Comprehensive characterization of keratin extracted from patients with androgenetic alopecia and healthy individuals through multimolecular spectroscopy and structural analysis.

Androgenetic alopecia (AGA) is a common disorder characterized by hair thinning and loss, significantly affecting individuals. Despite extensive research, the molecular alterations in hair keratin remain unclear owing to the limitations of single-spectrum analytical techniques. Herein, we developed a novel multimolecular spectral characterization method for keratin extracted from the hair samples of patients with AGA (AH-KRT) versus that extracted from the hair samples of healthy individuals (NH-KRT). Through multimolecular infrared imaging and amino acid analysis, key structural differences between AH-KRT and NH-KRT were visualized. Results revealed two characteristic peaks at 1192 cm-1 (sulfonyl alanine, SO vibration) and 1043 cm-1 (cysteine sulfonate); changes in the contents of key amino acids such as cysteine, glycine, and alanine; and shifts in the β-sheet-to-α-helix ratio. These findings provide potential biomarkers for evaluating changes in AH-KRT and offer novel insights into the structural differences between AH-KRT and NH-KRT. In conclusion, this study characterizes the chemical structure of AH-KRT, and investigating potential keratin repair mechanisms and therapeutic implications, thus providing a theoretical foundation for developing novel treatment strategies for AGA.