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Changtor P, Rodriguez-Mateos P, Buddhachat K, Wattanachaiyingcharoen W, Iles A, Kerdphon S, Yimtragool N, Pamme N. Integration of IFAST-based nucleic acid extraction and LAMP for on-chip rapid detection of Agroathelia rolfsii in soil. Biosens Bioelectron 2024; 250:116051. [PMID: 38301544 DOI: 10.1016/j.bios.2024.116051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 01/15/2024] [Accepted: 01/17/2024] [Indexed: 02/03/2024]
Abstract
Agroathelia rolfsii (A. rolfsii) is a fungal infection and poses a significant threat to over 500 plant species worldwide. It can reduce crop yields drastically resulting in substantial economic losses. While conventional detection methods like PCR offer high sensitivity and specificity, they require specialized and expensive equipment, limiting their applicability in resource-limited settings and in the field. Herein, we present an integrated workflow with nucleic acid extraction and isothermal amplification in a lab-on-a-chip cartridge based on immiscible filtration assisted by surface tension (IFAST) to detect A. rolfsii fungi in soil for point-of-need application. Our approach enabled both DNA extraction of A. rolfsii from soil and subsequent colorimetric loop-mediated isothermal amplification (LAMP) to be completed on a single chip, termed IFAST-LAMP. LAMP primers targeting ITS region of A. rolfsii were newly designed and tested. Two DNA extraction methods based on silica paramagnetic particles (PMPs) and three LAMP assays were compared. The best-performing assay was selected for on-chip extraction and detection of A. rolfsii from soil samples inoculated with concentrations of 3.75, 0.375 and 0.0375 mg fresh weight per 100-g soil (%FW). The full on-chip workflow was achieved within a 1-h turnaround time. The platform was capable of detecting as low as 3.75 %FW at 2 days after inoculation and down to 0.0375 %FW at 3 days after inoculation. The IFAST-LAMP could be suitable for field-applicability for A. rolfsii detection in low-resource settings.
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Affiliation(s)
- Phanupong Changtor
- Department of Materials and Environmental Chemistry, Stockholm University, Stockholm, Sweden; Department of Biology, Faculty of Science, Naresuan University, Phitsanulok, Thailand
| | - Pablo Rodriguez-Mateos
- Department of Materials and Environmental Chemistry, Stockholm University, Stockholm, Sweden
| | - Kittisak Buddhachat
- Department of Biology, Faculty of Science, Naresuan University, Phitsanulok, Thailand
| | - Wandee Wattanachaiyingcharoen
- Department of Biology, Faculty of Science, Naresuan University, Phitsanulok, Thailand; Center of Excellence for Biodiversity, Faculty of Science, Naresuan University, Phitsanulok, Thailand
| | - Alexander Iles
- Department of Materials and Environmental Chemistry, Stockholm University, Stockholm, Sweden
| | - Sutthichat Kerdphon
- Department of Chemistry, Faculty of Science, Naresuan University, Phitsanulok, Thailand
| | - Nonglak Yimtragool
- Department of Biology, Faculty of Science, Naresuan University, Phitsanulok, Thailand; Center of Excellence for Biodiversity, Faculty of Science, Naresuan University, Phitsanulok, Thailand.
| | - Nicole Pamme
- Department of Materials and Environmental Chemistry, Stockholm University, Stockholm, Sweden.
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2
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Oday J, Hadi H, Hashim P, Richardson S, Iles A, Pamme N. Development and validation of spectrophotometric method and paper-based microfluidic devices for the quantitative determination of Amoxicillin in pure form and pharmaceutical formulations. Heliyon 2024; 10:e24968. [PMID: 38318013 PMCID: PMC10839972 DOI: 10.1016/j.heliyon.2024.e24968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 01/17/2024] [Accepted: 01/17/2024] [Indexed: 02/07/2024] Open
Abstract
There is a growing need for easy-to-use, low cost and portable quantitative assays to determine active pharmaceutical ingredients in the pharmaceutical industry. Here, we developed a batch spectrophotometric method and a method employing a paper-based microfluidic device for the estimation of Amoxicillin (AMX) in pure solution and pharmaceutical preparations. The detection depends on the coupling reaction of Amoxicillin with diazotized sulfadimidine (DSDM) in an alkaline medium. The yellow azo dye reaction product was measured at λmax 425 nm and linearity was observed from 2 to 30 mg L-1 with a detection limit of 0.32 mg L-1 and a quantification limit of 1.2 mg L-1 was found. The reaction was then transferred onto the paper-based microfluidic device and a plateau change in color intensity was found above 10 mg L-1. Thus, the paper-based microfluidic device can be applied for the semi-quantitative determination of Amoxicillin in pure solution and commercial pharmaceutical products for rapid screening.
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Affiliation(s)
- Jwan Oday
- Department of Chemistry, College of Science, Mustansiriyah University, Baghdad, Iraq
| | - Hind Hadi
- Department of Chemistry, College of Science, University of Baghdad, Baghdad, Iraq
| | - Parween Hashim
- Department of Chemistry, College of Science, University of Duhok, Duhok, Iraq
| | - Samantha Richardson
- School of Natural Sciences, University of Hull, Cottingham Road, Hull, HU6 7RX, UK
| | - Alexander Iles
- Department of Materials and Environmental Chemistry, Stockholm University, 106 91, Stockholm, Sweden
| | - Nicole Pamme
- Department of Materials and Environmental Chemistry, Stockholm University, 106 91, Stockholm, Sweden
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3
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Baldwin L, Jones EJ, Iles A, Carding SR, Pamme N, Dyer CE, Greenman J. Development of a dual-flow tissue perfusion device for modeling the gastrointestinal tract-brain axis. Biomicrofluidics 2023; 17:054104. [PMID: 37840538 PMCID: PMC10569815 DOI: 10.1063/5.0168953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Accepted: 09/26/2023] [Indexed: 10/17/2023]
Abstract
Despite the large number of microfluidic devices that have been described over the past decade for the study of tissues and organs, few have become widely adopted. There are many reasons for this lack of adoption, primarily that devices are constructed for a single purpose or because they are highly complex and require relatively expensive investment in facilities and training. Here, we describe a microphysiological system (MPS) that is simple to use and provides fluid channels above and below cells, or tissue biopsies, maintained on a disposable, poly(methyl methacrylate), carrier held between polycarbonate outer plates. All other fittings are standard Luer sizes for ease of adoption. The carrier can be coated with cells on both sides to generate membrane barriers, and the devices can be established in series to allow medium to flow from one cell layer to another. Furthermore, the carrier containing cells can be easily removed after treatment on the device and the cells can be visualized or recovered for additional off-chip analysis. A 0.4 μm membrane with cell monolayers proved most effective in maintaining separate fluid flows, allowing apical and basal surfaces to be perfused independently. A panel of different cell lines (Caco-2, HT29-MTX-E12, SH-SY5Y, and HUVEC) were successfully maintained in the MPS for up to 7 days, either alone or on devices connected in series. The presence of tight junctions and mucin was expressed as expected by Caco-2 and HT-29-MTX-E12, with Concanavalin A showing uniform staining. Addition of Annexin V and PI showed viability of these cells to be >80% at 7 days. Bacterial extracellular vesicles (BEVs) produced by Bacteroides thetaiotaomicron and labeled with 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbo-cyanine perchlorate (DiD) were used as a model component of the human colonic microbiota and were visualized translocating from an apical surface containing Caco-2 cells to differentiated SH-SY5Y neuronal cells cultured on the basal surface of connected devices. The newly described MPS can be easily adapted, by changing the carrier to maintain spheroids, pieces, or slices of biopsy tissue and joined in series to study a variety of cell and tissue processes. The cell layers can be made more complex through the addition of multiple cell types and/or different patterning of extracellular matrix and the ability to culture cells adjacent to one another to allow study of cell:cell transfer, e.g., passive or active drug transfer, virus or bacterial entry or BEV uptake and transfer.
