Helen Bridle

• Heriot-Watt University

Buffer exchange is a common process in manufacturing protocols for a wide range of bioprocessing applications, with a variety of technologies available to manipulate biological materials for culture medium exchange, cell washing and buffer removal. Microfluidics is an emerging field for buffer exchange and has shown promising results with both prot...

The manufacturing of clinical cellular therapies is a complex process frequently requiring manipulation of cells, exchange of buffers and volume reduction. Current manufacturing processes rely on either low throughput open centrifugation-based devices, or expensive closed-process alternatives. Inertial focusing (IF) microfluidic devices offer the p...

The aim of this study was to explore an alternative mode of operation for inertial focusing systems and determine the maximum inlet volume fractions at which device performance can be maintained (i.e. cell retention efficiency remains high, here defined as >95%). Microalgae dewatering was selected as a demonstrator application, specifically using C...

This chapter presents an overview of approaches to separations utilizing microfluidics, covering both passive and active methods. Hybrid techniques incorporating both passive and active methods are also covered. The chapter reviews both chemical separations and particle separations, briefly describing the different approaches and discussing advanta...

Spiral microchannels have shown promising results for separation applications. Hydrodynamic particle–particle interactions are a known factor strongly influencing focusing behaviors in inertial devices, with recent work highlighting how the performance of bidisperse mixtures is altered when compared with pure components in square channels. This phe...

Correction for ‘Deformability-induced lift force in spiral microchannels for cell separation’ by Ewa Guzniczak et al., Lab Chip, 2020, 20, 614–625.

Cell‐based therapeutics, such as in vitro manufactured red blood cells (mRBCs), are different to traditional biopharmaceutical products (the final product being the cells themselves as opposed to biological molecules such as proteins) and that presents a challenge of developing new robust and economically feasible manufacturing processes, especiall...

A microfluidic based system was developed for automated online method for the rapid detection and monitoring of drinking water contamination utilising microbial Adrenosine-5'-Triphosphate (ATP) as a bacterial indicator. The system comprises a polymethyl methacrylate based microfluidic cartridge inserted into an enclosure incorporating the functions...

Giardia duodenalis is a ubiquitous flagellated protozoan parasite known to cause giardiasis throughout the world. Potential transmission vehicles for this zoonotic parasite are both water and food sources. As such consumption of water contaminated by feces, or food sources washed in contaminated water containing parasite cysts, may result in outbre...

Interdisciplinarity is often quoted as a means to solve the complex social challenges faced by humanity, and the future of research is thus seen as increasingly interdisciplinary. However, there are risks and challenges to embarking on interdisciplinary research, particularly for early-career researchers. Encounters – bringing together early-career...

This article reviews existing clinical practices and sensor research undertaken to monitor fetal well-being during labour. Current clinical practices that include fetal heart rate monitoring and fetal scalp blood sampling are shown to be either inadequate or time-consuming. Monitoring of lactate in blood is identified as a potential alternative for...

Detection of waterborne pathogens, such as Cryptosporidium, is essential for ensuring drinking water safety. Biosensors are one emerging technology aiming to improve the existing time-consuming and expensive monitoring approach. Surface functionalisation is a key aspect of biosensor development and here we propose that lectins offer an excellent al...

Advances in cellular therapies have led to the development of new approaches for cell product purification and formulation, e.g., utilizing cell endogenous properties such as size and deformability as a basis for separation from potentially harmful undesirable by-products. However, commonly used additives such as Pluronic F-68 and other poloxamer m...

Continuous and reliable monitoring of water sources for human consumption is imperative for public health. For protozoa, which cannot be multiplied efficiently in laboratory settings, concentration and recovery steps are key to a successful detection procedure. Recently, the use of megasonic energy was demonstrated to recover Cryptosporidium from c...

Stem cell products, including manufactured red blood cells, require efficient sorting and purification methods to remove components potentially harmful for clinical application. However, standard approaches for cellular downstream processing rely on the use of specific and expensive labels (e.g. FACS or MACS). Techniques relying on inherent mechani...

Inertial focusing is a microfluidic based separation and concentration technology that has expanded rapidly in the last few years. Throughput is high compared to other microfluidic approaches although sample volumes have typically remained in the millilitre range. Here we present a strategy for achieving rapid high volume processing with stacked an...

