Engineering with keratin: A functional material and a source of bioinspiration

Abstract

Summary Keratin is a highly multifunctional biopolymer serving various roles in nature due to its diverse material properties, wide spectrum of structural designs, and impressive performance. Keratin-based materials are mechanically robust, thermally insulating, lightweight, capable of undergoing reversible adhesion through van der Waals forces, and exhibit structural coloration and hydrophobic surfaces. Thus, they have become templates for bioinspired designs and have even been applied as a functional material for biomedical applications and environmentally sustainable fiber-reinforced composites. This review aims to highlight keratin's remarkable capabilities as a biological component, a source of design inspiration, and an engineering material. We conclude with future directions for the exploration of keratinous materials.

Bioactive Low Molecular Weight Keratin Hydrolysates for Improving Skin Wound Healing

“…Keratin extracted from sheep wool or human hair showed a high potential for wound healing biomaterials design [ 37 , 38 , 39 ], but the methods for keratin solubilization are very sophisticated and the mechanisms of cellular response are not completely understood [ 26 ]. The present research proposes the keratin hydrolysates with low molecular weights as wound healing additive, prepared by complete solubilization of sheep wool and by enzymatic refinery of molecular weight with still preserved secondary structure and showing bioactivity in integrin signaling, cell cycle modulation and vascular-cell-adhesion molecules inhibition.…”

“…It is recognized that few commercial products based on keratin reached the market of wound healing biomaterials as compared to other materials due to the complex methods of preparation and the insufficient understanding of cellular interaction with keratin [ 25 , 26 ]. In this regard the present research proposes keratin hydrolysates prepared by a green, reproducible and easy method of solubilization [ 24 ] and brings evidences in several molecular factors, decisive for restoring the skin homeostasis as new potential wound dressing active component.…”

Waste Reutilization in Polymeric Membrane Fabrication: A New Direction in Membranes for Separation

“…Keratin extracted from wool or hair can be formed into various forms and shapes, such as film and coating [51], scaffold [52], hydrogel [53], and nanofibre. Keratin has very wide application, ranging from biomedical and water remediation to food packaging and cosmetics, owing to their biocompatibility, biodegradability, absorptivity, and antibacterial properties [54][55][56].…”

Valorization of Livestock Keratin Waste: Application in Agricultural Fields

“…However, the unique structure of livestock keratin makes its valorization and application difficult. Keratin has both alpha-helix and beta-fold structures, which protect and maintain its structural stability [ 5 , 6 ]. Alpha-keratin is present in many mammalian tissues and body parts, such as hair, wool, nails, horns, and hooves, while beta-keratin is present in the nails, claws, shells, and beaks of animals [ 7 ].…”