Micro/nano devices for blood analysis

[Excerpt] The development of microdevices for blood analysis is an interdisciplinary subject that demandsan integration of several research fields such as biotechnology, medicine, chemistry, informatics, optics,electronics, mechanics, and micro/nanotechnologies.Over the last few decades, there has been a notably fast development in the miniaturization ofmechanical microdevices, later known as microelectromechanical systems (MEMS), which combineelectrical and mechanical components at a microscale level. The integration of microflow and opticalcomponents in MEMS microdevices, as well as the development of micropumps and microvalves,have promoted the interest of several research fields dealing with fluid flow and transport phenomenahappening at microscale devices. [...

Test analysis & fault simulation of microfluidic systems

This work presents a design, simulation and test methodology for microfluidic systems, with particular focus on simulation for test. A Microfluidic Fault Simulator (MFS) has been created based around COMSOL which allows a fault-free system model to undergo fault injection and provide test measurements. A post MFS test analysis procedure is also described.A range of fault-free system simulations have been cross-validated to experimental work to gauge the accuracy of the fundamental simulation approach prior to further investigation and development of the simulation and test procedure.A generic mechanism, termed a fault block, has been developed to provide fault injection and a method of describing a low abstraction behavioural fault model within the system. This technique has allowed the creation of a fault library containing a range of different microfluidic fault conditions. Each of the fault models has been cross-validated to experimental conditions or published results to determine their accuracy.Two test methods, namely, impedance spectroscopy and Levich electro-chemical sensors have been investigated as general methods of microfluidic test, each of which has been shown to be sensitive to a multitude of fault. Each method has successfully been implemented within the simulation environment and each cross-validated by first-hand experimentation or published work.A test analysis procedure based around the Neyman-Pearson criterion has been developed to allow a probabilistic metric for each test applied for a given fault condition, providing a quantitive assessment of each test. These metrics are used to analyse the sensitivity of each test method, useful when determining which tests to employ in the final system. Furthermore, these probabilistic metrics may be combined to provide a fault coverage metric for the complete system.The complete MFS method has been applied to two system cases studies; a hydrodynamic “Y” channel and a flow cytometry system for prognosing head and neck cancer.Decision trees are trained based on the test measurement data and fault conditions as a means of classifying the systems fault condition state. The classification rules created by the decision trees may be displayed graphically or as a set of rules which can be loaded into test instrumentation. During the course of this research a high voltage power supply instrument has been developed to aid electro-osmotic experimentation and an impedance spectrometer to provide embedded test

Micro/nanofluidic and lab-on-a-chip devices for biomedical applications

Micro/Nanofluidic and lab-on-a-chip devices have been increasingly used in biomedical research [1]. Because of their adaptability, feasibility, and cost-efficiency, these devices can revolutionize the future of preclinical technologies. Furthermore, they allow insights into the performance and toxic effects of responsive drug delivery nanocarriers to be obtained, which consequently allow the shortcomings of two/three-dimensional static cultures and animal testing to be overcome and help to reduce drug development costs and time [2–4]. With the constant advancements in biomedical technology, the development of enhanced microfluidic devices has accelerated, and numerous models have been reported. Given the multidisciplinary of this Special Issue (SI), papers on different subjects were published making a total of 14 contributions, 10 original research papers, and 4 review papers. The review paper of Ko et al. [1] provides a comprehensive overview of the significant advancements in engineered organ-on-a-chip research in a general way while in the review presented by Kanabekova and colleagues [2], a thorough analysis of microphysiological platforms used for modeling liver diseases can be found. To get a summary of the numerical models of microfluidic organ-on-a-chip devices developed in recent years, the review presented by Carvalho et al. [5] can be read. On the other hand, Maia et al. [6] report a systematic review of the diagnosis methods developed for COVID-19, providing an overview of the advancements made since the start of the pandemic. In the following, a brief summary of the research papers published in this SI will be presented, with organs-on-a-chip, microfluidic devices for detection, and device optimization having been identified as the main topics.info:eu-repo/semantics/publishedVersio

