A*STAR scientists achieve breakthrough in growing skin that helps reduce animal testing

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Scientists from A*STAR’s Singapore Institute of Manufacturing Technology (SIMTech) and Institute of Medical Biology (IMB) have successfully reconstructed human skin on a credit-card sized device that could help to reduce or eventually replace animal testing in the pharmaceutical, toxicological, and cosmetic industries.

For their significant innovation in developing this “skin-on-a-chip” solution, the team scored a Global 3Rs Award by Innovation & Quality (IQ) Consortium and the non-profit organisation, AAALAC International (www.aaalac.org), for advancing the Refinement, Replacement or Reduction of animal use in scientific research.

The device works based on microfluidics, meaning that it can process small quantities of fluids at microscale, more closely mimicking the structure, functionalities and microenvironment of human skin compared to static skin cultures that are commonly used in the industry.

This allows the testing of topical creams or skincare products for absorption, safety, and permeability. Since the device is made of hard plastic, it is amenable to cost-efficient mass production, enabling this screening solution to be easily scaled up to industrially-relevant capacities.

Another unique advantage of this microfluidics-based skin-on-a-chip is that the skin cells are grown on a matrix based on the natural protein fibrin that does not contract.

This overcomes the limitations of collagen-based skin equivalents typically used in conventional cell cultures, where the collagen matrix readily shrinks and creates gaps between the device and the skin, affecting the results of permeation tests.

“This skin-on-chip platform offers better skin structure and performance in terms of barrier function, compared to conventional skin reconstruction techniques,” said Dr Zhiping Wang, Principal Scientist at A*STAR’s SIMTech and lead researcher for the study.

“Our solution can also facilitate downstream assays using commercially available skin equivalents or natural skin,” he added.

“The skin reconstructed in the microfluidic system exhibited enhanced maturation of the epidermis, and almost twice the epidermal thickness of standard skin equivalents. This more closely mimics the full thickness of human skin, and therefore has a higher degree of accuracy in testing chemical permeability,” said Professor Zee Upton, Covering Executive Director of A*STAR’s IMB.

“To demonstrate the superior nature of the skin cultured in our platform, we performed an array of correlative tests, ranging from conventional immunostaining and chemical permeability experiments to cutting-edge bioimaging and spectroscopy,” she added.

The Global 3Rs Award was presented to the research team on October 31, 2018 during the AAALAC International luncheon held during the 69th National Meeting of the American Association for Laboratory Animal Science (AALAS) in Baltimore, Maryland (USA).

Awards are presented only to peer-reviewed papers that advance any of the 3Rs (i.e., the Refinement, Replacement or Reduction of animal use). Receiving the Global 3Rs Award proves that Singapore can lead the way for the global scientific community in the field of safety testing and non-animal alternative models.

The study was published in peer-reviewed journal Materials Today in May 2018 under the title of “Full-thickness human skin-on-chip with enhanced epidermal morphogenesis and barrier function”.

The above is a press release by The Agency for Science, Technology and Research is a statutory board under the Ministry of Trade and Industry of Singapore.