July 2023 – Penn Bioengineering Blog

Artificial intelligence is a new addition to the infectious disease researcher’s toolbox. Yet in merely half a decade, AI has accelerated progress on some of the most urgent issues in medical science and public health. Researchers in this field blend knowledge of life sciences with skill in computation, chemistry and design, satisfying decades-long appeals for interdisciplinary tactics to treat these disorders and stop their spread.

Diseases are “infectious” when they are caused by organisms, including parasites, viruses, bacteria and fungi. People and animals can contract infectious diseases from their environments or food, or through interactions with one another. Some, but not all, are contagious.

Infectious diseases are an intractable global challenge, posing problems that continue to grow in severity even as science has offered a steady pace of solutions. The world continues to become more interconnected, bringing people into new kinds and levels of relation, and the climate crisis is throwing environmental and ecological networks out of balance. Diseases that were once treatable by drugs have become resistant, and new drug discovery is more costly than ever. Uneven resource distribution means that certain parts of the world are perennial hotspots for diseases that others never fear.

Cesar de la Fuente brings an expert eye to how AI has transformed infectious disease research in a recently published piece in Science with co-authors Felix Wong and James J. Collins from MIT.

Presidential Assistant Professor in the Department of Bioengineering and the Department of Chemical and Biomolecular Engineering at the University of Pennsylvania School of Engineering and Applied Science, with additional primary appointments in Psychiatry and Microbiology within the Perelman School of Medicine, de la Fuente brings a multifaceted perspective to his survey of the field.

In the paper, de la Fuente and co-authors assess the progress, limitations and promise of research in AI and infectious diseases in three major areas of inquiry: anti-infective drug discovery, infection biology, and diagnostics for infectious diseases.

Read more in Penn Engineering Today.

July 26, 2023July 26, 2023

Penn Bioengineers Create Non-invasive Cartilage Implants for Pediatric Subglottic Stenosis

by Emily Shafer

Paul Gehret and Riccardo Gottardi accept the International Society for Biofabrication New Investigator Award onstage at the international conference. — Paul Gehret (left) and Riccardo Gottardi, PhD, at Biofabrication 2022, the International Conference on Biofabrication.

Bioengineering researchers at Children’s Hospital of Philadelphia are developing a less invasive and quicker method to create cartilage implants as an alternative to the current treatment for severe subglottic stenosis, which occurs in 10 percent of premature infants in the U.S.

Subglottic stenosis is a narrowing of the airway, in response to intubation. Severe cases require laryngotracheal reconstruction that involves grafting cartilage from the rib cage with an invasive surgery. With grant support from the National Institutes of Health, Riccardo Gottardi, PhD, who leads the Bioengineering and Biomaterials (Bio²) Lab at CHOP, is refining a technology called Meniscal Decellularized scaffold (MEND). Working with a porcine model meniscus, the researchers remove blood vessels and elastin fibers to create pathways that allow for recellularization. Dr. Gottardi and his team then harvest ear cartilage progenitor cells (CPCs) with a minimally invasive biopsy, combine them with MEND, and create cartilage implants that could be a substitute for the standard laryngotracheal reconstruction.

This work and similar work on the tympanic membrane earned Paul Gehret, a doctoral student in the Gottardi Lab, the International Society for Biofabrication New Investigator Award and the Wake Forest Institute for Regenerative Medicine Young Investigator Award. Gehret and Dr. Gottardi accepted the awards at Biofabrication 2022, the International Conference on Biofabrication, in Pisa Italy.

While laryngotracheal reconstruction in the adult population has a success rate of up to 96%, success rates in children range from 75% to 85%, and children often require revision surgery due to a high incidence of restenosis. The procedure also involves major surgery to remove cartilage from the rib cage, which is more difficult for childrens’ smaller bodies.

“Luckily not many children suffer from severe subglottic stenosis, but for those who do, it is really serious,” said Dr. Gottardi, who also is assistant professor in the Department of Pediatrics and Department of Bioengineering at CHOP and the University of Pennsylvania. “With our procedure, we have an easily accessible source for the cartilage and the cells, providing a straightforward and noninvasive treatment option with much potential.”

Read the full story in CHOP’s Cornerstone Blog.

Riccardo Gottardi is an Assistant Professor in the Department of Pediatrics, Division of Pulmonary Medicine in the Perelman School of Medicine and in the Department of Bioengineering in the School of Engineering and Applied Science. He also holds an appointment in the Children’s Hospital of Philadelphia (CHOP).

