Published September 22, 2020
SUNY Distinguished Professor Stelios Andreadis recently published work on Cell‐Free Vascular Grafts that Grow with the Host
Infants suffering from congenital heart disease receive vascular grafts to correct malformations of the blood vessels around the heart to redirect blood flow. These surgeries often need to be repeated with larger grafts that can accommodate increased blood flow as the infant grows into a child, adolescent and adult. To avoid multiple surgeries, the Andreadis lab developed a graft that can grow with the patient and develop biological function. The work was recently published in the journal Advanced Functional Materials.
Specifically, they developed cell-free vascular grafts engineered from a natural biomaterial that was functionalized with heparin and vascular endothelial growth factor (VEGF). Heparin is an anti-coagulant that serves to prevent clotting as well as for immobilizing VEGF on the graft lumen. In turn VEGF serves to recruit monocytes from blood to the graft lumen, where they turn into endothelial cells that keep the graft patent (prevent occlusion) and healthy, as the group recently demonstrated in another publication in Nature Communications.
These vascular grafts were of very small diameter (2.75mm) and were implanted into the carotid artery of neonatal lambs for 3 months and 6 months. During this time, the grafts remained patent (open) and grew in size with the animal host to a similar extent and with similar rate as native arteries. They were also infiltrated by the cells of the host and developed vascular function, such as the ability to contract and dilate in response to chemical agonists. The results suggest that these grafts may be employed for the treatment of pediatric disorders to avoid multiple surgeries as the kids grow.
Competing technologies utilize cell-based approaches that require cell banking and extensive culture in bioreactors for many weeks; and may also require addition of the patient’s endothelial cells to their lumen prior to implantation to avoid occlusion. In contrast, the cell-free grafts developed in the Andreadis lab can be manufactured in 1-2 days and stored for weeks prior to implantation, thereby providing truly off-the-shelf arteries for potential clinical applications.
The paper was co-authored by Bita Nasiri (first author), graduate student in the Andreadis lab, Dr. Sindhu Row and Dr. Daniel D. Swartz of Angiograft, LLC, a start-up company co-founded by Professor Andreadis with the goal to help bring the vascular graft technology from the laboratory to the clinic.