Tag: biomedical engineering

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Carl June on the Boundless Potential of CAR T Cell Therapy

by Meagan Raeke

Carl June, at the flash mob celebration of the FDA approval of the CAR T cell therapy he developed, in August 2017. (Image: Courtesy of Penn Medicine Magazine)

For most of modern medicine, cancer drugs have been developed the same way: by designing molecules to treat diseased cells. With the advent of immunotherapy, that changed. For the first time, scientists engineered patients’ own immune systems to recognize and attack diseased cells.

One of the best examples of this pioneering type of medicine is CAR T cell therapy. Invented in the Perelman School of Medicine by Carl June, the Richard W. Vague Professor in Immunotherapy, CAR T cell therapy works by collecting T cells from a patient, modifying those cells in the lab so that they are designed to destroy cancerous cells, and reinfusing them into the patient. June’s research led to the first FDA approval for this type of therapy, in 2017. Six different CAR T cell therapies are now approved to treat various types of blood cancers. Carl June, at the flash mob celebration of the FDA approval of the CAR T cell therapy he developed, in August 2017. (Image: Courtesy of Penn Medicine Magazine)

CAR T cell therapy holds the potential to help millions more patients—if it can be successfully translated to other conditions. June and colleagues, including Daniel Baker, a fourth-year doctoral student in the Cell and Molecular Biology department, discuss this potential in a perspective published in Nature.

In the piece, June and Baker highlight other diseases that CAR T cell therapy could be effective.

“CAR T cell therapy has been remarkably successful for blood cancers like leukemias and lymphomas. There’s a lot of work happening here at Penn and elsewhere to push it to other blood cancers and to earlier stage disease, so patients don’t have to go through chemo first,” June says. “Another big priority is patients with solid tumors because they make up the vast majority of cancer patients. Beyond cancer, we’re seeing early signs that CAR T cell therapy could work in autoimmune diseases, like lupus.”

As for which diseases to pursue as for possible future treatment, June says, “essentially it boils down to two questions: Can we identify a population of cells that are bad? And can we target them specifically? Whether that’s asthma or chronic diseases or lupus, if you can find a bad population of cells and get rid of them, then CAR T cells could be therapeutic in that context.”

“What’s exciting is it’s not just theoretical at this point. There have been clinical reports in other autoimmune diseases, including myasthenia gravis and inflammatory myopathy,” Baker says. “But we are seeing early evidence that CAR T cell therapy will be successful beyond cancer. And it’s really opening the minds of people in the field to think about how else we could use CAR T. For example, there’s some pioneering work at Penn from the Epstein lab for heart failure. The idea is that you could use CAR T cells to get rid of fibrotic tissue after a cardiac injury, and potentially restore the damage following a heart attack.”

Baker adds, “there’s no question that over the last decade, CAR T cell therapy has revolutionized cancer. I’m hoping to play a role in bringing these next generation therapies to patients and make a real impact over the next decade. I think there’s potential for cell therapy to be a new pillar of medicine at large, and not just a new pillar of oncology.”

Read the full story at Penn Medicine Today.

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An Improved Delivery System for mRNA Vaccines Provides More Powerful Protection

by Devorah Fischler

(From left to right) Xuexiang Han, Michael Mitchell and Mohamad-Gabriel Alameh

The COVID-19 vaccine swiftly undercut the worst of the pandemic for hundreds of millions around the world. Available sooner than almost anyone expected, these vaccines were a triumph of resourcefulness and skill.

Messenger RNA vaccines, like the ones manufactured by Moderna or Pfizer/BioNTech, owed their speed and success to decades of research reinforcing the safety and effectiveness of their unique immune-instructive technology.

Now, researchers from the University of Pennsylvania School of Engineering and Applied Science and the Perelman School of Medicine are refining the COVID-19 vaccine, creating an innovative delivery system for even more robust protection against the virus.

In addition to outlining a more flexible and effective COVID-19 vaccine, this work has potential to increase the scope of mRNA vaccines writ large, contributing to prevention and treatment for a range of different illnesses.

