Engineering Vessels as Good as New?

Blood vessels convey essential nutrients to end organs, and when diseased, they must be replaced or bypassed. Traditionally plastic and synthetic materials have been used but are susceptible to thrombosis, stenosis, and poor patency rates. A recent report in Science Translational Medicine describes a decellularized matrix grown in vitro from commercially sourced fibroblasts that can be used as a vascular graft. Fibroblasts are grown for several weeks on a fibrin scaffold, laying down a collagen layer. After decellularization and transplantation as an arteriovenous fistula, this group showed that grafts remained patent for several weeks. The lack of cellular material in this graft at the time of transplantation reduced the risk of immune rejection. The matrix laid down by the fibroblasts can serve as a scaffold for recipient cells to colonize after implantation, but also provides structural support for arterial blood flow. Other tissue-engineered grafts of decellularized matrices have recently been tested in clinical trial. For these strategies, the cell type, scaffold material, and culture conditions are key components that dictate not only the type and quality of the end product, but also allow standardization and quality control necessary for widespread translation into clinical use. These off-the-shelf decellularized products may be the first in a new generation of therapies for patients with cardiovascular disease.