Remodeling of a Cell-Free Vascular Graft with Nanolamellar Intima into a Neovessel.

Advances in cardiovascular materials have brought us the improved artificial vessels with larger diameters for reducing adverse responses that drive acute thrombosis and the associated complications. Nonetheless, the challenge is still considerable when applying these materials in small-diameter blood vessels. Here we report the biomimetic design of an acellular small-diameter vascular graft with specifically lamellar nanotopography on the luminal surface via a modified freeze-cast technique. The experimental findings verify that the well-designed nanolamellar structure is able to inhibit the adherence and activation of platelets, induce oriented growth of endothelial cells, and eventually remodel a neovessel to maintain long-term patency in vivo. Furthermore, the results of numerical simulations in physically mimetic conditions reveal that the regularly lamellar nanopattern can manipulate blood flow to reduce the flow disturbance compared with the random topography. Our current work not only creates a freeze-cast small-diameter vascular graft that employs topographic architecture to direct the vascular cell fates for revasculature, but also rekindles confidence in biophysical cues for modulating in situ tissue regeneration.