UNIVERSITY PARK, Pa. — To repair damaged tissue in the body — from a skin burn to a damaged organ — doctors use collagen, a protein that is naturally occurring in tissue. However, current methods of collagen use do not incorporate growth factors, which are another naturally occurring protein in tissues. These proteins can control the function of the cells and allow cell growth to be specific to a certain part of the body, which in turn would allow for better repair, according to Penn State Professor of Biomedical Engineering and the Huck Chair in Cell Medicine Yong Wang.
A team of Penn State researchers led by Wang was recently awarded a four-year, $2.02 million National Institutes of Health grant to explore how to safely add growth factors to collagen used by doctors for tissue repair.
“Even though collagen alone can help with tissue repair, it is far from optimal,” Wang said. “For example, if we get a burn on our face, even though this location can recover, this skin will never look like the original skin. This is because if you just use collagen, a lot of unwanted cells like fibroblasts will grow into the collagen. But if you also use growth factors, they can trigger the growth of the specific cells that we want, and then the chance for the face to full recovered will be much better.”
Despite these advantages, there is no way to control the speed of the release of the growth factors when surgically implemented with collagen. As a result, the growth factors release quickly, making the repair less effective and, in more serious cases, inducing rapid cell growth that can lead to cancer.
To solve this problem, Wang and his colleagues plan to use single-stranded, short nucleic acids known as aptamers to allow for a slow release of the growth factors. This more controlled approach, the researchers said, will likely improve success of the tissue repair without increasing the risk of cancer.
“The overall function of aptamers is to bind to the target mark,” Wang said. “They can bind to basically anything — viruses, growth factors, cells. In this case, they will bind to the growth factors, allowing for the slow release from the collagen.”
Wang emphasized that if their work is successful, it will have broad impact in the field of surgery.
“When the surgeon conducts the surgery — when they cut the tissue or open a valve or link two parts together or suture, any kind of surgery at all — they can use the aptamer to formalize the collagen to control the risk of growth factors for much better tissue repair or regeneration,” Wang said.
Wang will work with co-investigator Dino Ravnic, associate professor of surgery at Penn State College of Medicine and the Huck Chair in Regenerative Medicine and Surgical Sciences, on this project. Ravnic is also affiliated with the Penn State biomedical engineering department.