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Affiliation(s)
- Lydia Baldwin
- Centre of Biomedical Sciences, Hull York Medical School, University of Hull, Cottingham Road, Hull, HU6 7RX, United Kingdom
| | - Emily J. Jones
- Quadram Institute Bioscience, Rosalind Franklin Road, Norwich Research Park, Norwich, NR4 7UQ, United Kingdom
| | - Alexander Iles
- Department of Materials and Environmental Chemistry, Stockholm University, 106 91 Stockholm, Sweden
| | | | - Nicole Pamme
- Department of Materials and Environmental Chemistry, Stockholm University, 106 91 Stockholm, Sweden
| | - Charlotte E. Dyer
- Centre of Biomedical Sciences, Hull York Medical School, University of Hull, Cottingham Road, Hull, HU6 7RX, United Kingdom
| | - John Greenman
- Centre of Biomedical Sciences, Hull York Medical School, University of Hull, Cottingham Road, Hull, HU6 7RX, United Kingdom
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4
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Patel M, Alvarez-Fernandez A, Fornerod MJ, Radhakrishnan ANP, Taylor A, Ten Chua S, Vignolini S, Schmidt-Hansberg B, Iles A, Guldin S. Liquid Crystal-Templated Porous Microparticles via Photopolymerization of Temperature-Induced Droplets in a Binary Liquid Mixture. ACS Omega 2023; 8:20404-20411. [PMID: 37323413 PMCID: PMC10268013 DOI: 10.1021/acsomega.3c00490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 05/12/2023] [Indexed: 06/17/2023]
Abstract
Porous polymeric microspheres are an emerging class of materials, offering stimuli-responsive cargo uptake and release. Herein, we describe a new approach to fabricate porous microspheres based on temperature-induced droplet formation and light-induced polymerization. Microparticles were prepared by exploiting the partial miscibility of a thermotropic liquid crystal (LC) mixture composed of 4-cyano-4'-pentylbiphenyl (5CB, unreactive mesogens) with 2-methyl-1,4-phenylene bis4-[3-(acryloyloxy)propoxy] benzoate (RM257, reactive mesogens) in methanol (MeOH). Isotropic 5CB/RM257-rich droplets were generated by cooling below the binodal curve (20 °C), and the isotropic-to-nematic transition occurred after cooling below 0 °C. The resulting 5CB/RM257-rich droplets with radial configuration were subsequently polymerized under UV light, resulting in nematic microparticles. Upon heating the mixture, the 5CB mesogens underwent a nematic-isotropic transition and eventually became homogeneous with MeOH, while the polymerized RM257 preserved its radial configuration. Repeated cycles of cooling and heating resulted in swelling and shrinking of the porous microparticles. The use of a reversible materials templating approach to obtain porous microparticles provides new insights into binary liquid manipulation and potential for microparticle production.
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Affiliation(s)
- Mehzabin Patel
- Department
of Chemical Engineering, University College
London, London, WC1E 7JE, United
Kingdom
| | | | | | | | - Alaric Taylor
- Department
of Chemical Engineering, University College
London, London, WC1E 7JE, United
Kingdom
| | - Singg Ten Chua
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, Cambridge, CB2 1EW, United
Kingdom
| | - Silvia Vignolini
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, Cambridge, CB2 1EW, United
Kingdom
| | - Benjamin Schmidt-Hansberg
- Chemical
& Process Engineering, Coating & Film Processing, BASF SE, 67056 Ludwigshafen am Rhein, Germany
| | - Alexander Iles
- Lab-on-a-Chip
Research Group, Department of Chemistry and Biochemistry, University of Hull, Hull, HU6 7RX, United Kingdom
| | - Stefan Guldin
- Department
of Chemical Engineering, University College
London, London, WC1E 7JE, United
Kingdom
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5
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Barry A, Samuel SF, Hosni I, Moursi A, Feugere L, Sennett CJ, Deepak S, Achawal S, Rajaraman C, Iles A, Wollenberg Valero KC, Scott IS, Green V, Stead LF, Greenman J, Wade MA, Beltran-Alvarez P. Investigating the effects of arginine methylation inhibitors on microdissected brain tumour biopsies maintained in a miniaturised perfusion system. Lab Chip 2023; 23:2664-2682. [PMID: 37191188 DOI: 10.1039/d3lc00204g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Arginine methylation is a post-translational modification that consists of the transfer of one or two methyl (CH3) groups to arginine residues in proteins. Several types of arginine methylation occur, namely monomethylation, symmetric dimethylation and asymmetric dimethylation, which are catalysed by different protein arginine methyltransferases (PRMTs). Inhibitors of PRMTs have recently entered clinical trials to target several types of cancer, including gliomas (NCT04089449). People with glioblastoma (GBM), the most aggressive form of brain tumour, are among those with the poorest quality of life and likelihood of survival of anyone diagnosed with cancer. There is currently a lack of (pre)clinical research on the possible application of PRMT inhibitors to target brain tumours. Here, we set out to investigate the effects of clinically-relevant PRMT inhibitors on GBM biopsies. We present a new, low-cost, easy to fabricate perfusion device that can maintain GBM tissue in a viable condition for at least eight days post-surgical resection. The miniaturised perfusion device enables the treatment of GBM tissue with PRMT inhibitors ex vivo, and we observed a two-fold increase in apoptosis in treated samples compared to parallel control experiments. Mechanistically, we show thousands of differentially expressed genes after treatment, and changes in the type of arginine methylation of the RNA binding protein FUS that are consistent with hundreds of differential gene splicing events. This is the first time that cross-talk between different types of arginine methylation has been observed in clinical samples after treatment with PRMT inhibitors.
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Affiliation(s)
- Antonia Barry
- Centre for Biomedicine, Hull York Medical School, University of Hull, Hull, UK.
| | - Sabrina F Samuel
- Centre for Biomedicine, Hull York Medical School, University of Hull, Hull, UK.
| | - Ines Hosni
- Centre for Biomedicine, Hull York Medical School, University of Hull, Hull, UK.
| | - Amr Moursi
- Department of Neurosurgery, Hull University Teaching Hospitals NHS Trust, Hull Royal Infirmary, Hull, UK
| | - Lauric Feugere
- Department of Biological and Marine Sciences, University of Hull, Hull, UK
| | | | - Srihari Deepak
- Department of Neurosurgery, Hull University Teaching Hospitals NHS Trust, Hull Royal Infirmary, Hull, UK
| | - Shailendra Achawal
- Department of Neurosurgery, Hull University Teaching Hospitals NHS Trust, Hull Royal Infirmary, Hull, UK
| | - Chittoor Rajaraman
- Department of Neurosurgery, Hull University Teaching Hospitals NHS Trust, Hull Royal Infirmary, Hull, UK
| | | | | | - Ian S Scott
- Neuroscience Laboratories, The Walton Centre NHS Foundation Trust, Liverpool, UK
| | - Vicky Green
- Centre for Biomedicine, Hull York Medical School, University of Hull, Hull, UK.
| | - Lucy F Stead
- Leeds Institute of Medical Research at St James's, St James's University Hospital, Leeds, UK
| | - John Greenman
- Centre for Biomedicine, Hull York Medical School, University of Hull, Hull, UK.
| | - Mark A Wade
- Centre for Biomedicine, Hull York Medical School, University of Hull, Hull, UK.
