Researchers have developed a new UV blocking material out of naturally occurring molecules found in algae and fish slime that can be used to make more effective sunscreen, bandages and contact lenses.
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Organisms like algae and cyanobacteria have evolved to synthesise their own UV screening compounds, such as mycosporine-like amino acids (MAAs). MAAs are commonly found in the creatures that eat algae and cyanobacteria as well, such as tropical fish.
"Mycosporines are present a little bit everywhere, in many types of organisms," says Professor Vincent Bulone, co-author of the research paper and Director of the ARC Centre of Excellence in Plant Cell Walls at the University of Adelaide.
"We have attached these small UV absorbing molecules in a non-reversible manner to a polymer called chitosan, that you can extract from the shells of shrimp or crabs."
The result is an all-natural UVA and UVB screening material. Due to the versatility of chitosan, it can be used in a cream for topical application, a transparent film for use in materials like bandages, or coated on objects like textiles and outdoor furniture to protect them from UV damage.
Current sunscreen formulas use a combination of materials in order to screen both UVA and UVB radiation, including some that can have a negative effect on health in the long-term, such as titanium dioxide.
"It outperforms some of the compounds that are already used on the market in terms of the UV absorption capacity. The good thing is that it's completely natural. We've also tested them on cell cultures and know they are not toxic," Professor Bulone says.
While chitosan is already widely used for many applications and easily extracted from crustacean waste products such as prawn shells, MAAs are more difficult to produce.
"Extracting it from algae would be a very expensive process, but it is possible to produce them by engineering bacteria. This has been since the early 90s. It's not a cheap process, but it can be done." ■