‘RNA worked for COVID-19 vaccines. Could it be used to treat cancer and rare childhood diseases?’

William H. Peranteau, Michael J. Mitchell, Margaret Billingsley, Meghana Kashyap, and Rachel Riley (Clockwise from top left)

As COVID-19 vaccines roll out, the concept of using mRNA to fend off viruses has become a part of the public dialogue. However, scientists have been researching how mRNA can be used to in life-saving medical treatments well before the pandemic.

The “m” in “mRNA” is for “messenger.” A single-stranded counterpart to DNA, it translates the genetic code into the production of proteins, the building blocks of life. The Moderna and Pfizer COVID-19 vaccines work by introducing mRNA sequences that act as a set of instructions for the body to produce proteins that mimic parts of the virus itself. This prepares the body’s immune response to recognize the real virus and fight it off.

Because it can spur the production of proteins that the body can’t make on its own, mRNA therapies also have the potential to slow or prevent genetic diseases that develop before birth, such as cystic fibrosis and sickle-cell anemia.

However, because mRNA is a relatively unstable molecule that degrades quickly, it needs to be packaged in a way that maintains its integrity as its delivered to the cells of a developing fetus.

To solve this challenge, Michael J. Mitchell, Skirkanich Assistant Professor of Innovation in the Department of Bioengineering, is researching the use of lipid nanoparticles as packages that transport mRNA into the cell. He and William H. Peranteau, an attending surgeon in the Division of General, Thoracic and Fetal Surgery and the Adzick-McCausland Distinguished Chair in Fetal and Pediatric Surgery at Children’s Hospital of Philadelphia, recently co-authored a “proof-of-concept” paper investigating this technique.

In this study, published in Science Advances, Mitchel examined which nanoparticles were optimal in the transport of mRNA to fetal mice. Although no disease or organ was targeted in this study, the ability to administer mRNA to a mouse while still in the womb was demonstrated, and the results are promising for the next stages of targeted disease prevention in humans.

Mitchel spoke with Tom Avril at The Philadelphia Inquirer about the mouse study and its implications for treatment of rare infant diseases through the use of mRNA, ‘the messenger of life.’

Penn bioengineering professor Michael J. Mitchell, the other senior author of the mouse study, tested various combinations of lipids to see which would work best.

The appeal of the fatty substances is that they are biocompatible. In the vaccines, for example, two of the four lipids used to make the delivery spheres are identical to lipids found in the membranes of human cells — including plain old cholesterol.

When injected, the spheres, called nanoparticles, are engulfed by the person’s cells and then deposit their cargo, the RNA molecules, inside. The cells respond by making the proteins, just as they make proteins by following the instructions in the person’s own RNA. (Important reminder: The RNA in the vaccines cannot become part of your DNA.)

Among the different lipid combinations that Mitchell and his lab members tested, some were better at delivering their cargo to specific organs, such as the liver and lungs, meaning they could be a good vehicle for treating disease in those tissues.

Continue reading Tom Avril’s ‘RNA worked for COVID-19 vaccines. Could it be used to treat cancer and rare childhood diseases?’ at The Philadelphia Inquirer.

Hao Huang Named AIMBE Fellow

Hao Huang, Ph.D.

Hao Huang, Research Associate Professor of Radiology in the Perelman School of Medicine and member of the Penn Bioengineering Graduate Group, has been named an American Institute for Medical and Biological Engineering (AIMBE) Fellow.

Election to the AIMBE College of Fellows is among the highest professional distinctions accorded to a medical and biological engineer. “The College of Fellows is comprised of the top two percent of medical and biological engineers in the country. The most accomplished and distinguished engineering and medical school chairs, research directors, professors, innovators, and successful entrepreneurs comprise the College of Fellows. AIMBE Fellows are regularly recognized for their contributions in teaching, research, and innovation.”

Huang was “nominated, reviewed, and elected by peers and members of the College of Fellows for contributions to the development and applications of innovative MR methods to study the developing brain.”

A formal induction ceremony will be held during AIMBE’s virtual 2021 Annual Event on March 26. Huang will be inducted along with 174 colleagues who make up the AIMBE Fellow Class of 2021.

Read the full press release.

‘As More Women Enter Science, It’s Time to Redefine Mentorship’

 

Danielle Bassett, Ph.D.