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6
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Rodriguez-Mateos P, Ngamsom B, Ameyo D, Wakaba P, Shiluli C, Iles A, Gitaka J, Pamme N. Integrated microscale immiscible phase extraction and isothermal amplification for colorimetric detection of Neisseria gonorrhoeae. Anal Bioanal Chem 2023:10.1007/s00216-023-04734-3. [PMID: 37198361 PMCID: PMC10191819 DOI: 10.1007/s00216-023-04734-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 05/04/2023] [Accepted: 05/04/2023] [Indexed: 05/19/2023]
Abstract
Gonorrhea is the second most common sexually transmitted infection (STI) with around 87 million cases worldwide estimated in 2016 by the World Health Organization. With over half of the cases being asymptomatic, potential life-threatening complications and increasing numbers of drug-resistant strains, routine monitoring of prevalence and incidence of infections are key preventive measures. Whilst gold standard qPCR tests have excellent accuracy, they are neither affordable nor accessible in low-resource settings. In this study, we developed a lab-on-a-chip platform based on microscale immiscible filtration to extract, concentrate and purify Neisseria gonorrhoeae DNA with an integrated detection assay based on colorimetric isothermal amplification. The platform was capable of detecting as low as 500 copies/mL from spiked synthetic urine and showed no cross-reactivity when challenged with DNAs from other common STIs. The credit card-size device allows DNA extraction and purification without power or centrifuges, and the detection reaction only needs a low-tech block heater, providing a straightforward and visual positive/negative result within 1 h. These advantages offer great potential for accurate, affordable and accessible monitoring of gonorrhea infection in resource-poor settings.
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Affiliation(s)
- Pablo Rodriguez-Mateos
- Department of Materials and Environmental Chemistry, Stockholm University, Stockholm, Sweden
| | - Bongkot Ngamsom
- Centre for Biomedicine, Hull York Medical School, University of Hull, Hull, UK
| | - Daglus Ameyo
- Directorate of Research and Innovation, Mount Kenya University, Thika, Kenya
| | - Patrick Wakaba
- Directorate of Research and Innovation, Mount Kenya University, Thika, Kenya
| | - Clement Shiluli
- Directorate of Research and Innovation, Mount Kenya University, Thika, Kenya
| | - Alexander Iles
- Department of Materials and Environmental Chemistry, Stockholm University, Stockholm, Sweden
| | - Jesse Gitaka
- Directorate of Research and Innovation, Mount Kenya University, Thika, Kenya.
| | - Nicole Pamme
- Department of Materials and Environmental Chemistry, Stockholm University, Stockholm, Sweden.
- School of Natural Sciences, University of Hull, Hull, UK.
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7
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Ngamsom B, Iles A, Kamita M, Kimani R, Wakaba P, Rodriguez-Mateos P, Mungai M, Dyer CE, Walter C, Gitaka J, Pamme N. A sample-to-answer COVID-19 diagnostic device based on immiscible filtration and CRISPR-Cas12a-assisted detection. Talanta Open 2022; 6:100166. [PMID: 36406953 PMCID: PMC9640297 DOI: 10.1016/j.talo.2022.100166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 11/02/2022] [Accepted: 11/02/2022] [Indexed: 11/11/2022] Open
Abstract
In response to the ongoing coronavirus disease 2019 (COVID-19) pandemic and disparities of vaccination coverage in low-and middle-income countries, it is vital to adopt a widespread testing and screening programme, combined with contact tracing, to monitor and effectively control the infection dispersion in areas where medical resources are limited. This work presents a lab-on-a-chip device, namely 'IFAST-LAMP-CRISPR', as an affordable, rapid and high-precision molecular diagnostic means for detection of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). The herein proposed 'sample-to-answer' platform integrates RNA extraction, amplification and molecular detection with lateral flow readout in one device. The microscale dimensions of the device containing immiscible liquids, coupled with the use of silica paramagnetic beads and guanidine hydrochloride, streamline sample preparation (including RNA extraction, concentration and purification) in 15 min with minimal hands-on steps. The pre-amplification in combination with CRISPR-Cas12a detection assays targeting the nucleoprotein (N) gene achieved visual identification of ≥ 470 copies mL-1 genomic SARS-CoV-2 samples in 45 min. On-chip assays showed the ability to isolate and detect SARS-CoV-2 RNA from 100 genome copies mL-1 of replication-deficient viral particles in 1 h. This simple, affordable and integrated platform demonstrated a visual, faster, and yet specificity- and sensitivity-comparable alternative to the costly gold-standard reverse transcription-polymerase chain reaction (RT-PCR) assay, requiring only a simple heating source. Initial testing illustrates the platform viability both on nasopharyngeal swab and saliva samples collected using the easily accessible Swan-brand cigarette filter, providing a complete workflow for COVID-19 diagnostics in low-resource settings.
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Affiliation(s)
- Bongkot Ngamsom
- School of Natural Sciences, University of Hull, Hull HU6 7RX, UK
| | - Alexander Iles
- School of Natural Sciences, University of Hull, Hull HU6 7RX, UK,Department of Materials and Environmental Chemistry, Stockholm University, SE 106 91, Sweden
| | - Moses Kamita
- Directorate of Research and Innovation, Mount Kenya University, Thika, Kenya
| | - Racheal Kimani
- Directorate of Research and Innovation, Mount Kenya University, Thika, Kenya
| | - Patrick Wakaba
- Directorate of Research and Innovation, Mount Kenya University, Thika, Kenya
| | - Pablo Rodriguez-Mateos
- Department of Materials and Environmental Chemistry, Stockholm University, SE 106 91, Sweden
| | - Mary Mungai
- Centre for Virus Research, Kenya Medical Research Institute, Nairobi, Kenya
| | - Charlotte E. Dyer
- Centre for Biomedicine, Hull-York Medical School, University of Hull, Hull HU6 7RX, UK
| | - Cheryl Walter
- Centre for Biomedicine, Hull-York Medical School, University of Hull, Hull HU6 7RX, UK
| | - Jesse Gitaka
- Directorate of Research and Innovation, Mount Kenya University, Thika, Kenya,Corresponding author at: Stockholm University, Sweden
| | - Nicole Pamme
- School of Natural Sciences, University of Hull, Hull HU6 7RX, UK,Department of Materials and Environmental Chemistry, Stockholm University, SE 106 91, Sweden,Corresponding author at: Stockholm University, Sweden
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8
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Rodriguez-Mateos P, Ngamsom B, Iles A, Pamme N. Microscale immiscible phase magnetic processing for bioanalytical applications. Trends Analyt Chem 2022. [DOI: 10.1016/j.trac.2022.116867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
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9
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Richardson S, Iles A, Rotchell JM, Charlson T, Hanson A, Lorch M, Pamme N. Citizen-led sampling to monitor phosphate levels in freshwater environments using a simple paper microfluidic device. PLoS One 2021; 16:e0260102. [PMID: 34882681 PMCID: PMC8659362 DOI: 10.1371/journal.pone.0260102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 11/02/2021] [Indexed: 11/23/2022] Open
Abstract
Contamination of waterways is of increasing concern, with recent studies demonstrating elevated levels of antibiotics, antidepressants, household, agricultural and industrial chemicals in freshwater systems. Thus, there is a growing demand for methods to rapidly and conveniently monitor contaminants in waterways. Here we demonstrate how a combination of paper microfluidic devices and handheld mobile technology can be used by citizen scientists to carry out a sustained water monitoring campaign. We have developed a paper-based analytical device and a 3 minute sampling workflow that requires no more than a container, a test device and a smartphone app. The contaminant measured in these pilots are phosphates, detectable down to 3 mg L-1. Together these allow volunteers to successfully carry out cost-effective, high frequency, phosphate monitoring over an extended geographies and periods.
