The system, which lays down cells with the same fluid-based inkjet technology used in many printers, could print large swathes of living tissue directly onto the injuries of soldiers wounded on the battlefield. Covering burns and related wounds is of critical importance because, the scientists note, “any loss of full-thickness skin of more than 4 cm in diameter will not heal by itself.”
Tests on mice revealed advanced healing by both the second and third week of recovery, with complete closure and formation of scar tissue by week three in treated (but not untreated) subjects. The printer has two heads, one of which ejects skin cells mixed with fibrinogen (a blood coagulant) and type I collagen (the main component of the connective tissue in scars). The other head ejects thrombin (another coagulant).