Danielle Bassett, J. Peter Skirkanich Professor in the departments of Bioengineering and Electrical and Systems Engineering, investigates how the shape of networks impact the phenomena that arises from them. Much of that research is focused on networks of neurons, and how the different ways they are wired together in different people can influence their mental traits, such as memory or executive function.

Bassett is also interested in networks of people, however, as the shapes of those networks can have a major impact on a society’s traits. Last year, she and her colleagues published a study that investigated the network of citations neuroscience researchers produced in the course of their work, demonstrating a systemic gender bias that left women underrepresented in the literature.

Recently, Bassett spoke with WIRED’s Grace Huckins about the big-picture changes that must take place within academia for it to become truly equitable.

When a group of researchers at NYU Abu Dhabi published a paper in Nature Communications last fall suggesting that young women scientists should seek out men as mentors, the backlash was swift and vociferous. Countless scientists, many of them women, registered their indignation on Twitter—some even penning open letters and their own preprints in response. The original paper had found that female junior scientists who authored papers with male senior scientists saw their papers cited at higher rates. But a number of critics contested the assertion that this result established a link between male mentors and career performance. Scientists routinely coauthor articles with people who are not their mentors, they argued, and citation rates are just one metric of achievement. In response to these criticisms, the authors eventually retracted their paper. (They declined to comment to WIRED.)

But the paper had already stirred up a broader discussion about gender and mentorship in academia. For Danielle Bassett, a professor of bioengineering at the University of Pennsylvania, the methodological concerns that prompted the paper’s retraction were far from its worst sin. She herself has researched citation practices and found that, in neuroscience, papers with male senior authors are cited at a disproportionately high rate—primarily because other male scientists preferentially cite them. To suggest that young women should therefore try to author papers with men is, she believes, a grave error. “That was a problem in assigning blame,” she says. “The onus is on us to create a scientific culture that lets students choose a mentor that’s right for them.”

Continue reading Grace Huckins’s ‘As More Women Enter Science, It’s Time to Redefine Mentorship‘ at WIRED.

Originally posted in Penn Engineering Today.

An ‘Electronic Nose’ to Sniff Out COVID-19

by Erica K. Brockmeier

Postdoc Scott Zhang at work in the Johnson lab. (Photo: Eric Sucar, University Communications)

Even as COVID-19 vaccines are being rolled out across the country, the numerous challenges posed by the pandemic won’t all be solved immediately. Because herd immunity will take some time to reach and the vaccine has not yet been approved for some groups, such as children under 16 years of age, the coming months will see a continued need for tools to rapidly track the disease using real-time community monitoring.

A team of Penn researchers is working on a new “electronic nose” that could help track the spread of COVID-19. Led by physicist Charlie Johnson, the project, which was recently awarded a $2 million grant from the NIH, aims to develop rapid and scalable handheld devices that could spot people with COVID-19 based on the disease’s unique odor profile.

Dogs and devices that can detect diseases

Long before “coronavirus” entered into the vernacular, Johnson was collaborating with Cynthia Otto, director of the Penn Vet Working Dog Center, and Monell Chemical Senses Center’s George Preti to diagnose diseases using odor. Diseases are known to alter a number of physical processes, including body odors, and the goal of the collaboration was to develop new ways to detect the volatile organic compounds (VOCs) that were unique to ovarian cancer.

The next step is to scale down the current device, and the researchers are aiming to develop a prototype for testing on patients within the next year.

Since 2012, the researchers have been developing new ways to diagnose early-stage ovarian cancer. Otto trained dogs to recognize blood plasma samples from patients with ovarian cancer using their acute sense of smell. Preti, who passed away last March, was looking for the specific VOCs that gave ovarian cancer a unique odor. Johnson developed a sensor array, an electronic version of the dog’s nose, made of carbon nanotubes interwoven with single-stranded DNA. This device binds to VOCs and can determine samples that came from patients with ovarian cancer.

Last spring, as the pandemic’s threat became increasingly apparent, Johnson and Otto shifted their efforts to see if they could train their disease-detecting devices and dogs to spot patients with COVID-19.

Continue reading at Penn Today.

N.B.: A.T. Charlie Johnson, Rebecca W. Bushnell Professor of Physics and Astronomy at the Penn School of Arts & Sciences, and Lyle Ungar, Professor in Computer and Information Science at Penn Engineering and Psychology at the School of Arts & Sciences, are both members of the Penn Bioengineering Graduate Group.