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Affiliation(s)
- Samantha Richardson
- Department of Chemistry and Biochemistry, University of Hull, Hull, United Kingdom
| | - Alexander Iles
- Department of Chemistry and Biochemistry, University of Hull, Hull, United Kingdom
| | - Jeanette M. Rotchell
- Department of Biological and Marine Sciences, University of Hull, Hull, United Kingdom
| | - Tim Charlson
- Pocklington Canal Amenity Society, Pocklington, United Kingdom
| | - Annabel Hanson
- East Riding of Yorkshire Council, Beverley, United Kingdom
| | - Mark Lorch
- Department of Chemistry and Biochemistry, University of Hull, Hull, United Kingdom
- * E-mail:
| | - Nicole Pamme
- Department of Chemistry and Biochemistry, University of Hull, Hull, United Kingdom
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10
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Rodriguez-Mateos P, Ngamsom B, Walter C, Dyer CE, Gitaka J, Iles A, Pamme N. A lab-on-a-chip platform for integrated extraction and detection of SARS-CoV-2 RNA in resource-limited settings. Anal Chim Acta 2021; 1177:338758. [PMID: 34482896 PMCID: PMC8202086 DOI: 10.1016/j.aca.2021.338758] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 06/09/2021] [Accepted: 06/10/2021] [Indexed: 12/15/2022]
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused the unprecedented global pandemic of coronavirus disease-2019 (COVID-19). Efforts are needed to develop rapid and accurate diagnostic tools for extensive testing, allowing for effective containment of the infection via timely identification and isolation of SARS-CoV-2 carriers. Current gold standard nucleic acid tests require many separate steps that need trained personnel to operate specialist instrumentation in laboratory environments, hampering turnaround time and test accessibility, especially in low-resource settings. We devised an integrated on-chip platform coupling RNA extraction based on immiscible filtration assisted by surface tension (IFAST), with RNA amplification and detection via colorimetric reverse-transcription loop mediated isothermal amplification (RT-LAMP), using two sets of primers targeting open reading frame 1a (ORF1a) and nucleoprotein (N) genes of SARS-CoV-2. Results were identified visually, with a colour change from pink to yellow indicating positive amplification, and further confirmed by DNA gel electrophoresis. The specificity of the assay was tested against HCoV-OC43 and H1N1 RNAs. The assay based on use of gene N primers was 100% specific to SARS-CoV-2 with no cross-reactivity to HCoV-OC43 nor H1N1. Proof-of-concept studies on water and artificial sputum containing genomic SARS-CoV-2 RNA showed our IFAST RT-LAMP device to be capable of extracting and detecting 470 SARS-CoV-2 copies mL-1 within 1 h (from sample-in to answer-out). IFAST RT-LAMP is a simple-to-use, integrated, rapid and accurate COVID-19 diagnostic platform, which could provide an attractive means for extensive screening of SARS-CoV-2 infections at point-of-care, especially in resource-constrained settings.
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Affiliation(s)
| | - Bongkot Ngamsom
- Department of Chemistry and Biochemistry, University of Hull, UK
| | - Cheryl Walter
- Department of Biomedical Sciences, University of Hull, UK
| | | | - Jesse Gitaka
- Directorate of Research and Innovation, Mount Kenya University, Thika, Republic of Kenya
| | - Alexander Iles
- Department of Chemistry and Biochemistry, University of Hull, UK
| | - Nicole Pamme
- Department of Chemistry and Biochemistry, University of Hull, UK,Corresponding author. Department of Chemistry, Faculty of Science and Engineering, University of Hull, Cottingham Road, Hull, East Riding of Yorkshire, HU6 7RX, UK
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11
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Collins T, Pyne E, Christensen M, Iles A, Pamme N, Pires IM. Spheroid-on-chip microfluidic technology for the evaluation of the impact of continuous flow on metastatic potential in cancer models in vitro. Biomicrofluidics 2021; 15:044103. [PMID: 34504636 PMCID: PMC8403013 DOI: 10.1063/5.0061373] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 08/10/2021] [Indexed: 05/10/2023]
Abstract
The majority of cancer deaths are linked to tumor spread, or metastasis, but 3D in vitro metastasis models relevant to the tumor microenvironment (including interstitial fluid flow) remain an area of unmet need. Microfluidics allows us to introduce controlled flow to an in vitro cancer model to better understand the relationship between flow and metastasis. Here, we report new hybrid spheroid-on-chip in vitro models for the impact of interstitial fluid flow on cancer spread. We designed a series of reusable glass microfluidic devices to contain one spheroid in a microwell under continuous perfusion culture. Spheroids derived from established cancer cell lines were perfused with complete media at a flow rate relevant to tumor interstitial fluid flow. Spheroid viability and migratory/invasive capabilities were maintained on-chip when compared to off-chip static conditions. Importantly, using flow conditions modeled in vitro, we are the first to report flow-induced secretion of pro-metastatic factors, in this case cytokines vascular endothelial growth factor and interleukin 6. In summary, we have developed a new, streamlined spheroid-on-chip in vitro model that represents a feasible in vitro alternative to conventional murine in vivo metastasis assays, including complex tumor environmental factors, such as interstitial fluid flow, extracellular matrices, and using 3D models to model nutrient and oxygen gradients. Our device, therefore, constitutes a robust alternative to in vivo early-metastasis models for determination of novel metastasis biomarkers as well as evaluation of therapeutically relevant molecular targets not possible in in vivo murine models.
