For artificial skin to be useful, not only must blood vessels throughout the rebuilt skin be built, but supporting vasculature is required as well.  Sharon Gerecht, from Johns Hopkins University (Maryland, USA), and colleagues have developed a new customized sugary gel substance that helps to regrow skin and the associated blood vessels.  The method involves a specially designed hydrogel, a water-based polymer. This one is made of mostly water with dissolved dextran, a type of sugar, and polyethlyene glycol (a common substance found in everything from antifreeze to laxatives).  In a study involving mice, the researchers removed badly burned skin from the center of a burn wound, and covered this opening with the hydrogel. As a control, they covered some wounds with a material derived from cow collagen, which is currently used to treat human burn victims at the Hopkins Burn Center. The other wounds were left alone with just the hydrogel.