Cell‐Free Vascular Grafts That Grow with the Host

Cell‐free small diameter vascular grafts, based on small intestinal submucosa functionalized with heparin and vascular endothelial growth factor (VEGF) are manufactured and implanted successfully into the arterial system of neonatal lambs, where they remain patent and grow in size with the host to a similar extent and with similar rate as native arteries. Acellular tissue engineered vessels (A‐TEVs) integrate seamlessly into the native vasculature and develop confluent, functional endothelium that affords patency. The medial layer is infiltrated by smooth muscle cells, shows no signs of calcification, and develops contractile function. The vascular wall undergoes remarkable extracellular matrix remodeling exhibiting elastin fibers and even inner elastic lamina within six months. Taken together, the results suggest that VEGF‐based A‐TEVs may be suitable for treatment of congenital heart disorders to alleviate the need for repeated surgeries, which are currently standard practice. Cell‐free vascular grafts containing immobilized vascular endothelial growth factor are implanted into the arterial system of neonatal lambs, where they remain patent, undergo significant remodeling, and grow with the animal host in length and diameter. Successful size expansion, integration into the native vasculature, and development of vascular function may provide off‐the‐shelf bioengineered arteries for the treatment of congenital heart defects.