Advancing veterinary medicine through interdisciplinary research


For many, veterinary school is the gateway to a clearly defined career—diagnosing and treating animals in a clinical setting.

But for Amanda Watkins, that journey took an unexpected turn after she graduated from the School of Veterinary Medicine.

“I completed a three-year large animal surgery residency, but I realized there was more I wanted to investigate,” says Watkins. A Ph.D. was the next logical step.

Enter Katrin Hinrichs. Hinrichs is the chair of the Department of Clinical Studies at New Bolton Center (NBC) and co-director of the Penn Veterinary Scientist Training Program (PVSTP), a Ph.D. program specifically designed for post-residency trained veterinarians. Established in collaboration with the Biomedical Graduate Studies (BGS) program, the PVSTP aims to give veterinarians the research training needed to become clinical scientists.

“Our goal was to enable veterinarians who had completed clinical residencies to pursue research training,” says Hinrichs. “This has great potential to strengthen both the findings that result from the graduate work and the quality of the clinical practice to which their findings might be applied.”

For Watkins, PVSTP was the perfect fit. She enrolled when the program launched in the fall of 2022, and just three years later, she became the first student to complete it, successfully defending her dissertation on biofilm-related infections in November.

Her interest in these types of infections—in which bacteria grow in tough, sticky communities that make infections hard to clear—began with her clinical work.

“Horses and ruminants such as sheep, cows, and goats are frequently affected by biofilm-related infections especially in the form of septic joints and infected orthopedic implants,” she says.

Unlike humans, these animals can’t lie in bed while they recover. “If a racehorse gets a biofilm-related infection, it can be life threatening,” notes Watkins. “We desperately need a financially reasonable way to treat these infections.”

That need led her to Penn Vet’s Thomas Schaer, an associate professor of comparative orthopedic surgery and the director of the Animal Model Core at NBC.

“What Amanda set out to do as a board-certified surgeon was driven by unmet clinical needs she encountered in practice,” says Schaer. “Her task as a budding clinician-scientist was to turn observations from the laboratory, clinic, and community into inventions that improve the health of individuals and the public.” He adds that she was driven by the same frustration with clinical biofilm infections that he was years ago.

But joints are closed systems and have “immune privilege,” meaning the immune system is less active, making it challenging to test new technologies for fighting infections, says Watkins.

Enter Hyun (Michel) Koo, a professor in the School of Dental Medicine and the School of Engineering and Applied Science and the co-founder and co-director of the Center for Innovation & Precision Dentistry (CiPD). His lab has been pioneering the use of iron oxide nanoparticles to create robotic “bristles” to both sample and remove biofilms from teeth.

“When we met, it was immediately clear that Amanda was exceptional,” recalls Koo, who agreed to mentor her Ph.D. thesis. “She brought a rare combination of strong clinical skills, a translational mindset, and solid bench research experience,” he says.

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Watkins began by using these nanoparticles on the posterior teeth—an area where pathogenic biofilms accumulate, causing tooth decay, gum diseases, and systemic conditions like rheumatoid arthritis—before translating this work to a preclinical knee joint model.

“You can add the solution of iron oxide nanoparticles to any closed system,” Watkins explains, noting that the mouth can be “closed” with the help of a chamber like a night guard.

When two programmable electromagnets are placed on either side of the chamber or the joint, the nanoparticles form brushlike structures that can move between the teeth or around the joint where standard tools can’t reach.

“Targeting them is very tunable and very precise,” says Watkins. “We’ve shown that they adapt to different surface topographies. They can be guided into very small areas like between the teeth, where dentists have a hard time removing the biofilm because they can't quite get the right angle.”

These nanoparticle bristles not only remove biofilms, but they also capture of the bacteria forming them, which helps clinicians identify the pathogens, select the most appropriate treatment, and determine the risk for disease.

Looking ahead, Watkins says she plans to publish her dissertation results and then focus on grant writing, continuing to draw on the mentoring she received through her CiPD NIDCR T90 fellowship that spans Penn Dental Medicine, Penn Vet, and Penn Engineering.

“The interplay between the Penn Vet Clinician Scientist Training Program and the CiPD NIDCR T90 fellowship put me in this unique position to be able to have access to all of these amazing minds and resources,” she says.