Paul Gehret is a Ph.D. student in Bioengineering, an Ashton Fellow and a NSF Fellow. His research focuses on leveraging decellularized cartilage scaffolds and novel cell sources to reconstruct the pediatric airway.

July 21, 2023July 14, 2023

Balancing Dentistry and Engineering to Bring New Innovations to the Clinic

by Liana F. Wait

Kyle Vining, who is jointly appointed in the School of Dental Medicine and the School of Engineering and Applied Science, hopes that his research will help to push forward the state of clinical dentistry.

When trying to choose between two career paths—dentistry and engineering—Kyle Vining decided ‘Why not both?’ Vining joined Penn in July 2022 and is jointly appointed in the School of Dental Medicine and the School of Engineering and Applied Science.

“During my training, I saw that there was overlap where I could do clinical work and science at the same time, and so that’s what I’ve been doing ever since,” Vining says. “As far back as middle school, I always wanted to be a biomedical engineer, and then the clinical side became interesting to me because I didn’t want to only do the theoretical or research side of things. I also wanted the hands-on, practical interaction of a skilled profession.”

The benefits of a dual career: Variety and opportunities to give back

Vining finds that wearing two hats offers the best of both worlds: opportunities to help both individual patients and to contribute to scientific and clinical progress.

“On the dentistry side, what I enjoy is getting to see patients, solving clinical problems, and trying to perform the best treatment I can; it has this rapid pace, which is kind of exciting and keeps you motivated,” Vining says. “And then research allows me to explore my interests and think about making an impact more broadly, not just in dentistry, but in medicine or in the world in general.”

Vining says dental school was demanding, yet a good time to explore his varied interests. He says he’d encourage others to pursue dentistry with an interdisciplinary approach. “Having exposure to different fields or different knowledge while you’re a student is really good for students and the profession in general,” he says.

The path towards a dual career

Vining first delved into research as a biomedical engineering undergraduate at Northwestern University. “I had the opportunity to work in a materials science lab studying the chemistry of surfaces. We would use molecules to modify the properties and surfaces that environments or cells could interact with,” he says.

Then, as a student at the University of Minnesota School of Dentistry, Vining realized that this same materials science research had many applications in dentistry. While in dental school, Vining conducted independent research in a materials science lab and also took the opportunity to do a yearlong fellowship in a cell and developmental biology lab at the National Institutes of Health.

Vining credits this fellowship with launching him towards a Ph.D., which he completed in bioengineering at Harvard in 2020. After earning his Ph.D., Vining conducted research at the Dana-Farber Cancer Institute prior to joining Penn.

Using biomaterials to understand how cells and tissues interact

Vining’s research at Penn aims to understand how the biophysical properties of materials impact cellular processes such as inflammation and fibrosis.

“Fibrosis is a physical change in tissues that produces a scar-like matrix that can inhibit healing, impair cancer treatment, and in general is not compatible with tissues regeneration,” Vining says. “There’s been a lot of effort on antifibrotic drugs, but we’re trying to look at fibrosis a little bit differently. Instead of directly inhibiting fibrosis, we’re trying to understand its consequences for the immune system because the immune system can be hijacked and become detrimental for your tissues.”

Through a better understanding the feedback loop between fibrotic tissue and the immune system, Vining hopes to design interventions to facilitate wound healing and tissue remodeling during restorative dental procedures and for treating diseases including head and neck cancer.

He’s also investigating how biomaterials like the resin used in tooth fillings interact with dental tissues. “Dental fillings rely on decades-old technologies that have been grandfathered in and contain toxic monomers that are not safe for biological systems,” Vining says. “We found a biocompatible resin chemistry that supports cells in vitro, and we’re trying to apply this to new types of dental fillings that promote repair or generation of dental tissues.”

Fostering interdisciplinary collaborations at Penn

Vining was recruited to be part of the Center for Innovation & Precision Dentistry (CiPD), the joint center of Penn Dental Medicine and Penn Engineering.

“Dr. Vining is an ideal fit for the vision and mission of the CiPD,” says Penn Dental’s Hyun (Michel) Koo, co-founder and co-director of the CiPD. “With a secondary appointment in the School of Engineering, he will be instrumental in continuing to strengthen our engineering collaborations and teaching our students to work across disciplines to advance research, training, and entrepreneurship in this realm.”

