In a recent presentation at the American College of Surgeons Clinical Congress, researchers from the Wake Forest Institute for Regenerative Medicine showed off the results of a unique experiment involving a printer that uses living cells as its “ink.”
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).
Like the components of quick-setting resins which must be kept separate until mixing causes a chemical reaction that hardens the resin, the products of the two print heads mix to immediately form fibrin, yet a third protein involved in the clotting of blood. The whole confection is topped by a layer of keratinocytes (i.e. skin cells), which are also printed.
Future iterations of the research will be conducted on pigs (which have skin that more closely resembles that of humans), and it’s not clear when, if ever, such a device might appear in a field hospital in Afghanistan, not to mention your local burn center.
Full citation: In Situ Bioprinting of the Skin for Burns
Kyle W. Binder1, Weixin Zhao1, Gil Young Park2, Tao Xu1, Dennis Dice1, Anthony Atala1, James J. Yoo1
1 Wake Forest Institute for Regenerative Medicine, Winston-Salem, North Carolina, United States of America 2 Imperial College London, Department of Bioengineering, London, United Kingdom