Wandering and Wondering

Wangari Mbuthia at Marina Bay, Singapore (photo credit: Wangari Mbuthia)

Wangari Mbuthia, Penn Bioengineering Class of 2025, shares her experience in Singapore while studying abroad with the Global Research and Internship Program (GRIP) at Penn. GRIP provides outstanding undergraduate and graduate students the opportunity to intern or conduct research abroad for 8 to 12 weeks over the summer. Participants gain career-enhancing experience and global exposure that is essential in a global workforce.

Engineering Research in Singapore

If someone would have told me this time last year that I would be doing an engineering research program in Singapore, I wouldn’t have believed it. But rest assured here I am, two weeks in, and it has been an incredible experience.

Admittedly before coming to Singapore, basically everything I knew about this country could somewhat be summarized in that it was hot, beautiful and diverse. Before this I had never traveled to an Asian country and I was both excited and nervous about taking this trip. I was excited for food, sights and new experiences but I was also particularly nervous about being in a country where almost no one looks like me. Nevertheless, I decided to travel with an open mind, letting myself wander and wonder as I went and I thought I’d share some of my initial discoveries here.

Walking around Singapore it is clear that it is a place where many cultures have come together – Chinese, Malay, Indian and more – but I could probably count the number of Black people I saw on my two hands. This cultural landscape left me feeling very visible everywhere I went. But at the same time also somewhat invisible because for the most part, no one really made me feel like the odd one out. Rather, my presence only seemed to spark harmless (and sometimes comical) curiosity about where I was from or how I do my braids.

To my delight, the cultural diversity of Singapore is equally reflected in the food options. I can easily have access to almost any type of Asian cuisine at any given time and even quite a lot Western varieties too. I have eagerly been documenting the foods I try and rating them. One of my favorites has been a kaya (a type of sweet coconut spread) toast breakfast with soft-boiled eggs and teh-c (tea with evaporated milk). I also still need to try the unique, smelly fruit (so smelly it is not allowed on public transport), durian.

Another wonderful discovery was to see how Singapore lives up to its name, “garden city”. Not only is the city filled with beautiful buildings each with their own personality, but the city landscape is so artfully integrated with nature inside and out. I have seen indoor gardens and waterfalls but also gorgeous waterfront and outdoor spaces that I could sit in for hours.

It’s hard to believe how a country with such little land area and no natural resources has grown to be one of the richest cities in the world. Singapore truly feels like a place where so much is possible and that has been really special to see.

RNA Nanoparticle Therapy Stops the Spread of Incurable Bone Marrow Cancer

by

Myeloma cells producing monoclonal proteins of varying types, created by Scientific Animations under the Creative Commons Attributions-Share Alike International 4.0 License

Multiple myeloma is an incurable bone marrow cancer that kills over 100,000 people every year. Known for its quick and deadly spread, this disease is one of the most challenging to address. As these cancer cells move through different parts of the body, they mutate, outpacing possible treatments. People diagnosed with severe multiple myeloma that is resistant to chemotherapy typically survive for only three to six months. Innovative therapies are desperately needed to prevent the spread of this disease and provide a fighting chance for those who suffer from it.

Michael Mitchell, J. Peter and Geri Skirkanich Assistant Professor of Innovation in Bioengineering (BE), and Christian Figueroa-Espada, doctoral student in BE at the University of Pennsylvania School of Engineering and Applied Science, created an RNA nanoparticle therapy that makes it impossible for multiple myeloma to move and mutate. The treatment, described in their study published in PNAS, turns off a cancer-attracting function in blood vessels, disabling the pathways through which multiple myeloma cells travel.

By shutting down this “chemical GPS” that induces the migration of cancer cells, the team’s therapy stops the spread of multiple myeloma, helping to eliminate it altogether.

Read the full story in Penn Engineering Today.

Engineered White Blood Cells Eliminate Cancer

by

“Macrophages killing cancer cell” photographed by Susan Arnold.

