Melanoma is a deadly form of skin cancer that is typically removed surgically. Now, researchers publishing in ACS Nano report they have developed a potential noninvasive treatment for melanoma in the form of a stretchy, heat-activated patch similar to a bandage. When activated, the patch releases copper ions that kill the underlying cancer cells and prevent them from spreading. In tests with mice, the researchers say the patch reduced melanoma lesions without damaging surrounding tissue.