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Affiliation(s)
- Thomas Collins
- Hypoxia and Tumour Microenvironment Lab, Department of Biomedical Sciences, University of Hull, Cottingham Road, Hull HU6 7RX, United Kingdom
| | - Emily Pyne
- Hypoxia and Tumour Microenvironment Lab, Department of Biomedical Sciences, University of Hull, Cottingham Road, Hull HU6 7RX, United Kingdom
| | - Martin Christensen
- Lab-on-a-Chip Research Group, Department of Chemistry and Biochemistry, University of Hull, Cottingham Road, Hull HU6 7RX, United Kingdom
| | - Alexander Iles
- Lab-on-a-Chip Research Group, Department of Chemistry and Biochemistry, University of Hull, Cottingham Road, Hull HU6 7RX, United Kingdom
| | - Nicole Pamme
- Lab-on-a-Chip Research Group, Department of Chemistry and Biochemistry, University of Hull, Cottingham Road, Hull HU6 7RX, United Kingdom
- Authors to whom correspondence should be addressed: and
| | - Isabel M. Pires
- Hypoxia and Tumour Microenvironment Lab, Department of Biomedical Sciences, University of Hull, Cottingham Road, Hull HU6 7RX, United Kingdom
- Authors to whom correspondence should be addressed: and
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12
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Rodriguez-Mateos P, Ngamsom B, Dyer CE, Iles A, Pamme N. Inertial focusing of microparticles, bacteria, and blood in serpentine glass channels. Electrophoresis 2021; 42:2246-2255. [PMID: 34031893 DOI: 10.1002/elps.202100083] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 05/11/2021] [Accepted: 05/18/2021] [Indexed: 11/08/2022]
Abstract
Early detection of pathogenic microorganisms is pivotal to diagnosis and prevention of health and safety crises. Standard methods for pathogen detection often rely on lengthy culturing procedures, confirmed by biochemical assays, leading to >24 h for a diagnosis. The main challenge for pathogen detection is their low concentration within complex matrices. Detection of blood-borne pathogens via techniques such as PCR requires an initial positive blood culture and removal of inhibitory blood components, reducing its potential as a diagnostic tool. Among different label-free microfluidic techniques, inertial focusing on microscale channels holds great promise for automation, parallelization, and passive continuous separation of particles and cells. This work presents inertial microfluidic manipulation of small particles and cells (1-10 μm) in curved serpentine glass channels etched at different depths (deep and shallow designs) that can be exploited for (1) bacteria preconcentration from biological samples and (2) bacteria-blood cell separation. In our shallow device, the ability to focus Escherichia coli into the channel side streams with high recovery (89% at 2.2× preconcentration factor) could be applied for bacteria preconcentration in urine for diagnosis of urinary tract infections. Relying on differential equilibrium positions of red blood cells and E. coli inside the deep device, 97% red blood cells were depleted from 1:50 diluted blood with 54% E. coli recovered at a throughput of 0.7 mL/min. Parallelization of such devices could process relevant volumes of 7 mL whole blood in 10 min, allowing faster sample preparation for downstream molecular diagnostics of bacteria present in bloodstream.
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Affiliation(s)
| | - Bongkot Ngamsom
- Department of Chemistry and Biochemistry, University of Hull, Hull, UK
| | | | - Alexander Iles
- Department of Chemistry and Biochemistry, University of Hull, Hull, UK
| | - Nicole Pamme
- Department of Chemistry and Biochemistry, University of Hull, Hull, UK
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13
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Garg M, Christensen MG, Iles A, Sharma AL, Singh S, Pamme N. Microfluidic-Based Electrochemical Immunosensing of Ferritin. Biosensors (Basel) 2020; 10:bios10080091. [PMID: 32764518 PMCID: PMC7460419 DOI: 10.3390/bios10080091] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 08/01/2020] [Accepted: 08/02/2020] [Indexed: 02/01/2023]
Abstract
Ferritin is a clinically important biomarker which reflects the state of iron in the body and is directly involved with anemia. Current methods available for ferritin estimation are generally not portable or they do not provide a fast response. To combat these issues, an attempt was made for lab-on-a-chip-based electrochemical detection of ferritin, developed with an integrated electrochemically active screen-printed electrode (SPE), combining nanotechnology, microfluidics, and electrochemistry. The SPE surface was modified with amine-functionalized graphene oxide to facilitate the binding of ferritin antibodies on the electrode surface. The functionalized SPE was embedded in the microfluidic flow cell with a simple magnetic clamping mechanism to allow continuous electrochemical detection of ferritin. Ferritin detection was accomplished via cyclic voltammetry with a dynamic linear range from 7.81 to 500 ng·mL−1 and an LOD of 0.413 ng·mL−1. The sensor performance was verified with spiked human serum samples. Furthermore, the sensor was validated by comparing its response with the response of the conventional ELISA method. The current method of microfluidic flow cell-based electrochemical ferritin detection demonstrated promising sensitivity and selectivity. This confirmed the plausibility of using the reported technique in point-of-care testing applications at a much faster rate than conventional techniques.
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Affiliation(s)
- Mayank Garg
- CSIR-Central Scientific Instruments Organisation, Sector 30-C, Chandigarh 160030, India; (M.G.); (A.L.S.)
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
- Department of Chemistry and Biochemistry, University of Hull, Cottingham Road, Hull HU6 7RX, UK; (M.G.C.); (A.I.)
| | - Martin Gedsted Christensen
- Department of Chemistry and Biochemistry, University of Hull, Cottingham Road, Hull HU6 7RX, UK; (M.G.C.); (A.I.)
| | - Alexander Iles
- Department of Chemistry and Biochemistry, University of Hull, Cottingham Road, Hull HU6 7RX, UK; (M.G.C.); (A.I.)
| | - Amit L. Sharma
- CSIR-Central Scientific Instruments Organisation, Sector 30-C, Chandigarh 160030, India; (M.G.); (A.L.S.)
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Suman Singh
- CSIR-Central Scientific Instruments Organisation, Sector 30-C, Chandigarh 160030, India; (M.G.); (A.L.S.)
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
- Correspondence: (S.S.); (N.P.)
| | - Nicole Pamme
- Department of Chemistry and Biochemistry, University of Hull, Cottingham Road, Hull HU6 7RX, UK; (M.G.C.); (A.I.)
- Correspondence: (S.S.); (N.P.)
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Ngamsom B, Wandera EA, Iles A, Kimani R, Muregi F, Gitaka J, Pamme N. Rapid detection of Group B Streptococcus (GBS) from artificial urine samples based on IFAST and ATP bioluminescence assay: from development to practical challenges during protocol testing in Kenya. Analyst 2020; 144:6889-6897. [PMID: 31621696 DOI: 10.1039/c9an01808e] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report the rapid detection (20 min) of Streptococcus agalactiae, Group B Streptococcus (GBS) employing on-chip magnetic isolation of GBS based on immiscible filtration assisted by surface tension (IFAST), followed by detection of the isolated GBS using an adenosine triphosphate (ATP) bioluminescence assay. Up to 80% GBS cells were isolated from spiked artificial urine samples with linear responses of bioluminescence signals from isolated cells at 2.3 × 102-9.1 × 105 CFU mL-1, demonstrating great promise for point-of-care detection of pathogenic bacteria in screening urine samples from pregnant women. Practical challenges during initial testing of the developed protocol with urine samples in Kenya are also described.
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Affiliation(s)
- Bongkot Ngamsom
- Department of Chemistry and Biochemistry, Faculty of Science and Engineering. University of Hull, Hull, HU6 7RX, UK.
