Bioinspired and biomimetic protein-based fibers and their applications

Protein-based fibers combine unique mechanical properties with biocompatibility and biodegradability, and often outperform polymer-based fibers. Furthermore, a growing need for sustainable materials has triggered a revival in the study of protein fibers, including keratin, collagen, elastin, and silk, which do not require environmentally damaging petrochemicals for their synthesis. Nowadays, bioinspired research intends to mimic the underlying proteins as well as their natural assembly or spinning processes, to achieve fibers with properties equivalent to those of their natural counterparts. Protein-based fibers can also be used to mimic functions in nature, which can otherwise not be achieved with synthetic polymer-based fibers. Here, we review promising protein fibers, their synthesis, and applications, such as air and water filtration, energy conversion, smart textiles, and in biosensoring and biomedical fields. Interest in protein-based fibers is driven by their unique properties, including biocompatibility and biodegradability. This Review summarizes the synthesis and properties of biomimetic protein fibers, such as keratin, collagen, elastin and silk fibers, and their application in energy, air and water treatment, and biomedical uses.