PITTSBURGH (Mar. 26, 2021) … Marissa Behun, a first-year PhD
student in bioengineering at the University of Pittsburgh, received a Predoctoral
Clinical and Translational Science Fellowship. This competitive award
equips researchers with the skills to advance the translation of discoveries
into improved patient outcomes and health policy.
Behun’s research examines the correlation between aging,
skeletal muscle repair and immune cell populations. She works to address
defects in aging skeletal muscle, such as sarcopenia – a condition characterized by loss of
skeletal muscle mass and function that affects 10 percent of individuals over
65 years old.
“Sarcopenia is a chronic, debilitating condition with many
unsatisfactory treatment plans,” Behun explained. “This condition is often
present in elderly patients who experience adverse outcomes, morbidity and
mortality during surgery. Aging and sarcopenia are also associated with a
reduced capacity to heal muscle injury, contributing to the incidence of
While defects in extracellular matrix composition and/or cellular
response to injury are deemed explanations for this condition, both have been
“The cellular response to injury has been well characterized in
young animals, and evidence has shown that old cells placed on young matrix
have a youthful phenotype,” Behun said. “However, recent evidence from our lab
has shown that defective repair in aging is at least partially attributed to
defects in immune cell recruitment, not polarization.”
Behun uses special biomaterials in a well-established
body wall defect to assess tissue remodeling and compare young animals to aged ones.
“The main things we want to evaluate
are the types of cells that respond to injury, the effect of different
bioactive molecules delivered via biomaterials on infiltrating immune cell
types, and the contribution these cells have on constructive repair of injured
tissues,” she said.
Understanding these bioactive materials
may improve development, which could ultimately help clinicians more
effectively address defects in aging skeletal muscle in humans and improve surgical
Behun works in the Brown Lab, which is
led by Bryan Brown, a member of the McGowan Institute for Regenerative Medicine
and associate professor of bioengineering at Pitt’s Swanson School of Engineering.
The group’s research seeks to couple a mechanistic understanding of the host
inflammatory response with the development of biomaterials for regenerative
Contact: Leah Russell