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15
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Gómez-Pastora J, González-Fernández C, Real E, Iles A, Bringas E, Furlani EP, Ortiz I. Computational modeling and fluorescence microscopy characterization of a two-phase magnetophoretic microsystem for continuous-flow blood detoxification. Lab Chip 2018; 18:1593-1606. [PMID: 29748668 DOI: 10.1039/c8lc00396c] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Magnetic beads can be functionalized to capture and separate target pathogens from blood for extracorporeal detoxification. The beads can be magnetically separated from a blood stream and collected into a coflowing buffer solution using a two-phase liquid-liquid continuous-flow microfluidic device in the presence of an external field. However, device design and process optimization, i.e. high bead recovery with minimum blood loss or dilution remain a substantial technological challenge. We introduce a CFD-based Eulerian-Lagrangian computational model that enables the rational design and optimization of such systems. The model takes into account dominant magnetic and hydrodynamic forces on the beads as well as coupled bead-fluid interactions. Fluid flow (Navier-Stokes equations) and mass transfer (Fick's law) between the coflowing fluids are solved numerically, while the magnetic force on the beads is predicted using analytical methods. The model is demonstrated via application to a prototype device and used to predict key performance metrics; degree of bead separation, flow patterns, and mass transfer, i.e. blood diffusion to the buffer phase. The impact of different process variables and parameters - flow rates, bead and magnet dimensions and fluid viscosities - on both bead recovery and blood loss or dilution is quantified for the first time. The performance of the prototype device is characterized using fluorescence microscopy and the experimental results are found to match theoretical predictions within an absolute error of 15%. While the model is demonstrated here for analysis of a detoxification device, it can be readily adapted to a broad range of magnetically-enabled microfluidic applications, e.g. bioseparation, sorting and sensing.
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Affiliation(s)
- Jenifer Gómez-Pastora
- Department of Chemical and Biomolecular Engineering, University of Cantabria, Av. de los Castros s/n, 39005, Santander, Cantabria, Spain.
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Scheuble N, Iles A, Wootton RCR, Windhab EJ, Fischer P, Elvira KS. Microfluidic Technique for the Simultaneous Quantification of Emulsion Instabilities and Lipid Digestion Kinetics. Anal Chem 2017; 89:9116-9123. [DOI: 10.1021/acs.analchem.7b01853] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Nathalie Scheuble
- Institute
of Food, Nutrition and Health, ETH Zurich, Zurich 8092, Switzerland
| | - Alexander Iles
- Department
of Chemistry, University of Hull, Hull HU6 7RX, United Kingdom
| | - Robert C. R. Wootton
- Department
of Science and Technology, University of Suffolk, Ipswich IP4 1QJ, United Kingdom
| | - Erich J. Windhab
- Institute
of Food, Nutrition and Health, ETH Zurich, Zurich 8092, Switzerland
| | - Peter Fischer
- Institute
of Food, Nutrition and Health, ETH Zurich, Zurich 8092, Switzerland
| | - Katherine S. Elvira
- Department
of Chemistry, University of Victoria, Victoria, British Columbia V8W 2Y2, Canada
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17
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Ngamsom B, Truyts A, Fourie L, Kumar S, Tarn MD, Iles A, Moodley K, Land KJ, Pamme N. A Microfluidic Device for Rapid Screening of E. coli O157:H7 Based on IFAST and ATP Bioluminescence Assay for Water Analysis. Chemistry 2017; 23:12754-12757. [PMID: 28753730 DOI: 10.1002/chem.201703487] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Indexed: 11/08/2022]
Abstract
We present a simple microfluidic system for rapid screening of Escherichia coli (E. coli) O157:H7 employing the specificity of immunomagnetic separation (IMS) via immiscible filtration assisted by surface tension (IFAST), and the sensitivity of the subsequent adenosine triphosphate (ATP) assay by the bioluminescence luciferin/luciferase reaction. The developed device was capable of detecting E. coli O157:H7 from just 6 colony forming units (CFU) in 1 mL spiked buffer within 20 min. When tested with wastewater discharged effluent samples, without pre-concentration, the device demonstrated the ability to detect 104 CFU per mL seeded; suggesting great potential for point-of-need microbiological water quality monitoring.
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Affiliation(s)
- Bongkot Ngamsom
- School of Mathematics and Physical Sciences, The University of Hull, Cottingham Road, Hull, HU6 7RX, United Kingdom
| | - Alma Truyts
- Council for Scientific and Industrial Research (CSIR), Meiring Naude Road, Pretoria, 0184, South Africa
| | - Louis Fourie
- Council for Scientific and Industrial Research (CSIR), Meiring Naude Road, Pretoria, 0184, South Africa
| | - Shavon Kumar
- Council for Scientific and Industrial Research (CSIR), Meiring Naude Road, Pretoria, 0184, South Africa
| | - Mark D Tarn
- School of Mathematics and Physical Sciences, The University of Hull, Cottingham Road, Hull, HU6 7RX, United Kingdom
| | - Alexander Iles
- School of Mathematics and Physical Sciences, The University of Hull, Cottingham Road, Hull, HU6 7RX, United Kingdom
| | - Klariska Moodley
- Council for Scientific and Industrial Research (CSIR), Meiring Naude Road, Pretoria, 0184, South Africa
| | - Kevin J Land
- Council for Scientific and Industrial Research (CSIR), Meiring Naude Road, Pretoria, 0184, South Africa
| | - Nicole Pamme
- School of Mathematics and Physical Sciences, The University of Hull, Cottingham Road, Hull, HU6 7RX, United Kingdom
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18
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Iles A, Bessaid A. Quality of SENSE and GRAPPA Reconstructions in Parallel Imaging. J Med Imaging Hlth Inform 2013. [DOI: 10.1166/jmihi.2013.1187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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19
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Robert D, Pamme N, Conjeaud H, Gazeau F, Iles A, Wilhelm C. Cell sorting by endocytotic capacity in a microfluidic magnetophoresis device. Lab Chip 2011; 11:1902-10. [PMID: 21512692 DOI: 10.1039/c0lc00656d] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Magnetically labelled cells are finding a wealth of applications for in vitro analysis as well as in vivo treatments. Sorting of cells into subpopulations based on their magnetite loading is an important step in such procedures. Here, we study the sorting of monocytes and macrophages which internalise nanoparticles to different extents based on their endocytotic capacity. Macrophages featured a high endocytotic activity and were found to internalise between 4 and 60 pg of iron per cell. They were successfully sorted into five subpopulations of narrow iron loading distributions via on-chip free-flow magnetophoresis, thus demonstrating the potential of sorting of relatively similarly loaded cells. Monocytes featured a low endocytotic capacity and took on 1 to 4 pg of iron per cell. Mixtures of monocytes and macrophages were successfully sorted within the free-flow magnetophoresis chip and good purity (>88%), efficacy (>60%) and throughput (from 10 to 100 cells s(-1)) could be achieved. The introduced method constitutes a viable tool for studies of endocytotic capacity and sorting/selection of cells based on this functionality.
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Affiliation(s)
- Damien Robert
- Laboratoire Matière et Systèmes Complexes, UMR CNRS et Université Paris Diderot, France
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20
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Peyman SA, Kwan EY, Margarson O, Iles A, Pamme N. Diamagnetic repulsion—A versatile tool for label-free particle handling in microfluidic devices. J Chromatogr A 2009; 1216:9055-62. [DOI: 10.1016/j.chroma.2009.06.039] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2009] [Revised: 06/04/2009] [Accepted: 06/12/2009] [Indexed: 11/24/2022]
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21
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Abstract
An extremely versatile microfluidic device is demonstrated in which multi-step (bio)chemical procedures can be performed in continuous flow. The system operates by generating several co-laminar flow streams, which contain reagents for specific (bio)reactions across a rectangular reaction chamber. Functionalized magnetic microparticles are employed as mobile solid-supports and are pulled from one side of the reaction chamber to the other by use of an external magnetic field. As the particles traverse the co-laminar reagent streams, binding and washing steps are performed on their surface in one operation in continuous flow. The applicability of the platform was first demonstrated by performing a proof-of-principle binding assay between streptavidin coated magnetic particles and biotin in free solution with a limit of detection of 20 ng mL(-1) of free biotin. The system was then applied to a mouse IgG sandwich immunoassay as a first example of a process involving two binding steps and two washing steps, all performed within 60 s, a fraction of the time required for conventional testing.