This study evaluated five extracellular polymers of bacterial origin possessing mucoadhesive properties for their antimicrobial properties and toxicological characteristics. Of the five tested mucoadhesive biopolymers, the extracellular polymer produced by a strain of Acinetobacter haemolyticus exhibited broad antimicrobial efficacy towards Yersini...

Public engagement activities based on microfluidics are being increasingly delivered and reported on in the literature. Here, we evaluate the success of a novel approach to microfluidics outreach recently undertaken with schoolchildren aged 12–13. Unlike previous work, a problem-based learning approach was adopted whereby participants were asked to...

Aqueous micropollutants such as estradiol can have a large environmental impact-even at low concentrations. Part of understanding this impact involves determining the extent to which the micropollutants interact with macromolecules in water. In environmental samples, relevant macromolecules to which micropollutants bind are referred to as dissolved...

This paper reports on the first demonstration of polymeric microfluidic cantilever sensors. Microcantilever sensors, magnetic beads, and microfluidic technology has been combined to create a polymer based biosensor. Using cheap materials like polyimide, a simple fabrication method has been developed to produce cantilevers with an embedded microflui...

Microfluidics has shown rapid growth in both research and development and offers significant commercialisation potential for biomedical and diagnostic applications in particular. However, there is a lack of awareness of microfluidics outside the field of study, and few dedicated educational programmes are available. While many topics incorporate mi...

Optical micromanipulation techniques and microfluidic techniques can be used in same platform for manipulating biological samples at single cell level. Novel microfluidic devices with integrated channels and waveguides fabricated using ultrafast laser inscription combined with selective chemical etching can be used to enable sorting and isolation o...

We demonstrate that photonic lanterns based on tapered multicore fibres provide an efficient way to couple multimode states of light to a two-dimensional array of Single-Photon Avalanche Detectors (SPADs), each of which has its own Time-to-Digital Converter (TDC) for Time-Correlated Single-Photon-Counting (TCSPC). Exploiting this capability, we dem...

We report on an inertial focussing based microfluidics technology for concentrating waterborne protozoa, achieving a 96% recovery rate of Cryptosporidium parvum and 86% for Giardia lamblia at a throughput (mL/min) capable of replacing centrifugation. The approach can easily be extended to other parasites and also bacteria.

Many modern filtration technologies are incapable of the complete removal of Cryptosporidium oocysts from drinking-water. Consequently, Cryptosporidium-contaminated drinking-water supplies can severely implicate both water utilities and consumers. Existing methods for the detection of Cryptosporidium in drinking-water do not discern between non-pat...

Presence of Kinks in Force-Distance Curves. (PDF)

Data Analysis Procedure. (PDF)

Force-Distance Curve Corresponding to S1 Video. (PDF)

Discrimination Efficiency Estimation. (PDF)

Probability Density Functions Fitted to Cryptosporidium parvum Spring Constant Data. (PDF)

Rotational Movement of Oocyst During Measurement. (MP4)

Oocysts of the waterborne protozoan parasite, Cryptosporidium , are highly resistant to chlorine disinfection. We show here for the first time that both silver nanoparticles (Ag NPs) and silver ions significantly decrease oocyst viability in a dose-dependent manner between concentrations of 0.005 and 500 μg/mL, as assessed by an excystation assay,...

Sample processing is a highly challenging stage in the monitoring of waterborne pathogens. This step is time-consuming, requires highly trained technicians and often results in low recovery rates of pathogens. In the UK but also in other parts of the world, Cryptosporidium is the only pathogen directly tested for in routine operational monitoring....

Detecting waterborne pathogens is a challenging task because of their low concentration in water and their wide diversity. In order to ease this detection process, the potential of microfluidics is investigated in this paper. Spiral channels are designed for separating particles, in a single device and without any external forces or additional buff...

In environments of scarce hygiene it is of primary importance to detect potentially harmful concentrations of pathogens in drinking water. In many situations, however, accurate analysis of water samples is prohibitively complex and often requires highly specialised apparatuses and technicians. In order to overcome these limitations, a method to emp...