Michael Mitchell, associate professor in Penn Engineering’s Department of Bioengineering, Xuexiang Han, postdoctoral fellow in Mitchell’s lab, and Mohamad-Gabriel Alameh, postdoctoral fellow in Drew Weissman’s lab at Penn Medicine and incoming assistant professor in the Department of Pathology and Laboratory Medicine at the Perelman School of Medicine, recently published their findings in Nature Nanotechnology.

mRNA, or messenger ribonucleic acid, is the body’s natural go-between. mRNA contains the instructions our cells need to produce proteins that play important roles in our bodies’ health, including mounting immune responses.

The COVID-19 vaccines follow suit, sending a single strand of RNA to teach our cells how to recognize and fight the virus.

Read the full story in Penn Engineering Today.

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The Physics of Fat Droplets Reveal DNA Danger

by Devorah Fischler

Fat is a normal and necessary part of the body. Fat cells store and release energy, as well as play significant roles in hormonal regulation and immunity.

Engineers and scientists at the University of Pennsylvania are the first to discover fat-filled lipid droplets’ (pictured above in green) surprising capability to indent and puncture the nucleus, the organelle which contains and regulates a cell’s DNA.

In recent decades, a concerning rise in metabolic illnesses – such as cardiovascular disease, high blood pressure and diabetes – has focused scientific attention on the biology and chemistry of fat, resulting in a wealth of information about how fat cells work.

But fat cells and their metabolic activities are only part of the story.

Fat-filled lipid droplets, tiny spheres of fat many times smaller than fat cells, are a growing subject of scientific interest. Found inside many different cell types, these lipid particles have long been little understood. Studies have begun to illuminate these droplets’ participation in metabolic functions and cellular protection, but we still know next to nothing about the physical nature of fat.

Now, researchers at the University of Pennsylvania School of Engineering and Applied Science have looked beyond biochemistry to publish groundbreaking work on the physics of these droplets, revealing them to be a potential threat to a cell’s nucleus. In the August issue of the Journal of Cell Biology, they are the first to discover fat-filled lipid droplets’ surprising capability to indent and puncture the nucleus, the organelle which contains and regulates a cell’s DNA.

The stakes of their findings are high: a ruptured nucleus can lead to elevated DNA damage that is characteristic of many diseases, including cancer.

The study was led by Dennis E. Discher, Robert D. Bent Professor in the Department of Chemical and Biomolecular Engineering, Bioengineering, and in Mechanical Engineering and Applied Mechanics, Irena Ivanovska, Ph.D. research associate in Penn’s Molecular and Cell Biophysics Lab, and Michael Tobin, Ph.D. candidate in the Department of Bioengineering.

“Intuitively, people think of fat as soft,” says Discher. “And on a cellular level it is. But at this small size of droplet— measuring just a few microns rather than the hundreds of microns of a mature fat cell—it stops being soft. Its shape has a much higher curvature, bending other objects very sharply. This changes its physics in the cell. It can deform. It can damage. It can rupture.”

Read the full story in Penn Engineering Today.

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Chasing the Mysteries of Microbiome Communication in Our Bodies

by Kelsey Geesler

Perelman School of Medicine’s Maayan Levy, and Christoph Thaiss. (Image: Courtesy of Penn Medicine News)

When we hear about gut bacteria, we may think about probiotics and supplements marketed to help with digestion, about how taking antibiotics might affect our intestinal tract, or perhaps about trendy diets that aim to improve gut health.

But two researchers at Penn Medicine think that understanding the microbiome, the entirety of microbial organisms associated with the human body, might be the key to deciphering the fundamental mechanisms that make our bodies work. They think these microbes may work like a call center switchboard, making connections to help different organs, biological systems, and the brain communicate. Maayan Levy, and Christoph Thaiss, both assistant professors of microbiology at the Perelman School of Medicine, argue that the microbiome is instrumental to revealing how signals from the gastrointestinal tract are received by the rest of the body—which may hold the key to understanding inter-organ communication in general. Perelman School of Medicine’s Maayan Levy, and Christoph Thaiss. (Image: Courtesy of Penn Medicine News)

While the gut sends signals to all parts of the body to initiate various biological processes, the mechanisms underlying this communication—and communication between different organs involved in these processes—is relatively unknown.

