Safer Sunscreens Natures Approach to UV Protection Team players: - PowerPoint PPT Presentation

Safer Sunscreens Nature’s Approach to UV Protection Team players: Amanda, Angela, Sophia, Steven, Tessa Source: flickr.com

Motivation Background Approach Evaluation Conclusions

Method - “People against dirty”-wants to do better! Can we find safer alternatives for sunscreen? No dirty ingredients B corporation Cradle-to-cradle product design Motivation Background Approach Evaluation Conclusions

Beyond the burn: why do we need sunscreen? ● Ultraviolet (UV) radiation causes cellular and DNA damage ● ~90,000 cases of skin cancer annually with 10% mortality rate ● 5 bad sunburns early in life can increase melanoma risk by 80% Wu, S. et al. AACR (2014). Motivation Background Approach Evaluation Conclusions

How does UV radiation penetrate skin? UVC (100-280 nm) UVA Blocked by Earth’s (320-400 nm) atmosphere Aging, wrinkling, UVB skin cancer (290-320 nm) Sunburn, skin cancer, aging epidermis dermis hypodermis Motivation Background Approach Evaluation Conclusions

UV radiation causes detrimental effects at the cellular and systemic levels UVA/ UVB Direct DNA Damage Altered Gene Expression and Inflammatory Response ROS Indirect DNA Damage Reactive Oxygen Protein ROS Species Oxidation and Deactivation Lipid Peroxidation Motivation Background Approach Evaluation Conclusions

Common active ingredients in your sunscreen What structural attributes make these ingredients ‘sunscreens’? titanium dioxide zinc oxide Motivation Background Approach Evaluation Conclusions

Common active ingredients in your sunscreen Excited state Increasing energy Heat UV light photons Organic molecule Motivation Background Approach Evaluation Conclusions

Chemical absorbers: more harm than good Pros Cons Motivation Background: Chemical Hazards Approach Evaluation Conclusions

Current products are bleaching coral Bleached Healthy Hughes, T., et al., Science , 2018 Image: Healthy fire coral compared with bleached coral - Images taken in Bermuda by Jayne Jenkins of the Catlin Seaview Survey. National Ocean Service National Oceanic and Atmospheric Administration U.S. Department of Commerce Motivation Background: Chemical Hazards Approach Evaluation Conclusions

Current products are bleaching coral Image: Healthy fire coral compared with bleached coral - Images taken in Bermuda by Jayne Jenkins of the Catlin Seaview Survey. Motivation Background: Chemical Hazards Approach Evaluation Conclusions

Chemical UV blockers damage marine ecosystems in many ways 1. Endocrine disruption https://www.niehs.nih.gov/health/topics/agents/endocrine/index.cfm Okinawa Institute of Science and Technology Graduate University (www.oist.jp) Motivation Background: Chemical Hazards Approach Evaluation Conclusions

Chemical UV blockers damage marine ecosystems in many ways 1. Endocrine disruption 2. Decreased coral larvae activity Okinawa Institute of Science and Technology Graduate University (www.oist.jp) Motivation Background: Chemical Hazards Approach Evaluation Conclusions

Chemical UV blockers damage marine ecosystems in many ways 1. Endocrine disruption 2. Decreased coral larvae activity 3. Morphological deformities (Downs et al., Ecotoxicology , 2016) Motivation Background: Chemical Hazards Approach Evaluation Conclusions

Chemical UV blockers damage marine ecosystems in many ways 1. Endocrine disruption 2. Decreased coral larvae activity 3. Morphological deformities 4. DNA damage (Downs et al., Ecotoxicology , 2016) Motivation Background: Chemical Hazards Approach Evaluation Conclusions

Chemical UV blockers damage marine ecosystems in many ways 1. Endocrine disruption 2. Decreased coral larvae activity 3. Morphological deformities 4. DNA damage 5. Bioaccumulates in fish https://socratic.org/questions/what-is-bioaccumulation-2 Motivation Background: Chemical Hazards Approach Evaluation Conclusions

Current chemical UV blockers are known human endocrine disruptors Stamatian, F. et al., Obstetrica si Ginecologia, 2016 Motivation Background: Chemical Hazards Approach Evaluation Conclusions

Common active ingredients in your sunscreen How to mineral blockers work? titanium dioxide zinc oxide Motivation Background: Mineral Hazards Approach Evaluation Conclusions

