Category: students

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Precision Pulmonary Medicine: Penn Engineers Target Lung Disease with Lipid Nanoparticles

by Ian Scheffler

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. 

Read the full story in Penn Engineering Today.

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Penn Bioengineering Student Kaitlin Mrksich Named 2024 Goldwater Scholar

by Louisa Shepard

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.

Penn’s 2024 Goldwater Scholars are third-years Hayle Kim, Eric Myzelev, and Eric Tao in the College of Arts and Sciences, and Kaitlin Mrksich in the School of Engineering and Applied Science.

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.

The students applied for the Goldwater Scholarship with assistance from Penn’s Center for Undergraduate Research and Fellowships. Penn has had 63 Goldwater Scholars named since Congress established the scholarship in 1986 to honor U.S. Senator Barry Goldwater.

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.

Read the full announcement in Penn Today.

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.

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A Moonshot for Obesity: New Molecules, Inspired by Space Shuttles, Advance Lipid Nanoparticle Delivery for Weight Control

by Ian Scheffler

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. 

Read the full story in Penn Engineering Today.

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Beyond Bias: The Annual Women in Data Science Conference Unites Women across Penn

by Ian Scheffler

Lasya Sreepada, a doctoral student in Bioengineering (BE), addresses the crowd. (Image: Lamont Abrams)

In Invisible Women: Data Bias in a World Designed for Men, Caroline Criado Perez notes that the default perspective for virtually all data collection and analysis is male. (Hence crash test dummies being designed to mimic male bodies, air conditioning systems relying on a model of the male metabolism, and women’s unique heart attack symptoms other than chest pain — like nausea and back pain — often going unrecognized, even by women experiencing them.)

Nearly a decade ago, a group of women at Stanford decided to address this issue by convening a one-day technical conference on data science; that meeting has now grown into a worldwide movement, with hundreds of sister conferences each year — a tradition in which Penn Engineering is proud to take part.

By 2030, Women in Data Science (WiDS), the non-profit that spun out of that early meeting, hopes to achieve 30% representation of women in data science globally. For Susan Davidson, Weiss Professor in Computer and Information Science (CIS) and a co-chair of the annual WiDS @ Penn conference, the benefits of participating in WiDS go beyond just networking. “To see women who are successful in your field is extremely encouraging,” says Davidson.

This year, Penn Engineering partnered with Analytics at Wharton (AAW) and the Penn Museum to co-host the fifth annual WiDS @ Penn conference, bringing together dozens of women from across the University and beyond to learn about the latest applications of data science in topics as diverse as online education and health care.

“It gave me the opportunity to not only show others what it means to be a data scientist,” says Lasya Sreepada, a doctoral student in Bioengineering, who presented her work studying early-onset Alzheimer’s disease using large data sets, “but also what it means to be a woman applying data science to integrate multiple disciplines spanning neuroscience, genomics and radiology.”

Penn Engineering students from all levels of their academic careers participated, from Aashika Vishwanath, a sophomore in CIS, president of the Wharton Undergraduate Data Analytics Club and senior data science consultant at Wharton Analytics Fellows, who shared her work developing an AI-powered teaching assistant, to Betty Xu, a master’s student in Electrical and Systems Engineering, who collaborated with the Wharton Neuroscience Initiative to study financial decision making. “Data can help us know the unknown in every field,” says Xu. “You can be a great data scientist no matter your background.”

Read the full story in Penn Engineering Today.

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Illuminating the Invisible: Bringing the Smallest Protein Clusters into Focus

by Ian Scheffler

The bright white spots represent tiny clusters of proteins detected by CluMPS. (Photo by: Thomas Mumford)

Penn Engineers have pioneered a new way to visualize the smallest protein clusters, skirting the physical limitations of light-powered microscopes and opening new avenues for detecting the proteins implicated in diseases like Alzheimer’s and testing new treatments.

In a paper in Cell Systems, Lukasz Bugaj, Assistant Professor in Bioengineering, describes the creation of CluMPS, or Clusters Magnified by Phase Separation, a molecular tool that activates by forming conspicuous blobs in the presence of target protein clusters as small as just a few nanometers. In essence, CluMPS functions like an on/off switch that responds to the presence of clusters of the protein it is programmed to detect.

Normally, says Bugaj, detecting such clusters requires laborious techniques. “With CluMPS, you don’t need anything beyond the standard lab microscope.” The tool fuses with the target protein to form condensates orders of magnitude larger than the protein clusters themselves that resemble the colorful blobs in a lava lamp. “We think the simplicity of the approach is one of its main benefits,” says Bugaj. “You don’t need specialized skills or equipment to quickly see whether there are small clusters in your cells.”

Read the full story in Penn Engineering Today.