“The more we learn about the role the microbiome plays in a wide range of diseases— from cancer to neurodegenerative diseases to inflammatory diseases—the more important it becomes to understand what exactly its role is,” says Thaiss. “And hopefully once we understand how it works, we can use the microbiome to treat these diseases.”

Levy and Thaiss joined the faculty at Penn Medicine after completing their graduate studies in 2018. Here, they continue to investigate the role of the microbiome in various biological processes.

In his lab, Thaiss focuses on the impact of the microbiome on the brain. He recently identified species of gut-dwelling bacteria that activate nerves in the gut to promote the desire to exercise. Most recently, Thaiss published a study that identified the cells that communicate psychological stress signals from the brain to the gastrointestinal tract, and cause symptoms of inflammatory bowel disease.

Meanwhile, in her lab, Levy examines how the microbiome influences the development of diseases, like cancer, and other conditions throughout the body.

A recent publication authored by Levy suggested that the ketogenic diet (high fat, low carbohydrate) causes the production of a metabolite called beta-hydroxybutyrate (BHB), that suppresses colorectal cancer in small animal models.

Now, Levy is collaborating with Bryson Katona, an assistant professor of Medicine in the division of gastroenterology who specializes in gastrointestinal cancers, to investigate whether BHB has the same effect in patients with Lynch syndrome, which causes individuals to have a genetic predisposition to many different kinds of cancer, including colon cancer. These efforts are part of a growing emphasis at Penn on finding methods to intercept cancer in its earliest stages.

“It’s remarkable that we were able to quickly take the findings from our animal models and rapidly design a clinical trial,” Levy says. “One of the most exciting aspects of our work is not only making discoveries about how our bodies work on a biological level, but then being able to work with the world’s leading clinical experts to translate these discoveries into therapies for patients.”

Further, studies led by Levy and Thaiss often utilize human samples and data from the Penn Medicine BioBank, to validate animal model findings in the tissue of human patients suffering from the diseases which they are investigating.

While Levy and Thaiss pursue different research interests with their labs, they also collaborate often, building on their previous research into what the microbiome does, and its role in the biological processes that keep us healthy. Their long-term goal is to learn about the mechanisms by which the gastrointestinal tract influences disease processes in other organs to treat various diseases of the body using the gastrointestinal tract as a noninvasive entry point to the body.

“Some of the most common and devastating diseases in humans—like cancer or neurodegeneration—are difficult to treat because they are no existing therapies that can reach the brain,” says Thaiss. “If we can understand how the gastrointestinal tract interacts with other organs in the body, including the brain, we might be able to develop treatments that ‘send messages’ to these organs through the body’s natural communication pathways.”

“Obviously there is a lot more basic biology to be uncovered before we get there,” adds Levy. “Most importantly, we want to map all the different routes by which the gastrointestinal tract interacts with the body, and how that communication happens.”

Read the full story in Penn Medicine News.

Christopher Thaiss is Assistant Professor in Microbiology in the Perelman School of Medicine. He is a member of the Penn Bioengineering Graduate Group.

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SCALAR: A Microchip Designed to Transform the Production of mRNA Therapeutics and Vaccines

Led by Michael Mitchell and David Issadore of the School of Engineering and Applied Science, a team of researchers has developed a platform that could rapidly accelerate the development of mRNA-based lipid nanoparticle vaccines and therapeutics at both the small and large scale, SCALAR. (Image: iStock / Anatoly Morozov)

Following the global COVID-19 pandemic, the development and rapid deployment of mRNA vaccines highlighted the critical role of lipid nanoparticles (LNPs) in the context of pharmaceuticals. Used as the essential delivery vehicles for fragile RNA-based therapies and vaccines, LNPs protect the RNA from degradation and ensure effective delivery within the body.

Despite their critical importance, the large-scale manufacturing of these LNPs saw numerous bottlenecks during the pandemic, underscoring the need for scalable production techniques that could keep pace with global demand.

Now, in a paper published in the Proceedings of the National Academy of the Sciences, researchers at the University of Pennsylvania describe how the Silicon Scalable Lipid Nanoparticle Generation platform (SCALAR), a reusable silicon- and glass-based platform designed to transform the production landscape of LNPs for RNA therapeutics and vaccines, offers a scalable and efficient solution to the challenges exposed during the COVID-19 crisis.