Ultimately, Vining says it was Penn’s scientific community and the opportunities for interdisciplinary collaborations that drew him here.

“It was very apparent that there were a lot of potential research paths to pursue here and a lot of opportunities for collaborations,” Vining says. “One of the most exciting things for me so far has been meeting with faculty, whether it’s at Penn Medicine, the School of Engineering, Wharton, Penn Dental, or the Veterinary School. These meetings have already opened up new projects and collaborations.”

One such collaboration is with Michael Mitchell, associate professor of bioengineering. The pair were awarded the second annual IDEA (Innovation in Dental Medicine and Engineering to Advance Oral Health) Prize in May 2023 to kickstart a project exploring the potential for using lipid nanoparticles to treat dental decay.

The collaboration sparked when Vining saw Mitchell present on a new technology that uses lipid nanoparticles to bind and target bone marrow cells at the 2022 CiPD first annual symposium. “It got me thinking because the dentin inside of teeth is a mineralized tissue very similar to bone, and the pulp inside the dentin is analogous to bone marrow tissue,” Vining says.

Read the full story in Penn Today.

Vining and Koo are members of the Penn Bioengineering Graduate Group.

July 14, 2023

Why New Cancer Treatments are Proliferating

by Karen L. Brooks

Doctors performing surgery. — Image: Penn Medicine News

In the five years since the FDA’s initial approval of chimeric antigen receptor (CAR) T cell therapy, Penn Medicine has gleaned 20 additional approvals related to drugs and techniques to treat or detect cancer.

Rather than being the single disease class many people refer to, “cancer” is a blanket term that covers more than 100 distinct diseases, many of which have little in common aside from originating with rapidly dividing cells. Since different cancers demand different treatments, it follows that any given new therapy emerging from any institution would be likely to be a new cancer treatment.

But why so many in just this five-year period?

The volume of new cancer treatments makes sense, says Abramson Cancer Center (ACC) director Robert Vonderheide, attributing the flurry of new cancer drug approvals to a recent “explosion” in knowledge about cancer biology.

“Much of that knowledge is about the immune system’s ability to attack cancer, which people seriously doubted until about 20 years ago. As soon as we had a clinical validation for this Achilles heel in cancer, the dam burst for ideas about other ways to exploit that vulnerability to come forward,” he says. “The first drug that came out to activate the immune system inspired the rest of the field to find the next drug, and the one after that. We as a field have moved from serendipity and empiricism to science-driven drug design.”

The first CAR T cell therapy approval invigorated Penn faculty interested in finding new ways to harness the immune system to fight cancer.

“An approval like that makes what you’re working on more of a reality,” says Avery Posey, an assistant professor of systems pharmacology and translational therapeutics in the Perelman School of Medicine, whose lab team spends much of its time trying to identify more specific antigens for solid tumors and also studies ways to optimize engineered donor T cells. “It brings a new perspective, showing that your work is more than basic research and can actually become drugs that impact patients’ lives. That’s a real motivator to keep pushing forward.”

Honing new immunotherapies is a priority among Penn researchers, but not every recently approved new cancer treatment or detection tool developed at the institution engages the immune system. Faculty have explored and introduced widely varying approaches to improving the standard of care for cancer patients.

Read the full story in Penn Medicine Magazine.

Avery Posey is a member of the Penn Bioengineering Graduate Group. Read more stories featuring Posey here.

July 13, 2023

2023 Graduate Research Fellowships for Bioengineering Students

Congratulations to the fourteen Bioengineering students to receive 2023 National Science Foundation Graduate Research Fellowship Program (NSF GRFP) fellowships. The prestigious NSF GRFP program recognizes and supports outstanding graduate students in NSF-supported fields. The recipients honorees were selected from a highly-competitive, nationwide pool. Further information about the program can be found on the NSF website.

Carlos Armando Aguila, Ph.D. student in Bioengineering, is a member of the Center of Neuroengineering and Therapeutics, advised by Erin Conrad, Assistant Professor in Neurology, and Brian Litt, Professor in Bioengineering and Neurology. His research focuses on analyzing electroencephalogram (EEG) signals to better understand epilepsy.

Joseph Lance Victoria Casila is a Ph.D. student in Bioengineering in the lab of Riccardo Gottardi, Assistant Professor in Pediatrics and Bioengineering. His research focuses on probing environmental factors that influence stem cell differentiation towards chondrogenesis for cartilage engineering and regeneration.

