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 the use of irritating chemicals. The extracted keratin particles were water-soluble and maintained typical feather keratin structures, including α-helices and β-sheets. Gel electrophoresis and mass spectrometry confirmed the presence of keratin with a molecular mass of 10.1 kDa and 98 amino acids. 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 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.