03 May 2019
Vol 364, Issue 6439

About The Cover

Cover image expansion

COVER Focus-stacked photograph of a 3D printed multivascular hydrogel containing a bioinspired alveolar air sac (width at bottom: ~4.5 mm) surrounded by a network of blood vessels (diameter: ≥0.3 mm) mimicking distal lung architecture. The ventilated, distending air sac provides oxygen to human red blood cells that flow through the ensheathing vasculature. A materials innovation provides a means to build and study multivascular topology within engineered tissues. See page 458. For more on the process behind the cover image, see
Image: Dan Sazer, Jeff Fitlow, and Jordan Miller