Various applications of electrospun keratin-based nanofibers

Keratin is a biocompatible and biodegradable protein as main component of wool and animal hair fibers. Keratin-based materials support fibroblasts and osteoblasts growth. Keratin has been extracted by sulphitolysis, a green method (not harmful chemicals) with a yield of 38-45%. Keratin has been electrospun into nanofibers from solutions of formic acid or from water for three different applications: 1) Production of electrospun keratin nanofiber membranes for air and water treatment. Keratin electrospun nanofibers have been successfully fabricated and coated with nylon woven fabric and characterized in terms of morphology, pore size, surface properties, pore size and performance, as water and air permeability. The results of nanofibers characterization suggest their potentiality in different applications including the removal of micron size and suspended solid particles such as flocs, bacteria, etc. in both water and wastewater treatment, adsorption of heavy metal and organic compounds, ion adsorption and also for air/gas filtration [1]. 2) For dental implants application, a new technology based on mechanically produced nanogrooves (0.1-0.2 ?m) and keratin nanofibers deposited by electrospinning has been proposed in order to obtain titanium surfaces able to drive gingival fibroblasts alignment and proliferation without increasing bacterial adhesion. The morphological signal exerted by uniaxially aligned keratin fibres was clearly predominant with respect to those of surface topography, thus leading to increased cells proliferation on the surfaces with nanofibers, disregarding the presence of the surfaces grooves [2, 3]. 3) Production of composite nanofibers consist of keratin and other polymer. In the bilateral collaboration project between CNR and NRC Egypt for "Multi-jet Electrospinning of Renewable Biopolymers-based composites", keratin and sericin proteins were electrospun for the production of active nanofiber membranes. Keratin was extracted from wool fibers by sulfitolysis. Sericin was extracted from raw natural silk simply using hot water. The purified keratin or sericin was mixed with PEO or PVA to obtain electro-spinnable solutions. The solutions were electrospun into nanofibers by using a multi-nozzle electrospinning plant and a nozzle-less electrospinning plant.