Von Plattformen zu miRNA-Biomarkern : Methoden zur miRNA-Molekulardiagnostik

An obvious way to improve human healthcare is to develop new and more effective drugs. Another opportunity is however to develop solutions that allow to utilize the available drugs better. This includes more accurate and early diagnosis of pathologies, improved therapy selection as well as digital and patient centric solutions in healthcare systems. Especially in molecular diagnostics new biomarkers have been developed and partially shown promising results in terms of improving patient care. In this work I describe the development of respective platform techniques, biomarkers and computational solutions during my PhD thesis. First, I briefly introduce the concept of a flexible microarray platform and assays, such as the MPEA assay, tailored for the fast and efficient quantification of miRNA signatures. Then, I describe how we made use of respective platforms along with computational solutions to improve the understanding of physiological and pathophysiological processes. Further, I present results on my efforts to develop new molecular diagnostic biomarkers based on circulating miRNAs. Here, my special focus was in cancer (most importantly lung cancer) and diseases affecting the Central Nervous System (most importantly Multiple Sclerosis, Alzheimer’s Disease and Parkinson’s Disease). Together with the supervisors of my thesis I was among the first researchers worldwide to recognize that small non-coding RNAs (most importantly microRNAs) measured from body fluids have a great potential as biomarkers. An obvious advantage to messenger RNAs is the small length of the molecules of only 17-22 nucleotides. This makes microRNAs stable in vivo but also in vitro. Finally, I will mention recent developments in patient care. The current trend is clearly the digitalization of central parts of healthcare. This affects all stakeholders in the healthcare system, most importantly medical doctors and patients. Especially patient empowerment and self-containment of medical data is becoming more important. Again, Multiple Sclerosis is used as an example. But also for physicians, computational tools have to be implemented to support them in making treatment decisions from highly complex data. In sum, my thesis describes the road from developing a molecular diagnostic platform over the research on biomarkers for detecting disease in time towards holistic computational solutions to improve patient care.Es ist offensichtlich, dass man Krankheiten besser behandeln kann, wenn man neue und effektivere Medikamente und Therapien entwickelt. Eine andere Möglichkeit ist es, Lösungen zu entwickeln, die es erlauben, vorhandene Medikamente besser einzusetzen. Das schließt die frühzeitige Diagnose von Erkrankungen, eine verbesserte Wahl der richtigen Therapie und die Entwicklung von patienten-zentrischen digitalisierten Lösungen mit ein. Insbesondere in der Molekulardiagnostik wurden neue vielversprechende Biomarker entwickelt. In dieser Arbeit führe ich meine Beiträge zur Entwicklung von Plattform Technologien zum Messen von Biomarkern aus, erläutere die Erforschung von Biomarkern selbst und beschreibe die Anwendung der dazugehörigen, computergestützten Methoden. Beginnen möchte ich mit einer Beschreibung der Entwicklung einer flexiblen Mikroarray Plattform und Assays, wie zum Beispiel des MPEA Assays, die maßgeschneidert für die schnelle und effiziente Quantifizierung von miRNA Biomarkern sind. Dann gehe ich darauf ein, wie wir Plattformen, Assays und computergestützte Lösungen eingesetzt haben, um physiologische und pathologische Prozesse besser zu verstehen. Außerdem präsentiere ich Resultate meiner Bemühung, neue molekulardiagnostische Biomarker basierend auf zirkulierenden miRNA Mustern zu entwickeln. Hierbei habe ich mich auf Krebs (vornehmlich Lungentumore) und Erkrankungen, die das Zentrale Nervensystem betreffen (Multiple Sklerose und die Alzheimer Erkrankung), konzentriert. Gemeinsam mit meinen Betreuern war ich unter den ersten Forschern weltweit, die das große Potenzial kleiner nicht-kodierender RNAs (am wichtigsten dabei microRNAs), die aus Blut gemessen werden können, erkannt haben. Ein offensichtlicher Vorteil gegenüber mRNA Biomarkern ist die kurze Länge von nur 17-22 Nukleotiden. Diese macht miRNAs sowohl in-vivo als auch in-vitro stabil. Letztlich gehe ich in meiner Arbeit auf momentane Entwicklungen in der Patientenversorgung ein. Ein klarer Trend ist die Digitalisierung zentraler Teile der Gesundheitsversorgung. Das betrifft alle Personen im Gesundheitswesen, allen voran Mediziner und Patienten. Selbstbestimmung des Patienten wird besonders wichtig werden. Hier dient mir wieder Multiple Sklerose als ein Beispiel. Auch für Ärzte müssen, angesichts der immer komplexeren Daten, computergestützte Lösungen entwickelt werden, die ihnen helfen, die richtige Therapieentscheidung zu treffen. Zusammenfassend halte ich fest, dass meine Arbeit den Weg von der Entwicklung einer molekulardiagnostischen Plattform über die Entwicklung von Biomarkern zur Frühdiagnose von Erkrankungen bis hin zu ganzheitlichen computergestützten Lösungen, die die Patientenversorgung verbessern, beschreibt