Contaminated drinking water is one of the most important environmental contributors to the human disease burden. Monitoring of water for the presence of pathogens is an essential part of ensuring drinking water safety. In order to assess water quality it is essential to have methods available to sample and detect the type, level and viability of pa...

Access to safe drinking is “a human right that is essential for the full enjoyment of life and all human rights" as recognized by the United Nations General Assembly resolution (A/RES/64/292-2010). However, despite this, several outbreaks are reported each month across Europe. For instance, 47,617 episodes of illness have been reported between 2000...

Bacterial transcriptomics is widely used to investigate gene regulation, bacterial susceptibility to antibiotics, host-pathogen interactions, and pathogenesis. Transcriptomics is crucially dependent on suitable methods to isolate and detect bacterial RNA. Microfluidics offer ways of creating integrated point-of-care systems, analysing a sample from...

Water monitoring is essential to ensure safe drinking water for consumers. However existing methods have several drawbacks, particularly with regard to the poor recovery of Cryptosporidium due to the inability to efficiently elute Cryptosporidium oocysts during the established detection process used by water utilities. Thus the development of new i...

Export Date: 7 April 2017, References: Nichols, R., Connelly, L., Sullivan, C., Smith, H., Identification of cryptosporidium species and genotypes in scottish raw and drinking waters during a one-year monitoring period (2010) Applied and Environmental Microbiology, 76 (17), pp. 5977-5986;

This chapter considers the guidelines and regulations in order to reduce, or prevent adverse health effects associated with unsafe drinking water. The chapter focuses specifically on the role of monitoring the IN delivery of safe drinking water and presents the existing methods of detection, which are routinely adopted. First, a brief overview of t...

Nanotechnology is the characterization, fabrication and/or manipulation of structures, devices or materials between 1 and 100 nm. The properties observed in materials at this size range are different to those found in the bulk material, mainly due to a large surface-to-volume ratio. This results in enhanced surface reactivity, quantum confinement e...

This chapter provides an introduction to waterborne pathogens, which can be divided into three main categories; viruses, bacteria and parasites, the latter of which are comprised of protozoa and helminths. Each category comprises a section within the chapter. The World Health Organisation has compiled a List of Relevant Waterborne Pathogens, which...

Access to potable water is essential to life. It is a right enshrined in the Universal Declaration of Human Rights and it is critical to meeting all of the Millennium Development Goals. Due to population growth, increased industrialization and climate change, the scarcity of safe, pollutant-free drinking water sources is a major problem. In terms o...

This chapter concludes the book on waterborne pathogen monitoring, summarizing the main findings from the other chapters and looking forward to the future of waterborne pathogen monitoring. A background and overview of waterborne pathogens and the need for monitoring is given. Subsequently, the main findings of each chapter, summarizing the latest...

The purpose of this paper is to present a new approach for introducing to a non-scientific audience a major public health issue: access to safe drinking water. Access to safe drinking water is a privilege in developed countries and an urgent need in the third world, which implies always more efficient and reliable engineering tools to be developed....

Deterministic lateral displacement (DLD), a hydrodynamic, microfluidic technology, was first reported by Huang et al. in 2004 to separate particles on the basis of size in continuous flow with a resolution of down to 10 nm. For 10 years, DLD has been extensively studied, employed and modified by researchers in terms of theory, design, microfabricat...

A review of the recent advances in microfluidics based systems for the monitoring of waterborne pathogens is provided in this article. Emphasis has been made on existing, commercial and state-of-the-art systems and research activities in laboratories worldwide. The review separates sample processing systems and monitoring systems, highlighting the...

We report a novel approach for determining the enzymatic activity within a single suspended cell. Using a steady-state microfluidic delivery device, and timed exposure to the pore-forming agent digitonin, we controlled the plasma membrane permeation of individual NG108-15 cells. Mildly permeabilized cells (~100 pores) were exposed to a series of co...

Increasingly, research is moving towards more interdisciplinary endeavours. Effective collaboration between people from different disciplines is necessary to maximize the potential benefits of interdisciplinarity for future research activity. This paper analyses an approach to fostering the skills required for successful cross-disciplinary collabor...

