3D-Culture, Organoids and Organs-on-Chips 2021 Agenda

Strategies For in vitro Perfusion of iPSC-derived Organoids: A Tough Nut to Crack
Roger Kamm, Cecil and Ida Green Distinguished Professor of Biological and Mechanical Engineering, Massachusetts Institute of Technology (MIT), United States of America

Now that organoids can be generated for a variety of organs and tissues from induced pluripotent stem cells, there is tremendous interest in developing methods to connect an external perfusion system to an internal vasculature.  Success in this quest would help facilitate continuous perfusion, leading to improved viability and functionality of the developing organ, and supporting the introduction of therapeutics for drug screening and development.  For more than 5 years, we have had the capability to grow self-assembled microvascular beds, or pattern small vessels within various hydrogels.  Methods are also increasingly available to induce the growth vascular networks inside of the organoid. To date, however, it has proved challenging to induce anastomosis between these two networks and enable continuous perfusion. In this presentation, different methods will be discussed that hold promise to address this critical problem.

Advanced In vitro Inhalation Lung-on-Chip Platforms For Preclinical Research
Josué Sznitman, Associate Professor, Technion – Israel Institute of Technology, Israel

With rapid advances, the development of lung-on-chip platforms is offering novel avenues for more realistic inhalation assays in pharmaceutical research, and an opportunity to depart from traditional in vitro lung assays. As advanced models capturing the cellular pulmonary make-up at an air-liquid interface (ALI), lung-on-chips emulate both morphological features and biological functionality of the airway barrier with the ability to integrate respiratory breathing motions and ensuing tissue strains. Such in vitro systems allow importantly to mimic more realistic physiological respiratory flow conditions, with the opportunity to integrate physically-relevant transport determinants of aerosol inhalation therapy, i.e. recapitulating the pathway from airborne flight to deposition on the airway lumen. In this presentation, we discuss recent developments in our group on devising such advanced human-relevant lung-on-chip models that mimic in situ-like inhalation assays with endpoints geared at cytotoxicity, respiratory diseases and therapies.

Body on a Chip: A Transformative Approach to Improve Drug Development
Michael Shuler, Samuel B. Eckert Professor of Engineering, Cornell University, President & CEO, Hesperos, Inc., United States of America

A physiologically representative, multi-organ microphysiological systems (MPS) based on human tissues (also known as “human-on-a-chip” TM) may be a transformative technology to improve the selection of drug candidates most likely to earn regulatory approval from clinical trials. Such microscale systems combine organized human tissues with the techniques of microfabrication based on PBPK (Physiologically Based Pharmacokinetic) models.

I will describe such systems being constructed at Hesperos and at Cornell. They are “self-contained” in that they can operate independently and do not require external pumps as is the case with many 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.

Intestine on Chip for Normal Physiology and Disease Models
Nancy Allbritton, Frank and Julie Jungers Dean of the College of Engineering and Professor of Bioengineering, University of Washington in Seattle, United States of America

Organ-on-chips are miniaturized devices that arrange living cells to simulate functional subunits of tissues and organs. These microdevices provide exquisite control of tissue microenvironment for the investigation of organ-level physiology and disease. A 3D polarized epithelium using primary human or mouse gastrointestinal stem cells was developed to fully recapitulate gastrointestinal epithelial architecture and physiology. A planar monolayer comprised of stem/proliferative and differentiated primary cells is cultured on a shaped hydrogel scaffold with an array of crypt-like structures replicating the intestinal architecture. Imposition of chemical gradients across the crypt long axis yields a polarized epithelium with a stem-cell niche and differentiated cell zone. The stem cells proliferate, migrate and differentiate along the crypt axis as they do in vivo. A dense mucus layer is formed on the luminal epithelial surface that is impermeable to bacteria and acts a barrier to toxins. An oxygen gradient across the tissue mimic permits luminal culture of anaerobic bacteria while maintaining an oxygenated stem cell niche. This in vitro human colon crypt array replicates the architecture, luminal accessibility, tissue polarity, cell migration, and cellular responses of in vivo intestinal crypts. A thick impenetrable layer of mucus with biophysical parameters similar to that of a living human can be formed for epithelial cell-microbe studies. Intestinal biopsy samples can be used to populate these constructs to produce patient-specific tissues for personalized medicine and disease modeling. This bioanalytical platform is envisioned as a next-generation system for assay of microbiome-behavior, drug-delivery and toxin-interactions with the intestinal epithelia.

Microphysiological Systems as Testbeds Spanning Drug Discovery to Organ Preservation
Kevin Healy, Jan Fandrianto and Selfia Halim Distinguished Professorship in Engineering, University of California, Berkeley, United States of America

Our work has emphasized creating both healthy and diseased model organ systems, called microphysiological systems, to address the costly and inefficient drug discovery process. While organ chips are poised to disrupt the drug development process and significantly reduce the cost of bringing a new drug candidate to market, organ chip technology is much more robust and creates a whole new paradigm in how to study biology, and advances medicine in revolutionary ways. Emerging use of microphysiological systems span organ preservation, biomaterials development, gene editing, and environmental toxicology. This presentation will discuss examples of exploiting microphysiological systems as unique testbeds for these cutting edge areas.

Humanizing Models of Liver Diseases
Linda Griffith, Professor, Massachusetts Institute of Technology (MIT), United States of America

The growing commercial availability of high quality cryopreserved human hepatocytes, expansion of hepatocytes via organoid technology, and advances in derivation of hepatic organoids from iPSC, along with advances in mesofluidic platforms that provide gut-liver interactions, open opportunities for building accessible human disease models.   This talk will describe conceptual and technical considerations in building models of liver metabolic and inflammatory diseases, including cell sourcing, culture media design, microphysiological system platform design, incorporation of immune cells, and cross talk with the gut with examples illustrating how to integrate multi-omic data.

What Do We Need to Make Microphysiological Systems Drug Assays Massively Parallel?
John Wikswo, Gordon A. Cain University Professor, A.B. Learned Professor of Living State Physics; Founding Director, Vanderbilt Institute for Integrative Biosystems, Vanderbilt University, United States of America

Organs-on-chips, organoids and coupled microphysiological systems (MPS) will never reach the level of automation possible with single-pass, high throughput screening of million-compound drug libraries using robots for acoustic seeding, feeding, and dosing-of cells or spheroids in 1536 well plates, followed by either end-point imaging or acoustic delivery of media to a mass spectrometer. Nor should they. But one can wonder exactly how many MPS devices could be created, maintained, and analyzed by an appropriate robotic perfusion system. We will describe a convergence of microfluidic, robotic, and analytic technologies that could easily service a thousand organ-chips or 10,000 separate organoids in a 42U telecom rack/incubator, each undergoing different pharmacokinetic exposures and dynamic metabolomic readouts.

Live-Cell Kinetic Assays of 3D Cultures to Monitor Cell Health and Metabolite Levels Used to Select Samples For Further Analysis
Terry Riss, Senior Product Manager, Cell Health, Promega Corporation, United States of America

With the increased use of physiologically relevant models comes the need for sensitive assay methods to monitor health of cells cultured in a 3D environment. Live-cell kinetic assays are available to interrogate 3D culture models and report the number of live cells, dead cells, apoptotic cells, or key metabolite levels remaining in the medium. Because the live-cell kinetic assays do not kill the cells, data from real-time monitoring of changes in viability or metabolite utilization can be set as a threshold to cherry pick a subset of individual samples for more time consuming image recording and computational analysis using high content screening. We will describe how we use the power of luminescence detection to overcome the limitations in sensitivity and create live-cell kinetic assays to monitor 3D culture models.