Gadusol Labs, an Oregon State University spinoff founded in 2017, has pioneered a new kind of sunscreen inspired by the biological world. Their researchers took the Zebrafish as their model, a freshwater species that protects their spawn from sun damage using a compound called gadusol.
Its product is a biosynthesis method to grow the Zebrafish’s anti-UV compound inside the bodies of rapidly reproducing microorganisms. In 2022, US beauty company Arcaea snapped up the company.
The acquisition aims at bringing Gadusol’s bio-sunscreen idea to market, signalling rising consumer demand for eco-friendly alternatives to the anti-UV chemicals dominating the industry today.
The problem with sunscreen
Sunlight is a silent killer. Invisible UV rays inside it trigger reactive oxygen species (ROS) to form in cells, highly unstable compounds that damage DNA, protein, and lipids. They can also rupture cell membranes, leading to cell death. All this increases skin cancer risk, prematurely ages skin, causes cataracts and weakens immune systems.
For decades we have guarded against sun damage by putting anti-UV chemicals inside topical creams. These chemicals absorb, scatter, or reflect ultraviolet B (UVB) and ultraviolet A rays (UVA), the invisible waves that cause sunburn and tanning.
Conventional anti-UV chemicals are classed either as “organic”, made from petrochemicals (common examples being oxybenzone or avobenzone) or “inorganic”, which refer to the mineral compounds (these are titanium dioxide TiO2 or zinc dioxide ZnO, used in non-greasy sunscreen formulations).
These UV filters have become an important preventative health tool that cuts down the risks of skin cancer. Yet they also belong to the thousands of other modern industrial pollutants poisoning the world’s seas and lakes. Anti-UV chemicals from sunscreen are now found in seawater and sediments around the world from municipal wastewater streams or more directly from the bodies of swimmers.
Their deadly effects are wide-ranging. Corals and anemones metabolise them into new molecules that are extremely toxic under sunlight and which contribute to coral bleaching and death.
Oxybenzone can cause erratic swimming and developmental problems in zooplankton larvae and fish, which limits feeding ability and reduces survival rates. Organisms take up even more anti-UV molecules when the substance interacts with some other sunscreen chemicals.
Many jurisdictions have banned the sale and use of certain anti-UV chemicals, including the state of Hawaii, the United States Virgin Islands, the Republic of Palau, nature reserves in Mexico, and the Dutch islands of Bonaire and Aruba.
However, these bans mainly target organics like oxybenzone and avobenzone. Sunscreen manufacturers market inorganic UV-filters as eco-friendly alternatives but scientists point out these can harm wildlife just as much as the organic ones.
Algae sunscreen: the first bio-based anti-UVs
The eco-toxic properties of both dominant anti-UV filter classes is spurring a search for bio-based alternatives that could balance skin protection with long-term planetary health.
Already, some natural anti-UV compounds have already hit the market. Among the most commercially successful belong to a class of chemicals called mycosporine-like amino acids (MMAs) and there were around 48 patents relating to these reported in 2020.
MMAs are structurally similar to the gadusol that Gadusol Labs has worked on. They are produced by marine fungi, algae, and cyanobacteria and being colourless, water-soluble amino acids, they are ideal for topical application. They absorb UV rays ranging from 310 to 360 nanometres, which covers some of the UVA spectrum that runs between 400 nm – 320 nm.
Switzerland-based Mibelle Biochemistry’s Heliogaurd 365 and Marseille-based Gelyma’s Helionoris have been on the market for a while. Both are sunscreen filters based on MAAs from the red seaweed Porphyra umbilicalis. Coty-Lancaster, a beauty company listed on the New York stock exchange, has been bio-synthesising sunscreen ingredients that mimic marine coral MMAs since around 2019.
With researchers still discovering new kinds of MMAs in marine microbes, the potential store of marine anti-UV compounds could be vast. Researchers have recently shown that the land-dwelling Coelastrella rubescens algae species is able to absorb visible light in the blue-green part of the light spectrum. The uncovered two previously unknown MMAs within the species, showing the organism uses a broad range of compounds to build up its defences against sunlight and concluded the strain could hold potential for anti-UV biotech.
