Regenerative Wound Healing Technology May Help Prevent Amputations
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37.3 million people in the United States have diabetes; a quarter of these individuals will develop diabetic foot ulcers due to high blood sugar from poorly managed diabetes. Ultimately, about 2.3 million people with diabetic foot ulcers will need to amputate a limb. That is equivalent to the population of New Mexico.
Tailynn McCarty, a PhD student in Biomedical Engineering, is trying to solve this problem through regenerative medicine. Her goal is to permanently heal chronic diabetic foot ulcers so that patients do not need to amputate a limb.
Regenerative wound healing is different from natural wound repair. With current treatments, damaged tissue is only repaired, leaving behind scarred tissue that is no longer healthy. However, with regenerative wound healing, “we can encourage wounds to heal on their own so that they are healthier than before,” McCarty says. That is, damaged tissue is replaced by healthy tissue that is not scarred. Using regenerative wound healing technologies, McCarty wants to prevent chronic and severe diabetic foot ulcers: “the goal is to permanently repair skin.”
McCarty started her research journey as an undergraduate at the University of Rhode Island (URI) where she participated in a Research Experience for Undergraduates program. There she worked on drug delivery using nanoparticles. Tailynn describes her experience at the program as eye opening, so she went to work in the industry in that line of work after graduation.
After a stint at Rubius Therapeutics making genetically engineered red blood cells, McCarty went on to work as a research associate in the regenerative medicine department at Astellas Pharmaceutical. There, she studied how extracellular vesicles (EVs) from stem cells could be used for regenerative medicine.
McCarty explains EVs as “lipid bilayered vesicles that carry the cell’s cargo to other parts of the body.” Simply, they are tiny bubbles that function as a cell’s very own transport vehicle. They transport components that cells produce to other parts of the body where those components are needed.
McCarty’s work experience with EVs at Astellas Pharmaceutical soon became her biggest merit as she started applying for graduate school. Her skill set got the attention of her now PhD advisor Dr. Cathal Kearney. He recognized that her experience with EV research would be an asset to his research group, so he brought her on board to develop a regenerative wound healing technology to treat diabetic foot ulcers using EVs.
Today, McCarty is using reprogrammed stem cells called induced pluripotent stem cells (iPSCs) which make EVs that can heal wounds. McCarty describes iPSCs as “cells that are reprogrammed to their most basic state; back to a state when it is in the embryo. These cells can be programmed into many different cell types.”
Her PhD advisor had done research in the past to show that these cells produced components that encouraged wound healing. Dr. Kearney and McCarty believe these components are being released by the cells through EVs, so being able to apply those EVs onto diabetic foot ulcers could effectively restore skin and treat chronic foot ulcers. Here, McCarty’s experience in EV research is proving to be pivotal.
Using the reprogrammed stem cells, McCarty has successfully collected EVs. Her next step is to show that the EVs do produce components for wound healing. Later on, she plans to develop a treatment using these EVs, and for that she is trying to repurpose a method already being used to treat diabetic foot ulcers. The treatment is a collagen scaffold that promotes wound healing. “The collagen scaffold is akin to a construction scaffold – it provides support for the tissue” while the tissue repairs itself. However, tissue repair with collagen is temporary, and the ulcers can come back.
McCarty plans to supplement the collagen scaffold with a gel containing EVs from reprogrammed stem cells. When applied to diabetic foot ulcers, EVs will release their regenerative wound healing components onto the ulcer and encourage new skin to grow. The new skin will permanently replace the damaged skin and hopefully prevent the foot ulcer from reoccurring.
The treatment McCarty is developing gives patients with chronic and severe diabetic foot ulcers hope; they will not need to amputate a limb. They need not worry about having to choose between losing a limb or risking getting a life-threatening infection because regenerative wound healing treatment will restore their skin to its original, healthy state.
McCarty’s treatment technology has another big selling point: it is customizable. The EVs can be “released slower or faster or can be replaced with other EVs to treat different conditions.” Therefore, the technology can be made to suit different regenerative purposes to treat many chronic conditions, not just diabetic foot ulcers. She is combining her expertise with UMass Amherst resources such as the Biophysical Core Facility to better understand EVs and make big strides in the field of regenerative medicine.
McCarty has been recognized for her excellence by more than her PhD advisor. She has been awarded the National Science Foundation’s prestigious Graduate Research Fellowship. Within UMass, she has received the College of Engineering Dean’s First Year Fellowship and the Spaulding-Smith Fellowship.
Through her journey from an undergraduate student at URI to her stints in industry and now as a graduate student, McCarty is realizing new career paths she had not considered before. She found passion in teaching and mentoring while training undergraduate students in her lab. After graduating, McCarty wants to be the principal investigator of her own lab and mentor a new generation of scientists who will go on to solve problems and save more lives.
Written by Harita Sistu, PhD candidate in Microbiology, as part of the Graduate School's Public Writing Fellows Program.