A medical startup has developed an experimental "SkinGun"—the world's first device to use a patient's stem cells to directly heal the skin.

This quick and easy-to-use device emits a web of "skin" that stays put for weeks. No changing required.

The idea is huge, and the benefits are big for burn patients. Spray on skin, called RECELL, is now approved for both adults and children, sparing them the unnecessary pain of dozens of skin grafts ...