Trevor Chan is a Ph.D. student in Bioengineering in the lab of Felix Wehrli, Professor of Radiologic Science. His research is in developing computational methods for medical image refinement and analysis. Two ongoing projects are: self-supervised methods for CT super-resolution and assessment of osteoporosis, and semi-supervised segmentation of 3D and 4D echocardiograms for surgical correction of congenital heart-valve defects.

Rakan El-Mayta is an incoming Ph.D. student in the lab of Drew Weissman, Roberts Family Professor in Vaccine Research. Rakan studies messenger RNA-lipid nanoparticle vaccines for the treatment and prevention of infectious diseases. Prior to starting in the Bioengineering graduate program, he worked as a Research Assistant in Weissman lab and in the lab of Michael Mitchell, Associate Professor in Bioengineering.

Austin Jenk is a Ph.D. student in the lab of Robert Mauck, Mary Black Ralston Professor in Orthopaedic Surgery and Bioengineering. Austin aims to develop early intervention, intra-articular therapeutics to combat the onset of post-traumatic osteoarthritis following acute joint injuries. His work focuses on developing a therapeutic that can be employed not only in conventional healthcare settings, but also emergency and battlefield medicine.

Jiageng Liu is a Ph.D. student in the lab of Alex Hughes, Assistant Professor in Bioengineering. His work aims to precisely control the bio-physical/chemical properties of iPSC-derived organoids with advanced synthetic biology approaches to create functional replacement renal tissues.

Alexandra Neeser is a Ph.D. student in the lab of Leyuan Ma, Assistant Professor of Pathology and Laboratory Medicine. Her research focuses on solid tumor microenvironment delivery of therapeutics.

William Karl Selboe Ojemann, a Ph.D. Student in Bioengineering, is a member of the Center for Neuroengineering and Therapeutics directed by Brian Litt, Professor in Bioengineering and Neurology. His research is focused on developing improved neurostimulation therapies for epilepsy and other neurological disorders.

Savan Patel (BSE Class of 2023) conducted research in the lab of Michael Mitchell, Associate Professor in Bioengineering, where he worked to develop lipid nanoparticle formulations for immunotherapy and extrahepatic delivery of mRNA. He will be joining the Harvard-MIT HST MEMP Ph.D. program in the fall of 2023.

David E. Reynolds, a Ph.D. student in Bioengineering, is a member of the lab of Jina Ko, Assistant Professor in Bioengineering and Pathology and Laboratory Medicine. His research focuses on developing novel and translatable technologies to address currently intractable diagnostic challenges for precision medicine.

Andre Roots is a Ph.D. student in the lab of Christopher Madl, Assistant Professor in Materials Science and Engineering. His research focuses on the use of protein engineering techniques and an optimized 3D human skeletal muscle microtissue platform to study the effects of biophysical material properties on cells.

Emily Sharp, a second year Ph.D. student in Bioengineering, is a member of the lab of Robert Mauck, Mary Black Ralston Professor in Orthopaedic Surgery and Bioengineering, part of the McKay Orthopaedic Research Laboratories. Her research focuses on designing multi-functional biomaterials to enhance tissue repair, specifically intervertebral disc repair following herniation and discectomy.

Nat Thurlow is a Ph.D. student in the lab of Louis J. Soslowsky, Fairhill Professor in Orthopedic Surgery and Bioengineering. Their current work focuses on delineating the roles of collagens V and XI in tendon mechanics, fibril structure, and gene expression during tendon development and healing.

Maggie Wagner, Ph.D. student in Bioengineering, is a member in the labs of Josh Baxter, Assistant Professor of Orthopaedic Surgery, and Flavia Vitale, Assistant Professor in Neurology and Bioengineering. Her research focuses on the development of novel sensors to record and monitor muscle neuromechanics.

July 12, 2023

César de la Fuente Receives 2023 Rao Makineni Lectureship Award

by Holly Wojcik

The American Peptide Society has selected César de la Fuente, Presidential Assistant Professor in Psychiatry, Microbiology, Bioengineering and in Chemical and Biomolecular Engineering, as the recipient of the prestigious 2023 Rao Makineni Lectureship Award.

Presented at the biennial American Peptide Symposium, the Makineni Lectureship Award recognizes an individual who has made a recent contribution of unusual merit to research in the field of peptide science, and is intended to acknowledge original and singular discoveries.

