Category: issues

Posted on

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.

Posted on

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.

Posted on

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.

Posted on

Penn, Carnegie Mellon and Johns Hopkins to Develop New Turing Tests, Investigate How AI Can Become More Like Biological Intelligence

by Evan Lerner

While artificial intelligence is becoming a bigger part of nearly every industry and increasingly present in everyday life, even the most impressive AI is no match for a toddler, chimpanzee, or even a honeybee when it comes to learning, creativity, abstract thinking or connecting cause and effect in ways they haven’t been explicitly programmed to recognize.

This discrepancy gets at one of the field’s fundamental questions: what does it mean to say an artificial system is “intelligent” in the first place?

Konrad Kording, Timothy Verstynen, Joshua T. Vogelstein, and Leyla Isik (clockwise from top left)

Seventy years ago, Alan Turing famously proposed such a benchmark; a machine could be considered to have artificial intelligence if it could successfully fool a person into thinking it was a human as well. Now, many artificial systems could pass a “Turing Test” in certain limited domains, but none come close to imitating the holistic sense of intelligence we recognize in animals and people.

Understanding how AI might someday be more like this kind of biological intelligence — and developing new versions of the Turing Test with those principles in mind — is the goal of a new collaboration between researchers at the University of Pennsylvania, Carnegie Mellon University and Johns Hopkins University.

The project, called “From Biological Intelligence to Human Intelligence to Artificial General Intelligence,” is led by Konrad Kording, a Penn Integrates Knowledge Professor with appointments in the Departments of Bioengineering and Computer and Information Science in Penn Engineering and the Department of Neuroscience at Penn’s Perelman School of Medicine. Kording will collaborate with Timothy Verstynen of Carnegie Mellon University, as well Joshua T. Vogelstein and Leyla Isik, both of Johns Hopkins University, on the project.

Read the full story on Penn Engineering Today.

Posted on

Bioengineering Faculty Contribute to New Treatment That “Halts Osteoarthritis-Like Knee Cartilage Degeneration”

A recent study published in Science Translational Medicine announces a discovery which could halt cartilage degeneration caused by osteoarthritis: “These researchers showed that they could target a specific protein pathway in mice, put it into overdrive and halt cartilage degeneration over time. Building on that finding, they were able to show that treating mice with surgery-induced knee cartilage degeneration through the same pathway via the state of the art of nanomedicine could dramatically reduce the cartilage degeneration and knee pain.” This development could eventually lead to treating osteoarthritis with injection rather than more complicated surgery.

Among a team of Penn Engineering and Penn Medicine researchers, the study was co-written by Zhiliang Cheng, Research Associate Professor in Bioengineering, Andrew Tsourkas, Professor in Bioengineering, and Ling Qin, Associate Professor of Orthopaedic Surgery in the Perelman School of Medicine and member of the Bioengineering Graduate Group. The lead author was Yulong Wei of the Department of Orthopaedic Surgery and the McKay Orthopaedic Research Laboratory.

Read the press release in Penn Medicine News.

Posted on

Engineering and Medicine Researchers Collaborate on Studies of Genome Folding in Health and Disease

(Left to right) Top row: Jennifer E. Phillips-Cremins, Rajan Jain, and Eric Joyce. Middle row: Melike Lakadamyali, Golnaz Vahedi, and Gerd Blobel. Bottom row: Bomyi Lim, Arjun Raj, and Stanley Qi.

Popular accounts of the human genome often depict it as a long string of DNA base pairs, but in reality the genome is separated into chromosomes that are tightly twisted and coiled into complex three-dimensional structures. These structures create a myriad of connections between sites on the genome that would be distant from one another if stretched out end-to-end. These “long range interactions” are not incidental — they regulate the activity of our genes during development and can cause disease when disrupted.

Now two teams of researchers at the Perelman School of Medicine at the University of Pennsylvania, each led by Jennifer E. Phillips-Cremins,  associate professor and Dean’s Faculty Fellow in the Department of Bioengineering at the School of Engineering and Applied Science and of Genetics at the Perelman School of Medicine have been awarded grants totaling $9 million from the National Institutes of Health (NIH), as part of a major NIH Common Fund initiative to understand such 3D-genomic interactions.

The initiative, known as the 4D Nucleome Program, broadly aims to map higher-order genome structures across space and time, as well as to understand how the twists and loops of the DNA sequence govern genome function and cellular phenotype in health and disease.

Read the full story in Penn Engineering Today.

N.B.: In addition to Phillips-Cremins, collaborators include Arjun Raj, Professor in Bioengineering and Genetics, and Bioengineering Graduate Group Members Melike Lakadamyali, Associate Professor in Physiology, and Bomyi Lim, Assistant Professor in Chemical and Biomolecular Engineering.

