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| Main Authors: | , , , , , |
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| Format: | Artículo Open Access |
| Published: |
Wiley
2025
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| Subjects: | |
| Online Access: | https://onlinelibrary.wiley.com/doi/10.1111/php.70035 |
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Table of Contents:
- Melanin in art: Photobleaching of melanin‐on‐paper is accompanied by robust modification of eumelanin structure Lucy Kim Guillermo Gosset Nina G. Jablonski Linda Oyesiku Kazumasa Wakamatsu Shosuke Ito Photochemistry and Photobiology AbstractMelanin pigments find a diverse field of practical application including art. One of the authors has developed a method of printing images with genetically modified Escherichia coli cells that produce melanin onto paper using the screen‐printing process. The method prints the cell culture and then incubates the paper over 3 days, allowing the cells to deposit the melanin as they reproduce. However, using melanin comes with challenges related to color fading of “melanin‐on‐paper.” The aim of this study was to evaluate how melanin‐on‐paper was photobleached. First, we characterized E. coli (EC)‐melanins by spectrophotometric and chemical degradation methods, which indicated that EC‐melanins consisted of 98% eumelanin and 2% pheomelanin with high purity (ca. 80%). Second, we evaluated photomodification of melanin‐on‐paper during 19 months of exposure to ambient light, showing that the exposure caused photobleaching of the melanin color intensity to a half with cross‐linking of 5,6‐dihydroxyindole‐2‐carboxylic acid units of eumelanin structure and photodegradation of 5,6‐dihydroxyindole units. These results indicate that melanin‐on‐paper undergoes gradual bleaching during months of exposure to sunlight with robust changes in melanin structure. To mitigate deterioration of melanin‐on‐paper by sunlight, one option would be to frame it under UV protective acrylic. 10.1111/php.70035 http://onlinelibrary.wiley.com/termsAndConditions#vor