Increasingly, the future of marine microbe sunscreen will centre around improvements to industrial-scale biosynthesis that will allow manufacturers to compete on production costs. Biosynthesis avoids the need to cultivate or catch biomass and could potentially limit the ecological distortions that come with surging demand for biological products.
Apart from biosynthesis, companies like Gylema still use more traditional extraction techniques that draw out target compounds directly from algae and concentrate them. The problem to solve here is largescale algae cultivation – a bottleneck that the entire algae biochemicals sector is having to grapple with.
Phenols as an emerging anti-UV filter
MMA compounds are a promising first step to an all-natural sunscreen formulation but they are mostly better at absorbing UVA light. This component of sunlight spans 320 nm to 290 nm range of the wavelength range.
UVA comprises 95% of all sunlight that hits the earth’s surface but the rarer UVB is much more potent. As the market for natural sunscreen formulations develops, producers will likely incorporate additional biochemicals that cover the entire spectrum of damaging rays.
Luckily, MMAs are not the only natural compounds offering sun protection. Phenols – a chemical class found across plant families – are also a contender for new generation sunscreen ingredients.
Researchers have known for a decade or more that lignin, a biopolymer that helps keep plants upright, could be a source of anti-UV phenols for sunscreen applications as it seems to cover the entire UVA to UVB wavelength range. Lignin does not just absorb UV: it also provides antioxidant properties that help the body fight off ROS, the agents of cellular damage that form when UV rays hit living bodies.
The main obstacle to commercialising lignin phenol sunscreens is that lignin has a dark colour whereas MMAs are ideal for topical applications because they are transparent. An ongoing research programme is looking at ways to eliminate the colouring from lignin compounds.
Despite this challenge, US startup Lygg is among the earliest contenders in lignin sunscreen production. Founded in 2020 by Stanford chemistry graduate Graham Dick, its mission is to use plants as a replacement for octocrylene, a common organic UV filter. By replacing the petrochemical ingredient, Lygg argues that it will also be possible to formulate a much more consumer-friendly product without eye-irritation and greasiness.
Biotech must be part of systemic solutions
The environmental problems that come with conventional sunscreen chemicals show us that we need to think more holistically about human and public health as we face the ecological and climate crisis.
While chemical anti-UV molecules are essential in protecting us against certain illnesses – cell damage and inflammatory effects of UV exposure – they are also exposing us to wide scale ecological ruptures that will degrade human health in no less profound ways.
Phytoplankton, highly sensitive to conventional anti-UV molecules, demonstrate this. These tiny marine creatures are the foundation of the ocean’s food chain, which we humans also rely on. They are also vital in sustaining a liveable planet: scientists estimate at least half the oxygen produced on earth comes from these creatures.
The number of biochemicals now under investigation as potential anti-UV filters show the dynamism of this field. Even though some MMAs have already entered the market as sunscreens, researchers continue to discover new specimens that might yield new chemical properties.
Many more classes of protective natural compounds are waiting to get incorporated in consumer topical products, such as astaxanthin, phenols, and fucoxanthin. Due to the multi-functional properties of many of these biochemicals, the biobased sunscreen of the future will likely combine UV-deflecting compounds with antioxidants that boost the body’s chemical responses to dangerous free radicals caused by light exposure.
Given the technologies available right now, however, the role of biobased anti-UV chemicals will likely be in reducing the amount of toxic anti-UV filters we use in our products rather than eliminate them altogether. This is because so far, no bio-based compounds match the SPF factors provided by the eco-toxic molecules that we rely on today.
In future, public health directives around sun protection could centre around multiple practices that take into account both human and ecological health. These could cinlude bio-based anti-UV absorbers, ROS-scavenging antioxidant boosters, and behavioural shifts such as adopting eco-friendly anti-UV clothing.
A multi-pronged approach to anti-UV pollution would also involve more research into wastewater management and treatments to remove these eco-toxic compounds from wastewater. Together with bio-based UV filters that can cut down the use of legacy chemicals, this holds the potential to slow the rate at which consumer chemicals are accumulating in the environment.