If eumelanin didn't shield us, UV light from the sun would attack the DNA and proteins within our bodies, causing effects like wrinkling and skin cancer. Photo / File
If eumelanin didn't shield us, UV light from the sun would attack the DNA and proteins within our bodies, causing effects like wrinkling and skin cancer. Photo / File
Scientists will harness the power of ultra-fast lasers to finally reveal how an intriguing and complex UV filter within our bodies protects us from the sun.
What Dr Justin Hodgkiss and his team discover could potentially lead to a new generation of UV-blocking innovations.
In a Marsden Fund-supported study, the Victoria University physical chemist will focus on eumelanin, a type of melanin and the natural brown skin pigment that protects us from sunburn.
If we didn't have it, the UV light would attack the DNA and proteins within our bodies, causing effects like wrinkling and skin cancer.
But, unlike proteins and DNA, eumelanin doesn't get damaged when it absorbs UV radiation, and instead forms "nano-assemblies" to disperse the light as heat, protecting our skin from the damaging effects of sunlight.
How it does this has long perplexed scientists, who have been held back by technology and the tricky nature of trying to investigate this chemically and physically complex process.
"The main challenge of studying it is that eumelanin is extremely disordered; there's no single chemical formula or recipe," Hodgkiss said.
"It's just a real mess of molecules, joined together in polymers and oligomers."
One of the key questions of his study was whether this jumble formed accidentally, or whether eumelanin had actually evolved to function from disorder.
Hodgkiss will work alongside Professor Paul Meredith from the University of Queensland, who has pioneered how to work with the material and "tame" its messy properties to gain meaningful insights.
But the biggest strength of the $870,000 project will be the cutting-edge laser technology that Hodgkiss will use to unravel the photobiological processes at play.
Victoria University physical chemist Dr Justin Hodgkiss. Photo / Supplied
"Our unique angle is that we will be using so-called ultrafast laser spectroscopy - that is, firing pulses of light at the sample."
This approach could show how materials are able to convert light energy into heat instead of causing damaging chemical reactions.
"We've established a bit of expertise in using these methods for completely different problems - and we can apply the some of the same tools to study this problem."
By using a combination of these sophisticated lasers - firing pulses lasting just femtoseconds, or one millionth of a billionth of a second - the effect on the samples could be observed from multiple angles.
Figuring out how eumelanin functions has the potential to unlock a new generation of optical components and sunscreens - and could later be applied to a host of other materials, such as paints, that are affected by UV light.
"If we can understand how to protect ourselves and our environment from UV, there are a lot of applications."
