Ayse Asatekin, Tufts University
Host: Prof. Jay Werber
Membranes offer a highly energy-efficient, simple to operate, scalable and portable separation method for many applications, from water treatment to oil and gas processing to pharmaceutical manufacturing. Yet, their broader use is often limited by insufficient selectivity and/or fouling with complex feeds. There are no commercial membranes that can separate small molecules of similar size in the liquid phase based on their chemical properties. We aim to develop new synthetic polymer membranes that accomplish this by self-assemble and create structures that mimic key features of biological pores like ion channels and porins: Constricted pores <5 nm in diameter that confine permeation, lined with functional groups that interact with the target during passage. Our first approach utilized the self-assembly of zwitterionic amphiphilic copolymers (ZACs), synthesized from a hydrophobic and a zwitterionic monomer. When ZACs are coated onto a support to form a thin film composite (TFC) membrane, self-assembled zwitterionic domains act as a network of nanochannels for water permeation. Our first ZAC-based thin film composite (TFC) membranes were size-selective with an effective pore size of ~1.3-1.5 nm. These membranes are exceptionally fouling resistant. We then developed cross-linkable ZACs (X-ZACs), which enabled us to access smaller effective pore sizes, down to ~0.9 nm, where ion separations are possible. Our membranes with the smallest pore sizes exhibited unprecedented selectivity between equally charged anions, including the highest Cl–/F– selectivity in the literature. This selectivity arises from zwitterion-ion interactions, which affect both ion partitioning and ion diffusivity, further emphasized through nanoconfinement. This opens the door to novel membranes with novel selectivity between molecules and ions of similar size and charge, mediated through channel-solute interactions. More recently, we have been exploring new avenues to prepare membranes the self-assembled nanopores and fouling resistance of ZAC-based membranes, but expand the range of separations accessible. We have developed amphiphilic polyampholytes (APAs), where hydrophobic, anionic, and cationic monomers form a random/statistical terpolymer that is insoluble in water. This approach allows access to a very broad array of functional groups lining the effective nanopores of these membranes, opening the door for complex separations. Alternatively, we have formed amphiphilic polyelectrolyte complex (APEC) membranes by coating consecutive layers of two amphiphilic polyelectrolytes (i.e. water-insoluble copolymers combining a hydrophobic monomer with either an anionic or a cationic monomer). Interestingly, these bilayer membranes exhibit very small effective pore sizes as well as higher permeances, implying selectivity arises from the formation of polyelectrolyte complexes at a thin interface between these layers. These approaches demonstrate a versatile and highly customizable approach for developing novel high-performance membranes.
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Ayse Asatekin is an associate professor in the Chemical and Biological Engineering Department at Tufts University, and Steve and Kristen Remondi Faculty Fellow. She received bachelor’s degrees in chemical engineering and chemistry from the Middle East Technical University (METU) in Ankara, Turkey. She went on to receive her Ph.D. in chemical engineering through the Program in Polymer Science and Technology (PPST) at MIT. She pursued her post-doctoral work with Prof. Karen K. Gleason, also at MIT. She co-founded Clean Membranes, Inc., a start-up company that commercialized a membrane technology that she began developing during her doctoral research, and worked as its Principal Scientist before joining the Tufts faculty in 2012. Novel membrane technologies developed in her lab are currently being commercialized by ZwitterCo, Inc., where she serves as the Senior Scientific Advisor. She is a Senior Member of the National Academy of Inventors, and the recipient of the NSF CAREER Award, Massachusetts Clean Energy Council’s Catalyst Award, and the Turkish American Scientists and Scholars Young Scholar Award. Her research interests are in developing novel membranes for clean water and energy-efficient separations through polymer self-assembly. She is also interested in multi-functional membranes, controlling surface chemistry for biomedical applications, polymer science, and energy storage.
