Research & Innovation

Stevens Student Works to Find New Ways to Fight Off Medical Implant Infections

The microgel work that Stevens researchers conduct could prevent bacteria from contaminating implanted medical devices and help combat a crucial societal problem

Wenhan Zhao working onsite at Orthobond with Dr. Meredith Prysak, Director of Product Development at Orthobond
Wenhan Zhao working onsite at Orthobond with Dr. Meredith Prysak, Director of Product Development at Orthobond.

Biomaterials-associated infections or “implant infections” are some of the most serious complications associated with surgeries, with mortality rates of some device infections even surpassing those for breast cancer. Devices that are susceptible to infections include orthopedic implants, heart valves and pacemakers, among many others. They become infected when a bacterial biofilm develops on the implant surface and contaminates the tissue around it. Often, the only treatment is to remove the device, which can be a very costly process with many challenges to the patient.

Researchers at Stevens Institute of Technology continue to develop technology to help counter this clinical problem and prevent implant infections. Wenhan Zhao, who is pursuing a Ph.D. in materials science, is one student leading the way. For almost a year, Zhao has been working as a graduate intern with the Orthobond Corporation, with funding from the National Science Foundation. Zhao will be presenting some of the results of her work with Orthobond at the upcoming Society for Biomaterials Conference in Baltimore.

One of the sources of infection that Zhao is examining centers on airborne bacteria that contaminate device surfaces as they are being implanted. Bacteria get into the operating room though ventilation systems, shedding from clothing and sneezing or coughing.

To counter this, Zhao and her colleagues at Orthobond have developed an aerosolizing system that sprays small amounts of bacteria onto a surface to imitate the contamination process in the operating room. Using antimicrobial-loaded microgels to modify the surfaces of biomedical devices, Zhao has found a way to substantially decrease the number of contaminating bacteria that can survive on a surface. This advance can potentially reduce the rate of device infection seen clinically.

“Clinically, we’re trying to find an anti-infection system that can be delivered in the human body,” Zhao said, "and working as a graduate intern with the scientists and engineers at Orthobond has really helped us move our project closer towards that goal."

Matthew Libera, Professor of chemical engineering and materials science at Stevens, serves as Zhao’s doctoral thesis advisor and emphasized the importance of her research.

“Stevens has a long history of working on problems of societal relevance and impact,” Libera said, "and the implant-infection problem is a really good example of that focus."

Before enrolling at Stevens, Zhao received a degree in polymer science from the Beijing University of Chemical Technology and her master’s degree in polymer science from the University of Akron. She learned about Stevens and some of the Ph.D. research opportunities by attending an on-campus open-house event. After joining as a doctoral student, she was nervous at first about how she would tackle her new challenges. However, after interacting with the faculty and with Professor Libera, she felt more confident and was impressed with the opportunity in front of her.

“Professor Libera encouraged me to try out my ideas and gave me a lot of time to learn and go deeper into my experiments,” Zhao said, “He inspired me and kept me involved and focused.”

Sometimes, Libera provided the push Zhao needed.

“He always encouraged me and said, ‘research is never easy; if it was, then everyone would be doing it.’”

It was Libera who first explored the possibility of the internship at Orthobond, and, though nerve-racking at first, Zhao believes getting pushed towards some real-world experience has been very beneficial for her.

“As a Ph.D. student, I know not everyone has a chance to get an internship when doing their research,” Zhao said. “It’s a really good experience and I’m very lucky.”

Libera added, "“It’s one thing to take courses and study hard, but it’s different when a student works in an industry environment where the pressures and priorities are often very different than in the university world.”

Dr. Jordan Katz, who oversees the work at Orthobond, praised the work Zhao completed.

“Her efforts helped us establish the validity of the bacterial aerosolization device in testing the potential of antimicrobial materials to resist intraoperative bacterial contamination,” he said.

Katz was also pleased with the connection Orthobond has developed with Stevens, and the students that work with Professor Libera.

“All of the Stevens students we have worked with have been well-trained and highly motivated,” Katz said, “We actively seek high quality scientific talent, and we currently have multiple Stevens graduates working at our company.” While Zhao hasn’t committed to anything after she graduates, she wants to continue learning and adding to her knowledge of biomaterials. She stressed that it’s important to soak up as much information as possible.

“Good fundamentals are essential to a scientist and innovation will come after that.”

As their work continues, both Zhao and Libera are hopeful that their work will translate to clinical use in the future.

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