Artificial skin grown by Japanese researchers may prevent cosmetic testing on animals

Scientists from the RIKEN Center for Developmental Biology (CDB) have grown complex skin tissue with hair follicles and sebaceous glands, in collaboration with Tokyo University of Science and other Japanese institution, which could signal the end of cosmetic tests on animals.

Researchers have also implanted the artificial three-dimensional tissues into living mice.

The tissues formed accurate connections with other organ systems, including nerves and muscle fibres of the mice.

Published in Science Advances, the work has opened a way to create functional skin transplants for burn and other patients who need new skin.

Previously, other researches have helped epithelial cells grow into implantable sheets, but they did not have the proper appendages such as the oil-secreting and sweat glands that would help them to function as normal tissue.

However, the newly developed artificial skin can sweat and grow hair.

This development is expected to be useful for cosmetic companies to test their products on artificial lab grown skin rather than animals.

During the research, the scientists acquired cells from mouse gums and used chemicals to transform them into stem cell-like iPS cells.

Cells developed into an embryoid body (EB), which is a three-dimensional clump of cells that partly resembles the developing embryo in an actual body.

The EBs were created from iPS cells using Wnt10b signalling. Scientists then implanted several EBs into immune-deficient mice, where they gradually changed into differentiated tissue, following the pattern of an actual embryo.

After the tissue had differentiated, researchers transplanted them out of those mice and into the skin tissue of other mice, where the tissues developed normally as integumentary tissue, which is the tissue between the outer and inner skin that helps functioning of much of the skin in terms of hair shaft eruption and fat excretion.

Researchers also found that the implanted tissues made normal connections with the surrounding nerve and muscle tissues, allowing it to function normally.

RIKEN Center for Developmental Biology official and head of the study Takashi Tsuji said: "Up until now, artificial skin development has been hampered by the fact that the skin lacked the important organs, such as hair follicles and exocrine glands, which allow the skin to play its important role in regulation.

"With this new technique, we have successfully grown skin that replicates the function of normal tissue.

"We are coming ever closer to the dream of being able to recreate actual organs in the lab for transplantation, and also believe that tissue grown through this method could be used as an alternative to animal testing of chemicals."

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Image: The newly developed artificial skin can sweat and grow hair. Photo: courtesy of Riken.