Mats of wool-derived keratin nanofibre have been prepared by electrospinning 
solutions of keratin in formic acid at 20 and 15 wt.%, and obtaining nanofibres 
with mean diameter of about 400 and 250 nm, respectively. These mats can find 
applications in tissue engineering (they can mimic the native extracellular 
matrix) and in wastewater treatment (they can trap small particles and adsorb 
heavy-metals). A drawback to overcome is their solubility in water. A 
stabilization method, based on a thermal treatment alternative to the use of 
formaldehyde, is proposed. The solubility test in the dithiothreitol/urea 
extraction buffer, the amino acid composition analysis and studies on keratin 
secondary structures suggest that the improved stability in water of thermally 
treated mats can be ascribed to the formation of amide bonds between acid and 
basic groups of some amino acid side chains.