Setback Leads to Success for Blood-Brain Barrier Researcher

Being rejected as a medical school applicant was one in a series of serendipitous moments that helped Patrick T. Ronaldson, PhD, discover his passion for biomedical research.

Today, Dr. Ronaldson runs a busy laboratory at the University of Arizona Health Sciences, where he is an associate professor in the College of Medicine – Tucson’s Department of Pharmacology and is affiliated with the Comprehensive Pain and Addiction Center, which is part of Health Sciences’ strategic efforts to design and develop precision treatments for all populations.

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Scientific research is often highly specialized, yet on any given day, Dr. Ronaldson might be found studying novel stroke therapies, searching for therapeutic targets for Alzheimer’s disease or tackling the problem of drug addiction.

The diversity of his research portfolio is a result of years of gaining knowledge and experience in understanding the blood-brain barrier, a network of blood vessels that run through the brain and protect it from toxins. (Watch a visual explanation of the blood-brain barrier.)

“It takes unique expertise to really understand the complexity of the blood-brain barrier and how to effectively deliver a drug to the brain to treat stroke or Alzheimer's disease or drug abuse,” Dr. Ronaldson said. “Neurological diseases all have a common thread – drug delivery is a primary limiting factor in why it's so difficult to treat these diseases. And most of the challenges in drug delivery to the brain relate to the fact that we still have a lot to learn about the blood-brain barrier.”

Following a family tradition

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A native of Toronto, Dr. Ronaldson grew up in a family of health professionals where his mother was a registered nurse. His grandfather, Dr. Kenneth Butler, was a hematologist and was particularly influential in Dr. Ronaldson’s early desire to become a medical doctor.

His decision to attend the University of Toronto was logical – it was close to home and both of his parents were alumni – and also fortuitous. When it was time to choose a major, he picked pharmacology, swayed in no small part by the University of Toronto’s world-renowned pharmacology program.

Bachelor’s degree in hand, he applied to medical school. He didn’t even get an interview.

Making the most of Plan B

In response to the unexpected setback, Dr. Ronaldson opted to enroll in graduate school, figuring a master’s degree would improve his medical school application package.

As he embarked on his new journey, he landed on the doorstep of Reina Bendayan, PharmD, a professor in the Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy at the University of Toronto who studied the mechanisms that regulate drug transport across cellular membranes, including in the brain.

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“When I started in her lab, she was mostly working in the area of HIV infection and understanding how antiretroviral drugs were distributed throughout the brain,” Dr. Ronaldson said. “I started doing some work in cell culture and looking at drug disposition, and I was really captivated.”

Bitten by the research bug, Dr. Ronaldson made the pivotal decision to give up his dream of attending medical school and pursue a doctoral degree instead.

“Very soon after Patrick started working in my lab, we all knew that he was a giant intellectually and a deep scientist with a lot of thought and curiosity, which is extremely important in research,” Dr. Bendayan said. “Patrick completed his PhD in my lab with an impressive number of research papers – close to 10 when he finished.”

Finding his way to Tucson

One of those papers resulted in Dr. Ronaldson giving a presentation at the 2007 Cerebrovascular Biology Conference in Ottawa, Canada. As luck would have it, Thomas P. Davis, PhD, a professor of pharmacology at the University of Arizona, was in the audience and looking for a postdoctoral researcher.

The two men met over coffee to talk about Dr. Davis’ research, which focused on neuropharmacology drug delivery issues related to treatment of neurological diseases.

It was exactly what Dr. Ronaldson was seeking. While working as a postdoc, a faculty position opened and he joined the Department of Pharmacology on a tenure track in 2011.

Carving out a niche

“Neurological diseases all have a common thread – drug delivery is a primary limiting factor in why it's so difficult to treat these diseases.”Patrick Ronaldson, PhD, associate professor of pharmacology, College of Medicine – Tucson

Now with a lab of his own, Dr. Ronaldson knew he needed to find his unique place in the research community. So, when Dr. Davis asked if anyone was studying drug delivery to the brain and stroke, and neither of them could think of anyone who was, Dr. Ronaldson knew he found his niche.

His preliminary experiments immediately yielded compelling results. In 2014, he published a paper identifying the transporter that carries statins across the blood-brain barrier, which has important implications in treating stroke patients.

In addition to his stroke research, he collaborates with Rui Chang, PhD, in the Center for Innovation in Brain Science to identify drug targets in the brain for potential therapeutics for Alzheimer’s disease. He and Dr. Davis still work together, most recently receiving a grant to study effects of prescription pain medications containing acetaminophen and opioids on the blood-brain barrier and its relationship to drug addiction.

“I want my research to be translational. I want it to be something that, at the end of the day, is going to have an impact, whether it is on drug treatment, strategies to treat diseases, or even uncovering a better understanding of the way that diseases affect the body,” he said. “I love what I'm doing. I'm at the point now where I would never look back. I know for a fact that I made the right decision, and I'm glad I picked the career path that I did.”