Colin J Campbell

Colin J Campbell
The University of Edinburgh | UoE · School of Chemistry

About

120
Publications
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2,494
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Publications

Publications (120)
Article
Full-text available
Significant improvements in time-correlated single photon counting (TCSPC) Raman spectroscopy acquisition times can be achieved through exploitation of megahertz (MHz) laser repetition rates. We have developed a TCSPC Raman spectroscopy system based on a high peak power (>40W) pulsed laser, a high pulse repetition rate (40 MHz), a custom f/1.5 spec...
Article
Carvalho et al.(1) raise two issues related to our manuscript.(2) The first addresses our finding that removing blood can reduce liver injury. With an increased utilisation of DCD livers and variable procurement protocols, we sought to investigate whether blood removal prior to the start of normothermic regional perfusion has any effect on liver fu...
Article
Full-text available
Background and aims: Liver graft quality is evaluated by visual inspection prior to transplantation, a process highly dependent on surgeon's experience. We present an objective, non-invasive, quantitative way of assessing liver quality in real time using Raman spectroscopy, a laser-based tool for analysing biomolecular composition. Approach and r...
Article
Hypoxia is a ubiquitous feature of cancers, encouraging glycolytic metabolism, proliferation, and resistance to therapy. Nonetheless, hypoxia is a poorly defined term with confounding features described in the literature. Redox biology provides an important link between the external cellular microenvironment and the cell’s response to changing oxyg...
Article
Full-text available
Background: Defective macrophage phagolysosomal acidification is implicated in numerous lung diseases including Cystic Fibrosis (CF) and may contribute to defective pathogen killing. Conflicting reports relating to phagolysosomal pH in CF macrophages have been published, in part related to the use of pH-sensitive fluorescent probes where potential...
Article
Multicellular tumor spheroids (MTS) are a well-established model system for drug development and are a valuable in vitro research tool for use prior to employing animal models. These 3D-cell cultures are thought to display chemical gradients of oxygen and nutrients throughout their structure, giving rise to distinct microenvironments in radial laye...
Article
Full-text available
The alveolar space forms the distal end of the respiratory tract where chemoreceptor driven gas exchange processes occur. In healthy humans, the physiological state within the alveoli is tightly regulated by normal homeostatic mechanisms. However, pulmonary abnormalities such as chronic obstructive pulmonary disease may induce significant perturbat...
Article
The exploitation of fibre based Raman probes has been challenged by often complicated fabrication procedures and difficulties in reproducibility. Here, we have demonstrated a simple and cost-effective approach for sensing pH through an optical fibre, by employing a wax patterned filter paper-based substrate for surface enhanced Raman spectroscopy (...
Article
Full-text available
Measuring Raman spectra through an optical fibre is usually complicated by the high intrinsic Raman scatter of the fibre material. Common solutions such as the use of multiple fibres and distal optics are complex and bulky. We demonstrate the use of single novel hollow core negative curvature fibres (NCFs) for Raman and surface enhanced Raman spect...
Article
There has been increasing use of in vitro cell culture models that more realistically replicate the three dimensional (3D) environment found in vivo. Multicellular tumour spheroids (MTS) using cell lines or patient‐derived organoids have become an important in vitro drug development tool, where cells are grown in a 3D ‘sphere’ that exhibits many of...
Article
Successful matrix-assisted laser desorption ionization (MALDI) mass spectrometry imaging (MSI) relies on the selection of the most appropriate matrix and optimization of the matrix application parameters. In order to achieve reproducible high spatial-resolution imaging data, several commercially available automated matrix application platforms have...
Conference Paper
We demonstrated hollow core negative curvature fibres (NCFs) for Raman sensing. The background Raman emission from the silica in the NCF was at least 1000× smaller than in a conventional solid fibre while maintaining the same collection efficiency.
Article
Full exploitation of fibre Raman probes has been limited by the obstruction of weak Raman signals by background fluorescence of the sample and the intrinsic Raman signal of the delivery fibre. Here we utilised functionalised gold nanoshells (NS) to take advantage of the surface-enhanced Raman spectroscopy (SERS) effect to enhance the pH responsive...
Article
The development of engineered nanomaterials is growing exponentially, despite concerns over their potential similarities to environmental nanoparticles that are associated with significant cardiorespiratory morbidity and mortality. The mechanisms through which inhalation of nanoparticles could trigger acute cardiovascular events are emerging, but a...
Article
Full-text available
The field of regenerative medicine spans a wide area of the biomedical landscape—from single cell culture in laboratories to human whole-organ transplantation. To ensure that research is transferrable from bench to bedside, it is critical that we are able to assess regenerative processes in cells, tissues, organs and patients at a biochemical level...
Article
Previously unobtainable measurements of alveolar pH were obtained using an endoscope-deployable optrode. The pH sensing was achieved using functionalized gold nanoshell sensors and surface enhanced Raman spectroscopy (SERS). The optrode consisted of an asymmetric dual-core optical fiber designed for spatially separating the optical pump delivery an...
