An international team led by researchers from Kings College London (KCL) has developed the first lab-grown epidermis – the thin layer of cells that make up the outermost layer of skin, preventing infection from entering the body.
The epidermis was created using pluripotent stem cells, cells that are capable of growing in a variety of ways to fit different functions.
KCL scientists believe the breakthrough will provide a cost-effective, alternative lab model for testing drugs and cosmetics, negating the need for animals, and could also help to develop new therapies for skin disorders.
Drug companies will now be able to test drugs on a large scale using the new functional skin, screening them for any potential harm.
According to Dr Theodora Mauro, research team leader: “The ability to obtain an unlimited number of genetically identical units can be used to study a range of conditions where the skin’s barrier is defective due to mutations in genes involved in skin barrier formation, such as ichthyosis (dry, flaky skin) or atopic dermatitis (eczema).”
Until now tissue engineers have struggled to grow the complex epidermis with its protective barrier.
The study, published in the journal “Stem Cell Reports”, describe how stem cells were induced into producing an unlimited supply of keratinocytes (skin cells) that were then exposed to a number of humidities and built into layers until they formed a functioning barrier identical to skin.
Biopsies revealed that the keratinocytes developed from stem cells showed no significant difference in their structural or functional properties compared with the outermost layer of normal human skin.
Dr Dusko Ilic, head of the KCL research team said: “Our new method can be used to grow much greater quantities of lab-grown human epidermal equivalents, and thus could be scaled up for commercial testing of drugs and cosmetics.
"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.”
The announcement comes weeks after a separate KCL team reported that they had identified specific bone marrow cells that can transform into skin cells to repair damaged skin tissue.