Established in 2003 by an endowment by PolyPeptide Laboratories and Murray and Zelda Goodman, this lectureship honors Rao Makineni, a long-time supporter of peptide science, peptide scientists, and the American Peptide Society.

This story originally appeared in Penn Engineering Today.

July 7, 2023July 6, 2023

Breaking Down Barriers to Blood Donation for LGBTQ+ People

by Meredith Mann

Close-up of a person's arm and hand as they donate blood. — (Image: iStock/hxdbzxy)

For decades, LGBTQ+ patients have faced stringent requirements to donate blood—most gay and bisexual men were not allowed to donate at all. Now, however, many more of them will be able to give this selfless gift. The U.S. Food and Drug Administration, which regulates blood donation in this country, has reworked the donor-screening criteria, and in the process opened the door to donation for more Americans.

The previous restriction on accepting blood from men who have sex with men (MSM) dates back to the early days of the AIDS epidemic, when blood donations weren’t able to be screened for HIV, leading to cases of transfusion-transmitted HIV. In 1985, the FDA instituted a lifetime ban on blood donation for MSM, effectively preventing gay and bisexual men from donating. (Also included were women who have sex with MSM.)

Twenty years later, the agency rescinded the ban—but added a restriction that only MSM who had been abstinent from sex for at least one year could donate. In 2020, the FDA shortened the “deferral” period to 90 days of abstinence. While the changes were welcome news for those who had been unable to donate, they still prevented many MSM from giving blood. As he wrote in an op-ed for the Philadelphia Inquirer last year, Kevin B. Johnson, the David L. Cohen University Professor with appointments in the School of Engineering and Applied Science, the Perelman School of Medicine, and Annenberg School for Communication, was one of them. He and his husband were shocked to learn when they went to donate blood during a shortage early in the COVID-19 pandemic, that despite being married and monogamous for close to 17 years, they could not donate unless they were celibate for three months.

“It is time to move quickly to a policy under which all donors are evaluated equally and fairly, and to encourage local blood collection facilities to comply with that policy,” Johnson wrote last year.

Now, such changes are underway. As the pandemic wound down, the FDA moved forward with plans to re-evaluate its donation criteria. The first big change was removal of an indefinite ban on people who lived in or spent significant amounts of time in the United Kingdom, Ireland, and France, a measure that aimed to protect the U.S. blood supply against Creutzfeldt-Jakob disease (CJD; also known as “mad cow disease”), a terminal brain condition caused by hard-to-detect prions that occurred in those countries in the 1980s and 1990s.

Extensive and careful evaluation of epidemiological studies and statistical analysis has shown that the risk of CJD transmission is no longer a concern. The changes to eligibility for LGBTQ+ patients are related to advances in medical and social science, and have also been very thoroughly studied to ensure that the changes will maintain the safety of the blood supply without being discriminatory.

“In the decades since HIV was first recognized, there have been advances in testing methods for detection of the virus, changes in how we process blood products, public health advances, and extensive study of the evolving risk of disease transmission given these advances,” says Sarah Nassau, vice chair of pathology and laboratory medicine at Lancaster General Hospital.

They also draw on rethinking the reliability of the guidelines. For example, while the rules partially or fully prevented gay and bisexual men from donating blood, they did not erect similar barriers to other people engaging in anal sex, or people who have multiple partners.

“Specifying the sexual orientation of the person rather than a behavior in which they engaged was discriminatory and not evidence based,” points out Judd David Flesch, vice chief of inpatient operations in the Department of Medicine at Penn Presbyterian Medical Center and co-director of the Penn Medicine Program for LGBT Health.

Read the full story in Penn Medicine News.

Kevin Johnson is the David L. Cohen University of Pennsylvania Professor in the Departments of Biostatistics, Epidemiology and Informatics and Computer and Information Science. As a Penn Integrates Knowlegde (PIK) University Professor, Johnson also holds appointments in the Departments of Bioengineering and Pediatrics, as well as in the Annenberg School of Communication.

July 6, 2023July 5, 2023

The Art and Science of Living-Like Architecture

by Devorah Fischler

Collaborators from Penn Engineering and the Stuart Weitzman School of Design have created “living-like” bioactive interior architecture designed to one day protect us from hidden airborne threats. The figure above demonstrates (A) design for support lattices for the team’s innovative bioactive sites, (B) a ribbon-like geometry for hanging and (C, D) how these structures may be integrated into indoor environments to biologically sense and react to air.