By silencing the molecular pathway that prevents macrophages from attacking our own cells, Penn Engineers have manipulated these white blood cells to eliminate solid tumors.

Cancer remains one of the leading causes of death in the U.S. at over 600,000 deaths per year. Cancers that form solid tumors such as in the breast, brain or skin are particularly hard to treat. Surgery is typically the first line of defense for patients fighting solid tumors. But surgery may not remove all cancerous cells, and leftover cells can mutate and spread throughout the body. A more targeted and wholistic treatment could replace the blunt approach of surgery with one that eliminates cancer from the inside using our own cells.

Dennis Discher, Robert D. Bent Professor in Chemical and Biomolecular Engineering, Bioengineering, and Mechanical Engineering and Applied Mechanics, and postdoctoral fellow, Larry Dooling, provide a new approach in targeted therapies for solid tumor cancers in their study, published in Nature Biomedical Engineering. Their therapy not only eliminates cancerous cells, but teaches the immune system to recognize and kill them in the future.

“Due to a solid tumor’s physical properties, it is challenging to design molecules that can enter these masses,” says Discher. “Instead of creating a new molecule to do the job, we propose using cells that ‘eat’ invaders – macrophages.”

Macrophages, a type of white blood cell, immediately engulf and destroy – phagocytize – invaders such as bacteria, viruses, and even implants to remove them from the body. A macrophage’s innate immune response teaches our bodies to remember and attack invading cells in the future. This learned immunity is essential to creating a kind of cancer vaccine.

But, a macrophage can’t attack what it can’t see.

“Macrophages recognize cancer cells as part of the body, not invaders,” says Dooling. “To allow these white blood cells to see and attack cancer cells, we had to investigate the molecular pathway that controls cell-to-cell communication. Turning off this pathway – a checkpoint interaction between a protein called SIRPa on the macrophage and the CD47 protein found on all ‘self’ cells – was the key to creating this therapy.”

Read the full story in Penn Engineering Today.

Multiple members in the biophysical engineering lab lead by Dennis Discher, including co-lead author and postdoctoral fellow and Penn Bioengineering alumnus Jason Andrechak and Bioengineering Ph.D. student Brandon Hayes, contributed to this study. The research was funded by grants from the National Heart, Lung, and Blood Institute and the National Cancer Institute, including the Physical Sciences Oncology Network, of the US National Institutes of Health.

On a Different Wavelength, Nader Engheta Leads a Community in Light

Nader Engheta was puzzled when he got a call from the psychology department about a fish.
In the early 1990s, Engheta, a newly minted associate professor of electrical engineering in Penn’s School of Engineering and Applied Science, was a respected expert in radio wave technologies. But in recent years, his work had been expanding into subjects at once more eccentric and fundamental.

Nader Engheta was puzzled when he got a call from the psychology department about a fish.

In the early 1990s, Engheta, a newly minted associate professor of electrical engineering in Penn’s School of Engineering and Applied Science, was a respected expert in radio wave technologies. But in recent years, his work had been expanding into subjects at once more eccentric and fundamental.

Engheta’s interest in electromagnetic waves was not limited to radio frequencies, as a spate of fresh publications could attest. Some studies investigated a range of wave interactions with a class of matter known as a “chiral media,” materials with molecular configurations that exhibit qualities of left or right “handedness.” Others established practical electromagnetic applications for a bewildering branch of mathematics called “fractional calculus,” an area with the same Newtonian roots as calculus proper but a premise as eyebrow-raising as the suggestion a family might literally include two-and-a-half children.

Electromagnetic waves are organized on a spectrum of wavelengths. On the shorter end of the spectrum are high-energy waves, such as X-rays. In the middle, there is the limited range we see as visible light. And on the longer end are the lower-energy regimes of radio and heat.

Researchers tend to focus on one kind of wave or one section of the spectrum, exploring quirks and functions unique to each. But all waves, electromagnetic or not, share the same characteristics: They consist of a repeating pattern with a certain height (amplitude), rate of vibration (frequency), and distance between peaks (wavelength). These qualities can define a laser beam, a broadcasting voice, a wind-swept lake, or a violin string.

