Even in the context of a home office, loud, conspicuously mechanical inkjet printers feel like an anachronism. This is not without basis, either: they've been in use since the 50s, and have been nearly ubiquitous since the 90s. But in the context of regenerative medicine, inkjets are poised to be the next big thing. Or should I say... skinjets.
Researchers at the Wake Forest Institute for Regenerative Medicine have devised an inkjet-style printing device for applying living tissue directly to wounds, accelerating healing for areas of severe skin loss. Technology Review gives a play-by-play of the specific process by which this works. Warning! The casual mixing of medical and printer terminology may cause nausea:
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.
Early tests on mice have been successful, and researchers will testing to pigs next. The ultimate goal, of course, is to bring technology like this into hospitals, burn units or even battlefields, but such deployments would require both extensive testing and the construction of a much larger printer, as depicted here:
It works exactly how it looks like it would: Patients lay on the printer bed as its dual rails send a tissue-filled cartridge darting about their bodies, patching their wounds with gooey, coagulating skin-stuff. (I'll opt for general anesthesia, thanks.) It's worth noting, though, that the resulting nature of the wound wouldn't be smooth skin, or even seem as though it had healed--the skin cells are applied to the wound as part of a hardening goop, which encourages rapid healing but doesn't actually constitute it. The formation of true, connected skin takes weeks.
This is far from the first effort to printer-ize skin grafting. Says a 2005 LiveScience report:
Scientists expect to eventually build commercial skin printers for hospital use. Doctors would take cells from a patient’s body, multiply them and suspend them in a nutrient-rich liquid similar to ink. A technician would enter measurements of a patient’s wound into a computer and feed the suspended cells into the printer.
Wake Forest University's advancements are notable for applying a widely researched concept to living animals with reproducible success. (For somewhat graphic images of the results, click here.)