TLDR Treatments improved hair surface and scale structure but didn't increase certain bonds in the hair cortex.
The study investigated the structural changes in keratin from bleached hair treated with commercial reconstructive agents, shikimic acid, and dimethyl maleate using vibrational spectroscopy and scanning electron microscopy. Results showed that these agents interacted with both the cortex and cuticle regions of hair fibers, with more significant modifications observed in hair bleached three times compared to four times. Commercial agents were more effective than the model compounds in modifying hair fibers at the molecular level.
23 citations
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June 2014 in “International Journal of Cosmetic Science” Glyoxylic acid is a safer alternative to formaldehyde for hair straightening and effectively changes hair structure.
19 citations
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May 2008 in “Applied spectroscopy” Human hair has different protein structures in its cuticle and cortex.
21 citations
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October 2006 in “International Journal of Dermatology” Asian hair is stronger and more damage-resistant than Caucasian hair due to a thicker cuticle layer.
January 2024 in “Molecules (Basel. Online)” Juglone from walnut extracts may help repair damaged hair.
28 citations
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December 2011 in “Biocatalysis and biotransformation” PDI helps restore over-bleached hair's strength and structure by attaching special peptides.
12 citations
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October 2018 in “Biotechnology reports” Recombinant keratin K31 makes damaged hair thicker, stronger, and straighter.
11 citations
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March 2005 in “International Journal of Cosmetic Science” Bleached hair loses more protein than virgin hair when brushed, indicating more damage.
5 citations
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April 2005 in “Journal of applied polymer science” PEI diffuses into hair at a constant rate, and urea speeds up this process.
