Collaborating researchers from the University of Pennsylvania School of Dental Medicine and the Adams School of Dentistry and Gillings School of Global Public Health at the University of North Carolina have discovered that a bacterial species called Selenomonas sputigena can have a major role in causing tooth decay.
Scientists have long considered another bacterial species, the plaque-forming, acid-making Streptococcus mutans, as the principal cause of tooth decay—also known as dental caries. However, in the study, published in Nature Communications, the Penn Dental Medicine and UNC researchers showed that S. sputigena, previously associated only with gum disease, can work as a key partner of S. mutans, greatly enhancing its cavity-making power.
“This was an unexpected finding that gives us new insights into the development of caries, highlights potential future targets for cavity prevention, and reveals novel mechanisms of bacterial biofilm formation that may be relevant in other clinical contexts,” says study co-senior author Hyun (Michel) Koo, a professor in the Department of Orthodontics and Divisions of Pediatrics and Community Oral Health and co-director of the Center for Innovation & Precision Dentistry at Penn Dental Medicine.
The other two co-senior authors of the study were Kimon Divaris, professor at UNC’s Adams School of Dentistry, and Di Wu, associate professor at the Adams School and at the UNC Gillings School of Global Public Health.
“This was a perfect example of collaborative science that couldn’t have been done without the complementary expertise of many groups and individual investigators and trainees,” Divaris says.
Michel Koo is a professor in the Department of Orthodontics and divisions of Community Oral Health and Pediatric Dentistry in Penn Dental Medicine and co-director of the Center for Innovation & Precision Dentistry. He is a member of the Penn Bioengineering Graduate Group.
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.
In a recent CNN feature, César de la Fuente, Presidential Assistant Professor in Bioengineering, Psychiatry, Microbiology, and in Chemical and Biomolecular Engineering commented on a study about a new type of antibiotic that was discovered with artificial intelligence:
“I think AI, as we’ve seen, can be applied successfully in many domains, and I think drug discovery is sort of the next frontier.”
The de la Fuente lab uses machine learning and biology to help prevent, detect, and treat infectious diseases, and is pioneering the research and discovery of new antibiotics.
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.
“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.”
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.
Mustafa Mir, Assistant Professor of Cell and Developmental Biology in the Perelman School of Medicine and member of the Penn Bioengineering Graduate Group, was selected as one of Howard Hughes Medical Institute’s 31 new Freeman Hrabowski Scholars. The group consists of outstanding early career faculty in science who have potential to become leaders in their research fields and to create diverse and inclusive lab environments in which everyone can thrive. Mir and his lab develop and apply new microscopes to directly visualize the molecular scale events that underlie gene expression within live embryos.
Thank you to everyone who attended the 2023 Department of Bioengineering Juneteenth Address. For those who were unable to attend or who may wish to share the opportunity to view the lecture, a recording of Dr. Kevin Johnson’s talk, “A White Neighbor, a Black Surgeon, and a Mormon Computer Scientist Walk into a Bar…” is available below.
Speaker: Kevin B. Johnson, MD, MS, FAAP, FAMIA, FACMI
David L. Cohen University Professor
Computer and Information Science
Biostatistics, Epidemiology and Informatics
Bioengineering
Annenberg School for Communication
Pediatrics
VP for Applied Informatics (UPHS), University of Pennsylvania
Abstract:
As we recognize Juneteenth, a holiday that brings awareness to what journalist Corey Mitchell calls “…a complex understanding of the nation’s past,” we also need to understand how many of our neighbors, staff, and faculty — even those born in the last 100 years — continue to navigate through the environment that made Juneteenth remarkable. In this talk, Dr. Johnson shares a bit of his personal story and how this story informs his national service and passion for teaching.
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.
We hope you will join us for the 2023 Department of Bioengineering Juneteenth Address by Dr. Kevin B. Johnson.
Date: Wednesday, June 14, 2023
Start Time: 11:00 AM ET
Location: Berger Auditorium (Skirkanich Hall basement room 013)
Zoom link
Meeting ID: 925 0325 6013
Passcode: 801060
Following the event, a limited number of box lunches will be available for in-person attendees. If you would like a box lunch, please RSVP here by Monday, June 12 so we can get an accurate headcount.
Speaker: Kevin B. Johnson, MD, MS, FAAP, FAMIA, FACMI
David L. Cohen University Professor
Annenberg School for Communication, Bioengineering, Biostatistics, Epidemiology and Informatics, Computer and Information Science, Pediatrics
VP for Applied Informatics (UPHS), University of Pennsylvania
Title: “A White Neighbor, a Black Surgeon, and a Mormon Computer Scientist Walk into a Bar…”
Abstract: As we recognize Juneteenth, a holiday that brings awareness to what journalist Corey Mitchell calls “…a complex understanding of the nation’s past”, we also need to understand how many of our neighbors, staff, and faculty—even those born in the last 100 years—continue to navigate through the environment that made Juneteenth remarkable. Dr. Johnson will share a bit of his personal story and how this story informs his national service and passion for teaching.
Bio: Dr. Johnson is a leader of medical information technologies to improve patient care and safety. He is well regarded and widely known for pioneering discoveries in clinical informatics, leading to advances in data acquisition, medication management, and information aggregation in medical settings.
He is a board-certified pediatrician who has aligned the powers of medicine, engineering and technology to improve the health of individuals and communities. In work that bridges biomedical informatics, bioengineering and computer science, he has championed the development and implementation of clinical information systems and artificial intelligence to drive medical research. He has encouraged the effective use of technology at the bedside, and he has empowered patients to use new tools that help them to understand how medications and supplements may affect their health. He is interested in using advanced technologies such as smart devices and in developing computer-based documentation systems for the point of care. He also is an emerging champion of the use of digital media to enhance science communication, with a successful feature-length documentary describing health information exchange, a podcast (Informatics in the Round) and most recently, a children’s book series aimed at STEM education featuring scientists underrepresented in healthcare.
Dr. Johnson holds joint appointments in the Department of Computer and Information Science of the School of Engineering and Applied Science, and secondary appointments in Bioengineering and the Annenberg School for Communication. He serves as Vice President for Applied Informatics in the University of Pennsylvania Health System and as a Professor of Pediatrics at the Children’s Hospital of Philadelphia.
Before arriving at Penn, he served as the Cornelius Vanderbilt Professor and Chair of the Department of Biomedical Informatics at the Vanderbilt University School of Medicine, where he had taught since 2002. As Senior Vice President for Health Information Technology at the Vanderbilt University Medical Center, he led the development of clinical systems that enabled doctors to make better treatment and care decisions for individual patients, and introduced new systems to integrate artificial intelligence into patient care workflows.
The author of more than 150 publications, Dr. Johnson has held numerous leadership positions in the American Medical Informatics Association and the American Academy of Pediatrics. He leads the American Board of Pediatrics Informatics Advisory Committee, directs the Board of Scientific Counselors of the National Library of Medicine, and is a member of the NIH Council of Councils. He is an elected member of the National Academy of Medicine, American College of Medical Informatics and Academic Pediatric Society. He has received awards from the Robert Wood Johnson Foundation and American Academy of Pediatrics, among many others.
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.
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 Journaland 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.