“This technology is not alive,” says Laia Mogas-Soldevila. “It is living-like.”

The distinction is an important one for the assistant professor at the Stuart Weitzman School of Design, for reasons both scientific and artistic. With a doctorate in biomedical engineering, several degrees in architecture, and a devotion to sustainable design, Mogas-Soldevila brings biology to everyday life, creating materials for a future built halfway between nature and artifice.

The architectural technology she describes is unassuming at first look: A freeze-dried pellet, small enough to get lost in your pocket. But this tiny lump of matter, the result of more than a year’s collaboration between designers, engineers and biologists, is a biomaterial that contains a “living-like” system.

When touched by water, the pellet activates and expresses a glowing protein, its fluorescence demonstrating that life and art can harmonize into a third and very different thing, as ready to please as to protect. Woven into lattices made of flexible natural materials promoting air and moisture flow, the pellets form striking interior design elements that could one day keep us healthy.

“We envision them as sensors,” explains Mogas-Soldevila. “They may detect pathogens, such as bacteria or viruses, or alert people to toxins inside their home. The pellets are designed to interact with air. With development, they could monitor or even clean it.”

For now, they glow, a triumphant first stop on the team’s roadmap to the future. The fluorescence establishes that the lab’s biomaterial manufacturing process is compatible with the leading-edge cell-free engineering that gives the pellets their life-like properties.

A rapidly expanding technology, cell-free protein expression systems allow researchers to manufacture proteins without the use of living cells.

Gabrielle Ho, Ph.D. candidate in the Department of Bioengineering and co-leader of the project, explains how the team’s design work came to be cell-free, a technique rarely explored outside of lab study or medical applications.

“Typically, we’d use living E. coli cells to make a protein,” says Ho. “E. coli is a biological workhorse, accessible and very productive. We’d introduce DNA to the cell to encourage expression of specific proteins. But this traditional method was not an option for this project. You can’t have engineered E. coli hanging on your walls.”

Cell-free systems contain all the components a living cell requires to manufacture protein —energy, enzymes and amino acids — and not much else. These systems are therefore not alive. They do not replicate, and neither can they cause infection. They are “living-like,” designed to take in DNA and push out protein in ways that previously were only possible using living cells.

“One of the nicest things about these materials not being alive,” says Mogas-Soldevila, “is that we don’t need to worry about keeping them that way.”

Unlike living cells, cell-free materials don’t need a wet environment or constant monitoring in a lab. The team’s research has established a process for making these dry pellets that preserves bioactivity throughout manufacturing, storage and use.

Bioactive, expressive and programmable, this technology is designed to capitalize on the unique properties of organic materials.

Mogas-Soldevila, whose lab focuses exclusively on biodegradable architecture, understands the value of biomaterials as both environmentally responsible and aesthetically rich.

“Architects are coming to the realization that conventional materials — concrete, steel, glass, ceramic, etc. — are environmentally damaging and they are becoming more and more interested in alternatives to replace at least some of them. Because we use so much, even being able to replace a small percentage would result in a significant reduction in waste and pollution.”

Her lab’s signature materials — biopolymers made from shrimp shells, wood pulp, sand and soil, silk cocoons, and algae gums — lend qualities over and above their sustainable advantages.

“My obsession is diagnostic, but my passion is playfulness,” says Mogas-Soldevila. “Biomaterials are the only materials that can encapsulate this double function observed in nature.”

This multivalent approach benefited from the help of Penn Engineering’s George H. Stephenson Foundation Educational Laboratory & Bio-MakerSpace, and the support of its director, Sevile Mannickarottu. In addition to contributing essential equipment and research infrastructure to the team, Mannickarottu was instrumental in enabling the interdisciplinary relationships that led the team to success, introducing Ho to the DumoLab Research team collaborators. These include Mogas-Soldevila, Camila Irabien, a Penn Biology major who provided crucial contributions to experimental work, and Fulbright design fellow Vlasta Kubušová, who co-led the project during her time at Penn and who will continue fueling the project’s next steps.

Read the full story in Penn Engineering Today.

July 5, 2023

Penn Dental Medicine Collaboration Identifies New Bacterial Species Involved in Tooth Decay

S. sputigena cells form a honeycomb-like structure that encapsulates S. mutans to greatly increase and concentrate acid production that boost caries development and severity. — Image: Courtesy of Penn Dental Medicine

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.