From The National Geographic:
Currently doctors treat extensive burns by creating a graft. A piece of healthy skin from a victim is stretched up to six times its original size. The process creates holes in the skin so that it resembles a fine mesh fabric. The graft is then placed over the victim’s burned skin and, as the patient recovers, new skin cells grow to fill in the holes. The new trial will test whether spraying extra cultured skin cells in the holes of the mesh makes burns heal better or more quickly.
More here.