Session Organizers: Brenda Ogle, University of Minnesota and John Bischof, University of Minnesota
A Protocol for Cryopreservation of Drosophila Embryos
Amanda Neisch
Research Assistant Professor
University of Minnesota
Abstract: Drosophila melanogaster is one of the premier genetic model organisms for biomedical research. Because of this, stock centers around the world exist to maintain >150,000 unique live Drosophila strains. Continuous maintenance of live Drosophila strains allows for genetic drift and the possibility of cross-contamination of strains during transfers. In addition, the maintenance can be costly. Significant efforts were made in the past to develop a Drosophila embryo cryopreservation protocol, but these methods were never adopted by the community. We have now developed a robust and simple protocol for Drosophila embryo cryopreservation. We aim to disseminate this protocol for adoption by the community through an online website with tutorials that we have developed, as well as through hands-on workshops.
Bio: Amanda Neisch is a research assistant professor in the Department of Genetics, Cell Biology and Development at the University of Minnesota. She uses the highly tractable genetic model organism, Drosophila melanogaster, for her research studies. Her research focuses on the regulation of axonal transport and its role in neurodegenerative disorders, and cryopreservation of Drosophila melanogaster embryos for strain preservation.
Cryopreservation to Enable Broad Access to Organoids and Microphysiologic Systems
Brenda Ogle, PhD
Professor and Department Head
Department of Biomedical Engineering
University of Minnesota
Bio: Brenda Ogle is Professor and Head of Biomedical Engineering, Professor of Pediatrics, and Director of the Stem Cell Institute at the University of Minnesota. Her research team investigates the impact of extracellular matrix proteins on stem cell behavior especially in the context of the cardiovascular system. Insights gleaned over the years established mechanistic links between integrin engagement and the activity of critical transcription factors and most recently led to the development of optimized, extracellular matrix-based bioinks for 3D printing of cardiac muscle mimics featured in Newsweek. The primary strength of her laboratory is the ability to span multiple subdisciplines within both basic science (i.e., stem cell biology, cell-cell fusion, and extracellular matrices) and engineering (cytometry, instrumentation, and 3D printing) fields. Her work received funding from the National Institutes of Health, the National Science Foundation, the Department of Defense, the American Heart Association, the Coulter Foundation, Regenerative Medicine Minnesota, Minnesota Partnership, and MnDRIVE. She has partnered on research projects with Becton Dickinson, iCyt, 3M and Medtronic. Professor Ogle is an elected fellow of the American Institute for Medical and Biological Engineering and the Biomedical Engineering Society. She has served as a member of the Board of Directors of the Biomedical Engineering Society, as co-chair of the Women’s Faculty Cabinet, UMN and is recipient of the Mullen-Spector-Truax Women’s Leadership Award.
Cryopreservation of Organs for Transplantation
Erik Finger, MD, PhD
Professor, Surgery
University of Minnesota
Abstract: Banking cryopreserved organs could transform transplantation into a planned procedure that equitably reaches patients regardless of geographical and time constraints. Previous attempts at organ cryopreservation have largely failed due to ice formation, but a promising alternative is vitrification—the rapid cooling of organs to a stable, ice-free, glass-like state. However, rewarming of vitrified organs can similarly fail due to ice crystallization if too slow or cracking from thermal stress if not uniform. Here, we use "nanowarming," which employs alternating magnetic fields to heat nanoparticles within the organ vasculature, achieving both rapid and uniform warming, after which the nanoparticles are removed by perfusion. We demonstrate that vitrified kidneys can be cryogenically stored (up to 100 days) and successfully recovered by nanowarming to allow transplantation and restore life-sustaining full renal function in nephrectomized recipients in a male rat model. Our work extends this approach beyond kidneys to additional organs, and we are actively scaling the technology for larger organs, bringing us closer to the goal of organ banking for improved transplantation.
Bio: I am a transplant surgeon specializing in transplant immunology and organ preservation. My work is dedicated to overcoming the three major challenges in transplantation: the shortage of available organs, the need for lifelong immunosuppression, and the limited longevity of transplanted organs. I strive to develop solutions that ultimately improve outcomes for patients.
Cryopreservation of Zebrafish for Improved Biomedical Research
Joseph Kangas, PhD
Research Faculty and Lecturer
University of Minnesota
Abstract: Zebrafish (Danio rerio) are a critical model organism in genetic and biomedical research due to their genetic similarity to humans, rapid embryonic development, and utility in studying a wide range of diseases. Researchers have over 45,000 zebrafish lines, but maintaining these genetic resources is costly, logistically challenging, and prone to genetic drift, particularly for lines with complex genetics and/or mitochondrial and maternal traits that cannot be preserved via sperm cryopreservation.
Reliable zebrafish embryo cryopreservation methods would resolve these challenges, enabling long-term storage and recovery of entire (diploid and mitochondrial) genomes. Our group has developed the first successful zebrafish embryo cryopreservation protocol, combining microinjection of cryoprotectants (CPAs) and plasmonic nanoparticles with laser rewarming. This method has demonstrated survival to adulthood with normal fecundity and physiology, with recent refinements achieving nearly a 10% survival rate to day 5 post-fertilization.
Bio: Joseph Kangas is research faculty in the Department of Mechanical Engineering at the University of Minnesota. His research focuses on applied cryopreservation and low temperature physics. Specialties: cell and organism cryopreservation, advanced cooling and warming technologies, biotransport, heat transfer, fluid dynamics, laser-nanoparticle systems, and multiphysics modeling of complex systems.
Session Organizer
John Bischof, PhD
Director, Institute for Engineering in Medicine
Director, Advanced Technologies for the Preservation of Biological Systems (ATP-Bio)
Director, Clinical and Translational Science Institute, Office of Discovery and Translation
Medtronic-Bakken Endowed Chair for Engineering in Medicine
Distinguished McKnight University Professor, Department of Mechanical Engineering