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Affiliation(s)
- Sally A Peyman
- Department of Chemistry, University of Hull, Cottingham Road, Hull HU67RX, United Kingdom
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Tarn MD, Hirota N, Iles A, Pamme N. On-chip diamagnetic repulsion in continuous flow. Sci Technol Adv Mater 2009; 10:014611. [PMID: 27877262 PMCID: PMC5109609 DOI: 10.1088/1468-6996/10/1/014611] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2008] [Revised: 05/22/2009] [Accepted: 01/13/2009] [Indexed: 05/20/2023]
Abstract
We explore the potential of a microfluidic continuous flow particle separation system based on the repulsion of diamagnetic materials from a high magnetic field. Diamagnetic polystyrene particles in paramagnetic manganese (II) chloride solution were pumped into a microfluidic chamber and their deflection behaviour in a high magnetic field applied by a superconducting magnet was investigated. Two particle sizes (5 and 10 μm) were examined in two concentrations of MnCl2 (6 and 10%). The larger particles were repelled to a greater extent than the smaller ones, and the effect was greatly enhanced when the particles were suspended in a higher concentration of MnCl2. These findings indicate that the system could be viable for the separation of materials of differing size and/or diamagnetic susceptibility, and as such could be suitable for the separation and sorting of small biological species for subsequent studies.
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Affiliation(s)
- Mark D Tarn
- Department of Chemistry, The University of Hull, Cottingham Road, Hull HU6 7RX, UK
| | - Noriyuki Hirota
- Nano Ceramics Center, National Institute for Materials Science, Tsukuba 305-0047, Japan
| | - Alexander Iles
- Department of Chemistry, The University of Hull, Cottingham Road, Hull HU6 7RX, UK
| | - Nicole Pamme
- Department of Chemistry, The University of Hull, Cottingham Road, Hull HU6 7RX, UK
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Peyman SA, Iles A, Pamme N. Rapid on-chip multi-step (bio)chemical procedures in continuous flow – manoeuvring particles through co-laminar reagent streams. Chem Commun (Camb) 2008:1220-2. [DOI: 10.1039/b716532c] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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McKenzie A, Briggs G, Buchanan R, Harvey L, Iles A, Kirby M, Mayles P, Thomas S, Williams M. 48 Cost-benefit analysis of quality control in UK. Radiother Oncol 2005. [DOI: 10.1016/s0167-8140(05)81026-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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27
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Iles A, Fortt R, de Mello AJ. Thermal optimisation of the Reimer-Tiemann reaction using thermochromic liquid crystals on a microfluidic reactor. Lab Chip 2005; 5:540-4. [PMID: 15856092 DOI: 10.1039/b419081e] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Microreactors incorporating thin film resistive heating elements for continuous flow organic synthesis are presented. Internal thermal conditions were monitored in real time using reflectance spectra of temperature sensitive thermochromic liquid crystals (TLC) in a collateral microfluidic network. To demonstrate the precise temperature control provided by this method, the thermal optimisation of the Reimer-Tiemann formylation of beta-naphthol was performed under hydrodynamic pumping regimes.
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Affiliation(s)
- Alexander Iles
- National Institute for Materials Science, International Centre for Young Scientists, Tsukuba, Ibaraki 305-0044, Japan
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Fugetsu B, Satoh S, Iles A, Tanaka K, Nishi N, Watari F. Encapsulation of multi-walled carbon nanotubes (MWCNTs) in Ba2+-alginate to form coated micro-beads and their application to the pre-concentration/elimination of dibenzo-p-dioxin, dibenzofuran, and biphenyl from contaminated water. Analyst 2004; 129:565-6. [PMID: 15213818 DOI: 10.1039/b405325g] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report preliminary data on the first use of multi-walled carbon nanotubes as adsorbents for the pre-concentration/elimination of dibenzo-p-dioxin, dibenzofuran and biphenyl from contaminated water.
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Affiliation(s)
- Bunshi Fugetsu
- Graduate School of Environmental Earth Science, Hokkaido University, Sapporo 060-0810, Japan
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Iles A. Whistleblowing twice as common as in 1998. West J Med 2003. [DOI: 10.1136/bmj.327.7420.890-c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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31
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Iles A. Forty per cent of carers have illness or disability. West J Med 2003. [DOI: 10.1136/bmj.327.7419.832-j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Iles A. Giving patients choice puts more pressure on GPs, survey shows. West J Med 2003. [DOI: 10.1136/bmj.327.7414.522-a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Takasu T, Iles A, Hasebe K. Determination of alkylphenols and alkylphenol polyethoxylates by reversed-phase high-performance liquid chromatography and solid-phase extraction. Anal Bioanal Chem 2002; 372:554-61. [PMID: 11939631 DOI: 10.1007/s00216-001-1135-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2001] [Revised: 08/30/2001] [Accepted: 09/08/2001] [Indexed: 11/27/2022]
Abstract
A simple, accurate and reproducible reversed-phase high-performance liquid chromatography (HPLC) method was developed for the separation and characterisation of alkylphenols (APs) and alkylphenol polyethoxylates (APEOs), using a C18 octadecyl silica (ODS) column. APs and each APEO oligomer were separated successfully within a reasonable time without gradient elution. An excellent resolution was obtained, even for mixtures of APs and low EO number APEOs, which are otherwise difficult to separate using conventional normal-phase HPLC methods. This method, combined with solid-phase extraction, was highly applicable for the simultaneous determination of alkylphenols and alkylphenol ethoxylates in real samples.
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Affiliation(s)
- Takuma Takasu
- Division of Material Science, Graduate School of Environmental Earth Science, Hokkaido University, Sapporo, Japan.
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Abstract
A unified ion chromatographic (IC) system was developed for the determination of acidity or alkalinity. Separation column used was a reversed-phase ODS packed column, which had been modified by saturating it with lithium dodecylsulfate. A slightly acidified LiCl (50 mM LiCl and 0.05 mM H2SO4) aqueous solution was used as the eluent. By conditioning the separation column in this way, both H+ and Li+ ions became bound to the stationary phase. Dodecylsulfate groups with Li+ counterions acted as cation-exchange sites for the separation of hydrogen ions (free acidity determination). The remaining dodecylsulfate groups, with H+ counterions acted as a titrant, which reacted with basic species (total alkalinity determination). The acidity or alkalinity of each sample was measured according to the change in conductance from the eluent baseline level. A positive peak was observed from those samples with a free acidity greater than their total alkalinity, due to the separation/elution of free H+ ions. A negative peak was observed from those samples with a free acidity less than their total alkalinity. This was due to an equivalent amount of eluent H+ ions being re-supplied to the stationary phase while the "solid titrant" consumed by the acid-base reaction was regenerated. The retention time for the peak corresponding to the acidity or alkalinity was governed by the retention time for H+ ions in this IC system. Samples with a free acidity greater than 2.25 microM (tested by determination of H+ ions in pure water in equilibrium with atmospheric CO2) could be analyzed by this method. A very similar detection level was obtained for alkalinity (tested by analyzing standard aqueous NaHCO3 solutions). Aqueous solutions of some strong-acid/strong-base inorganic salts were found to be slightly alkaline. This was measured as a percentage, relative to an NaHCO3 solution at the same concentration. Solutions of NaClO4, Na2SO4, NaI, NaNO3, and NaCl, gave comparative alkalinity values of 8.75%, 1.83%, 0.42%, 0.35%, and 0.33%, respectively.
