Point-of-Care, Biosensors & Mobile Diagnostics Europe 2020 Agenda

Detection of Antibodies Against SARS-CoV-2 Spike Protein by Gold Nanospikes in an Optomicrofluidic Chip
Amy Shen, Professor and Provost, Okinawa Institute of Science and Technology Graduate University, Japan

The ongoing global pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to active research in its associated diagnostics and medical treatments. While quantitative reverse transcription polymerase chain reaction (qRT--PCR) is the most reliable method to detect viral genes of SARS-CoV-2, serological tests for specific antiviral antibodies are also important as they identify false negative qRT--PCR responses, track how effectively the patient's immune system is fighting the infection, and are potentially helpful for plasma transfusion therapies. In this work, based on the principle of localized surface plasmon resonance (LSPR), we develop an optomicrofluidic sensing platform with gold nanospikes, fabricated by electrodeposition, to detect the presence and amount of antibodies specific to the SARS-CoV-2 spike protein in 1 uL of human plasma diluted in 1 mL of buffer solution, within ~30~min. The target antibody concentration can be correlated with the LSPR wavelength peak shift of gold nanospikes caused by the local refractive index change due to the antigen-antibody binding. This label-free microfluidic platform achieves a limit of detection of ~0.08~ng/mL (~0.5~pM), falling under the clinical relevant concentration range. We demonstrate that our opto-microfluidic platform offers a promising point-of-care testing tool to complement standard serological assays and make SARS-CoV-2 quantitative diagnostics easier, cheaper, and faster.

Using Microfluidics for Non-Invasive Cancer Diagnosis
Lorena Diéguez, Leader of the Medical Devices Research Group, INL- International Iberian Nanotechnology Laboratory, Portugal

Microfluidics presents numerous advantages for the handling of biological samples, as it provides careful control of fluids in the microscale. When it comes to biomarkers enrichment, microfluidics has demonstrated superior sensitivity and enhanced recovery compared to traditional methods. Incorporating sensors, lab-on-a-chip technologies offer efficient characterization of disease biomarkers from body fluids, making microfluidics ideal for clinical practice, enabling high throughput, portability, and automation. Early dissemination of cancer is difficult to detect by traditional imaging and pathological methods. While the presence of cancer material in body fluids is well known, current techniques for the isolation, analysis and characterization of these biomarkers are not efficient enough to be fully applied in clinical routine. In this talk, we present our work for isolation and multiplex analysis of cancer biomarkers from body fluids based on microfluidics, and biosensors towards personalized medicine and earlier diagnosis of cancer.

Novel Organoid Models to Develop Drug Treatment Strategies
Robert Vries, CEO, HUB Organoids, Netherlands

Organoids such as IPSC derived brain organoids (Lancaster et al Nature 2013) or our adults epithelial stem cell derived organoids (Sato et al., Nature 2009, 2011) are proving to be a major breakthrough in preclinical models. The new patient like models are fundamental change in the way drug discovery and development can be performed. The development of the HUB Organoids started in the lab of Hans Clevers with the discovery of the identity of adult stem cells in human epithelial tissues such as intestine and liver (Barker et al., Nature 2007; Huch et al., Nature 2013). With the identification of these stem cells, we were able to develop a culture system that allowed for the virtually unlimited, genetically and phenotypically stable expansion of the epithelial cells from animals including humans, both from healthy and diseased tissue (Sato et al., Nature 2009, 2011; Gastroenterology 2011; Huch et al., Nature 2013, Cell 2015; Boj et al., Cell 2015).

We have now generated HUB organoid models from most epithelial organs. Recently, we and others have demonstrated that the in vitro response of organoids correlates with the clinical outcome of the patient from which the organoid was derived (Dekkers et al., Sci Trans Med 2016; Sachs et al., Cell 2018; Vlachogiannis et al., Science 2018). In addition, we have developed a coculture system using HUB Organoids and the immune system to study this interaction and drugs that target the role of the immune system in cancer and other diseases.

We have recently developed new models to study intestinal and lung barrier function and transport of the epithelium of these organs. These experiments show how organoids can be used to study mechanism that underly barrier function disruption in IBD or COPD. Furthermore, we have developed new models to study the interaction between immune system and epithelium. The combination of the new coculture models and assay development to study the epithelium allows us new insights into disease mechanisms and drug treatment strategies.

Droplet-based Microfluidics for Cancer Research
Valérie Taly, CNRS Research Director, Professor and Group leader Translational Research and Microfluidics, Université Paris Cité, France

Droplet-based microfluidics has led to the development of highly powerful tools with great potential in High-Throughput Screening where individual assays are compartmentalized within aqueous droplets acting as independent microreactors. Thanks to the combination of a decrease of assay volume and an increase of throughput, this technology goes beyond the capacities of conventional screening systems. Added to the flexibility and versatility of platform designs, such progresses in the manipulation of sub-nanoliter droplets has allowed to dramatically increase experimental level of control and precision. The presentation will aim at demonstrating through selected example, the great potential of this technology for biotechnology and cancer research. A first part of the presentation will exemplify how microfluidic systems can be used to compartmentalize and assay various types of cells without deleterious effects on their viability within complex and controlled platforms. The application of microfluidic systems for different cell-based assays will be demonstrated. Illustrative examples of droplet-based microfluidic platforms with high potential impact for cancer research will be presented. We will also show how by combining microfluidic systems and clinical advances in molecular diagnostic we have developed an original method to perform millions of single molecule PCR in parallel to detect and quantify a minority of target sequences in complex mixture of DNA with a sensitivity unreachable by conventional procedures. To demonstrate the pertinence of our procedures to overcome clinical oncology challenges, the results of clinical studies will be presented.

