Researchers from King's College London grew a human skin layer out of stem cells, the body's master cells. It is the first artificial skin that could be used as an alternative to animal testing of cosmetics and drugs.
Researchers were able to turn skin from stem cells before but this time, the skin is more real because of its permeable barrier, a functional barrier that prevents water from leaving the body, guarding it away from toxins and germs. This barrier is an important element for drug testing and until now, no epidermis with functional barrier had been grown successfully in the laboratory before.
The grown human skin showed no major differences in function or structure against real skin and artificial patches. These constructs are called "3D epidermal equivalents." Scientists likened the functional barrier to a three or four-storey building with roof. They said when the roof always leaks, the tiles would not stick together. It is similar to producing new creams, where the amount of drugs that goes through the skin must be determined because too much can cause damage.
The approach is also cost-effective because iPS cells can multiply infinitely. In the Stem Cell Reports journal, the study describes how the stem cells were induced to produce an infinite supply of skin cells or keratinocytes which were exposed to various humidities and layered until a functional barrier identical to human skin was formed.
Grown out of human pluripotent stem cells, the keratinocytes had the same functional and structural properties like a real human skin's outermost layer. This new epidermis could also be useful in developing new therapies for common and rare skin disorders.
It is now possible to reproduce genetically identical samples of skin, which can be used for studying a broad range of skin problems where the barrier is damaged because of gene mutations involved in skin carrier formation. These conditions include atopic dermatitis or eczema and ichthyosis or dry and flaky skin.
"Human epidermal equivalents representing different types of skin could also be grown, depending on the source of the stem cells used, and could thus be tailored to study a range of skin conditions and sensitivities in different populations," study lead Dr. Theodora Mauro said. "We can use this model to study how the skin barrier develops normally, how the barrier is impaired in different diseases and how we can stimulate its repair and recovery."
