Extraction of Keratin Particles as Intact Protein Sequences from Chicken Feathers and Their Characterization

The study successfully extracted intact keratin proteins from chicken feathers using a urea and L-cysteine-based method, avoiding irritating substances. The extracted keratins were water-soluble and maintained typical structural characteristics, such as α-helical structures and β-sheets. Gel electrophoresis and mass spectrometry confirmed the presence of keratins with a molecular mass of 10 kDa and 98 amino acids. In aqueous dispersion, the keratin particles were colloidal with an average size of 300 nm and a zeta potential of -40 mV. Tests on human dermal fibroblasts and epidermal keratinocytes showed positive physiological effects, and an ex vivo study on hen's eggs indicated no irritative potential, supporting their use on damaged or irritated skin.