Mineral blockers reflect UV light titanium dioxide zinc oxide Incorporated into formulations as nanoparticles to avoid streaky white appearance of sunscreen https://inchemistry.acs.org/content/inchemistry/en/atomic-news/suncreen-science.html Motivation Background: Mineral Hazards Approach Evaluation Conclusions

Nanoparticles have multiple points of exposure and environmental release WORKPLACE WORKPLACE CONSUMER Formulation Packaging USE Waste Inhalation/ Intentional Washes off stream to ingestion by discard into in home, environment workers landfill pool, lakes Motivation Background: Mineral Hazards Approach Evaluation Conclusions

Nanoparticles: the pitfall of mineral sunscreens ● Protective coating breaks down ● Biggest threat is ROS generation ● Chemosensitizers - increase toxicity of other Nanoparticles chemicals Johnson, E.C. NSU Works. (2018) Motivation Background: Mineral Hazards Approach Evaluation Conclusions

Mineral sunscreen hazard assessment: Group I & II endpoints Key L Low hazard H High hazard M-L Moderate to low hazard DG Data gap M Moderate hazard * High confidence H-M High to moderate hazard Motivation Background: Mineral Hazards Approach Evaluation Conclusions

Mineral sunscreen hazard assessment: Environmental endpoints Key L Low hazard vH Very high hazard M Moderate hazard DG Data gap H High hazard * High confidence Vh-H Very high to high hazard Motivation Background: Mineral Hazards Approach Evaluation Conclusions

Technical Performance Criteria: How can we identify effective alternatives? 1 2 3 4 Broad Spectrum Antioxidant Skin Emollience UV Absorbance Capacity Compatibility ● OH U U O V V H 2 B A O 2 ● - Motivation Background Approach: Technical Evaluation Conclusions

Broad spectrum UVA/UVB absorbance to prevent cellular damage Alternative Molar extinction coefficient How strongly a UVB UVA substance absorbs light Motivation Background Approach: Technical Evaluation Conclusions

Antioxidant additives to eliminate ROS species ROS ● Antioxidants eliminate ‘free radicals’ reactive oxygen species 1 , OH, and NO such as O 2 antioxidant ● Skin naturally uses antioxidants obtained from dietary sources to protect Stable DNA against sun damage molecule ≠ damage DNA damage ● Topically applied antioxidants can be effective protection against sun damage Motivation Background Approach: Technical Evaluation Conclusions

Skin compatibility: Will a compound be dermally absorbed? High Molecular High hydrophobicity Weight Remains on skin, Little skin penetration May penetrate skin Water Skin Motivation Background Approach: Technical Evaluation Conclusions

Emollience provides a smooth on-skin feel Key Structural Components saturated hydrocarbon unsaturated hydrocarbon Emollients are derived from petrochemical or natural sources, such as alcohols vegetable oils and fats. Motivation Background Approach: Technical Evaluation Conclusions

Human & Environmental Health Criteria: Can we find bio-compatible ingredients? 1 2 3 Non-Toxic to Non-Toxic to Biodegradable Humans Aquatic Life Motivation Background Approach: Safety Evaluation Conclusions

Hazard assessment process Hazard Assessment 1. Literature review 2. Comparison of structural analogs 3. Health & environmental criteria a. Endocrine disruption b. Safety of related structures c. Environmental fate d. Positive health impacts Motivation Background Approach: Safety Evaluation Conclusions

Inferences on data gaps cannot replace safety testing Hazard Assessment 1. Literature review 2. Comparison of structural analogs 3. Health & environmental criteria a. Endocrine disruption b. Safety of related structures c. Environmental fate d. Positive health impacts Motivation Background Approach: Safety Evaluation Conclusions

Looking to nature for alternatives: Bio-inspired design, bio-compatible formulation How do plants protect Are there UV blocking Can we use plant-derived themselves from UV compounds that exist naturally ingredients with established damage? in aquatic ecosystems? health benefits? Motivation Background Approach: Safety Evaluation Conclusions

How do plants avoid sunburn? chlorophyll absorbs light energy to convert CO 2 , H 2 O to sugars, O 2 chromoplasts make and store carotenoids photoreceptors detect light Motivation Background Approach: Inspiration Evaluation Conclusions

Carotenoid antioxidants quench reactive species ‘Excited state’ chlorophyll damaging to plant cells + can produce other ROSs Carotenoids quench excited state species to prevent cellular damage Stable species ROSs no cellular damage damaging to plant cells Motivation Background Approach: Inspiration Evaluation Conclusions