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Join author Jeff Karp to celebrate the launch of his much-anticipated new book, LIT: Life Ignition Tools. The event will feature a conversation between Jeff Karp and University of Toronto Professor Dr. Milicia Radisic, followed by a reading, Q&A, and signing.
About the Speakers
Jeff Karp, PhD, is an acclaimed mentor and biomedical engineering professor at Harvard Medical School and MIT, a Distinguished Chair at Brigham and Women’s Hospital, and a fellow of the National Academy of Inventors. He has dedicated his research to bioinspired medical problem-solving, and his lab’s technologies have led to the formation of twelve companies. The technologies they have developed include a tissue glue that can seal holes inside a beating heart; targeted therapy for osteoarthritis, Crohn’s disease, and brain disorders; “smart needles” that automatically stop when they reach their target; a nasal spray that neutralizes pathogens; and immunotherapy approaches to annihilate cancer. Dr. Karp is also head of innovation at Geoversity, Nature’s University, a rainforest conservancy located in one of the top biodiversity hotspots in the world. He was selected as the Outstanding Faculty Undergraduate Mentor among all faculty at MIT and the top graduate student mentor of Harvard-MIT students. Dr. Karp lives in Brookline, Massachusetts, with his wife, children, and two Cavalier King Charles spaniels.
Dr. Milica Radisic is a Professor at the University of Toronto, Tier 1 Canada Research Chair in Organ-on-a-Chip Engineering and a Senior Scientist at the Toronto General Research Institute. She is also Director of the NSERC CREATE Training Program in Organ-on-a-Chip Engineering & Entrepreneurship and a co-lead for the Center for Research and Applications in Fluidic Technologies. She is a Fellow of the Royal Society of Canada-Academy of Science, Canadian Academy of Engineering, the American Institute for Medical & Biological Engineering, Tissue Engineering & Regenerative Medicine Society as well as Biomedical Engineering Society. Her impressive accolades include being recognized in the MIT Technology Review Top 35 Under 35, as well as receiving the Queen Elizabeth II Diamond Jubilee Medal, NSERC E.W.R Steacie Fellowship, YWCA Woman of Distinction Award, Killam Fellowship, Acta Biomaterialia Silver Medal, and Humboldt Research Award to name a few. Her research focuses on organ-on-a-chip engineering and development of new biomaterials that promote healing and attenuate scarring.
About LIT: Life Ignition Tools
In the age of convenience, information overload, and endless exposure to stimuli, it’s easy to trudge through the motions of life, pressured, distracted, and seeking instant gratification. When this way of living becomes the norm, it can immobilize us, making it feel impossible to reclaim control of our lives with intention and enthusiasm.
In LIT (William Morrow; April 9, 2024), Harvard Medical School professor, Mass General Brigham and MIT researcher, and renowned bioinspirationalist Jeff Karp, PhD, teaches us to harness the vital wisdom and power of nature to place us into a lit state. Lit is a life magnifier, a heightened state of awareness that drives curiosity, connection, and energy. In short: being lit takes us off autopilot and helps us stay alert, present, and fully engaged.
Diagnosed with learning differences and ADHD at a young age, Karp persisted through nearly insurmountable struggles. After discovering that he could think about thinking at age seven, he became his own science experiment, tapping into the lit state through trial and error to achieve hyper-awareness and explore his curiosity, creativity, and connection to nature. Decades later, as a biotech innovator, husband, and father, lit continues to encourage opportunities for innovation in his professional and personal lives.
He has honed those methods into a diverse toolkit that he calls Life Ignition Tools (LIT), which help us:
- Break out of habitual thinking to discover our own imaginative power.
- Stimulate creativity and excitement at work.
- Integrate our spiritual and personal lives to repair and deepen our relationships.
- Navigate multiple streams of sensory input and manage information overload.