Self-Coalescing Flows: A Powerful Method For Integrating Biochemical Reactions In Portable Diagnostic Devices
Emmanuel Delamarche, Manager Precision Diagnostics, IBM Research - Zürich, Switzerland

Diagnostics are ubiquitous in healthcare because they support prevention, monitoring, and treatment of diseases. Specifically, point-of-care diagnostics (POCDs) are particularly attractive for identifying diseases near patients, quickly, and in many settings and scenarios. POCDs can also trace exposure and acquired immunity of populations exposed to infectious diseases and screen metabolic deficiencies of individuals, who may be exposed to severe drug side effects. However, a long-standing challenge with POCDs is the need to integrate reagents in closed devices for a large number of potential applications. Following our previous contributions on developing capillary-driven microfluidic chips for highly miniaturized immunoassays, controlling and monitoring flow with nanoliter precision, and securing diagnostics against counterfeiting with dynamic optical security codes, we recently demonstrated how to shape and fold liquids inside microfluidic chambers to dissolve reagents with extreme precision. In this presentation, I will explain the underlying concept of this method, called self-coalescing flows, and will illustrate how it can be used to perform various assays, ranging from enzymatic assays, to immunoassays and molecular assays. Despite self-coalescing flows being still an open research topic in fluid physics, their implementation is surprisingly facile and robust and therefore may benefit the entire community working on POCDs.

Nervous Systems-on-a-Chip: From Technology to Applied Biomedical Sciences
Regina Luttge, Professor, Eindhoven University of Technology, Netherlands

Challenges in eavesdropping on the complex cell signaling of the human central nervous system is an essential driver for the development of advanced in vitro technologies, called Brain-on-a-Chip. Developments in Brain-on-a-Chip technology focus primarily on the implementation of cortical cells from human stem cell source in a 3D cultured microenvironment. The aim of a recently launched EU project CONNECT is to mimic the in vivo functions of the nervous system in one connected chip system. The creation of new neurodegenerative disease models in this project brings together the knowledge accumulated among neuroscientists, stem cell experts and engineers to investigate the origins and possible treatments for Parkinson's disease. In this presentation, we will discuss in detail the technical approach of a nervous system on a chip as a unique tool for modelling the neural pathway of connected tissues on the brain-gut axis. In addition to design criteria for these microliter-sized physiological cell culture systems, the presentation will focus on guidance of the growth process of axon protrusions and the local control of cell differentiation processes while maintaining physiological conditions.

Biosensor Systems For Bacterial Detection and Characterization
Winnie Edith Svendsen, Professor, Technical University of Denmark, Denmark

Bacteria can cause severe infections in humans and animals and are an increasing health risk due to the spreading of resistant strains that cannot be treated with antibiotics. A main source of bacteria infections is from contaminated surfaces, food or water, usually by inadequate cleaning of surfaces or by spills in drinking water. Bacteria concentrations are monitored closely, but for practical reasons monitoring is not continuous, which means that an infection source can sometimes remain undetected for several days. The development of sensors for fast and accurate detection of bacteria is therefore imperative. In this talk I will present various methods using micro and nanotechnology to detect, probe and characterize bacteria in different environments. The methods includes microfluidics based impedance flow cytometry, electrochemical methods and paper based microfluidic systems. The methods chosen depends on the environment in question.  I will demonstrate systems to count bacteria in swab samples or in water units with the potential to identify the viability state of the bacteria. I will touch upon detection and identification of bacteria in cow milk, pigfarms and human infections. Finally, I will discuss how to enhance the sensitivity of the sensors, using microfluidic systems combined with nanostructures through use of numerical simulations, and experimental integration.

Mobile Diagnostics - Multiplexed DNA Malaria Sensing using Origami Paper Folding and Blockchain/Expert AI Digital Healthcare Systems
Jonathan Cooper, The Wolfson Chair of Bioengineering, University of Glasgow, United Kingdom

Identification of the species of pathogen is often key to informing the treatment of patients with infectious diseases. Here, we use paper-based folding, in a manner similar to origami, to process patient samples from a finger-prick of blood and diagnose malaria amongst communities in rural villages.   The design of the DNA sensing device means that testing can be done by a non-expert, integrating sample preparation into a multiplexed lateral flow device – akin to a conventional pregnancy test. We have tested our devices working with the Ministry of Health in Uganda, using a mobile phone to run the tests, collect and collate data and provide expert decision support for the healthcare workers. The technique has the potential to provide new diagnostic information that can direct therapy, thereby reducing the future threat of anti-microbial resistance.  The tests could also find applications in identifying asymptomatic carriers with low levels of infection, thereby supporting the delivery of disease elimination programmes.

Single Step and Fast Membrane Pre-Concentration for Continuous Biosensing and Point-of-Care Diagnostic Devices
Jason Heikenfeld, Professor and VP Operations, UC Office of Innovation, University of Cincinnati, United States of America

If there were a simple and passive technique, that would downshift the range of detection of all your sensors and analytes by 10-100X, what value would you place on such a breakthrough? Presented are single step and fast membrane pre-concentration devices for applications ranging from continuous wearable biosensing (sweat, interstitial fluid) to point of care diagnostics (blood, urine, saliva).  These devices now show >10X preconcentration in minutes for analytes ranging from small molecules (e.g. cortisol) to large proteins (influenza).  Further demonstrated are techniques that allow rapid adaptation of the devices for a wide variety of sensing modalities, including those sensitive to changes in pH or salinity.