Using frog foam as an antiseptic delivery system

A team of researchers affiliated with several institutions in the U.K. has found that the foam produced by a certain kind of frog can be used as an antiseptic delivery system. In their paper published in the journal Royal Society Open Science, the group describes their study of the foam and the many ways they tested its usefulness.

The work by the researchers began after team members discovered female Túngara frogs in Trinidad covering their fertilized eggs with a type of foam they had created. Observation showed the foam covering provided protection for the eggs for up to a week. The researchers collected samples and took them back to a lab for study in the U.K. They found that the foam was made up of closely packed bubbles known as vesicles that provide protection from dehydration, heat, and to some degree, bacterial infections. Initial testing of the foam showed that it was not harmful to humans—the foam also degraded very slowly when placed on human skin due to its warmth and lower pH levels.

Further testing of the foam showed that it was capable of holding onto material that was mixed into it—material that would be introduced slowly over time onto whatever the foam was covering. The researchers found that the foam could hold onto easily-dissolvable test dyes, which suggested it was capable of carrying useful drugs. They then tried mixing in some antibiotics and found that the foam could deliver them to a test pad over a span of several days. They noted that approximately half of the antibiotic rifamycin, for example, was released over the first 24 hours after application but the rest was slowly released over the following six days.

The researchers note that current medicinal synthetic foams typically last from a few hours to a few days, after which dressings must be changed—a painful process that puts patients at risk of infection. They acknowledge that further testing of the foam is required to make sure it is safe for human use. Also, a means for manufacturing the foam is required before it can be considered as a possible new approach for treating injuries, including burns.