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.

Joint-on-a-Chip: Monitoring the Onset and Progression of Inflammatory Responses in a Personalized Rheumatoid Arthritis Model
Peter Ertl, Professor of Lab-on-a-Chip Systems, Vienna University of Technology, Austria

Rheumatoid arthritis is an autoimmune disease that causes inflamed joints through recruitment of immune cells, synovitis as well as degradation of cartilage. As a result, patients suffer from intense joint pain, are limited in their daily activities and have a lower life expectancy. To date almost 1% of the population worldwide is affected by arthritis, but no cure is available and pain reduction remains the treatment of choice. Although a number of drugs have shown to decrease disease progression, remission is achieved in less than 50% of patients, indicating a patient-specific drug response. Consequently, a personalized disease model is urgently needed to identify suitable drug combinations and concentrations for each individual patient. In this presentation the development of a sensor-integrated joint-on-a-chip platform capable of mimicking the physiological environment of a human diarthrodial joint is presented and observed patient variability discussed.

Organ-on-a-Chip Platforms for Assisted Reproductive Technologies
Séverine Le Gac, Professor, Applied Microfluidics for Bioengineering Research, MESA+ Institute for Nanotechnology, University of Twente, Netherlands

Organ-on-a-chip platforms are currently considered as the next-generation in vitro models for various fields of applications such as drug and toxicity screening, disease modeling, tissue regeneration, metabolic studies, etc. Key-advantages offered by these platforms compared to standard in vitro models are, for instance, the possibility to accurately control the cellular microenvironment and to implement dynamic culture conditions in a microfluidic format, to emulate the architecture and/or the function of targeted organs by combining specific microstructures with cells, and to stimulate the cells in the device, e.g., chemically, mechanically, electrically, with an excellent spatiotemporal control. In my presentation, I will present current work from our group in the field of organ-on-a-chip with a particular focus on the field of assisted reproductive technologies (ART), with devices for the in vitro culture of mammalian embryos, the in vitro production of bovine embryos (oviduct-on-a-chip platform) and the ex vivo culture of testis tissues.

Body on a Chip: Human Microscale Models for Drug Development
James Hickman, Professor, Nanoscience Technology, Chemistry, Biomolecular Science and Electrical Engineering, University of Central Florida; Chief Scientist, Hesperos, United States of America

The preclinical drug development process is inefficient at selecting drug candidates for human clinical trials, since only 11% of drug candidates selected for clinical trials exit with regulatory approval. Current technology is based on isolated human cells and animal surrogates.  We believe that a “human” multiorgan model based on physiologically based pharmacokinetics-pharmacodynamic (PBPK-PD) models that house interconnected modules with tissue mimics of various organs.  The system captures key aspects of human physiology that would potentially reduce drug attrition in clinical trials and decrease the cost of development. Integrated, multi-organ microphysiological systems (MPS) based on human tissues (also known as “body-on-a-chip”) could be important tools to improve the selection of drug candidates exiting preclinical trials for those drug most likely to earn regulatory approval from clinical trials. This methodology integrates microsystems fabrication technology and surface modifications with protein and cellular components, for initiating and maintaining self-assembly and growth into biologically, mechanically and electronically interactive functional multi-component systems.

I will describe such systems being constructed at Hesperos and at UCF that are guided in their design by a PBPK model. They are “self-contained” in that they can operate independently and do not require external pumps as is the case with man other microphysiological systems. They are “low cost”, in part, because of the simplicity and reliability of operation. They maintain a ratio of fluid (blood surrogate) to cells that is more physiologic than in many other in vitro systems allowing the observation of the effects of not only drugs but their metabolites. While systems can be sampled to measure the concentrations of drugs, metabolites, or biomarkers, they also can be interrogated in situ for functional responses such as electrical activity, force generation, or integrity of barrier function. Operation up to 28 days has been achieved allowing observation of both acute and chronic responses with serum free media. We have worked with various combinations of internal organ modules (liver, fat, neuromuscular junction, skeletal muscle, cardiac, bone marrow, blood vessels and brain) and barrier tissues (eg skin, GI tract, blood brain barrier, lung, and kidney). The use of microelectrode arrays to monitor electrically active tissues (cardiac and neuronal) and micro cantilevers (muscle) have been demonstrated. Most importantly these technical advances allow prediction of both a drug’s potential efficacy and toxicity (side-effects) in pre-clinical studies. This talk will also give results of six workshops held at NIH to explore what is needed for validation and qualification of these new systems.

Development of an Automated Tissue-Engineering Platform to Produce Human Liver Tissue for Basic and Applied Research
David Hay, Chair of Tissue Engineering, MRC Centre for Regenerative Medicine, University of Edinburgh, United Kingdom

Liver disease represents an increasing cause of global morbidity and mortality. Currently, liver transplant is the only treatment curative for end stage liver disease. Donor organs cannot meet the demand and therefore scalable treatments and new disease models are required to improve clinical intervention. Pluripotent stem cells represent a renewable source of human tissue. Recent advances in three-dimensional cell culture have provided the field with more complex systems that better mimic liver physiology and function. Despite these improvements, current cell based models are variable in performance and expensive to manufacture at scale. This is due, in part, to the use of poorly defined or cross-species materials within the process, severely affecting technology translation. To address this issue, we have developed an automated and economical platform to produce liver tissue at scale for modelling disease and small molecule screening. Stem cell derived liver spheres were formed by combining hepatic progenitors with endothelial cells and stellate cells, in the ratios found within the liver. The resulting tissue permitted the study of human liver biology ‘in the dish ‘and could be scaled for screening.Going forward we believe that this resource will not only serve as an in vitro resource and may have an important role to play in supporting failing liver function in humans.