Lit has inspired Dr. Karp’s innovative medical discoveries such as surgical glue inspired by slugs, a diagnostic for cancer based on the tentacles of jellyfish, and surgical staples based on the quills of a porcupine – but you don’t have to be a scientist to live lit. Anyone can use these principles to redirect their lives with energy, focus, creativity, and motivation to create the lives they truly want to lead.
Abstract
Sustainability has many facets and, in this presentation, I will share my recent research endeavors aimed at advancing sustainability in the realms of energy, water, and medicine. The first part of my talk delves into electrochemical transport phenomena in energy storage systems, with a focus on Li plating and dendritic growth on graphite/Li-metal anode, which are the leading causes of degradation and catastrophic failure for batteries under fast charging conditions. Deep understanding of these phenomena would facilitate the design of strategies to reduce, or completely suppress, the onset of lithium plating on the graphite anode, and the instabilities characterizing electrodeposition on the lithium metal anode.
In the second part of my talk, I will present my recent work on the efficient estimation of evapotranspiration for smart agriculture. This includes advancements that accelerate computational time by two orders of magnitude compared to the current standard approach. Finally, I will discuss two biomedical applications: blood transfusion and hypertonic treatment of acute respiratory distress syndrome (ARDS). These efforts contribute to sustainable energy conversion and storage, sustainable agricultural practices, and sustainable blood management, steering us towards a more sustainable future.
Biography
Weiyu Li is a postdoctoral scholar in the Departments of Physics and Materials Science and Engineering at Stanford University. Her research focuses on modeling and simulation of electrochemical transport in energy storage systems. She received her PhD in Energy Science and Engineering from Stanford University. Her other research interests include data assimilation and biomedical modeling. Prior to her doctoral studies, Weiyu obtained her M.Sc. degree in Mechanical and Aerospace Engineering from Princeton University. Weiyu is the sole recipient of the Siebel Scholars Award in Energy Science, class of 2023. She has also received Henry J. Ramey Fellowship Award at Stanford University, and the Princeton University Fellowship in Natural Sciences and Engineering.
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Idiopathic Pulmonary Fibrosis (IPF) is a chronic, progressive, and often fatal disorder for which there are two FDA-approved anti-fibrotic drugs, nintedanib, and pirfenidone. While these drugs slow the rate of decline in lung function, responses are variable and side effects are common. Using an in-silico data-driven approach, we identified a strong inverse connection between the transcriptomic perturbations in IPF disease and those induced by saracatinib, a selective Src kinase inhibitor, originally developed for oncological indications. Accordingly, we investigated the anti-fibrotic efficacy of saracatinib relative to nintedanib and pirfenidone in three preclinical models: (i) in vitro in normal human lung fibroblasts (NHLFs); (ii) in vivo in bleomycin and recombinant adenovirus transforming growth factor-beta (Ad-TGF-β) murine models of pulmonary fibrosis; and (iii) ex vivo in mice and human precision cut lung slices from these two murine models as well as from patients with IPF and healthy donors. In each model, the effectiveness of saracatinib in blocking fibrogenic responses was equal or superior to nintedanib and pirfenidone. Transcriptomic analyses of TGF-β-stimulated NHLFs identified specific gene sets associated with fibrosis including epithelial mesenchymal transition (EMT), TGF-β, and WNT signaling that was uniquely altered by saracatinib. Transcriptomic analysis of whole lung extracts from the two animal models of pulmonary fibrosis revealed that saracatinib reverted many fibrogenic pathways including EMT, immune responses, and extracellular matrix organization. Amelioration of fibrosis and inflammatory cascades in human precision cut lung slices confirmed the potential therapeutic efficacy of saracatinib in human lung fibrosis. These studies identify novel Src-dependent fibrogenic pathways and support the study of the therapeutic effectiveness of saracatinib in IPF treatment.
