Visualization of a CAR T cell (in red) attacking a cancer cell (in blue) (Meletios Varras via Getty Images)
For patients with certain types of cancer, CAR T cell therapy has been nothing short of life changing. Developed in part by Carl June, Richard W. Vague Professor at Penn Medicine, and approved by the Food and Drug Administration (FDA) in 2017, CAR T cell therapy mobilizes patients’ own immune systems to fight lymphoma and leukemia, among other cancers.
However, the process for manufacturing CAR T cells themselves is time-consuming and costly, requiring multiple steps across days. The state of the art involves extracting patients’ T cells, then activating them with tiny magnetic beads, before giving the T cells genetic instructions to make chimeric antigen receptors (CARs), the specialized receptors that help T cells eliminate cancer cells.
Now, Penn Engineers have developed a novel method for manufacturing CAR T cells, one that takes just 24 hours and requires only one step, thanks to the use of lipid nanoparticles (LNPs), the potent delivery vehicles that played a critical role in the Moderna and Pfizer-BioNTech COVID-19 vaccines.
In a new paper in Advanced Materials, Michael J. Mitchell, Associate Professor in Bioengineering, describes the creation of “activating lipid nanoparticles” (aLNPs), which can activate T cells and deliver the genetic instructions for CARs in a single step, greatly simplifying the CAR T cell manufacturing process. “We wanted to combine these two extremely promising areas of research,” says Ann Metzloff, a doctoral student in Bioengineering and NSF Graduate Research Fellow in the Mitchell lab and the paper’s lead author. “How could we apply lipid nanoparticles to CAR T cell therapy?”
Penn Engineers have developed a way to target lung diseases, including lung cancer, with lipid nanoparticles (LNPs). (wildpixel via Getty Images)
Penn Engineers have developed a new means of targeting the lungs with lipid nanoparticles (LNPs), the miniscule capsules used by the Moderna and Pfizer-BioNTech COVID-19 vaccines to deliver mRNA, opening the door to novel treatments for pulmonary diseases like cystic fibrosis.
In a paper in Nature Communications, Michael J. Mitchell, Associate Professor in the Department of Bioengineering, demonstrates a new method for efficiently determining which LNPs are likely to bind to the lungs, rather than the liver. “The way the liver is designed,” says Mitchell, “LNPs tend to filter into hepatic cells, and struggle to arrive anywhere else. Being able to target the lungs is potentially life-changing for someone with lung cancer or cystic fibrosis.”
Previous studies have shown that cationic lipids — lipids that are positively charged — are more likely to successfully deliver their contents to lung tissue. “However, the commercial cationic lipids are usually highly positively charged and toxic,” says Lulu Xue, a postdoctoral fellow in the Mitchell Lab and the paper’s first author. Since cell membranes are negatively charged, lipids with too strong a positive charge can literally rip apart target cells.
Typically, it would require hundreds of mice to individually test the members of a “library” of LNPs — chemical variants with different structures and properties — to find one with a low charge that has a higher likelihood of delivering a medicinal payload to the lungs.
Instead, Xue, Mitchell and their collaborators used what is known as “barcoded DNA” (b-DNA) to tag each LNP with a unique strand of genetic material, so that they could inject a pool of LNPs into just a handful of animal models. Then, once the LNPs had propagated to different organs, the b-DNA could be scanned, like an item at the supermarket, to determine which LNPs wound up in the lungs.
Four University of Pennsylvania undergraduates have received 2024 Goldwater Scholarships, awarded to second- or third-year students planning research careers in mathematics, the natural sciences, or engineering.
They are among the 438 students named 2024 Goldwater Scholars from 1,353 undergraduates students nominated by 446 academic institutions in the United States, according to the Barry Goldwater Scholarship & Excellence in Education Foundation. Each scholarship provides as much as $7,500 each year for as many as two years of undergraduate study.
Mrksich, from Hinsdale, Illinois, is majoring in bioengineering. She is interested in developing drug delivery systems that can serve as novel therapeutics for a variety of diseases. Mrksich works in the lab of Michael J. Mitchell where she investigates the ionizable lipid component of lipid nanoparticles for mRNA delivery. At Penn, Mrksich is the president of the Biomedical Engineering Society, where she plans community building and professional development events for bioengineering majors. She is a member of the Kite and Key Society, where she organizes virtual programming to introduce prospective students to Penn. She is a member of Tau Beta Pi engineering honor society, and the Sigma Kappa sorority. She also teaches chemistry to high schoolers as a volunteer in the West Philadelphia Tutoring Project through the Civic House. After graduating, Mrksich plans to pursue an M.D./Ph.D. in bioengineering.