Penn Engineers’ New Bioprinting Technique Allows for Complex Microtissues

by Evan Lerner

Jason Burdick, Andrew C. Daly and Matthew Davidson

Bioprinting is currently used to generate model tissues for research and has potential applications in regenerative medicine. Existing bioprinting techniques rely on printing cells embedded in hydrogels, which results in low-cell-density constructs that are well below what is required to grow functional tissues. Maneuvering different kinds of cells into position to replicate the complex makeup of an organ, particularly at organlike cell densities, is still beyond their capabilities.

Now, researchers at the School of Engineering and Applied Science have demonstrated a new bioprinting technique that enables the bioprinting of spatially complex, high-cell-density tissues.

Using a self-healing hydrogel that allows dense clusters of cells to be picked and placed in a three-dimensional suspension, the researchers constructed a model of heart tissue that featured a mix of cells that mimic the results of a heart attack.

The study was led by Jason Burdick, Robert D. Bent Professor in the Department of Bioengineering, and Andrew C. Daly, a postdoctoral researcher in his lab. Fellow Burdick lab postdoc Matthew Davidson also contributed to the study, which has been published in the journal Nature Communications.

Even without a bioprinter, groups of cells can be made to clump into larger aggregates, known as spheroids. For Burdick and colleagues, these spheroids represented a potential building block for a better approach to bioprinting.

“Spheroids are often useful for studying biological questions that rely on the cells’ 3D microenvironments or in the construction of new tissues,” says Burdick. “However, we’d like to produce even higher levels of organization by ‘printing’ different kinds of spheroids in specific arrangements and have them fuse together into structurally complex microtissues.”

Read more at Penn Engineering Today.

Arjun Yodh Named 2021 Michael S. Feld Biophotonics Award Recipient by The Optical Society

Arjun Yodh, Ph.D.

The Department of Phsyics in the Penn School of Arts & Sciences has announced that Arjun Yodh, Professor in Physics and Astronomy and member of the Bioengineering Graduate Group, was awarded the 2021 Michael S. Biophotonics Award by the Optical Society (OSA):

“He was selected for his ‘pioneering research on optical sensing in scattering media, especially diffuse optical and correlation spectroscopy and tomography, and for advancing the field of biophotonics through mentorship.’

The award ‘recognizes innovative and influential contributions to the field of biophotonics, regardless of career stage.'”

Penn Dental, Penn Engineering Unite to Form Center for Innovation & Precision Dentistry

by Beth Adams

With the shared vision to transform the future of oral health care, Penn Dental Medicine and Penn’s School of Engineering and Applied Sciences have united to form the Center for Innovation & Precision Dentistry (CiPD). The new Center marked its official launch on January 22 with a virtual program celebrating the goals and plans of this unique partnership. Along with the Deans from both schools, the event gathered partners from throughout the University of Pennsylvania and invited guests, including the National Institute of Dental and Craniofacial Research Director (NIDCR) Dr. Rena D’Souza and IADR Executive Director Chris Fox.

Conceived and brought to fruition by co-directors Dr. Michel Koo of Penn Dental Medicine and Dr. Kathleen Stebe of Penn Engineering, the CiPD is bridging the two schools through cutting-edge research and technologies to accelerate the development of new solutions and devices to address unmet needs in oral health, particularly in the areas of dental caries, periodontal disease, and head and neck cancer. The CiPD will also place a high priority on programs to train the next generation of leaders in oral health care innovation.

“We have a tremendous global health challenge. Oral diseases and craniofacial disorders affect 3.5 billion people, disproportionately affecting the poor and the medically and physically compromised,” says Dr. Koo, Professor in the Department of Orthodontics and Divisions of Community Oral Health and Pediatric Dentistry, in describing their motivation to form the Center. “There is an urgent need to find better ways to diagnose, prevent, and treat these conditions, particularly in ways that are affordable and accessible for the most susceptible populations. That is our driving force for putting this Center together.”

“We have united our schools around this mission,” adds Dr. Stebe, Richer & Elizabeth Goodwin Professor in the Department of Chemical and Biomolecular Engineering. “We have formed a community of scholars to develop and harness new engineering paradigms, to generate new knowledge, and to seek new approaches that are more effective, precise, and affordable to address oral health. More importantly, we will train a new community of scholars to impact this space.”