Biography
Dr. Downey received his MD from the University of Manitoba and completed Internship and Residency in Internal Medicine at Harvard Medical School, Beth Israel and Brigham and Women’s Hospital, Boston. He then completed clinical training in Pulmonary and Critical Care Medicine at the University of Colorado, Denver. He undertook post-doctoral research training in Immunology in the laboratory of Dr. Peter Henson at National Jewish Health. He was appointed Assistant Professor at the University of Toronto rising through the ranks to become the Director of the Division of Respirology, Professor and Vice-Chair, Department of Medicine, and the recipient of a Tier 1 Canada Research Chair in Respiration Sciences. Dr. Downey returned to Colorado as Executive Vice President of Academic Affairs and Provost and Professor of Medicine, Pediatrics, and Immunology and Genomic Medicine at National Jewish Health, and Professor of Medicine and Immunology and Microbiology and Associate Dean of the School of Medicine, University of Colorado. His current research interests include innate immunity, signaling mechanisms involved in acute lung injury/ARDS, the effects of particulate matter exposure on lung health, and mechanisms and treatment of pulmonary fibrosis. His research has been funded by the National Institutes of Health, the Canadian Institutes of Health Research, and the US Department of Defense for over 30 years. Dr. Downey has >250 publications in top ranked journals including the New England Journal of Medicine, Science, Science Translational Medicine, Nature Cell Biology, the Journal of Cell Biology, the American Journal of Respiratory and Critical Care Medicine, the Journal of Experimental Medicine, Blood, PNAS, the American Journal of Respiratory Cell and Molecular Biology, and the Journal of Immunology and his work has been cited over 23,000 times by other authors (h-index 83). Dr. Downey is a member of the American Society for Clinical Investigation, the Association of American Physicians, the American Thoracic Society, the American College of Chest Physicians, the Royal College of Physicians and Surgeons of Canada. He currently serves as the Immediate Past President of the American Thoracic Society.
This talk presents some preliminary findings from an in-process study of hydrocarbon-eating microbes and the humans who have discovered, researched, cared for, grown, killed, sold, and otherwise interacted with them. Following some discussion of why this topic seems of interest in and beyond anthropology and science/technology studies, I focus on some historical examples that range from the early years of petroleum microbiology in Russia through the Cold War-era race to develop “petroprotein.” I conclude with some questions prompted by contemporary research in this field, including but not limited to bioremediation.
Douglas Rogers
is Professor of Anthropology at Yale University and author of two award-winning books about Russia. For the past few years, he has been collecting materials for a new research project about the history and contemporary practice of petroleum microbiology and biotechnology. He was recently named a 2024 Fellow of the John Simon Guggenheim Memorial Foundation.
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Academic libraries are facing a myriad number of challenges and opportunities ahead. AI is just one example. Paint a picture of the science library of the future – what will it offer to remain core to teaching, learning, research and the overall student experience? How will you, as a leader, prepare the health science and science libraries for that future?
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Abstract
Bioaugmentation has emerged as an effective way to remediate groundwater of anthropogenic contaminants, such as chloroform (CF) and dichloromethane (DCM). The Dehalobacter genus can anaerobically respire many of these chlorinated compounds using reductive dehalogenases, often as part of a heterogenous microbial community. One such community is SC05, which dechlorinates CF completely to carbon dioxide and hydrogen. Despite its effective use at contaminated sites, prior to this work SC05 remained unstudied in terms of taxonomy and broader metabolism, without identification of the active DCM degrader(s?). This thesis seeks to ascertain key microbes in the culture and their metabolic mechanisms using experimental, metagenomic, and metabolic modelling approaches.
A unique characteristic of “self-feeding” is first established in SC05, wherein electron equivalents produced from DCM mineralization are harnessed for CF dechlorination. An SC05 subculture continually dechlorinated CF for over 1400 days with no exogenous electron donor. Dehalobacter was the only bacterial genus that grew in either the CF dechlorination or DCM mineralization phase, implicating it as a key mediator of both CF and DCM degradation. Dehalobacter expressed a single reductive dehalogenase that dechlorinates CF to DCM but has no activity on DCM, as well as the mec cassette—core proteins for DCM degradation. These two modules were within 10 kb in a single genomic neighbourhood.