Mrksich was awarded a Student Award for Outstanding Research (Undergraduate) by the Society for Biomaterials earlier this year. Read the story in the BE Blog.
Like space shuttles using booster rockets to breach the atmosphere, lipid nanoparticles (LNPs) equipped with the new molecule more successfully deliver medicinal payloads. (Love Employee via Getty Images)
Inspired by the design of space shuttles, Penn Engineering researchers have invented a new way to synthesize a key component of lipid nanoparticles (LNPs), the revolutionary delivery vehicle for mRNA treatments including the Pfizer-BioNTech and Moderna COVID-19 vaccines, simplifying the manufacture of LNPs while boosting their efficacy at delivering mRNA to cells for medicinal purposes.
In a paper in Nature Communications, Michael J. Mitchell, Associate Professor in the Department of Bioengineering, describes a new way to synthesize ionizable lipidoids, key chemical components of LNPs that help protect and deliver medicinal payloads. For this paper, Mitchell and his co-authors tested delivery of an mRNA drug for treating obesity and gene-editing tools for treating genetic disease.
Previous experiments have shown that lipidoids with branched tails perform better at delivering mRNA to cells, but the methods for creating these molecules are time- and cost-intensive. “We offer a novel construction strategy for rapid and cost-efficient synthesis of these lipidoids,” says Xuexiang Han, a postdoctoral student in the Mitchell Lab and the paper’s co-first author.
In the human body, the lungs and their vasculature can be likened to a building with an intricate plumbing system. The lungs’ blood vessels are the pipes essential for transporting blood and nutrients for oxygen delivery and carbon dioxide removal. Much like how pipes can get rusty or clogged, disrupting normal water flow, damage from respiratory viruses, like SARS-CoV-2 or influenza, can interfere with this “plumbing system.”
In a recent study, researchers looked at the critical role of vascular endothelial cells in lung repair. Their work, published in Science Translational Medicine, was led by Andrew Vaughan of the University of Pennsylvania’s School of Veterinary Medicine and shows that, by using techniques that deliver vascular endothelial growth factor alpha (VEGFA) via lipid nanoparticles (LNPs), that they were able to greatly enhance modes of repair for these damaged blood vessels, much like how plumbers patch sections of broken pipes and add new ones.
“While our lab and others have previously shown that endothelial cells are among the unsung heroes in repairing the lungs after viral infections like the flu, this tells us more about the story and sheds light on the molecular mechanisms at play,” says Vaughan, assistant professor of biomedical sciences at Penn Vet. “Here we’ve identified and isolated pathways involved in repairing this tissue, delivered mRNA to endothelial cells, and consequently observed enhanced recovery of the damaged tissue. These findings hint at a more efficient way to promote lung recovery after diseases like COVID-19.”
They found VEGFA’s involvement in this recovery, while building on work in which they used single cell RNA sequencing to identify transforming growth factor beta receptor 2 (TGFBR2) as a major signaling pathway. The researchers saw that when TGFBR2 was missing it stopped the activation of VEGFA. This lack of signal made the blood vessel cells less able to multiply and renew themselves, which is vital for the exchange of oxygen and carbon dioxide in the tiny air sacs of the lungs.
“We’d known there was a link between these two pathways, but this motivated us to see if delivering VEGFA mRNA into endothelial cells could improve lung recovery after disease-related injury,” says first author Gan Zhao, a postdoctoral researcher in the Vaughan Lab.
“LNPs have been great for vaccine delivery and have proven incredibly effective delivery vehicles for genetic information. But the challenge here was to get the LNPs into the bloodstream without them heading to the liver, which is where they tend to congregate as its porous structure lends favor to substances passing from the blood into hepatic cells for filtration,” says Mitchell, an associate professor of bioengineering at Penn Engineering and a coauthor of the paper. “So, we had to devise a way to specifically target the endothelial cells in the lungs.”
Lulu Xue, a postdoctoral researcher in the Mitchell Lab and a co-first author of the paper, explains that they engineered the LNP to have an affinity for lung endothelial cells, this is known as extra hepatic delivery, going beyond the liver.
From left: Emily Han, Rohan Palanki, Jacqueline Li, Michael Mitchell, Dongyoon Kim, and Marshall Padilla of Penn Engineering.
Imagine the brain as an air traffic control tower, overseeing the crucial and complex operations of the body’s ‘airport.’ This tower, essential for coordinating the ceaseless flow of neurological signals, is guarded by a formidable layer that functions like the airport’s security team, diligently screening everything and everyone, ensuring no unwanted intruders disrupt the vital workings inside.
