A scientist and an advocate

Ph.D. candidate and Susan E. Kennedy Scholarship recipient Edna Santos wants to change the landscape of pain treatment.

Edna Santos, a Ph.D. candidate in the Department of Pharmacology and Toxicology, studies opioid efficacy.

By Anthony DePalma VCU School of Medicine anthony.depalma@vcuhealth.org

October 31, 2022

October is National Substance Abuse Prevention Month, and as opioid-involved overdose deaths in the U.S. have continued to rise, there is a growing charge to find new and better ways to treat pain. The dissertation research of Edna Santos, a Ph.D. candidate in the Department of Pharmacology and Toxicology and president of the Women in Science group at VCU, aligns with that charge. Santos is also this year’s recipient of the Susan E. Kennedy Scholarship, which VCU’s chapter of the national honor society Phi Kappa Phi awards to graduate students who have advanced the presence of women in higher education.

As a Ph.D. candidate studying opioid efficacy, Santos hopes her research will eventually contribute to the development of novel drugs that treat acute and chronic pain without adverse side effects.

Curiosity and connection

Originally from Los Angeles, Calif., Santos studied biology in community college, with plans to attend medical school. After moving to Virginia to be with her family, she transferred to VCU to finish her undergraduate degree. An undergraduate pharmacology course piqued her interest in drug composition and function, and during a research opportunity in the Department of Neurology, a mentor encouraged her to apply to the Department of Pharmacology and Toxicology’s Ph.D. program. Santos described it as “the best decision ever.”

Her connection to the subject matter goes beyond an academic interest — living with chronic low back pain and sciatica herself, Santos studies pain as a researcher while also seeking treatment as a patient. Seeing a doctor for her own pain also provides a window into the clinical side of her research, and she often makes note of the questions health care providers ask her.

That sense of curiosity and desire to make scientific connections is what Steve Negus III, Ph.D., Santos’ faculty adviser, looks for in graduate students.

“Perhaps the most important trait I look for is a burning curiosity about scientific questions,” said Negus. “It helps to have a strong academic background and a mature work ethic, but it’s the curiosity about nature that sparks creative and meaningful research. Edna has been a disciplined and productive research partner committed to learning about the treatment of chronic pain.”

Exploring the ‘ever-changing’ field of pain

On track to graduate with her Ph.D. in 2023, Santos studies low-efficacy opioids. The efficacy of opioids, or their ability to produce an effect after binding to a receptor, exists on a spectrum. Powerful drugs with severe side effects that have contributed to the opioid crisis, such as fentanyl, morphine and oxycodone, are on the high end of that spectrum. Santos’ working hypothesis is that novel opioids with lower efficacy at the receptor can produce a sufficient level of pain relief without the harmful side effects associated with high-efficacy opioids.

To achieve this, she first assessed pain-related behaviors in preclinical models, which are thought to mimic the functional impairment that often brings patients to the clinic seeking pain treatment. Once those behaviors are established in the lab, Santos can evaluate the pain-relieving effects and side effects of low-efficacy opioids at the mu-opioid receptor.

This research has helped lay the groundwork for future studies testing novel low-efficacy opioids to treat both acute and chronic pain.

“Pain-related impairment of normal behavior is an enormous clinical problem,” said Negus. “Edna's work has given us a highly sensitive tool to detect opioid side effects and illustrated for us that opioids and other analgesics can be effective to treat some pain behaviors but not others.”

After presenting her work at conferences, Santos has encountered enthusiasm, curiosity and wariness, reflecting the caution of many researchers, health care providers and patients in response to the ongoing epidemic.  

But “the pain field is ever-changing,” Santos said. She and Negus believe opioids have a place in pharmacological research, and they are committed to being part of the solution, both as scientists and as advocates. The side effects of opioids have left some patients without options for their pain, and Santos and Negus want to be part of the solution by filling the gap with novel, low-efficacy and low-risk treatments.  

“Because opioid efficacy exists on a spectrum, we hypothesize that there is a large gap that can be filled with novel low-efficacy opioids, and our overall goal is that they become more readily available,” Santos said. “And that is one of the impacts I hope my research has.”