Posted on

Guest Post: Penn Bioengineering Lab Classes in the Time of Coronavirus

By Solumtochukwu (Somto) Egboga

Stephenson Lab student employees (L to R): Seth Fein (BSE 20, MSE 21), Nicole Wojnowski (BSE 22), and Somto Egboga (MSE 21)

Since the country began shutting down in March, I have joined the majority of the world in calling the times “unprecedented”: The word, which I rarely used before the pandemic, is now a staple of my lockdown lexicon. In March, we all got the email that changed the trajectory of the rest of our semester and the school year. Since then, COVID-19 has been impacting lives here at Penn, around the nation, and the world. Hanging out with friends and family on Zoom, managing work and school from home, social distancing, wearing masks everywhere, and constantly washing hands have been the reality of our new normal for months.

It has been almost ten months since the World Health Organization declared COVID-19 a pandemic and this has posed a global crisis like nothing most of us have experienced in our lifetime. At Penn, the campus community including students and staff have rallied to keep each other safe, all while doing what is possible to ensure that lectures, teaching, and research are possible in ways that uphold the university’s mission of “strengthening the quality of education and producing innovative research and models of healthcare delivery by fostering a vibrant inclusive environment and fully embracing diversity.”

BE students Alexa Rybicki, Ifeoluwa Popoola, and Caitlin Frazee meet for BE 309 in the Gather.Town virtual lab space.

In Penn Engineering’s Bioengineering Department, the Stephenson Foundation Educational Laboratory & Bio-MakerSpace has been at the heart of ensuring that lab-based classes run as smoothly as possible given the circumstances. First off, during the summer, the lab launched a Slack site that not only kept students engaged and connected through fun, daily “Questions of the Day” but also gave them the opportunity to reach out to our staff and obtain their expertise for coursework and personal projects. The staff at the Stephenson Lab also supported and continue to support Senior Design students (BE 495) with their projects by ordering, receiving, packaging, arranging pickups, or mailing supplies needed to complete their Senior Design projects. In addition, class time takes place using Gather.Town to recreate our Bio-MakerSpace virtually. In other classes, video tutorials of some of the experiments students were missing out on were produced over the summer and made available to students so they could learn by seeing what the lab staff were doing in the videos. For the Bioengineering Modeling, Analysis, and Design (BE MAD) class (BE 309), in addition to videos, our lab Engineer, Michael Patterson, developed software through which students can enter design criteria and have experimental data emailed to them.

Picking up lab supplies outside in the Engineering complex

The staff at the lab also supported a Rehabilitation Engineering course (BE 514) taught by Michelle Johnson, Associate Professor in Physical Medicine and Rehabilitation and Bioengineering, by putting together supplies that enabled students in the class to reengineer toy bunny rabbits to be more accessible to children with disabilities. Optical Microscopy (BE 518), another Bioengineering course, taught by Christopher Fang-Yen, Associate Professor in Bioengineering and Neuroscience, offers students an introduction to the fundamental concepts of optics and microscopy. The staff at the lab put together kits and made them available for pickup by the students in the class.

In a time when the shape of education looks vastly different from what we anticipated this year, the Bio-MakerSpace has been instrumental in ensuring that students still have access to resources that make their learning experience an enriching one. In these unprecedented times, the lab has been able to encourage students to keep up and be engaged with their coursework while also fostering creativity in students, virtually and remotely. While we may not know what life after the pandemic will look like, one thing to be sure of is that the Stephenson Lab will always be a reliable place for Penn students to get support for personal projects and coursework when needed.

Solumtochukwu (Somto) Egboga is a Master’s Student in Bioengineering, graduating December 2020. She also is a student employee for the Stephenson Foundation Bioengineering Laboratory & Bio-MakerSpace.

Posted on

Using Lung-on-a-chip Technology to Find Treatments for Chlorine Gas Exposure

Huh’s organ-on-a-chip devices contain human cells, allowing for experiments that could not otherwise be practically or ethically performed.

Chlorine gas is a commonly used industrial chemical. It is also highly toxic and potentially deadly; it was used as a chemical weapon in both World War I and the Syrian Civil War and has led to multiple deaths from industrial accidents. Mixing certain household cleaners can also produce the toxic gas, leading to lasting lung injuries for which there are currently no effective treatments.

Now, researchers at Penn Engineering and Penn’s Perelman School of Medicine are collaborating with BARDA, the U.S. Office of Health and Human Services’ Biomedical Advanced Research and Development Authority, to address this need using their lung-on-a-chip technology.