However, this security, while vital, comes with a significant drawback: sometimes, a ‘mechanic’—in the form of critical medication needed for treating neurological disorders—is needed inside the control tower to fix arising issues. But if the security is too stringent, denying even these essential agents entry, the very operations they’re meant to protect could be jeopardized.
Now, researchers led by Michael Mitchell of the University of Pennsylvania are broaching this long-standing boundary in biology, known as the blood-brain barrier, by developing a method akin to providing this mechanic with a special keycard to bypass security. Their findings, published in the journal Nano Letters, present a model that uses lipid nanoparticles (LNPs) to deliver mRNA, offering new hope for treating conditions like Alzheimer’s disease and seizures—not unlike fixing the control tower’s glitches without compromising its security.
“Our model performed better at crossing the blood-brain barrier than others and helped us identify organ-specific particles that we later validated in future models,” says Mitchell, associate professor of bioengineering at Penn’s School of Engineering and Applied Science, and senior author on the study. “It’s an exciting proof of concept that will no doubt inform novel approaches to treating conditions like traumatic brain injury, stroke, and Alzheimer’s.”
Kaitlin Mrksich, an undergraduate student in Penn Bioengineering, was honored with the Student Award for Outstanding Research (Undergraduate) by the Society for Biomaterials (SFB). This prestigious award recognizes undergraduate students who have shown outstanding achievement in biomaterials research.
Mrksich is a third-year student from Hinsdale, Illinois. She is interested in developing drug delivery systems that can serve as novel therapeutics for a variety of diseases. She works in the lab of Michael Mitchell, Associate Professor in Bioengineering. In the Mitchell Lab, Mrksich investigates the ionizable lipid component of lipid nanoparticles for mRNA delivery.
“In Kaitlin’s independent projects, she has focused on probing the role of lipophilicity and chirality for LNP-mediated mRNA delivery,” Mitchell said in the award announcement. “She has synthesized dozens of unique lipids, formulated these lipids into LNPs, and evaluated their potential for mRNA delivery in vivo and in primary T cells. She has been able to deduce structure-function relationships that help explain the role of lipid hydrophobicity in the delivery of mRNA by LNPs. Her findings have not only been instrumental in helping our lab design better LNPs but will also provide fundamental knowledge that will benefit all labs working on LNP technology.”
In addition to her academic activities, Mrksich is also the President of the Penn Biomedical Engineering Society (BMES), where she plans community-building and professional-development events for bioengineering majors, and the visit coordinator for special programs for the Kite and Key Society, where she organizes virtual programming to introduce prospective students to Penn. She also tutors a West Philadelphia high school student in chemistry as part of the West Philadelphia Tutoring Project and is a member of Tau Beta Pi engineering honor society and Sigma Kappa sorority. After graduating, she plans to pursue an M.D.-Ph.D. in Bioengineering.
Read the full list of 2024 SFB award recipients here.
Vaccines for COVID-19 were the first time that mRNA technology was used to address a worldwide health challenge. The Penn Medicine scientists behind that technology were awarded the 2023 Nobel Prize in Physiology or Medicine. Next come all the rest of the potential new treatments made possible by their discoveries.
But curbing the pandemic was only the beginning of the potential for this Nobel Prize-winning technology.
These biomedical innovations from Penn Medicine in using mRNA represent a multi-use tool, not just a treatment for a single disease. The technology’s potential is virtually unlimited; if researchers know the sequence of a particular protein they want to create or replace, it should be possible to target a specific disease. Through the Penn Institute for RNA Innovation led by Weissman, who is the Roberts Family Professor of Vaccine Research in Penn’s Perelman School of Medicine, researchers are working to ensure this limitless potential meets the world’s most challenging and important needs.
Infectious Diseases and Beyond
Just consider some of the many projects Weissman’s lab is partnering in: “We’re working on malaria with people across the U.S. and in Africa,” Weissman said. “We’re working on leptospirosis with people in Southeast Asia. We’re working on vaccines for peanut allergies. We’re working on vaccines for autoimmunity. And all of this is through collaboration.”
Clinical trials are underway for the new malaria vaccine, as well as for a Penn-developed mRNA vaccine for genital herpes and one that aims to protect against all varieties of coronaviruses. Trials should begin soon for vaccines for norovirus and the bacterium C. difficile.
Single-Injection Gene Therapies for Sickle Cell and Heart Disease
Drew Weissman, MD, PhD, is a co-winner of the 2023 Nobel Prize in Physiology or Medicine for discoveries with mRNA.