“We’re excited to create a piece of technology platform that bridges the gap between small-scale discovery and large-scale manufacturing in the realm of RNA lipid nanoparticle vaccines and therapeutics,” says co-author Michael Mitchell, associate professor of bioengineering in the School of Engineering and Applied Science at Penn. “By doing so, we’ve effectively leapfrogged the clunky, time-consuming, and costly barriers that slow down the production ramp-up of promising new RNA medicines and vaccines.”

The intricacies of RNA-based therapies require the RNA to be encased in a delivery system capable of navigating the body’s biological obstacles. LNPs fulfill this role, allowing the RNA to reach the intended cells for maximum therapeutic impact. SCALAR aims to take this a step further, allowing for an unprecedented three orders of magnitude scalability in LNP production rates, addressing the speed and consistency bottlenecks that hinder existing methods.

Sarah Shepherd, the first author of the paper and a recent Ph.D. graduate who worked in the Mitchell Lab, says, “With SCALAR, we’re not just reacting to today’s challenges but proactively preparing for tomorrow’s opportunities and crises. This technology is flexible, uses mixing architectures well-documented in microfluidics, and is scalable enough to meet future demands in real time. That’s an enormous leap forward for the field.”

Shepherd says that SCALAR builds on prior work from the Mitchell lab and is based on a microfluidic chip platform. Akin to a computer chip, wherein a computer’s electrically integrated circuit has numerous little transistors transporting signals as ones or zeroes to produce an output, the SCALAR microchip precisely controls their two key reagents, lipids and RNA, to generate LNPs.

Read the full story in Penn Today.

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Penn Engineers Create Low-Cost, Eco-Friendly COVID Test

by Kat Sas

Fabrication steps of the biodegradable BC substrate and the electrochemical devices. (1) Incubation of the bacterium Gluconacetobacter hansenii. (2) BC substrate collected and treated, resulting in a clear sheet. (3) The biodegradable BC sheet is screen-printed, (4) resulting in a device with 3 electrodes, (4) which are cut out using a scissor, (5) resulting in a portable, biodegradable, and inexpensive electrochemical sensor.

The availability of rapid, accessible testing was integral to overcoming the worst surges of the COVID-19 pandemic, and will be necessary to keep up with emerging variants. However, these tests come with unfortunate costs.

Polymerase chain reaction (PCR) tests, the “gold standard” for diagnostic testing, are hampered by waste. They require significant time (results can take up to a day or more) as well as specialized equipment and labor, all of which increase costs. The sophistication of PCR tests makes them harder to tweak, and therefore slower to respond to new variants. They also carry environmental impacts. For example, most biosensor tests developed to date use printed circuit boards, or PCBs, the same materials used in computers. PCBs are difficult to recycle and slow to biodegrade, using large amounts of metal, plastic and non-eco-friendly materials.

In addition, most PCR tests end up in landfills, resulting in material waste and secondary contamination. An analysis by the World Health Organization (WHO) estimated that, as of February 2022, “over 140 million test kits, with a potential to generate 2,600 tonnes of non-infectious waste (mainly plastic) and 731,000 litres of chemical waste (equivalent to one-third of an Olympic-size swimming pool) have been shipped.”

In order to balance the need for fast, affordable and accurate testing while addressing these environmental concerns, César de la Fuente, Presidential Assistant Professor in Bioengineering and Chemical and Biomolecular Engineering in the School of Engineering and Applied Science, with additional primary appointments in Psychiatry and Microbiology within the Perelman School of Medicine, has turned his attention to the urgent need for “green” testing materials.

The de la Fuente lab has been working on creative ways to create faster and cheaper testing for COVID-19 since the outbreak of the pandemic. Utilizing his lab’s focus on machine biology and the treatment of infectious disease, they created RAPID, an aptly named test that generates results in minutes with a high degree of accuracy. An even more cost-effective version, called LEAD, was created using electrodes made from graphite. A third test, called COLOR, was a low-cost optodiagnostic test printed on cotton swabs.