Microfluidics and Nanofluidics Handbook

The Microfluidics and Nanofluidics Handbook: Two-Volume Set comprehensively captures the cross-disciplinary breadth of the fields of micro- and nanofluidics, which encompass the biological sciences, chemistry, physics and engineering applications. To fill the knowledge gap between engineering and the basic sciences, the editors pulled together key individuals, well known in their respective areas, to author chapters that help graduate students, scientists, and practicing engineers understand the overall area of microfluidics and nanofluidics. Topics covered include Finite Volume Method for Numerical Simulation Lattice Boltzmann Method and Its Applications in Microfluidics Microparticle and Nanoparticle Manipulation Methane Solubility Enhancement in Water Confined to Nanoscale Pores Volume Two: Fabrication, Implementation, and Applications focuses on topics related to experimental and numerical methods. It also covers fabrication and applications in a variety of areas, from aerospace to biological systems. Reflecting the inherent nature of microfluidics and nanofluidics, the book includes as much interdisciplinary knowledge as possible. It provides the fundamental science background for newcomers and advanced techniques and concepts for experienced researchers and professionals

A modular multi electrode array system for electrogenic cell characterisation and cardiotoxicity applications

Multi electrode array (MEA) systems have evolved from custom-made experimental tools, exploited for neural research, into commercially available systems that are used throughout non-invasive electrophysiological study. MEA systems are used in conjunction with cells and tissues from a number of differing organisms (e.g. mice, monkeys, chickens, plants). The development of MEA systems has been incremental over the past 30 years due to constantly changing specific bioscientific requirements in research. As the application of MEA systems continues to diversify contemporary commercial systems are requiring increased levels of sophistication and greater throughput capabilities. [Continues.

Microdevices and Microsystems for Cell Manipulation

Microfabricated devices and systems capable of micromanipulation are well-suited for the manipulation of cells. These technologies are capable of a variety of functions, including cell trapping, cell sorting, cell culturing, and cell surgery, often at single-cell or sub-cellular resolution. These functionalities are achieved through a variety of mechanisms, including mechanical, electrical, magnetic, optical, and thermal forces. The operations that these microdevices and microsystems enable are relevant to many areas of biomedical research, including tissue engineering, cellular therapeutics, drug discovery, and diagnostics. This Special Issue will highlight recent advances in the field of cellular manipulation. Technologies capable of parallel single-cell manipulation are of special interest

Single Cell Analysis

Cells are the most fundamental building block of all living organisms. The investigation of any type of disease mechanism and its progression still remains challenging due to cellular heterogeneity characteristics and physiological state of cells in a given population. The bulk measurement of millions of cells together can provide some general information on cells, but it cannot evolve the cellular heterogeneity and molecular dynamics in a certain cell population. Compared to this bulk or the average measurement of a large number of cells together, single-cell analysis can provide detailed information on each cell, which could assist in developing an understanding of the specific biological context of cells, such as tumor progression or issues around stem cells. Single-cell omics can provide valuable information about functional mutation and a copy number of variations of cells. Information from single-cell investigations can help to produce a better understanding of intracellular interactions and environmental responses of cellular organelles, which can be beneficial for therapeutics development and diagnostics purposes. This Special Issue is inviting articles related to single-cell analysis and its advantages, limitations, and future prospects regarding health benefits