Engheta has never been the kind of scholar to limit the scope of his curiosity to a single field of research. He is interested in waves, and his fascination lies equally in the physics that determine wave behavior and the experimental technologies that push the boundaries of those laws.

So, when Edward Pugh, a mathematical psychologist studying the physiology of visual perception, explained that green sunfish might possess an evolutionary advantage for seeing underwater, Engheta listened.

Soon, the two Penn professors were pouring over microscope images of green sunfish retinas.

Read Devorah Fischler’s full story about Nader Engheta and watch an accompanying video at Penn Today.

Nader Engheta is H. Nedwill Ramsey Professor of Electrical and Systems Engineering at Penn Engineering, with secondary appointments in the departments of Bioengineering, Materials Science and Engineering, and Physics and Astronomy in the School of Arts & Sciences.

Penn Bioengineering Graduate Ella Atsavapranee Wins 2023 Fulbright Grant

Ella Atsavapranee (BE 2023)

Twenty-nine University of Pennsylvania students, recent graduates, and alumni have been offered Fulbright U.S. Student Program grants for the 2023-24 academic year, including eight seniors who graduated May 15.

They will conduct research, pursue graduate degrees, or teach English in Belgium, Brazil, Colombia, Denmark, Ecuador, Estonia, France, Germany, Guatemala, India, Israel, Latvia, Mexico, Nepal, New Zealand, the West Bank-Palestine territories, South Korea, Spain, Switzerland, Taiwan, and Thailand.

The Fulbright Program is the United States government’s flagship international educational exchange program, awarding grants to fund as long as 12 months of international experience.

Most of the Penn recipients applied for the Fulbright with support from the Center for Undergraduate Research and Fellowships.

Among the Penn Fulbright grant recipients for 2023-24 is Ella Atsavapranee, from Cabin John, Maryland, who graduated in May with a bachelor’s degree in bioengineering from the School of Engineering and Applied Science and a minor in chemistry from the College. She was offered a Fulbright to conduct research at the École Polytechnique Fédérale de Lausanne in Switzerland.

At Penn, Atsavapranee worked with Michael Mitchell, J. Peter and Geri Skirkanich Assistant Professor in Bioengineering, engineering lipid nanoparticles to deliver proteases that inhibit cancer cell proliferation. She has also worked with Shan Wang, Leland T. Edwards Professor in the School of Engineering and Professor of Electrical Engineering at Stanford University, using bioinformatics to discover blood biomarkers for cancer detection. To achieve more equitable health care, she worked with Lisa Shieh, Clinical Professor in Medicine at the Stanford School of Medicine,  to evaluate an AI model that predicts risk of hospital readmission and study how room placement affects patient experience.

Outside of research, Atsavapranee spread awareness of ethical issues in health care and technology as editor-in-chief of the Penn Bioethics Journal and a teaching assistant for Engineering Ethics (EAS 2030). She was also a Research Peer Advisor for the Penn Center for Undergraduate Research & Fellowships (CURF), a student ambassador for the Office of Admissions, and a volunteer for Service Link, Puentes de Salud, and the Hospital of the University of Pennsylvania. She plans to pursue a career as a physician-scientist to develop and translate technologies that are more affordable and accessible to underserved populations.

Read the full list of Penn Fulbright grant recipients for 2023-24 in Penn Today.

Nanorobotic Systems Presents New Options for Targeting Fungal Infections

by Nathi Magubane

Candida albicans is a species of yeast that is a normal part of the human microbiota but can also cause severe infections that pose a significant global health risk due to their resistance to existing treatments, so much so that the World Health Organization has highlighted this as a priority issue. The picture above shows a before (left) and after (right) fluorescence image of fungal biofilms being precisely targeted by nanozyme microrobots without bonding to or disturbing the tissue sample. (Image: Min Jun Oh and Seokyoung Yoon)

Infections caused by fungi, such as Candida albicans, pose a significant global health risk due to their resistance to existing treatments, so much so that the World Health Organization has highlighted this as a priority issue.