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Affiliation(s)
- W Hu
- Division of Chemistry, Graduate School of Science, Hokkaido University, Sapporo, Japan.
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Hu W, Hasebe K, Iles A, Tanaka K. High-resolution determination of H+ by ion chromatography. Application to the simultaneous determination of H+, Na+, NH4+ and K+ in acid rain. Analyst 2001; 126:821-4. [PMID: 11445944 DOI: 10.1039/b102292j] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An ion chromatographic (IC) method was developed for the high-resolution determination of a sample's free hydrogen ion concentration (H+). Highly purified lithium dodecyl sulfate was used as the stationary phase, a slightly acidified aqueous LiCl solution was used as the mobile phase and conductivity was used for analyte detection. An electrical double layer (EDL) containing H+ was established on the stationary phase by using a slightly acidified electrolyte solution as the eluent. H+ in the EDL protonated any weak acid groups (i.e., silanols) on the stationary phase so that H+ from the sample could be retained/separated purely by dodecyl sulfate. The optimum molar ratio of H+:Li+ in the EDL for this IC system was obtained by using an aqueous solution containing 40.0 mM LiCl and 0.07 mM H2SO4 as the eluent. After separation, H+ was detected by direct conductimetric measurement. An H+ detection limit of better than 8.2 x 10(-6) M was obtained from the analysis of standard aqueous H2SO4 solutions. Other monovalent cations could also be separated with this method, giving detection limits of 7.4 x 10(-5), 4.3 x 10(-5) and 4.2 x 10(-5) M for Na+, NH4+ and K+, respectively. The method was applied to the simultaneous determination of H+, Na+, NH4+ and K+ in acid rain. The results obtained showed a significant improvement in reproducibility when compared with those from a conventional pH-meter. Acid rain samples with a pH < 5 could be analyzed with this IC system.
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Affiliation(s)
- W Hu
- Division of Chemistry, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan.
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Hu W, Matsukami H, Iles A, Hasebe K, Cao S, Tanaka K. Use of zwitterionic micelles in the eluent II: a new approach to ion chromatographic analysis of inorganic cations in biological fluids with direct sample injection. Fresenius J Anal Chem 2001; 370:426-8. [PMID: 11495068 DOI: 10.1007/s002160100781] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
A new ion chromatographic (IC) technique has been developed for the determination of inorganic cations in biological fluids with direct sample injection. This involved the use of a mixed zwitterionic-micelle/electrolyte solution as an eluent. The proteins in the sample became bound to the zwitterionic micelles in the eluent and were thus eliminated from the column. The cations were separated by cation exchange. This method is ideal for the online, simultaneous determination of common inorganic cations (Na+, NH4+, K+, Mg2+, and Ca2+) in urine and serum samples. Such an application was demonstrated experimentally. Non-suppressed conductivity was used for analyte detection. The detection limits obtained using this IC system were 2.94, 5.22, 34.9, 32.6, and 56.7 microg/L for Na+, NH4+, K+, Mg2+, and Ca2+, respectively.
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Affiliation(s)
- W Hu
- Division of Chemistry, Graduate School of Science, Hokkaido University, Sapporo, Japan.
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Hu W, Iles A, Hasebe K, Matsukami H, Cao S, Tanaka K. Determination of hydrogen ion by ion chromatography (IC) with sulfonated cation-exchange resin as the stationary phase and aqueous EDTA (ethylenediamine-N,N,N',N'-tetraacetic acid) solution as the mobile phase. Fresenius J Anal Chem 2001; 370:48-51. [PMID: 11393236 DOI: 10.1007/s002160100774] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
An ion chromatographic (IC) method has been developed for determination of hydrogen ion (H+). It is based on the use of sulfonated cation-exchange resin as stationary phase, aqueous ethylenediamine-N,N,N',N'-tetraacetic acid (dipotassium salt, EDTA-2K, written as K2H2Y) solution as mobile phase, and conductivity for detection. H+ was separated mainly by cation-exchange, but its elution was accelerated by the presence of EDTA. The order of elution for the model cations was H+ > Li+ > Na+ > NH4+ > Ca2+ > > Mg2+. A sharp and highly symmetrical peak was obtained for H+ and this was attributed to the capacity of H2Y2(2-) to receive and bind H+. H+ was detected conductiometrically and detector response (reduction in conductivity as a result of H+ +H2Y2- --> H3Y-) was linearly proportional to the concentration of H+ in the sample. The detection limit for H+ with this IC system was better than 4.7 micromol L(-1). A significant advantage of this method was the ability to separate and determine, in one step, H+ and other cations. The successful determination of H+ and other cation species in real acid-rain samples demonstrated the usefulness of this method.
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Affiliation(s)
- W Hu
- Division of Chemistry, Graduate School of Science, Hokkaido University, Sapporo, Japan.
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Abstract
ALCOHOL-BASED CLEANSING SOLUTIONS STERILE GLOVES PROVIDE WOUND MEASURING GRID JOURNAL POLICY.
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Affiliation(s)
- L Ward
- Senior nurse, infection control Department of Infectious Diseases and Bacteriology Hammersmith Hospital London
| | - A Iles
- Senior pharmacy technician Gloucestershire Royal Hospital Gloucester
| | - M R Bliss
- Consultant physician in medicine for the elderly Directorate of Medicine for the Elderly Homerton Hospital London £9
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Abstract
High-affinity uptake systems for amino acid neurotransmitter precursors have been highly correlated with the use of the particular amino acid or its derivative as a transmitter. We have found interneurons in the Xenopus embryo spinal cord which accumulate GABA by a high-affinity uptake system. They originate near the end of gastrulation and their ability to accumulate GABA first appears at the early tail bud stage. By position and appearance they are comparable to some of the embryonic interneurons described by A. Roberts and J. D. W. Clarke (1982, Phil. Trans. R. Soc. London Ser. B 296, 195-212). GABA-accumulating neurons also develop in dissociated cell cultures made from the presumptive spinal cord of neural plate stage Xenopus embryos. GABA accumulation in cultured neurons, as in cells in vivo, occurs via a high-affinity uptake system; GABA-accumulating cells have the same time of origin as the cells in vivo, and the ability to accumulate GABA in the population of cultured neurons appears at a time equivalent to that observed in intact sibling embryos. Thus it seems likely that the population of GABA-accumulating neurons developing in cell culture corresponds to the GABA-accumulating interneurons in vivo. The development of these neurons in dissociated cell cultures permits perturbation experiments that would be difficult to perform in vivo. We have examined the development of high-affinity GABA uptake in conditions that permit no electrical impulse activity in the cultures. The onset and extent of development of GABA accumulation in the neuronal population are normal under these conditions.
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