The team’s latest innovation incorporates the speed and cost-effectiveness of previous tests with eco-friendly materials. In a paper published in Cell Reports Physical Science, the group introduces a new test made from Bacterial Cellulose (BC), an organic compound synthesized from several strains of bacteria, as a substitute for PCBs.

Read the full story in Penn Engineering Today.

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Penn and CHOP Researchers Show Gene Editing Tools Can be Delivered to Perinatal Brain

Genetic diseases that involve the central nervous system (CNS) often impact children before birth, meaning that once a child is born, irreversible damage has already been done. Given that many of these conditions result from a mutation in a single gene, there has been growing interest in using gene editing tools to correct these mutations before birth.

However, identifying the appropriate vehicle to deliver these gene editing tools to the CNS and brain has been a challenge. Viral vectors used to deliver gene therapies have some potential drawbacks, including pre-existing viral immunity and vector-related adverse events, and other options like lipid nanoparticles (LNPs) have not been investigated extensively in the perinatal brain.

Now, researchers in the Center for Fetal Research at Children’s Hospital of Philadelphia (CHOP) and Penn Engineering have identified an ionizable LNP that can deliver mRNA base editing tools to the brain and have shown it can mitigate CNS disease in perinatal mouse models. The findings, published in ACS Nano, open the door to mRNA therapies that could be delivered pre- or postnatally to treat genetic CNS diseases.

The research team began by screening a library of ionizable LNPs – microscopic fat bubbles that have a positive charge at low pH but neutral charge at physiological conditions in the body. After identifying which LNPs were best able to penetrate the blood-brain barrier in fetal and newborn mice, they optimized their top-performing LNP to be able to deliver base editing tools. The LNPs were then used to deliver mRNA for an adenine base editor, which would correct a disease-causing mutation in the lysosomal storage disease, MPSI, by changing the errant adenine to guanine.

The researchers showed that their LNP was able to improve the symptoms of the lysosomal storage disease in the neonatal mouse brain, as well as deliver mRNA base editing tools to the brain of other animal models. They also showed the LNP was stable in human cerebrospinal fluid and could deliver mRNA base editing tools to patient-derived brain tissue.

“This proof-of-concept study – co-led by Rohan Palanki, an MD/PhD student in my lab, and Michael Mitchell’s lab at Penn Bioengineering – supports the safety and efficacy of LNPs for the delivery of mRNA-based therapies to the central nervous system,” said co-senior author William H. Peranteau, MD, an attending surgeon in the Division of General, Thoracic and Fetal Surgery at CHOP and the Adzick-McCausland Distinguished Chair in Fetal and Pediatric Surgery. “Taken together, these experiments provide the foundation for additional translational studies and demonstrate base editing facilitated by a nonviral delivery carrier in the NHP fetal brain and primary human brain tissue.”

This story was written by Dana Bate. It originally appeared on CHOP’s website.

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Penn Bioengineers Recommend Improvements to Science Communication

Three graduate students in Bioengineering have collaborated to craft a list of recommendations to improve science communication during national health emergencies.

Doctoral students Miles J. Arnett, Dimitris Boufidis, and Melanie Hilman are part of the Penn Science Policy and Diplomacy Group (PSPDG), student organization which creates opportunities for students to get hands-on experience in Science Policy, Diplomacy, and Communication.

Their brief reviews the public health response to the COVID-19 pandemic and recommends specific improvements to science policy and communication by national scientific institutions:

“The public health response to the pandemic was dramatically weakened by an uncoordinated communication strategy, inconsistent messaging, and fractured media environments. These shortcomings had a real human cost, with an estimated hundreds of thousands of Americans dying as a consequence of high rates of vaccine hesitancy. Now, in the aftermath of the pandemic, we have a chance to learn from this crisis and develop a more robust science communication infrastructure for future health emergencies.“

Read “From Chaos to Clarity: Reinventing Science Communication After COVID-19” at Medium.

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For a New Generation of Antibiotics, Scientists are Bringing Extinct Molecules Back to Life – and Discovering the Hidden Genetics of Immunity Along the Way

by Devorah Fischler

Marrying artificial intelligence with advanced experimental methods, the Machine Biology Group has mined the ancient past for future medical breakthroughs, bringing extinct molecules back to life. (Image credit: Ella Marushchenko)

“We need to think big in antibiotics research,” says Cesar de la Fuente. “Over one million people die every year from drug-resistant infections, and this is predicted to reach 10 million by 2050. There hasn’t been a truly new class of antibiotics in decades, and there are so few of us tackling this issue that we need to be thinking about more than just new drugs. We need new frameworks.”

