Microbial sunscreens for better life

Cases of cosmeceuticals interfering with marine life are now widespread. This is largely due to increasing societal trends towards exposure to ultraviolet radiation (UVR) from sunlight. Sunscreens provide UVR-protection; however, this often comes at a cost as the desired sun protection factor (SPF) is achieved with high concentrations of UVR filters within a blend. This can lead to serious environmental issues. For example, some sunscreens are known to be damaging to marine life [1,2]; indeed Hawaii, will ban the use of certain UVR filters (e.g. oxybenzone) in sunscreen blends due to coral bleaching [3]. It is therefore key to develop next generation, safer sunscreens which preserve the quality of aquatic life.
The proposed CENTA2 project seeks to answer the overarching question: Can microorganism (e.g. algae, cyanobacteria etc.)-based UVR filters be chemically modified for human use, that combine the resilience to UVR exposure and, importantly to the ethos of NERC, are much safer to the environment? Three researchers within the University of Warwick (UoW) spanning Chemistry, Life Sciences and Centre for Scientific Computing, along with Lubrizol, a leading skin-care industry, propose to apply their complementary skills in experiment and theory to train a highly talented early career researcher to confront the multi-facetted challenges imposed by this question.
The proposed programme offers a potentially transformative contribution to the photophysically fascinating, and marine (and health)-care vital, field of sunscreen science. The present CENTA2 is an ideal platform to support this research, given the closely aligned links between NERC Research Areas including: (1) Pollution, Waste and Resources (closely aligned); (2) Marine Environments; and (3) Environmental Microbiology, as well as being intimately aligned with one of the Sciences Themes of CENTA2, that of Climate and Environmental Sustainability. Lastly, the present project provides an ideal opportunity to link with Lubrizol's division of Skin Care, led by Professor Laurent Blasco, Honorary Professor at the University of Warwick and Lubrizol's global skin care manager.
Methodology:
Theory and computation: steady-state calculations will employ TD-DFT [4,5]/CASPT2 [6,7] to yield details of molecular structure of UVR filters, while dynamics simulations will use trajectory surface hopping methods and solvation models to compute photorelaxation dynamics in solution/condensed- phases.
Biosynthesis: The UVR filters will involve bacterial expression, purification and characterisation. Bacterial production of these nature-derived systems will be based on well established procedures as discussed in REFS [8] and [9].
Spectroscopy: Transient absorption spectroscopy [10] will be used to track energy flow in these molecules following absorption of UVR. These techniques are crucial in enabling us to build molecular- movies of energy flow over the time window of 10-15-10-3 s.
Analytical chemistry: The most promising UVR filters will be converted to a sunscreen blend (UVR-
filter/moisturizer) and deposited on skin model VITRO-SKIN [11]. Following UVR exposure, the blend will be washed off in water and contents analysed for potential photogenerated/phototoxic products