Two unique Dehalobacter genomes were ultimately assembled, each of which encoded the acd- mec neighbourhood. When assessed pangenomically, this region was designated as a mobile genetic element resulting from horizontal gene transfer between Dehalobacter strains. Each strain could employ this shared genetic cargo to dechlorinate CF and mineralize DCM, with differing dynamics dependant on culture conditions. Genome-scale metabolic models of each strain were curated to predict and compare metabolism during each remediation step.
Overall, this work elucidates some of the former mysteries of SC05, informing considerations for field application such as electron donor demand. It also highlights the importance of hydrogen cycling and microbial syntrophy in anaerobic DCM degradation. Fundamentally, it expands the typical assumptions of the metabolic rigidity of Dehalobacter genus and posits mechanisms of evolution and horizontal gene transfer as it pertains to adaptation of microbial communities to anthropogenic chemicals.
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Abstract: Food fortification programs aim to provide meaningful amounts of micronutrients (e.g., 30%-50% of the daily adult requirements) at the average consumption level of one or more food vehicles. Foods that can be fortified include wheat and wheat products, maize, rice, milk and milk products, cooking oils, salt, sugar, and condiments. New vehicles widely and regularly consumed in certain regions, like bouillon cubes, flavouring sauces, or tea, are also gaining new attention. Micronutrient premixes for home fortification are also being promoted. Depending on the food processing methods, adding the micronutrients can be facilitated using different approaches to maximize nutrient retention. These include dry mixing, dissolution in water/oil, micronization, spraying, adhesion, coating, extrusion, micro-encapsulation, and dry mixing.
Cost, bioavailability, sensory acceptability, and stability (during storage and cooking) are the critical criteria for determining the best match between the nutrient and food vehicle. When added to food or beverage carriers, specific vitamins and minerals could interact with each other and the food, reducing their bioavailability and organoleptic quality. The development of appropriate technology to optimize the effectiveness of fortification needs special attention.
Better refining procedures and packaging have significantly improved the stability of iodine compounds in salt and vitamin A in cooking oils. The structure of the compounds can also be modified to improve absorption. In the case of iron, stabilizers, chelating agents, and absorption enhancers could be added along with the fortificant to retain it in an absorbable form or improve absorption. The extrusion and micro-encapsulation of micronutrients can ensure nutrient stability while ensuring breakdown and absorption in the gut. Technological improvements in the analytical methods for testing fortified foods have been developed specifically to monitor nutrient retention from production to consumption.
Speaker Bio
M.G. Venkatesh Mannar has pioneered several effective international nutrition, technology, and development initiatives focused on the world’s most vulnerable citizens. A chemical engineer and food technologist by training, Mannar served as the President of the Micronutrient Initiative Canada (MI) for nearly 20 years until February 2014. He directed the organization’s mission to develop, implement, and monitor cost-effective and sustainable solutions to address micronutrient deficiencies. Mannar’s work has focused on the world’s most vulnerable citizens, including staple food fortification, vitamin A supplementation, and scale-up of biofortified food production and marketing. His work on iodization and multiple fortification of salt has been scaled up to benefit billions of people worldwide. The double-fortified salt (with iron and iodine) and multiply fortified salts he worked on at the University of Toronto are being scaled in India and other countries. He has co-authored over 100 articles in leading nutrition journals and is the co-editor of ‘Food Fortification in a Globalized World. Mannar pursues research and teaching as an Adjunct Professor at the Centre for Global Engineering at the University of Toronto. He was co-chair of the Independent Expert Group for the Global Nutrition Report 2020 – the leading and most authoritative report on Global Nutrition. He has also served on the Technical Advisory Boards of leading multinational food companies. In 2013, Mannar was appointed an Officer of the Order of Canada, one of the country’s greatest civilian honors, for his leadership in the global fight against malnutrition and micronutrient deficiency. In 2015, the Indo-Canada Chamber of Commerce felicitated him with an Outstanding Lifetime Achievement Award. In Jun 2016, he was conferred with an Honorary Doctor of Science Degree by the University of Toronto.
