Improved synthetic skin could up stakes in animal replacement tests

The new research suggests that currently available types of synthetic skin may now be good enough to imitate animal skin in laboratory tests, and may be on their way to truly simulating human skin in the future.

Researchers compared the response of synthetic skins to rat skin when they were both exposed to a generic skin cream treatment, and the results indicated they both reacted similarly.

Ethical and practical issues​

As well as ethical issues of using animals in lab tests, the use of animal skin also comes with a variety of problems, the researchers explained.

"In addition to ethical issues, animal skin is hard to obtain, expensive, and gives highly variable results because of individual skin variability,"​ said Bharat Bhushan, Ohio Eminent Scholar and the Howard D. Winbigler Professor of mechanical engineering at Ohio State University.

"Animal skin will vary from animal to animal, which makes it hard to anticipate how it might affect burn victims, individually,"​ Bhushan said.

"But, synthetic skin's composition is consistent, making it a more reliable product,"​ he continued. Bhushan's research will appear in the June 5 issue of the Journal of Applied Polymer Science​.

Whether a synthetic skin feels and acts like real skin is very important, Bhushan explained. The skin must stand up to environmental effects such as sunlight or rain, while maintaining its texture and consistency.

Scientists have continued to improve the practical and aesthetic properties of synthetic skin, which may see it replace animal skin in lab tests.

"Right now, our main concern is to determine whether the synthetic skin behaves like any real skin. Then, scientists can go on to more complex problems like modeling synthetic products that behave exactly like human skin,"​ Bhushan said.

Skin research measures effect on tiny scales​

"Cellular events, like the effective and accurate delivery of drugs and the absorption of skin care products – these things occur at the nanoscale,"​ explained Bhushan.

Using a highly sensitive microscope, known as an atomic force microscope, Bhushan and Tang were able to view the skin and the affects of an applied skin cream on a scale of about 100 nanometers.

Despite the difference in surface features between the two synthetic skins and rat skin, the research showed that the skin cream had a comparable affect on all three samples.

"The skin cream reduced the surface roughness, increased the skin's ability to absorb moisture from the environment, and softened the skin surface,"​ said Bhushan.

"After treatment with skin cream, the trends of the peak-to-valley distance of the two synthetic skins and rat skin were the same, and both of them decreased. This indicates the skin cream treatment smoothed the skin surface,"​ said Bhushan.

Bhushan has said that their future work will involve improving test methods for measuring certain properties such as surface roughness. They also want to test a different skin cream.