Article
Full-text available
Multicellular tumour spheroids (MTS) are three-dimensional cell cultures that possess their own microenvironments and provide a more meaningful model of tumour biology than monolayer cultures. As a result, MTS are becoming increasingly used as tumor models when measuring the efficiency of therapies. Monitoring the viability of live MTS is complicat...
Article
Use of multicellular tumor spheroids (MTS) to investigate therapies has gained impetus because they have potential to mimic factors including zonation, hypoxia and drug-resistance. However, analysis remains difficult and often destroys 3D integrity. Here we report an optical technique using targeted nanosensors that allows in situ 3D mapping of red...
Article
Multicellular tumour spheroids (MTS) are three-dimensional cell cultures that possess their own microenvironments and provide a more meaningful model of tumour biology than monolayer cultures. As a result, MTS are becoming increasingly used as tumor models when measuring the efficiency of therapies. Monitoring the viability of live MTS is complicat...
Article
Full-text available
Duncan Graham opened a general discussion of the paper by Pavel Matousek: Regarding the temperature measurements, how did you do them? Stokes/anti-Stokes measurement? The values are not what I'd expect and seem lower. What was the wavelength and power of the laser and did you calculate what you thought the temperature measurement should be based on...
Article
Full-text available
Parvez Haris opened the discussion of the introductory lecture by Max Diem: Varying degrees of accuracy have been obtained for discrimination between cancerous and non-cancerous tissues using vibrational spectroscopic methods. What are the explanations for these variation in accuracy between cancerous and non-cancerous tissues and how do they corre...
Article
Richard Dluhy opened a general discussion of the paper by Duncan Graham: In your example of a heterogeneous solution-based assay for multicomponent analysis, what is the concentration of the target fungal ssPCR DNA that is used, and how do you manage the kinetics of the reaction such that the target reaches the probe in a time frame appropriate for...
Conference Paper
Background: Clinical trials now underway will assess the use of flavonoids (natural polyphenols) as anticancer agents. Previous work has shown the promising antitumor activity of Oncamex (a novel myricetin-derived flavonoid with redox properties and mitochondrial targeting) on preclinical breast cancer models and suggested the role of reactive oxyg...
Article
Full-text available
Background: The natural polyphenol myricetin induces cell cycle arrest and apoptosis in preclinical cancer models. We hypothesised that myricetin-derived flavonoids with enhanced redox properties, improved cell uptake and mitochondrial targeting might have increased potential as antitumour agents. Methods: We studied the effect of a second-gener...
Article
Current approaches to molecular diagnostics rely heavily on PCR amplification and optical detection methods which have restrictions when applied to point of care (POC) applications. Herein we describe the development of a label-free and amplification-free method of pathogen detection applied to Escherichia coli which overcomes the bottleneck of com...
Article
Oxidation/reduction of thiol residues in proteins is an important type of post-translational modification that is implicated in regulating a range of biological processes. The nature of the modification makes it possible to define a quantifiable electrochemical potential (E(⊕)) for oxidation/reduction that allows cysteine-containing proteins to be...
Article
Measuring markers of stress such as pH and redox potential are important when studying toxicology in in vitro models because they are markers of oxidative stress, apoptosis and viability. While Surface Enhanced Raman Spectroscopy is ideally suited to the measurement of redox potential and pH in live cells, the time-intensive nature and perceived di...
Article
Inhaled combustion-derived nanoparticles are associated with cardiovascular disease, however, the pathways linking the pulmonary and cardiovascular effects remain to be established. • Here we use complimentary human and animal studies to investigate whether gold nanoparticles can translocate from the lung into the blood and accumulate at sites of v...
Article
Cellular redox potential is important for the control and regulation of a vast number of processes occurring in cells. When the fine redox potential balance within cells is disturbed it can have serious consequences such as the initiation or progression of disease. It is thought that a redox gradient develops in cancer tumours where the peripheral...
Article
Redox potential is of key importance in the control and regulation of cellular function and lifecycle, and previous approaches to measuring the biological redox potential noninvasively in real time are limited to areas of hypoxia or normoxia. In this paper, we extend our previous work on nanoparticle-based intracellular nanosensors to cover a much...
Article
Full-text available
Conventional two dimensional (2D) monolayer cell culture has been considered the ‘gold standard’ technique for in vitro cellular experiments. However, the need for a model that better mimics the three dimensional (3D) architecture of tissue in vivo has led to the development of Multicellular Tumour Spheroids (MTS) as a 3D tissue culture model. To s...
Article
Full-text available
Intracellular redox potential is a highly regulated cellular characteristic and is critically involved in maintaining cellular health and function. The dysregulation of redox potential can result in the initiation and progression of numerous diseases. Redox potential is determined by the balance of oxidants and reductants in the cell and also by pH...
