Glantreo Ltd.

Cork, Ireland

Glantreo Ltd.

Cork, Ireland
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Omamogho J.O.,University College Cork | Hanrahan J.P.,Glantreo Ltd. | Tobin J.,Glantreo Ltd. | Glennon J.D.,University College Cork
Journal of Chromatography A | Year: 2011

Chromatographic and mass transfer kinetic properties of three narrow bore columns (2.1×50mm) packed with new core-shell 1.7μm EIROSHELL™-C 18 (EiS-C 18) particles have been studied. The particles in each column varied in the solid-core to shell particle size ratio (ρ), of 0.59, 0.71 and 0.82, with a porous silica shell thickness of 350, 250 and 150nm respectively. Scanning and transmission electron microscopy (SEM and TEM), Coulter counter analysis, gas pycnometry, nitrogen sorption analysis and inverse size exclusion chromatography (ISEC) elucidated the physical properties of these materials. The porosity measurement of the packed HILIC and C 18 modified phases provided the means to estimate the phase ratios of the three different shell columns (EiS-150-C 18, EiS-250-C 18 and EiS-350-C 18). The dependence of the chromatographic performance to the volume fraction of the porous shell was observed for all three columns. The naphtho[2,3-a]pyrene retention factor of k'∼10 on the three EiS-C 18s employed to obtain the height equivalents to theoretical plates (HETPs) data were achieved by varying the mobile phase compositions and applying the Wilke and Chang relationship to obtain a parallel reduced linear velocity. The Knox fit model gave the coefficient of the reduce HETPs for the three EiS-C 18s. The reduced plate height minimum h min=1.9 was achieved for the EiS-150-C 18 column, and generated an efficiency of over 350,000N/m and h min=2.5 equivalent to an efficiency of 200,000N/m for the EiS-350-C 18 column. The efficiency loss of the EiS-C18 column emanating from the system extra-column volume was discussed with respect to the porous shell thickness. © 2010 Elsevier B.V.

Delaney P.,Tyndall National Institute | Delaney P.,Trinity College Dublin | Healy R.M.,University College Cork | Hanrahan J.P.,Glantreo Ltd. | And 6 more authors.
Journal of Environmental Monitoring | Year: 2010

Porous silica spheres were investigated for their effectiveness in removing typical indoor air pollutants, such as aromatic and carbonyl-containing volatile organic compounds (VOCs), and compared to the commercially available polymer styrene-divinylbenzene (XAD-4). The silica spheres and the XAD-4 resin were coated on denuder sampling devices and their adsorption efficiencies for VOCs evaluated using an indoor air simulation chamber. Real indoor sampling was also undertaken to evaluate the affinity of the silica adsorbents for a variety of indoor VOCs. The silica sphere adsorbents were found to have a high affinity for polar carbonyls and found to be more efficient than the XAD-4 resin at adsorbing carbonyls in an indoor environment. © 2010 The Royal Society of Chemistry.

Mohamed B.M.,Trinity College Dublin | Verma N.K.,Trinity College Dublin | Prina-Mello A.,Trinity College Dublin | Williams Y.,Trinity College Dublin | And 10 more authors.
Journal of Nanobiotechnology | Year: 2011

Nanomaterials such as SiO2nanoparticles (SiO2NP) are finding increasing applications in the biomedical and biotechnological fields such as disease diagnostics, imaging, drug delivery, food, cosmetics and biosensors development. Thus, a mechanistic and systematic evaluation of the potential biological and toxic effects of SiO2NP becomes crucial in order to assess their complete safe applicability limits.Results: In this study, human monocytic leukemia cell line THP-1 and human alveolar epithelial cell line A549 were exposed to a range of amorphous SiO2NP of various sizes and concentrations (0.01, 0.1 and 0.5 mg/ml). Key biological indicators of cellular functions including cell population density, cellular morphology, membrane permeability, lysosomal mass/pH and activation of transcription factor-2 (ATF-2) were evaluated utilizing quantitative high content screening (HCS) approach and biochemical techniques. Despite the use of extremely high nanoparticle concentrations, our findings showed a low degree of cytotoxicity within the panel of SiO2NP investigated. However, at these concentrations, we observed the onset of stress-related cellular response induced by SiO2NP. Interestingly, cells exposed to alumina-coated SiO2NP showed low level, and in some cases complete absence, of stress response and this was consistent up to the highest dose of 0.5 mg/ml.Conclusions: The present study demonstrates and highlights the importance of subtle biological changes downstream of primary membrane and endocytosis-associated phenomena resulting from high dose SiO2NP exposure. Increased activation of transcription factors, such as ATF-2, was quantitatively assessed as a function of i) human cell line specific stress-response, ii) SiO2NP size and iii) concentration. Despite the low level of cytotoxicity detected for the amorphous SiO2NP investigated, these findings prompt an in-depth focus for future SiO2NP-cell/tissue investigations based on the combined analysis of more subtle signalling pathways associated with accumulation mechanisms, which is essential for establishing the bio-safety of existing and new nanomaterials. © 2011 Mohamed et al; licensee BioMed Central Ltd.

Abdallah N.H.,University of Limerick | Schlumpberger M.,University of Limerick | Gaffney D.A.,University of Limerick | Hanrahan J.P.,Glantreo Ltd. | And 2 more authors.
Journal of Molecular Catalysis B: Enzymatic | Year: 2014

The activity and stability of Candida antartica lipase B (CALB) and cytochrome c immobilised onto SBA-15 and a porous spherical silicate material (PPS) were examined. The materials possess similar pore diameters but have different morphologies, pore volumes and surface areas. CALB exhibited higher catalytic activity and stability on SBA-15 when compared to PPS, while cytochrome c showed similar catalytic activity on both materials. The activity of CALB immobilised on SBA-15 was retained (95%) after 7 uses, while CALB immobilised on PPS retained only 43% activity. Such changes can be mainly ascribed to the different physical properties (pore volume, surface area and pore shape) of the supports. © 2014 Elsevier B.V.

Waters L.J.,University of Huddersfield | Hussain T.,University of Huddersfield | Parkes G.,University of Huddersfield | Hanrahan J.P.,Glantreo Ltd. | Tobin J.M.,Glantreo Ltd.
European Journal of Pharmaceutics and Biopharmaceutics | Year: 2013

A selection of porous silicas were combined with a model drug using a recently developed, controlled microwave heating process to determine if the application of microwave irradiation could enhance subsequent drug release. Five mesoporous silica types were investigated (core shell, core shell rehydrox, SBA-15, silica gel, SYLOID®) and, for comparison, one non-porous silica (stober). These were formulated using a tailored microwave heating method at drug/excipient ratios of 1:1, 1:3 and 1:5. In addition, all experiments were performed both in the presence and absence of water, used as a fluidising media to aid interaction between drug and support, and compared with results obtained using more traditional heating methods. All formulations were then characterised using differential scanning calorimetry (DSC), powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transformation infrared spectroscopy (FT-IR). Pharmaceutical performance was investigated using in vitro drug release studies. A significant enhancement in the release profile of fenofibrate was observed for formulations prepared using microwave heating in the absence of water for five of the six silica based formulations. Of all the formulations analysed, the greatest extent of drug release within the experimental 30 min was the 1:5 core shell rehydrox achieving a total of 86.6 ± 2.8%. The non-porous (stober) particles did not exhibit an increased release of the drug under any experimental conditions studied. This anomaly is thought to be a result of the comparatively small surface area of the silica particles, thus preventing the adsorption of drug molecules. © 2013 Elsevier B.V. All rights reserved.

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