Although nanomaterials show promise as antifungal agents, current iterations lack the potency and specificity needed for quick and targeted treatment, leading to prolonged treatment times and potential off-target effects and drug resistance.

Now, in a groundbreaking development with far-reaching implications for global health, a team of researchers jointly led by Hyun (Michel) Koo of the University of Pennsylvania School of Dental Medicine and Edward Steager of Penn’s School of Engineering and Applied Science has created a microrobotic system capable of rapid, targeted elimination of fungal pathogens.

“Candida forms tenacious biofilm infections that are particularly hard to treat,” Koo says. “Current antifungal therapies lack the potency and specificity required to quickly and effectively eliminate these pathogens, so this collaboration draws from our clinical knowledge and combines Ed’s team and their robotic expertise to offer a new approach.”

The team of researchers is a part of Penn Dental’s Center for Innovation & Precision Dentistry, an initiative that leverages engineering and computational approaches to uncover new knowledge for disease mitigation and advance oral and craniofacial health care innovation.

For this paper, published in Advanced Materials, the researchers capitalized on recent advancements in catalytic nanoparticles, known as nanozymes, and they built miniature robotic systems that could accurately target and quickly destroy fungal cells. They achieved this by using electromagnetic fields to control the shape and movements of these nanozyme microrobots with great precision.

“The methods we use to control the nanoparticles in this study are magnetic, which allows us to direct them to the exact infection location,” Steager says. “We use iron oxide nanoparticles, which have another important property, namely that they’re catalytic.”

Read the full story in Penn Today.

Hyun (Michel) Koo is a professor in the Department of Orthodontics and in the divisions of Pediatric Dentistry and Community Oral Health and is the co-founder of the Center for Innovation & Precision Dentistry in the School of Dental Medicine at the University of Pennsylvania. He is a member of the Penn Bioengineering Graduate Group.

Edward Steager is a research investigator in the School of Engineering and Applied Science’s General Robotics, Automation, Sensing & Perception Laboratory at Penn.

Other authors include Min Jun Oh, Alaa Babeer, Yuan Liu, Zhi Ren, Zhenting Xiang, Yilan Miao, and Chider Chen of Penn Dental; and David P. Cormode and Seokyoung Yoon of the Perelman School of Medicine. Cormode also holds a secondary appointment in Bioengineering.

This research was supported in part by the National Institute for Dental and Craniofacial Research (R01 DE025848, R56 DE029985, R90DE031532 and; the Basic Science Research Program through the National Research Foundation of Korea of the Ministry of Education (NRF-2021R1A6A3A03044553).

Penn Bioengineering Graduate Student on T Cell Therapy Improvements

Image: Courtesy of Penn Medicine News

 Neil Sheppard,  Adjunct Associate Professor of Pathology and Laboratory Medicine in the Perelman School of Medicine, and David Mai, a Bioengineering graduate student in the School of Engineering and Applied Science, explained the findings of their recent study, which offered a potential strategy to improve T cell therapy in solid tumors, to the European biotech news website Labiotech.

Mai is a graduate student in the lab of Carl H. June, the Richard W. Vague Professor in Immunotherapy in Penn Medicine, Director of the Center for Cellular Immunotherapies (CCI) at the Abramson Cancer Center, and member of the Penn Bioengineering Graduate Group.

Read “Immunotherapy in the fight against solid tumors” in Labiotech.

Read more about this collaborative study here.

Folding@Home: How You, and Your Computer, Can Play Scientist

by

Greg Bowman kneels, working on a server.
Folding@home is led by Gregory Bowman, a Penn Integrates Knowledge Professor who has appointments in the Departments of Biochemistry and Biophysics in the Perelman School of Medicine and the Department of Bioengineering in the School of Engineering and Applied Science. (Image: Courtesy of Penn Medicine News)

Two heads are better than one. The ethos behind the scientific research project Folding@home is that same idea, multiplied: 50,000 computers are better than one.