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Penn Bioengineering Cockroach Lab Featured in Popular Mechanics

Every Penn Bioengineering semester culminates in a series of “demo days” — dedicated time in which undergraduate Bioengineering students demonstrate projects made in their Bioengineering lab courses or in Senior Design for their classmates and faculty. These are held in the George H. Stephenson Foundation Educational Laboratory & Bio-MakerSpace (or the Penn BE Labs), the dedicated teaching lab for the Bioengineering Department which also functions as an interdisciplinary bio-makerspace open to the entire Penn community.

For the Fall 2023 demos, Popular Mechanics paid a visit to the BE Labs to witness the (in)famous “cockroach lab,” a staple of the third year course “Bioengineering, Modeling, Analysis, and Design Laboratory” (affectionately known as BE MAD). This year’s cockroach demos featured a miniature Taylor Swift — flaunting a cockroach limb — and several projects featuring the faces of course faculty, David Meaney, Solomon R. Pollack Professor in Bioengineering and Senior Associate Dean in Penn Engineering, and Michael Patterson, Director of Educational Laboratories in Bioengineering.

Read “How Severed Cockroach Legs Could Help Us ‘Fully Rebuild’ Human Bodies” in Popular Mechanics.

Read more stories featuring the Penn BE Labs in the BE Blog here.

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Bioengineers on the Brink of Breaching Blood-brain Barrier

by Nathi Magubane

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.”

Read the full story in Penn Today.

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Penn Bioengineering Student Kaitlin Mrksich Wins Outstanding Research Award from the Society for Biomaterials

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.

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Lipid Nanoparticles That Deliver mRNA to T Cells Hold Promise for Autoimmune Diseases

by Janelle Weaver

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.

Now, a research team led by Michael Mitchell, Associate Professor in Bioengineering in the School of Engineering and Applied Science at the University of Pennsylvania, has developed a lipid nanoparticle (LNP) platform to deliver Foxp3 messenger RNA (mRNA) to T cells for applications in autoimmunity. Their findings are published in the journal Nano Letters.

“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.”

Read the full story in Penn Engineering Today.

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Leveraging the Body’s Postal System to Understand and Treat Disease

by Nathi Magubane

Microwell device with a solution in the reservoir (Image: Courtesy of David E. Reynolds)

Akin to the packages sent from one person to another via an elaborate postal system, cells send tiny parcels that bear contents and packaging material that serve key purposes: To protect the contents from the outside world and to make sure it gets to the right place via a label with an address. 

These packages are known as extracellular vesicles (EVs)—lipid-bound molecules that serve a variety of regulatory and maintenance functions throughout the body. They assist in the removal of unwanted materials within the cell, and they transport proteins, aid in DNA and RNA transfer, and promote tumorigeneses in cancerous cells. 

Given their myriad roles, EVs have taken center stage for many researchers in the biomedical space as they have the potential to improve current methods of disease detection and treatment. The main challenge, however, is accurately identifying the molecular contents of EVs while also characterizing the EVs, which, unlike other cellular components that are more homogenous, have more heterogeneity.

Now, a team of researchers at the University of Pennsylvania has developed a novel platform, droplet-free double digital assay, for not only profiling individual EVs but also accurately discerning their molecular contents. The researchers took the digital assay, which quantifies the contents of a molecule via binary metric—a 1 corresponds to the presence of a molecule and a zero to the lack thereof—and applies it to the EV. The work is published in Advanced Science.

The team was led by Jina Ko, an assistant professor with appointments in the School of Engineering and Applied Science and Perelman School of Medicine. “Our method allows for highly accurate quantification of the individual molecules inside an EV,” Ko says . “This opens up many doors in the realm of early disease detection and treatment.”

The researchers first compartmentalized individual EVs utilizing a microwell approach to isolate the EVs. Next, they captured individual molecules within the EVs and amplified the signal for clarity. The team then was able to determine the expression levels of pivotal EV biomarkers with remarkable precision via fluorescence.

Read the full story in Penn Today.

Jina Ko is an assistant professor in the Department of Pathology and Laboratory Medicine in the Perelman School of Medicine and an assistant professor in the Department of Bioengineering in the School of Engineering and Applied Science at the University of Pennsylvania.

David Reynolds is a Ph.D. candidate in the Department of Bioengineering in Penn Engineering.

Other authors include, Menghan Pan, George Galanis, Yoon Ho Roh, Renee-Tyler T. Morales, Shailesh Senthil Kumar, and Su-Jin Heo of the Department of Bioengineering at Penn Engineering; Jingbo Yang and Xiaowei Xu of the Department of Pathology and Laboratory Medicine at Penn Medicine; and Wei Guo of the Department of Biology in the School of Arts & Sciences at Penn.

The research was supported by the National Institutes of Health: grants R00CA256353, R35 GM141832, and CA174523 (SPORE).