The Weissman lab is working to deploy mRNA technology as an accessible gene therapy for sickle cell anemia, a devastating and painful genetic disease that affects about 20 million people around the world. About 300,000 babies are born each year with the condition, mainly in sub-Saharan Africa. Weissman’s team has developed technology to efficiently deliver modified mRNA to bone marrow stem cells, instructing red blood cells to produce normal hemoglobin instead of the malformed “sickle” version that causes the illness. Conventional gene therapies are complex and expensive treatments, but the mRNA gene therapy could be a simple, one-time intravenous injection to cure the disease. Such a treatment would have applications to many other congenital gene defects in blood and stem cells.
In another new program, Penn Medicine researchers have found a way to target the muscle cells of the heart. This gene therapy method developed by Weissman’s team, together with Vlad Muzykantov, MD, PhD, the Founders Professor in Nanoparticle Research could potentially repair the heart or increase blood flow to the heart, noninvasively, after a heart attack or to correct a genetic deficiency in the heart. “That is important because heart disease is the number one killer in the U.S. and in the world,” Weissman said. “Drugs for heart disease aren’t specific for the heart. And when you’re trying to treat a myocardial infarction or cardiomyopathy or other genetic deficiencies in the heart, it’s very difficult, because you can’t deliver to the heart.”
Weissman’s team also is partnering on programs for neurodevelopmental diseases and for neurodegenerative diseases, to replace genes or deliver therapeutic proteins that will treat and potentially cure these diseases.
“The potential is unbelievable,” Weissman said. “We haven’t thought of everything that can be done.”
Vladimir R. Muzykantov is Founders Professor in Nanoparticle Research in the Department of Systems Pharmacology and Translational Therapeutics in the Perelman School of Medicine. He is a member of the Penn Bioengineering Graduate Group.
Ajay Thatte, Benjamin Nachod, Rohan Palanki, Kelsey Swingle, Alex Hamilton, and Michael Mitchell (Left to Right – Courtesy of the Mitchell Lab)
Autoimmune disorders are among the most prevalent chronic diseases across the globe, affecting approximately 5-7% of the world’s population. Emerging treatments for autoimmune disorders focus on “adoptive cell therapies,” or those using cells from a patient’s own body to achieve immunosuppression. These therapeutic cells are recognized by the patient’s body as ‘self,’ therefore limiting side effects, and are specifically engineered to localize the intended therapeutic effect.
In treating autoimmune diseases, current adoptive cell therapies have largely centered around the regulatory T cell (Treg), which is defined by the expression of the Forkhead box protein 3, orFoxp3. Although Tregs offer great potential, using them for therapeutic purposes remains a major challenge. In particular, current delivery methods result in inefficient engineering of T cells.
Tregs only compose approximately 5-10% of circulating peripheral blood mononuclear cells. Furthermore, Tregs lack more specific surface markers that differentiate them from other T cell populations. These hurdles make it difficult to harvest, purify and grow Tregs to therapeutically relevant numbers. Although there are additional tissue-resident Tregs in non-lymphoid organs such as in skeletal muscle and visceral adipose tissue, these Tregs are severely inaccessible and low in number.
“The major challenges associated with ex vivo (outside the body) cell engineering are efficiency, toxicity, and scale-up: our mRNA lipid nanoparticles (mRNA LNPs) allow us to overcome all of these issues,” says Mitchell. “Our work’s novelty comes from three major components: first, the use of mRNA, which allows for the generation of transient immunosuppressive cells; second, the use of LNPs, which allow for effective delivery of mRNA and efficient cell engineering; and last, the ex vivo engineering of primary human T cells for autoimmune diseases, offering the most direct pipeline for clinical translation of this therapy from bench to bedside.”
“To our knowledge, this is one of the first mRNA LNP platforms that has been used to engineer T cells for autoimmune therapies,” he continues. “Broadly, this platform can be used to engineer adoptive cell therapies for specific autoimmune diseases and can potentially be used to create therapeutic avenues for allergies, organ transplantation and beyond.”
Delivering the Foxp3 protein to T cells has been difficult because proteins do not readily cross the cell membrane. “The mRNA encodes for Foxp3 protein, which is a transcription factor that makes the T cells immunosuppressive rather than active,” explains first author Ajay Thatte, a doctoral student in Bioengineering and NSF Fellow in the Mitchell Lab. “These engineered T cells can suppress effector T cell function, which is important as T cell hyperactivity is a common phenotype in autoimmune diseases.”