Folding@home is a distributed computing project which is used to simulate protein folding, or how protein molecules assemble themselves into 3-D shapes. Research into protein folding allows scientists to better understand how these molecules function or malfunction inside the human body. Often, mutations in proteins influence the progression of many diseases like Alzheimer’s disease, cancer, and even COVID-19.

Penn is home to both the computer brains and human minds behind the Folding@home project which, with its network, forms the largest supercomputer in the world. All of that computing power continually works together to answer scientific questions such as what areas of specific protein implicated in Parkinson’s disease may be susceptible to medication or other treatment.

Led by Gregory Bowman, a Penn Integrates Knowledge professor of Biochemistry and Biophysics in the Perelman School of Medicine who has joint appointments in the Department of Biochemistry and Biophysics in the Perelman School of Medicine and the Department of Bioengineering in the School of Engineering and Applied Science, Folding@home is open for any individual around the world to participate in and essentially volunteer their computer to join a huge network of computers and do research.

Using the network hub at Penn, Bowman and his team assign experiments to each individual computer which communicates with other computers and feeds info back to Philly. To date, the network is comprised of more than 50,000 computers spread across the world.

“What we do is like drawing a map,” said Bowman, explaining how the networked computers work together in a type of system that experts call Markov state models. “Each computer is like a driver visiting different places and reporting back info on those locations so we can get a sense of the landscape.”

Individuals can participate by signing up and then installing software to their standard personal desktop or laptop. Participants can direct the software to run in the background and limit it to a certain percentage of processing power or have the software run only when the computer is idle.

When the software is at work, it’s conducting unique experiments designed and assigned by Bowman and his team back at Penn. Users can play scientist and watch the results of simulations and monitor the data in real time, or they can simply let their computer do the work while they go about their lives.

Read the full story at Penn Medicine News.

Why is Machine Learning Trending in Medical Research but not in Our Doctor’s Offices?

by Melissa Pappas

Illustration of a robot in a white room with medical equipment.Machine learning (ML) programs computers to learn the way we do – through the continual assessment of data and identification of patterns based on past outcomes. ML can quickly pick out trends in big datasets, operate with little to no human interaction and improve its predictions over time. Due to these abilities, it is rapidly finding its way into medical research.

People with breast cancer may soon be diagnosed through ML faster than through a biopsy. Those suffering from depression might be able to predict mood changes through smart phone recordings of daily activities such as the time they wake up and amount of time they spend exercising. ML may also help paralyzed people regain autonomy using prosthetics controlled by patterns identified in brain scan data. ML research promises these and many other possibilities to help people lead healthier lives.

But while the number of ML studies grow, the actual use of it in doctors’ offices has not expanded much past simple functions such as converting voice to text for notetaking.

The limitations lie in medical research’s small sample sizes and unique datasets. This small data makes it hard for machines to identify meaningful patterns. The more data, the more accuracy in ML diagnoses and predictions. For many diagnostic uses, massive numbers of subjects in the thousands would be needed, but most studies use smaller numbers in the dozens of subjects.

But there are ways to find significant results from small datasets if you know how to manipulate the numbers. Running statistical tests over and over again with different subsets of your data can indicate significance in a dataset that in reality may be just random outliers.

This tactic, known as P-hacking or feature hacking in ML, leads to the creation of predictive models that are too limited to be useful in the real world. What looks good on paper doesn’t translate to a doctor’s ability to diagnose or treat us.

These statistical mistakes, oftentimes done unknowingly, can lead to dangerous conclusions.

To help scientists avoid these mistakes and push ML applications forward, Konrad Kording, Nathan Francis Mossell University 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, is leading an aspect of a large, NIH-funded program known as CENTER – Creating an Educational Nexus for Training in Experimental Rigor. Kording will lead Penn’s cohort by creating the Community for Rigor which will provide open-access resources on conducting sound science. Members of this inclusive scientific community will be able to engage with ML simulations and discussion-based courses.

