There's WHAT In My Sunscreen?!!

Photo courtesy: Discovery Channel Website

One day in the not-to-distant future, you may be on the beach when someone offers to pass you the hippo sweat which you generously slather all over your sun-worshipping body. The times they may be a’changing; but, hippo sweat?

Most people don’t realize that hippos actually have incredibly sensitive skin. Intrinsic to their survival is a red-coloured, glandular secretion known as “hippo sweat”,

Hippo sweat contains microscopic structures that scatter light thereby protecting the mammals (and their sensitive skin) from painful burns says a new study. Scientists are hoping they can put this knowledge to work in an advanced sunscreen/sunblock that may help protect humans from the harmful effects of the sun’s rays including skin cancers.

"It would be nice to also try and replicate the antiseptic and insect-repellent characteristics of the sweat, to obtain a four-in-one product: sunscreen, sunblock, antiseptic, insect repellent," co-author Christopher Viney told Discovery News.

"Just so long as the stuff doesn't smell like hippo," added Viney, a professor in the School of Engineering at the University of California, Merced.

In one experiment with hippo sweat, Christopher Viney, along with colleagues Emily Reed, Lisa Klumb and Maxwell Koobatian had keepers at Fresno’s Chaffee Zoo remove some of the sweat from an enclosure where the hippos had rested. The sweat was placed in sealed plastic containers where, even after several months of storage, no signs of yeast, bacteria or fungal contamination were found.

Microscopic analysis of the sweat revealed it contained two types of liquid crystalline structures: banded and non-banded. The banded structures are “characterized by concentric dark rings” when viewed under certain magnifications, Viney explains.

"The rings are the result of a structural periodicity that occurs on a scale comparable to the wavelengths of visible light," he said. "This means that the sweat is an effective scatterer of light, so that it combines both sun-blocking and sun-screening properties."

The non-banded structures "enhance the ability of the sweat to spread over the surface of the animal, by reducing the viscosity of the sweat."

Research on the molecules in the red and orange pigments contained in the sweat show that these pigments are capable of absorbing ultraviolet light. However, the pigments can cause the secretions to be of such a vivid red colour many onlookers have thought the hippo was bleeding when he/she was only sweating.

According to David Kaplan, chair of the Department of Biomedical Engineering at Tufts University School of Engineering has this to say about the study’s authors: they "have a terrific handle on novel functional materials that come out of nature." He added that Viney is leading world expert in the field.

Kaplan's own department often turns to natural materials in their work because "nature has provided us with substances that have emerged after eons of evolution. There is so much invaluable data that has yet to be mined."

Viney agrees. "As a student said to me several years ago, nature is full of solutions to our technical problems," he said. "We just have to figure out how to look in the right place, and ask the right questions."

I think I would reword that slightly to: “We just have to figure out how to look in the right place (if it still exists), and ask the right questions (if they’re still pertinent).”

Readers: would you wear a sunscreen/sunblock made from hippo sweat?

Wallabies...Not Just A Relative Of The Kangaroo

When people don’t remember history; they are bound to repeat it. This is true in many ways both large and small.

One of the lessons I remember learning in school was how the Spaniards managed to decimate the Indian population of the new world by bringing diseases with them that the native Indians had never been exposed to. Having never been exposed, they had never managed to build up any kind of immunity to them. Simple diseases like the cold and flu made the Spaniards sick; but, killed most of the inhabitants of this brave new world.

We have managed to recreate a similar circumstance today. Due to our love affair with antibiotics, disinfectants, antibacterials, antifungals and any other substance that promises to stop that germ dead in his tracks we have only managed to create superbugs that are immune to our best lines of defense. By constantly exposing them to our chemical warfare (even when we didn’t need to) we have allowed them to grow and adapt and now they are resistant to many of our best weapons.

But wait – I promised you wallabies, didn’t I? And here, it is, A Tammar wallaby to be exact (pic 1). This wallaby is capable of some pretty amazing stuff.

A newborn wallaby (pic 2) is a tiny, bean-shaped creature, called a joey that is barely more than a fetus. It lacks a developed immune system, relying on compounds in its mother's milk to protect it against pathogens. Now a unique antimicrobial has been discovered in wallaby milk that could be used in hospitals to fight deadly antibiotic-resistant bacteria. Apparently, this antimicrobial is 100 times stronger than penicillan.

"A huge amount of development happens in the pouch and during that time they just rely on milk," says Ben Cocks of the Victoria Department of Primary Industries in Melbourne, Australia.

Mr. Cocks has found that the mother's milk contains a molecule that is 100 times more effective against Gram-negative bacteria such as E. coli than the most potent form of penicillin. The molecule, called AGG01, also kills four types of Gram-positive bacteria and one type of fungus. The work was presented at the US Biotechnology Industry Organization 2006 meeting in Chicago.

When born, with a heart; but, no lungs, tammar wallabies (Macropus eugenii) crawl into their mother's pouch, where they latch on to milk-bearing teats for approximately 100 days. During these 100 days, the mother’s milk releases some kind of compound that enables her baby to develop full lung capacity in the pouch. Scientists feel that if this can be isolated and adapted for human use, it could save the lives of thousands of premature babies with lungs that are not fully functional.

AGG01 was probably lost from placental mammals, whose young have their own immune systems, when they split from marsupials.

Biomimicry is about taking notes from the pages of nature’s overly bountiful scrapbook and adapting them for human use. The great concern in the scientific world is that with umpteen species now on a new fast track to extinction, we may be left holding a book, from which many of the vital pages have been torn out.

The last picture in the trio is by Thorsten Milse, who was a category runner-up in the BBC Wildlife Photographer Of The Year 2005. Here's another one of his. I had to add it because it's so amazing.