This chapter is devoted to sample processing, which plays a key role in the ultimate success of any detection technology. Many of the techniques discussed in the following chapters process from microliter to a few milliliter, whereas it may be necessary to sample hundreds of milliliter to thousands of liters. In this chapter the need for sample pro...

This chapter provides an introduction to biosensing technology and reviews the applications for waterborne pathogens. The first sections of the chapter discuss the key performance criteria by which biosensor technology is assessed and summarize the different types of recognition chemistries vital for the specific capture and/or detection of pathoge...

This chapter will focus on the role that miniaturization, in particular using microfluidic systems, can play in the delivery of lab-on-a-chip devices to perform the detection procedures previously described. The chapter starts with an introduction to the field of microfluidics, covering microfabrication, the underlying fluid mechanics and the types...

This chapter covers a range of optical detection technologies, which either detect intrinsic properties of the microorganisms themselves or exploit external labels. The chapter first addresses optical detection techniques requiring sample labeling, mainly fluorescence. A brief explanation of the fluorescence process, and different approaches, is pr...

This book gives an overview of advanced emerging technologies for the detection of a range of waterborne pathogens. The book will present existing methodology and highlight where improvements can be made, as well as have a strong focus on applications and the ways in which new technology could be applied in water management. Additionally, it addres...

New methods of analysis for water quality monitoring to detect inorganic substances are required to meet the demands of determining concentration, particularly at low detection limits, analysing speciation and even identifying the pollution source. Such information is essential to inform public health decisions and to comply with more stringent leg...

Cryptosporidium is a waterborne protozoan parasite, which is problematic for the water industry due to widespread environmental presence, low infectious dose and resistance to chlorine disinfection. To replace the existing, slow regulatory monitoring procedure, immunosensors have been proposed. The performance of such sensors is often limited by th...

Polymer microarrays offer a high-throughput approach to the screening and assessment of a large number of polymeric materials. Here, we report the first study of protozoan-polymer interactions using a microarray approach. Specifically, from screening hundreds of synthetic polymers, we identified materials that either trap the waterborne protozoan p...

Contamination of drinking water with the protozoan pathogen, Cryptosporidium, represents a serious risk to human health due to the low infectious dose and the resistance of this parasite to chlorine disinfection. Therefore, several countries have legislated for the frequent monitoring of drinking water for Cryptosporidium presence. Existing approve...

The interaction of the waterborne protozoan parasite, Giardia lamblia, with polymeric materials was investigated by microarray screening of 652 polymers. Polymers were identified which either bound G. lamblia cysts or prevented their binding. Correlation of material properties such as wettability and surface roughness with cyst attachment revealed...

Methods that can control and vary the solution environment around single cells are abundant. In contrast, methods that offer direct access to the intracellular proteome and genome in single cells with the control, flexibility, and convenience given by microfluidic methods are both scarce and in great demand. Here, we present such a method based on...

We present a concept for the post production modification of commercially available microfluidic devices to incorporate local temperature control, thus allowing for the exact alignment of heating structures with the existing features, e.g. wells, channels or valves, of a system. Specifically, we demonstrate the application of programmable local hea...

We introduce a system for temperature control of a commercial microfluidic superfusion device that, in combination with patch-clamp, enables rapid acquisition of dose-response data at different temperatures. We obtained dose-response curves for the GABAA receptor, a ligand-gated ion channel, for two different agonists at temperatures between 25 and...

We present an open-volume microfluidic system capable of on-line modification of a patterned laminar flow by using programmable inlet valves. Each separate solution environment in the flow pattern can be independently exchanged between different preloaded input solutions where each exchange requires 20 s. The number of flow patterns that can be gen...

Algorithms and methods were developed to synthesize complex chemical waveforms in open volumes by using a scanning-probe microfluidic platform. Time-dependent variations and oscillations of one or several chemical species around the scanning probe, such as formation of sine waves, damped oscillations, and generation of more complex patterns, are de...

The dichlorooxabicyclo(3.1.0)hexane (Ia) and the thia analogue (Ib) react with tert-butoxide to form the bridgehead olefins (II) which are trapped by cycloaddition reaction with diphenylisobenzofuran (III) or furan (V), forming the polycycles (IV) or (VI).