeds) are rich in polysaccharides that could potentially be exploited as prebiotic functional ingredients for both human and animal health applications. Prebiotics are non-digestible, selectively fermented compounds that stimulate the growth an...

This is the first in-depth study examining the effect of morphology on the performance of 2-aminopyridine (2-apy) imprinted polymers. A series of polymers were prepared by varying the amount of crosslinking monomer (EGDMA) whilst the other polymer components remained constant. Physical characterisation was carried out using conventional techniques,...

The toxicity and mobility of Cr(VI) means that it is crucial that the amount of the heavy metal discharged in industrial waste streams is significantly decreased. Seaweed biomass represents a benign, cost-effective, sustainable and efficient solution for the detoxification of anionic Cr(VI) to the less hazardous cationic Cr(III). Chromium binding a...

Various chemical treatments have been applied to six brown, red and green seaweed species with a view to enhancing their metal removal for Cu(II), Cr(III) and Cr(VI). Treatment with acetone resulted in the greatest enhancement for both cationic and anionic species with relatively low mass losses (15-35%), indicating its low risk to biomass operatio...

A powerful method utilising direct probe thermal desorption GC-MS is presented for the study of molecularly imprinted polymers (MIPs). A series of 2-aminopyridine (2-apy)-imprinted methacrylic acid-ethyleneglycol dimethacrylate (MAA-EGDMA) copolymers were prepared under identical conditions but with varying amounts of EGDMA (crosslinking monomer)....

A detailed investigation into the functional groups responsible for the formation of a noncovalent complex between 2-aminopyridine (template) and methacrylic acid (functional monomer) has been carried out using FTIR spectroscopy and confirmed by 1H NMR spectroscopic data. The approach adopted to confirm the mechanism of interaction was the analysis...

Dried biomass of the macroalgae Fucus vesiculosus and Fucus spiralis (brown), Ulva spp. (comprising Ulva linza, Ulva compressa and Ulva intestinalis) and Ulva lactuca (green), Palmaria palmata and Polysiphonia lanosa (red) were studied in terms of their chromium biosorption performance. Metal sorption was highly pH dependent with maximum Cr(III) an...

The ability to prepare and develop novel pre-concentration media by the sol-gel process, and their integration with mid-infrared transparent waveguides has been demonstrated. This research approach resulted in a mid-infrared sensing methodology in which the properties (porosity, functionality, polarity, etc.) of the recognition layer could be tailo...

Dried biomass of the marine macroalgae Fucus spiralis and Fucus vesiculosus (brown), Ulva spp. (comprising Ulva linza, Ulva compressa and Ulva intestinalis) and Ulva lactuca (green), Palmaria palmata and Polysiphonia lanosa (red) were studied in terms of their Cu(II) biosorption performance. This is the first study of its kind to compare Cu(II) upt...

The potential of a novel polymer modified mid-infrared technique as a ‘smart’ sensing methodology is demonstrated. Diffusion of a penetrant (analyte molecule) was monitored into a Teflon® AF2400 membrane through observation of one of its infrared absorption bands. During the diffusion of select analytes, mid-IR polymer bands were observed to experi...

This paper outlines the development of a method for the determination of total germanium in foodstuffs utilising graphite furnace atomic absorption. It was found that by varying the drying times interferences could be minimised. Metals including calcium, cobalt, copper, magnesium, nickel, lead and zinc were tested for potential interferences. It wa...

Polymer-modified ATR-FTIR spectroscopy was investigated to determine its potential suitability for use as an analytical methodology for process stream analysis. The process stream under investigation contains toluene, tetrahydrofuran, ethanol, and acetonitrile in an aqueous matrix. Four polymers, Teflon® AF2400, poly(acrylonitrile-co-butadiene) (PA...

This paper illustrates the potential of the sol-gel process to imprint the pharmaceutical active--N-[N-[(1S)-1-carboxssy-3-phenylpropyl]-l-lysyl]-L-proline, (lisinopril dihydrate). This template exhibits unique difficulties such as limited solubility in non-polar and most polar porogens with multiple functionality evident in its 4 pKa values. Selec...

The synthesis and a detailed investigation into the electronic properties of mononuclear and dinuclear Ru(II) complexes of the ligand bis(2-hydroxyphenyl)-2,5-dihydropyrazine (H(2)BHD) is described. In these complexes the Ru(II) moieties are bound through O,N coordination to an anionic phenolate and the pyrazine bridge. Relatively few reports are a...