The laboratory of Dan Huh, associate professor in the Department of Bioengineering, has developed a series of organ-on-a-chip platforms. These devices incorporate human cells into precisely engineered microfluidic channels that mimic an organ’s natural environment, providing a way to conduct experiments that would not otherwise be feasible.

Dan Huh
Dan Huh, PhD

Huh’s previous research has involved using a placenta-on-a-chip to study which drugs are able to reach a developing fetus; investigating microgravity’s effect on the immune system by sending one of his chips to the International Space Station; and testing treatments for dry eye disease using an eye-on-a-chip, complete with a mechanical blinking eyelid.

Read the full story on Penn Engineering Today. Media contact Evan Lerner.

Posted on

Magnetic Field and Hydrogels Could Be Used to Grow New Cartilage

by Frank Otto

MRI Knee joint or Magnetic resonance imaging sagittal view for detect tear or sprain of the anterior cruciate ligament (ACL).

Using a magnetic field and hydrogels, a team of researchers in the Perelman School of Medicine have demonstrated a new possible way to rebuild complex body tissues, which could result in more lasting fixes to common injuries, such as cartilage degeneration. This research was published in Advanced Materials.

“We found that we were able to arrange objects, such as cells, in ways that could generate new, complex tissues without having to alter the cells themselves,” says the study’s first author, Hannah Zlotnick, a graduate student in bioengineering who works in the McKay Orthopaedic Research Laboratory at Penn Medicine. “Others have had to add magnetic particles to the cells so that they respond to a magnetic field, but that approach can have unwanted long-term effects on cell health. Instead, we manipulated the magnetic character of the environment surrounding the cells, allowing us to arrange the objects with magnets.”

In humans, tissues like cartilage can often break down, causing joint instability or pain. Often, the breakdown isn’t in total, but covers an area, forming a hole. Current fixes are to fill those holes in with synthetic or biologic materials, which can work but often wear away because they are not the same exact material as what was there before. It’s similar to fixing a pothole in a road by filling it with gravel and making a tar patch: The hole will be smoothed out but eventually wear away with use because it’s not the same material and can’t bond the same way.

What complicates fixing cartilage or other similar tissues is that their makeup is complex.

“There is a natural gradient from the top of cartilage to the bottom, where it contacts the bone,” Zlotnick explains. “Superficially, or at the surface, cartilage has a high cellularity, meaning there is a higher number of cells. But where cartilage attaches to the bone, deeper inside, its cellularity is low.”

So the researchers, which included senior author Robert Mauck, PhD, director of the McKay Lab and a professor of Orthopaedic Surgery and Bioengineering, sought to find a way to fix the potholes by repaving them instead of filling them in. With that in mind, the research team found that if they added a magnetic liquid to a three-dimensional hydrogel solution, cells, and other non-magnetic objects including drug delivery microcapsules, could be arranged into specific patterns that mimicked natural tissue through the use of an external magnetic field.

Read more at Penn Medicine News.

Posted on

Through Brain Imaging Analysis in Rats, Penn Researchers Show Potential to Predict Whether Pain Will be Acute or Persistent

Beth Winkelstein, Megan Sperry, and Eric Granquist

Pain may be a universal experience, but what actually causes that experience within our brains is still poorly understood. Pain often continues long after the relevant receptors in the body have stopped being stimulated and can persist even after those receptors cease to exist, as is the case with “phantom limb” pain.

The exact experience an individual will have after a painful incident comes down to the complex, variable connections formed between several different parts of the brain. The inability to predict how those connections will form and evolve can make pain management a tricky, frustrating endeavor for both healthcare providers and patients.

Now, a team of Penn researchers has shown a way to make such predictions from the pattern of neural connections that begin to take shape soon after the first onset of pain. Though their study was conducted in rats, it suggests that similar brain imaging techniques could be used to guide treatment decisions in humans, such as which individuals are most likely to benefit from different drugs or therapies.

The study, published in the journal Pain, was led by Beth Winkelstein, Eduardo D. Glandt President’s Distinguished Professor in Penn Engineering’s Department of Bioengineering and Deputy Provost of the University of Pennsylvania, along with Megan Sperry, then a graduate student in her lab. Eric Granquist, Director of the Center for Temporomandibular Joint Disease at the Hospital of the University of Pennsylvania in the Department of Oral & Maxillofacial Surgery, and assistant professor of Oral & Maxillofacial Surgery in Penn’s School of Dental Medicine, also contributed to the research.

“Our findings provide the first evidence that brain networks differ between acute and persistent pain states, even before those different groups of rats actually show different pain symptoms,” says Winkelstein.

Read the full story at Penn Engineering Today. Media contact Evan Lerner.