Dr. Jean-Christophe Leroux
Full Professor at the Department of Chemistry and Applied Biosciences
Deputy Head of Institute of Pharmaceutical Sciences, ETH Zürich
Abstract
Three-dimensional (3D) printing is a versatile technology enabling the cost-effective production of personalized medical devices. Among various 3D printing methods, digital light processing (DLP) stands out for its ability to rapidly create objects with high precision. However, the fabrication of bioresorbable medical devices using DLP is in part limited by the limited choice of suitable biomedical inks. In this study, we developed innovative polyester-based inks enabling DLP printing of therapeutic devices with adjustable mechanical characteristics and degradation profiles. The most promising materials were utilized to design biodegradable customized airway stents. These stents degraded into soft hydrogels in vitro and completely disappeared seven weeks after insertion in rabbits. Additionally, the 3D printed stents could be loaded with drugs like levofloxacin or nintedanib, and their release kinetics could be tailored by modifying the copolymer composition. Furthermore, we engineered near-infrared (NIR) light-responsive stents containing gold nanorods using tunable ink compositions. This allowed for the creation of shape-memory stents that expand upon NIR light activation, facilitating easy deployment. Lastly, DLP served as a prototyping method for the fabrication and optimization of mucosal suction patches investigated for transbuccal drug delivery. These studies open new perspectives for the rapid manufacturing of complex devices with superior properties.
Speaker Bio
Jean-Christophe Leroux is a full professor of Drug Formulation and Delivery at the Institute of Pharmaceutical Sciences at the ETH Zurich, Switzerland. He has made important fundamental and applied contributions to the fields of biomaterials and drug delivery and has been involved in the development of innovative bio-detoxification systems for the treatment of metabolite disorders. He is a fellow of the AAPS, EURASC, French Academy of Pharmacy, and the CRS, and the co-founder of the start-up pharmaceutical companies Versantis AG, Inositec AG and OBaris AG.
Abstract
Topological structures in ferroic materials can emerge as particle-like objects such as skyrmions
and merons, with real-space swirling arrangements of the order parameter that not only have
mathematical beauty but hold promise for potential applications in next generation nanodevices.
As those ferroic textures are intrinsically nm-scale and dynamic, developing methods for
visualizing and characterizing their detailed 3D structure is a critical step in understanding their
properties and exploring possible phase transitions. I will show how the measurement of
structural information such as polarization, strain, chirality, electric or magnetic fields was made
possible by new imaging methods, i.e., four-dimensional scanning transmission electron
microscopy (4D-STEM) diffraction imaging. I will report the observation of room temperature
Néel-type skyrmion in a van der Waals ferromagnet accompanied by a change in crystallographic
symmetry and chemical order. Second, I report the emergence of achiral polar meron lattice
(topological charge of +1/2) from disordered but chiral skyrmion (topological charge of +1) phase
transition driven by elastic boundary conditions. Further, using multislice electron ptychography,
the 3D structural distortions of unknown polar textures in complex oxide heterostructures can
be resolved at unprecedented resolution and precision.
Speaker Bio
Yu-Tsun Shao studies quantum materials by novel electron microscopy techniques, specifically
4D-STEM. He studies the (multi-)ferroic crystals with the aim to elucidate the microscopic origin
of interactions among local polar/magnetic order, strain, and chiralities during topological phase
transitions. Before joining USC, Yu-Tsun did postdoctoral work in Professor David Muller’s group
at Cornell University and received his Ph.D. in Materials Science and Engineering at the University
of Illinois at Urbana-Champaign in 2018, under the mentorship of Professor Jian-Min Zuo.