Article
Full-text available
The intracellular pH plays an important role in various cellular processes. In this work, we describe a method for monitoring of the intracellular pH in endothelial cells by using surface enhanced Raman spectroscopy (SERS) and 4-mercaptobenzoic acid (MBA) anchored to gold nanoparticles as pH-sensitive probes. Using the Raman microimaging technique,...
Article
Full-text available
Cobalt(III) tetrahedral capsules have been prepared using an assembly-followed-by-oxidation protocol from a Cobalt(II) precursor and a readily derivatizable pyridyl-triazole ligand system. Experiments designed to probe the constitutional dynamics show that these architectures are in a non-equilibrium state. A preliminary investigation into the host...
Article
Full-text available
Hypoxia is considered to be a reductive disorder of cells that is caused either by a lack of oxygen or by the dysregulation of metabolic pathways and is thought to play a role in the pathology of diseases including stroke and cancer. One aspect of hypoxia that remains poorly investigated is the dysregulation of cellular redox potential and its role...
Article
The measurement of intracellular analytes has been key in understanding cellular processes and function, and the use of biological nanosensors has revealed the spatial and temporal variation in their concentrations. In particular, ratiometric nanosensors allow quantitative measurements of analyte concentrations. The present review focuses on the re...
Patent
The present invention relates to methods of detecting specific cell surface antigens present in a sample of cells being tested and in particular blood group antigens, which methods do not employ the addition of extrinsic labels to detect said cell surface antigens. Typically detection is carried out using an intrinsic fluorescence capability of the...
Chapter
Raman spectroscopy is an increasingly exploited tool for the study of cell biology, and the focus of this chapter is surface-enhanced Raman spectroscopy (SERS). Using SERS, noble metal nanoparticles can be interrogated with wavelengths of light to which cells exhibit minimal autofluorescence and return useful information about their immediate chemi...
Article
Full-text available
An MRSA assay requiring neither labeling nor amplification of target DNA has been developed. Sequence specific binding of fragments of bacterial genomic DNA is detected at femtomolar concentrations using electrochemical impedance spectroscopy (EIS). This has been achieved using systematic optimisation of probe chemistry (PNA self-assembled monolaye...
Article
Abstract Two-dimensional graphitic carbon, graphene is a new form of nanomaterial with great potential in a wide variety of applications. It is therefore crucial to investigate the behavior of graphene in biological systems to assess potential adverse effects that might follow from inhalation exposure. In this study we focused on medium term effect...
Article
Electrodeposition of platinum metal from a chloride-based platinum electroplating bath at 35 °C onto high quality titanium nitride electrodes produced by standard microfabrication techniques has been demonstrated and characterised using electrochemical methods and scanning electron microscopy. When using a relatively simple two potential step elect...
Article
The mechanisms that enable viruses to harness cellular machinery for their own survival are primarily studied in cell lines cultured in two-dimensional (2-D) environments. However, there are increasing reports of biological differences between cells cultured in 2-D versus three-dimensional (3-D) environments. Here we report differences in host-viru...
Article
Full-text available
The role of cellular redox potential in the regulation of protein activity is becoming increasingly appreciated and characterized. In this paper we put forward a new hypothesis relating to redox regulation of cellular physiology. We have exemplified our hypothesis using apoptosis since its redox phenomenology is well established, but believe that i...
Article
Using electrochemical impedance spectroscopy (EIS) the sensitive and specific detection of the antibiotic resistance gene mecA has been demonstrated. The gene sequence was obtained from clinical Staphylococcus aureus isolates. Initially a mecA specific probe was selected from hybridisation tests with a 3' and 5' version of a previously published pr...
Chapter
There is a need in biomedical sciences for improved techniques for monitoring biomolecular interactions and physiological processes, especially those which can report in real time. New techniques may find use in (for example) live-cell imaging or in vitro diagnostics - one such technique is surface-enhanced Raman spectroscopy (SERS). While SERS has...
Article
Redox homeostasis and signaling are critically important in the regulation of cell function. There are significant challenges in quantitatively measuring intracellular redox potentials, and in this paper, we introduce a new approach. Our approach is based on the use of nanosensors which comprise molecules that sense the local redox potential, assem...
Article
Full-text available
A method for label-free, electrochemical impedance immunosensing for the detection and quantification of three infection biomarkers in both buffer and directly in the defined model matrix of mock wound fluid is demonstrated. Triggering Receptor-1 Expressed on Myeloid cells (TREM-1) and Matrix MetalloPeptidase 9 (MMP-9) are detected via direct assay...
Article
Hepatitis C virus (HCV) is a major cause of chronic liver disease and liver cancer, and remains a large health care burden to the world. In this study we developed a DNA microarray test to detect HCV RNA and a protein microarray to detect human anti-HCV antibodies on a single platform. A main focus of this study was to evaluate possibilities to red...
Article
We describe a novel surface enhanced Raman spectroscopy (SERS) sensing approach utilizing modified gold nanoshells and demonstrate its application to analysis of critical redox-potential dependent changes in antigen structure that are implicated in the initiation of a human autoimmune disease. In Goodpasture's disease, an autoimmune reaction is tho...