De la Fuente is Presidential Assistant Professor in the Department of Bioengineering and the Department of Chemical and Biomolecular Engineering at the University of Pennsylvania School of Engineering and Applied Science. He holds additional primary appointments in Psychiatry and Microbiology in the Perelman School of Medicine.

De la Fuente’s lab, the Machine Biology Group, creates these new frameworks using potent partnerships in engineering and the health sciences, drawing on the “power of machines to accelerate discoveries in biology and medicine.”

Marrying artificial intelligence with advanced experimental methods, the group has mined the ancient past for future medical breakthroughs. In a recent study published in Cell Host and Microbe, the team has launched the field of “molecular de-extinction.”

Our genomes – our genetic material – and the genomes of our ancient ancestors, express proteins with natural antimicrobial properties. “Molecular de-extinction” hypothesizes that these molecules could be prime candidates for safe new drugs. Naturally produced and selected through evolution, these molecules offer promising advantages over molecular discovery using AI alone.

In this paper, the team explored the proteomic expressions of two extinct organisms –Neanderthals and Denisovans, archaic precursors to the human species – and found dozens of small protein sequences with antibiotic qualities. Their lab then worked to synthesize these molecules, bringing these long-since-vanished chemistries back to life.

“The computer gives us a sequence of amino acids,” says de la Fuente. “These are the building blocks of a peptide, a small protein. Then we can make these molecules using a method called ‘solid-phase chemical synthesis.’ We translate the recipe of amino acids into an actual molecule and then build it.”

The team next applied these molecules to pathogens in a dish and in mice to test the veracity and efficacy of their computational predictions.

“The ones that worked, worked quite well,” continues de la Fuente. “In two cases, the peptides were comparable – if not better – than the standard of care. The ones that didn’t work helped us learn what needed to be improved in our AI tools. We think this research opens the door to new ways of thinking about antibiotics and drug discovery, and this first step will allow scientists to explore it with increasing creativity and precision.”

Read the full story in Penn Engineering Today.

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Student Spotlight: Cosette Tomita

Cosette TomitaCosette Tomita, a master’s student in Bioengineering, spoke with Penn Engineering Graduate Admissions about her research in cellular therapy and her path to Penn Engineering.

“What were you doing before you came to Penn Engineering? 

After college I wanted to get some industry experience before going to graduate school, so I spent a year working for a pharmaceutical company in New Jersey. I learned a lot—but mostly I learned that I wanted to go back into academia. So I was looking for a more research-oriented position to boost my graduate school applications, and I found a position at Penn’s cyclotron facility. Shortly after that, I applied to the master’s program. I’m still working at the cyclotron, so I’m doing the program part time. 

How has your experience in the program been so far? 

I love the research I’m doing here. I love the collaboration we have and the fact that I’m able to work with whoever I want to. And I can only say good things about my PI, Robert Mach. He’s a very busy man, but he makes time for his people. And he recognizes when somebody has a lot on their plate and he will go to bat for that person.

What’s your research all about? 

The focus of my PI’s lab is on neurodegenerative diseases and opiate use, so we’re looking to make imaging agents and antagonists that can help with the opioid crisis. 

For my project, I wanted to look at treating neurodegenerative disease from the perspective of cellular therapy. My PI doesn’t have that expertise, so when I came to him with this idea, he said I should talk to Mark Sellmyer in the bioengineering department. He does a lot of cellular therapies, cell engineering, protein engineering and things of that nature. So his lab is more biological. 

I don’t have a grant for my research, so my advisors are supporting it out of their own pockets. They could have said, no, you need to work on this project that’s already going on in the lab. But they gave me the intellectual freedom to do what I wanted to do.”

Read the full Q&A at the Penn Engineering Graduate Admissions website.

Mark Sellmeyer is Assistant Professor of Radiology in the Perelman School of Medicine and member of the Penn Bioengineering Graduate Group.