“The reason for the lack of ML in real-world scenarios is due to statistical misuse rather than the limitations of the tool itself,” says Kording. “If a study publishes a claim that seems too good to be true, it usually is, and many times we can track that back to their use of statistics.”

Such studies that make their way into peer-reviewed journals contribute to misinformation and mistrust in science and are more common than one might expect.

Read the full story in Penn Engineering Today.

CiPD Fellows Recognized with Research Awards

Members of the inaugural cohort of fellows in the Center for Innovation and Precision Dentistry (CiPD)’s NIDCR T90/R90 Postdoctoral Training Program have been recognized for their research activities with fellows receiving awards from the American Association for Dental, Oral, and Craniofacial Research (AADOCR), the Society for Biomaterials, and the Osteology Foundation. All four of the honored postdocs are affiliated with Penn Bioengineering.

Zhi Ren

Zhi Ren won first place in the Fives-Taylor Award at the AADOCR Mini Symposium for Young Investigators. A postdoctoral fellow in the labs of Dr. Hyun (Michel) Koo at Penn Dental Medicine (and member of the Penn Bioengineering Graduate Group) and Dr. Kathleen Stebe of Penn Engineering, Dr. Ren’s research focuses on understanding how bacterial and fungal pathogens interact in the oral cavity to form a sticky plaque biofilm on teeth, which gives rise to severe childhood tooth decay that affects millions of children worldwide. In his award-winning study, titled “Interkingdom Assemblages in Saliva Display Group-Level Migratory Surface Mobility”, Dr. Ren discovered that bacteria and fungi naturally present in the saliva of toddlers with severe decay can form superorganisms able to move and rapidly spread on tooth surfaces.

Justin Burrell

Justin Burrell won second place in the AADOCR Hatton Competition postdoctoral category for his research. Dr. Burrell has been working with Dr. Anh Le in Penn Dental Medicine’s Department of Oral Surgery/Pharmacology and Dr. D. Kacy Cullen of Penn Medicine and Penn Bioengineering. Together, their interdisciplinary team of clinician-scientists, biologists, and neuroengineers have been developing novel therapies to expedite facial nerve regeneration and increase meaningful functional recovery.

Marshall Padilla

Marshall Padilla earned third place at the Society for Biomaterials Postdoctoral Recognition Award Competition for a project titled, “Branched lipid architecture improves lipid-nanoparticle-based mRNA delivery to the liver via enhanced endosomal escape”. Padilla was also a finalist in the AADOCR Hatton Award Competition, presenting on a separate project titled, “Lipid Nanoparticle Optimization for mRNA-based Oral Cancer Therapy”. Both projects employ lipid nanoparticles, the same delivery vehicles used in the mRNA COVID-19 vaccine technology. A postdoctoral fellow in the lab of Dr. Michael J. Mitchell of Penn’s Department of Bioengineering, Dr. Padilla’s research focuses on developing new ways to enhance the efficacy and safety of lipid nanoparticle technology and its applications in dentistry and biomedicine. He has been working in collaboration with Dr. Shuying (Sheri) Yang and Dr. Anh Le in Penn Dental Medicine.

Dennis Sourvanos

Dennis Sourvanos (GD’23, DScD’23) was the recipient of the Trainee Travel Grant award through the Osteology Foundation (Lucerne Switzerland). Dr. Sourvanos will be presenting his research related to medical dosimetry and tissue regeneration at the International Osteology Symposium in Barcelona, Spain (April 27th – 29th 2023). He also presented at the 2023 AADOCR/CADR Annual Meeting for his project titled, “Validating Head-and-Neck Human-Tissue Optical Properties for Photobiomodulation and Photodynamic Therapies.” Dr. Sourvanos has been working with Dr. Joseph Fiorellini in Penn Dental Medicine’s Department of Periodontics and Dr. Timothy Zhu in the Hospital of the University of Pennsylvania’s Department of Radiation Oncology and the Smilow Center for Translational Research (and member of the Penn Bioengineering Graduate Group).

Read the full announcement in Penn Dental Medicine News.