Multiplexed affinity peptidomic assays: multiplexing and applications for testing protein biomarkers

Biomarkers are increasingly used in a wide range of areas such as sports and clinical diagnostics, biometric applications, forensic analysis and population screening. Testing for such biomarkers requires substantial resources and has traditionally involved centralised laboratory testing. From cancer diagnosis to COVID testing, there is an increasing demand for protein based assays that are portable, easy to use and ideally multiplexed, so that more than one biomarker can be tested at the same time, thus increasing the throughput and reducing time of the analysis and potentially the costs. Events in recent years, not least the ongoing investigations into claims of widespread state-sponsored doping schemes in sport and the COVID-19 pandemic of 2020 highlight the ever-growing requirement and importance of such tests across multiple frontiers. The project evaluated the feasibility of new antipeptide affinity reagents and suitable technologies for application to multiplexed affinity assays geared towards quantitatively analysing a range of analytes. In the first part of this project, key protein biomarkers available from blood serum and covering a range of conditions including cancer, inflammation, and various behavioural traits were chosen from the literature. Peptide antigens for the development of antipeptide polyclonal antibodies for each protein were selected following in silico proteolysis and ranking of the peptides using an algorithm devised as part of this research. A microarray format was used to achieve spatial multiplexing and increase throughput of the assays. The arrays were evaluated experimentally and were tested for their usability for studying up/down regulation of the target biomarkers in human sera samples. Another protein assay format tested for compatibility with affinity peptidomics approach was a gold nanoparticle based lateral flow test. An affinity-based lateral flow test device was built and used for the detection of the benzodiazepine Valium. Here spectral multiplexing of detection was considered. The principle was tested using quantum dot nanoparticles instead of traditionally used gold nanoparticles. The spectral deconvolution was achieved for mixtures containing up to six differently sized quantum dots. In the final part of this project, a search for novel peptide affinity reagents against insulin growth-like factor 1 (IGF-1) was conducted using phage display. Four peptides were identified after screening a phage display library, and the binding of these peptides to IGF-1 was compared to that of traditional antibody

Photonic discrimination and specific targeting of vascular stem cells.

Cardiovascular disease remains the leading cause of death and disability world-wide. The current treatment options include balloon angioplasty and the deployment of drug-eluting stents (DES) coated with anti-mitotic drugs to prevent intimal-medial thickening (IMT). Despite this, an unacceptably high failure rate remains due to non-specific targeting of cells and drug-depletion over time. The source of the cells contributing to IMT remains controversial; one theory suggests a reprogramming of native differentiated vascular smooth muscle cells (SMC) while the other proposes myogenic differentiation of resident vascular and/or circulating stem cells. Resolution of this controversy through identification of the source of the contributing cells would greatly assist in the development of future drug targeting strategies using novel DES platforms. The use of photonics and vibrational spectroscopy is gaining popularity for disease diagnosis. Both platforms have the ability to yield cellular and molecular information about cells and tissues label-free, making them attractive technologies for analysing biological specimen. The first main objective of this work was to analyse individual cells from normal (healthy) and arteriosclerotic (diseased) vessels ex vivo using autofluorescence (AF) in response to broadband light and to compare their AF signatures to undifferentiated stem cells and their myogenic progeny in vitro. The second aim was to use vibrational spectroscopy (Raman and FTIR) to examine undifferentiated stem cells, their myogenic and osteogenic progeny and and further compare their spectra to re- programmed differentiated SMC. Finally, a novel therapeutic platform for targeting stem cell-derived myogenic progeny using magnetic nanoparticles was developed. Using pharmacological inhibitors of glycogen synthase 3 beta (GSK3β), the effects on Notch, a well known mediator of myogenic differentiation were first evaluated in vitro. Further to this, a prototype GSK3β inhibitor was incorporated into a novel drug delivery system consisting of polymer coated Fe304 magnetic nanoparticles which can be systemically administered and specifically targeted to bare-metal stents by an external magnetic field