Born through Interdisciplinary Research

A serendipitous connection born through Penn’s interdisciplinary research environment itself brought Drs. Koo and Stebe together more than five years ago, an introduction that would eventually lead to creating the CiPD.

Dr. Tagbo Niepa, now assistant professor at the University of Pittsburgh, came to Penn Engineering in 2014 as part of Penn’s Postdoctoral Fellowship for Academic Diversity, an initiative from the office of the Vice Provost for Research. His studies on the microbiome led him to reach out to Dr. Stebe and Dr. Daeyeon Lee (also at Penn Engineering), and to connect them to Dr. Koo, initiating collaboration between their labs.

“Tagbo embodies what we are trying to do with the CiPD,” recalls Dr. Stebe. “He had initiative, he identified new tools and important context, and he did good science that may help us understand how to interrupt the disease process and identify new underlying mechanisms that can inspire new therapies.” Dr. Niepa worked on applying microfluidics and engineering to study the oral microbiome and better understand how the interactions between fungi and bacteria could impact dental caries.

“Upon meeting Michel, we became excited about the possibilities of bringing talent from the two schools together,” notes Dr. Stebe. A 2018 workshop organized by Drs. Koo and Stebe and funded by Penn’s Vice Provost of Research explored the potential for expanding cross-school research. “We invited researchers from dental medicine and engineering as well as relevant people from the arts and sciences to see if we could find a way to collaborate to advance oral and craniofacial health,” says Dr. Koo. “That was the catalyst for the Center; after the workshop, we put together a task force which would become the core members of the CiPD.”

In addition to Drs. Koo and Stebe, the CiPD Executive Committee includes Associate Directors Dr. Henry Daniell, Vice-Chair and W.D. Miller Professor, Department of Basic & Translational Sciences, Penn Dental Medicine, and Dr. Anh Le, Chair and Norman Vine Endowed Professor of Oral Rehabilitation, Department of Oral and Maxillofacial Surgery / Pharmacology, Penn Dental Medicine; as well as Dr. Andrew Tsourkas, Professor, Department of Bioengineering, Co-Director, Center for Targeted Therapeutics & Translational Nanomedicine (CT3N) and Chemical and Nanoparticle Synthesis Core, Penn Engineering; and Dr. Jason Moore, Edward Rose Professor of Informatics, Director of the Penn Institute for Biomedical Informatics. The core members of CiPD include 26 faculty from across both Penn Dental Medicine and Penn Engineering, and also from the Schools of Medicine and Arts & Sciences.

Read the full story in Penn Today.

Penn Bioengineers Develop Implantable Living Electrodes

Living Electrode Panels (image courtesy of the Cullen Lab)

Connecting the human brain to electrical devices is a long-standing goal of neuroscientists, bioengineers, and clinicians, with applications ranging from deep brain stimulation (DBS) to treat Parkinson’s disease to more futuristic endeavors such as Elon Musk’s NeuraLink initiative to record and translate brain activity. However, these approaches currently rely on using implantable metallic electrodes that inherently provoke a lasting immune response due to their non-biological nature, generally complicating the reliability and stability of these interfaces over time. To address these challenges, D. Kacy Cullen, Associate Professor in Neurosurgery and Bioengineering, and Dayo Adewole, a doctoral candidate in Bioengineering, worked with a multi-disciplinary team of collaborators to develop the first “living electrodes” as an implantable, biological bridge between the brain and external devices. In a recent article published in Science Advances, the team demonstrated the fabrication of hair-like microtissue comprised of living neuronal networks and bundled tracts of axons the signal sending fibers of the nervous system protected within soft hydrogel cylinders. They showed that these axon-based living electrodes could be fully controlled and monitored with light thus eliminating the need for electrical contact and are capable of surviving and forming synapses with the brain as demonstrated in an adult rat model. While further advancements are necessary prior to clinical use, the current findings provide the foundation for a new class of “living electrodes” as a biological intermediary between humans and devices capable of leveraging natural mechanisms to potentially provide a stable interface for clinical applications.

Cullen has a primary appointment in the Department of Neurosurgery in the Perelman School of Medicine, with a secondary appointment in the Department of Bioengineering in the School of Engineering and Applied Science, and an appointment in the Corporal Michael J. Crescenz VA Medical Center in Philadelphia.