The synthesis, purification and characterisation of two coordination isomers of ruthenium(II) and osmium (II) complexes containing the ligand 3-(pyrazin-2'-yl)-5-(pyridin-2"-yl)-1,2,4-triazole (Hppt) are described. The X-ray and molecular structure of the complex [Ru(bipy)2(ppt)]PF6·CH3OH is reported, where the Ru(bipy)2-centre is bound to the ppt-...

This paper examines the practice of total quality management (TQM) philosophy within companies operating in Ireland. The main objective of this study is to establish whether, or not, TQM philosophy is suitable for adoption by organisations in Ireland. The study is quantitative in nature and is based on the findings of two research questionnaires. D...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The photochemical and photophysical properties of ruthenium polypyridyl complexes containing 1,24-triazole-based ligands, such as pyridine- and pyrazine triazoles are reviewed. The excited-state behaviour of such complexes is discussed in relation to the asymmetry inherently present in these ligands. For the pyridine triazole-containing complexes a...

The process flow diagram for the multi-stage flash (MSF) desalination process is quiet complex, where it includes several stages for brine flashing, preheaters for feed seawater, two sections for heat recovery and rejection, cooling water stream, and brine recycle stream. The process fundamentals are analyzed in order to have a better understanding...

The heat transfer characteristics on the HTSC-surface in a pool of liquid nitrogen under conditions of slow increasing or decreasing transport current have been experimentally studied. It was observed that there are instabilities of heat transfer regimes regarding the small thermal disturbances (fluctuations). These unstable heat transfer regimes a...

The excited-state properties of mononuclear and dinuclear Ru(bpy)(2) complexes with bpzt(-) bridging ligand (bpy = 2,2'-bipyridine, and bpzt(-) = 3,5-bis(pyrazin-2-yl)-1,2,4-triazole) have been probed by resonance Raman (RR), excited-state absorption (ESA), and spectroelectrochemical techniques. Excited-state RR spectroscopy provides evidence of a...

Resonance Raman (RR) spectroscopic studies, supplemented by excited state absorption techniques, were used to probe the effect of modifications to the electronic environment on the excited states of mono- and di-nuclear Ru(II) polypyridyl complexes containing triazole-based bridging ligands. Ground state RR spectroscopy showed that coordination of...

Resonance Raman (RR) spectroscopic studies, supplemented by excited state absorption techniques, were used to probe the effect of modifications to the electronic environment on the excited states of mono- and di-nuclear Ru(II) polypyridyl complexes containing triazole-based bridging ligands. Ground state RR spectroscopy showed that coordination of...

Photolysis of the dinuclear complex [Ru(bpy)(2))(2)-(bpzt)](3+) (bpzt is 3,5-bis(Pyrazin-2-yl)-1,2,4-triazole) leads to a unique labilization of the metal moiety bound to the triazole N4 site. This is contrary to results obtained for the analogous compound based on the 3,5-bis(pyridin-2-yl)-1,2,4-triazole (Hbpt) ligand for which both the N1 and the...

The excited state and redox properties of the two mixed-ligand species [Ru(bpy)2(bpt)Ru(phen)2](PF6)3 and [Ru-(phen)2(bpt)Ru(bpy)2](PF6)3 are reported (where bpy = 2,2'-bipyridine, phen = 1,10-phenanthroline, and Hbpt = 3,5-bis(pyridin-2-yl)-1,2,4-triazole) and compared with those obtained for [Ru(bpy)2(bpt)]PF6.1/2H2O, [(Ru-(bpy)2)2(bpt)](PF6)3, [...

A series of RuII(bipy)2 complexes (bipy = 2,2′-bipyridine) containing monodentate co-ordinated pyridyltriazole ligands has been prepared and characterised. The species are obtained by either thermal or photochemical methods. The co-ordination mode of the products obtained has been investigated using spectroscopic techniques. The molecular structure...

The isolation and characterisation of an intermediate produced upon photolysis of [Ru(bipy)2(L-L’)I(PF4)2 in MeCN [bipy = 2,2’-bipyridyl and L-L’ = 4-methyl-3-(pyridin-2-yl)-,I2 ,4-triazole], in which L-L’ is coordinated to the metal centre in a monodentate fashion, via the nitrogen of the triazole ring, is reported; this photochemically induced re...