Aquatic organisms inspire the development of ingenious sunscreen

By Erica Mather 31/07/2015

A newly designed sunscreen has harnessed the biological strategies that aquatic organisms evolved to prevent the negative effect of UV radiations.  Despite being made from fish mucus, crustacean shells and fungi, the sunscreen is more effective than current products and can be applied to skin as well as your backyard furniture.

There is an urgent need to create new sunscreens that are an improvement on the currently used UV-protective products.  Existing options are made from a combination of synthetic and natural compounds that can be unstable and do not provide full protection against both UV-A and UV-B.  They also pose a threat to the environment and human health with long-term use.

Professor Vincent Bulone and colleagues exploited the UV-absorbing properties of small compounds – ‘molecular sunscreens’ isolated from algae, microorganisms and the mucus and lenses of reef fish.  These compounds, called mycosporines are synthesised to naturally protect organisms from UV radiations.  Mycosporines have the highest UV-absorbing capacity (both UV-A and B) of all natural compounds with this function.

Fish on the Great Barrier Reef

The mycosporines were attached to a matrix made of chitosan, an organic material sourced from crustacean shells and the cell walls of fungi, creating a novel sunscreen that consists entirely of natural compounds.  This research is reported in the journal ACS Applied Materials & Interfaces.

“Our tests show that this novel sunscreen has superior quality to existing options by providing increased protection against both UVA and UVB radiation and is stable in variable heat and light conditions,” says Professor Bulone.

In addition to the incredible functionality of mycosporines, they are a good choice as an active ingredient because they could be produced on a large scale by genetic engineering in bacteria.  Bulone et al. also comment on the suitability of chitosan.  There is increasing appreciation for its use in materials for many different applications – owing to the array of physical, chemical and biological properties it boasts.

The impressive properties of mycosporines have been recently recognised and have been added to products for skin protection and to nonbiological materials such as plastics and paints to increase their durability.  However, they have only been incorporated as free molecules.  The authors discuss how immobilising mycosporines onto matrixes is advantageous as it allows for precise tailoring of the matrix (polymer) for optimum efficacy in a variety of applications.

The results of this study highlight the potential for this biodegradable sunscreen to be effective in wide-ranging environments with UV exposure and high temperatures.  This includes protection for the skin, outdoor materials and textiles.

Interestingly, Bulone et al. extended their research to conclude that their material could also be exploited in many biomedical applications, such as emulating the structures required for cell growth and tissue regeneration.  The authors suggest the material could be uniquely designed to have a role in wound healing, artificial skin, contact lenses and artificial corneas.

This research appears to be the tip of the iceberg with regard to the potential of this multifunctional material.

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