By Dave DeFusco, Applied Physical Sciences
When Kyle Riker started his graduate training at UNC-Chapel Hill, he had a rare opportunity — and an even rarer goal. As the first and only M.D.-Ph.D. student in the Department of Applied Physical Sciences (APS), he set out to bridge the gap between biology, engineering and clinical medicine. His mission was to develop “smart” materials that can talk to cells, tell them what to do and help heal the body in more natural, dynamic ways.
Riker joined APS just as Ronit Freeman was launching her lab at UNC. She had reached out to the M.D.-Ph.D. program because she was interested in working with students with an interest in biomaterial design, with the potential to view science from an end-user perspective. Their connection was almost serendipitous.
“What struck me right away was her excitement about the science and how clearly it was aimed toward real biological and medical applications,” said Riker, “and to have a positive impact on the world.”
Freeman’s lab offered something Riker hadn’t quite found elsewhere: the chance to work on projects grounded in fundamental science but designed with therapeutic goals in mind. Freeman’s focus on translational research — moving discoveries from the lab bench to the hospital bedside — was a perfect match for Riker’s dual training in medicine and materials science.
The nontraditional M.D.-PhD has provided him with a “very unique Ph.D. experience,” Riker said. “It not only has opened doors, it makes me feel like my research is applicable to really any area of clinical practice that I might decide I want to go into, whereas if I had taken a straight biological approach, I probably would have focused on only one clinical area. It’s given me the ability to approach scientific questions from many different angles.”
Riker’s research focuses on designing synthetic materials able to mimic how living tissues work — specifically, how cells respond to the complex web of proteins, signals and structures around them, known as the extracellular matrix (ECM). The idea is to use carefully designed molecules that bind and activate specific receptors on the cell’s surface — to guide cells to move, grow or heal by “nudging” them with synthetic materials.
“In our body, the environment surrounding cells is constantly changing — getting stiffer, softer, sending signals at just the right time,” he said. “We’re trying to re-create that kind of responsiveness using materials we can control. The eventual aim is to be able to instruct cells to heal wounds and disease without flooding the body with medication that can’t target where the need is.”
In one project, Riker and his colleagues built a material made of short amino acids, or peptides, to reveal or conceal a cell-binding signal. By using this “molecular switch,” he found that he could control signals to influence how cells spread and form attachments.
Before diving into his Ph.D. research, Riker completed two years of medical school, focusing on disease mechanisms and human biology. That knowledge helped shape how he approached his lab work, while his engineering training has changed how he thinks about medical treatment.
“A lot of therapies we use in the clinic either don’t get to the root of the problem or we don’t fully understand how they work,” he said. “That’s where materials science can come in. We can design treatments that respond in ways that mimic how real biological systems work.”
As he finalizes his Ph.D. dissertation and returns to clinical rotations, Riker’s path remains unique — and increasingly valuable. With deep knowledge in both materials science and medicine, he’s positioned to help design the next generation of therapies that truly integrate with the body.
“The long-term goal is to treat disease more effectively by mimicking how biology really works,” he said. “To build materials that aren’t just tolerated by the body but actively help it heal. My APS experience has helped shaped that vision for my career.”