Researchers at Lund University have identified how skin properties can change depending on the surrounding environment. These findings were published in the Proceedings of the National Academy of Sciences of the United States of America.
According to the article abstract, skin hinders water evaporation and maintains it at a nearly constant rate, independent of humidity. Interestingly, these researchers showed that simple amphiphiles/water systems reproduced this behavior. This suggested a common underlying mechanism.
Changes in such systems due to evaporation were characterized and the researchers found a thin, dry outer phase that responded to changes in air humidity by increasing its thickness as the air became drier. This, in turn, decreased its permeability to water. So, the outer phase shielded the system from variations in humidity, and such a "feedback loop" homeostatically regulated water evaporation.
“Our results are interesting in several ways," said Prof. Emma Sparr at the Department of Chemistry in Lund, in a Science Daily report. "Among other things, it increases our understanding of skin functions. The results are relevant for the development of, for instance, cosmetics and pharmaceutical preparations of which certain substances are intended to penetrate the skin."