On September 14, Wexford Science & Technology, LLC and the University of Pennsylvania announced that the University has signed a lease for new laboratory space that will usher in a wave of novel vaccine, therapeutics, and engineered diagnostics research to West Philadelphia. Research teams from Penn are poised to move into 115,000 square feet of space at One uCity Square, the 13-story, 400,000 square foot purpose-built lab and office building within the vibrant uCity Square Knowledge Community being developed by Wexford. This is the largest lease in the building, encompassing four floors, and bringing the building to over 90% leased. The building currently includes industry tenants Century Therapeutics (NASDAQ: IPSC), Integral Molecular, Exponent (NASDAQ: EXPO), and Charles River Laboratories (NYSE: CRL).
The new University space will house Penn Medicine’s Institute for RNA Innovation and Penn Engineering’s Center for Precision Engineering for Health, underscoring the University’s commitment to a multi-disciplinary and collaborative approach to research that will attract and retain the best talent and engage partners from across the region. Penn’s decision to locate at One uCity Square reinforces uCity Square’s evolution as a central cluster of academic, clinical, commercial, entrepreneurial, and amenity spaces for the area’s innovation ecosystem, and further cements Philadelphia’s position as a top life sciences market.
Jonathan Epstein, MD, Executive Vice Dean and Chief Scientific Officer of Penn Medicine, shared his anticipation for the opportunities that lie ahead: “Penn Medicine is proud to build on its existing clinical presence in uCity Square and establish an innovative and collaborative research presence at the heart of uCity Square’s multidisciplinary innovation ecosystem. This strategic move underscores our commitment to accelerating advancements in biomedical research, industry collaboration, and equipping our talented teams with the resources they need to shape the future of healthcare.”
Locating the Penn Institute for RNA Innovation in the heart of the uCity Square community brings together researchers across disciplines who are already pursuing new vaccines and treatments, and better ways to deliver them. Their shared work will help to power the next phase of vaccine discovery and development.
Likewise, anchoring the work of Penn Engineering’s Center in the One uCity Square space will allow the School’s multi-disciplinary researchers and their collaborators to advance new clinical and diagnostic methods that will focus on intelligent therapeutics, genome design, diagnostics for discovery of human biology, and engineering the human immune shield.
“Penn Engineering has made a substantial commitment to precision engineering for health, an area that is not only important and relevant to engineering, but also critical to the future of humanity,” said Vijay Kumar, Nemirovsky Family Dean of Penn Engineering. “The space in One uCity Square will add another 30,000 square feet of space for our engineers to develop technologies that will fight future pandemics, cure incurable diseases, and extend healthy life spans around the world.”
Spearheading the Penn Institute for RNA Innovation will be Drew Weissman, MD, PhD, the Roberts Family Professor for Vaccine Research, who along with Katalin Karikó, PhD, adjunct professor of Neurosurgery, discovered foundational mRNA technology that enabled the creation of vital vaccine technology, including the FDA-approved mRNA-based COVID-19 vaccines developed by Pfizer-BioNTech and Moderna.
In this new space at One uCity Square, Weissman and his research team and collaborators will further pursue their groundbreaking research efforts with a goal to develop new therapeutics and vaccines and initiate clinical trials for other devastating diseases.
In addition, two established researchers will join the Institute at One uCity Square: Harvey Friedman, MD, a professor of Infectious Diseases, who leads a team researching various vaccines. He will be joined by Vladimir Muzykantov, MD, PhD, Founders Professor in Nanoparticle Research, who focuses on several projects related to targeting the delivery of drugs, including mRNA, to create more effective, targeted pathways to deliver drugs to the vascular system, treating a wide range of diseases that impact the brain, lung, heart, and blood.
Dan Hammer, Alfred G. and Meta A. Ennis Professor in the Departments of Bioengineering and Chemical and Biomolecular Engineering in Penn Engineering and Director of the Center for Precision Engineering for Health, will oversee the Center’s innovations in diagnostics and delivery, cellular and tissue engineering, and the development of new devices that integrate novel materials with human tissues. The Center will bring together scholars from all departments within Penn Engineering and will help to foster increased collaboration with campus colleagues at Penn’s Perelman School of Medicine and with industry partners.
Joining the Center researchers in One uCity Square are Noor Momin, Sherry Gao, and Michael Mitchell. Noor Momin, who will join Penn Engineering in early 2024 as an assistant professor in Bioengineering, will leverage her lab’s expertise in cardiovascular immunology, protein engineering and pharmacokinetic modeling to develop next-generation treatments and diagnostics for cardiovascular diseases.
