Now, two studies detail how advanced skin grafts containing living cells could one day be injected using a syringe to help heal those wounds. When most people think of “skin,” they’re actually picturing the epidermis—the outermost layer of skin that’s regularly replaced every month or so. This complex, three-dimensional layer of your body’s largest organ contains nerve endings, hair follicles, glands, and blood vessels. This material forms the foundation of artificial blood cells, which help keep the cells in these high-tech skin grafts alive. These artificial blood vessels could help scientists surpass current size thresholds.