Penn Engineering and CHOP Researchers Identify Nanoparticles that Could Be Used in Therapeutic mRNA Delivery before Birth

by Evan Lerner

William H. Peranteau, Michael J. Mitchell, Margaret Billingsley, Meghana Kashyap, and Rachel Riley (Clockwise from top left)

Researchers at Children’s Hospital of Philadelphia and the School of Engineering and Applied Science at the University of Pennsylvania have identified ionizable lipid nanoparticles that could be used to deliver mRNA as part of fetal therapy. The proof-of-concept study, published today in Science Advances, engineered and screened a number of lipid nanoparticle formulations for targeting mouse fetal organs and has laid the groundwork for testing potential therapies to treat genetic diseases before birth.

“This is an important first step in identifying nonviral mediated approaches for delivering cutting-edge therapies before birth,” said co-senior author William H. Peranteau, MD, an attending surgeon in the Division of General, Thoracic and Fetal Surgery and the Adzick-McCausland Distinguished Chair in Fetal and Pediatric Surgery at CHOP. “These lipid nanoparticles may provide a platform for in utero mRNA delivery, which would be used in therapies like fetal protein replacement and gene editing.”

Michael J. Mitchell, Skirkanich Assistant Professor of Innovation in Penn Engineering’s Department of Bioengineering, is the other co-senior author of the study. The co-first authors are Mitchell Lab members Rachel Riley, a postdoctoral fellow, and Margaret Billingsley, a graduate student, and Peranteau Lab member Meghana Kashyap, a research fellow.

Recent advances in DNA sequencing technology and prenatal diagnostics have made it possible to diagnose many genetic diseases before birth. Some of these diseases are treated by protein or enzyme replacement therapies after birth, but by then, some of the damaging effects of the disease have taken hold. Thus, applying therapies while the patient is still in the womb has the potential to be more effective for some conditions. The small fetal size allows for maximal therapeutic dosing, and the immature fetal immune system may be more tolerant of replacement therapy.

Read the full story in Penn Engineering Today.

NB: Rachel Riley is now Assistant Professor in Biomedical Engineering at Rowan University.

Studying ‘Hunters and Busybodies,’ Penn and American University Researchers Measure Different Types of Curiosity

by Melissa Pappas

Knowledge networks were created as participants browsed Wikipedia, where pages became nodes and relatedness between pages became edges. Two diverging styles emerged — “the busybody” and “the hunter.” (Illustrations by Melissa Pappas)

Curiosity has been found to play a role in our learning and emotional well-being, but due to the open-ended nature of how curiosity is actually practiced, measuring it is challenging. Psychological studies have attempted to gauge participants’ curiosity through their engagement in specific activities, such as asking questions, playing trivia games, and gossiping. However, such methods focus on quantifying a person’s curiosity rather than understanding the different ways it can be expressed.

Efforts to better understand what curiosity actually looks like for different people have underappreciated roots in the field of philosophy. Varying styles have been described with loose archetypes, like “hunter” and “busybody” — evocative, but hard to objectively measure when it comes to studying how people collect new information.

A new study led by researchers at the University of Pennsylvania’s School of Engineering and Applied Science, the Annenberg School for Communication, and the Department of Philosophy and Religion at American University, uses Wikipedia browsing as a method for describing curiosity styles. Using a branch of mathematics known as graph theory, their analysis of curiosity opens doors for using it as a tool to improve learning and life satisfaction.

The interdisciplinary study, published in Nature Human Behavior, was undertaken by Danielle Bassett, J. Peter Skirkanich Professor in Penn Engineering’s Departments of Bioengineering and Electrical and Systems Engineering, David Lydon-Staley, then a post-doctoral fellow in her lab, now an assistant professor in the Annenberg School of Communication, two members of Bassett’s Complex Systems Lab, graduate student Dale Zhou and postdoctoral fellow Ann Sizemore Blevins, and Perry Zurn, assistant professor from American University’s Department of Philosophy.

“The reason this paper exists is because of the participation of many people from different fields,” says Lydon-Staley. “Perry has been researching curiosity in novel ways that show the spectrum of curious practice and Dani has been using networks to describe form and function in many different systems. My background in human behavior allowed me to design and conduct a study linking the styles of curiosity to a measurable activity: Wikipedia searches.”

Zurn’s research on how different people express curiosity provided a framework for the study.

Read the full story in Penn Engineering Today.