Electrosprayed recovered wool keratin nanoparticles

This work reports on producing wool keratin nanoparticles through electrospraying. Wool keratin is a natural biodegradable and biocompatible protein. Keratin powder has found application in hygiene, cosmetics, filtration, tissue engineering scaffolds, and controlled drug release. Like other nano materials, the performance of keratin in submicron size range changes drastically. Electrospraying is a technique that is capable of producing nanosized, regular, and spherical particles. To prepare the electrospraying wool keratin solution, keratin was recovered from descaled wool fibers by dissolving it in mercaptoethanol first, and keratin sponge was obtained. Then, the keratin sponge was dissolved in formic acid that provided the electrospraying solution. This research involved primarily an investigation on the effect of important electrospraying conditions such as polymer concentration, feed rate, voltage, and nozzle-collector distance on the average particle size of the electrosprayed nanoparticles. The results showed that the proper concentration of keratin in formic acid for the electrospraying keratin nanoparticle was about 0.5% (w/v). As far as electrospraying conditions are concerned, decreasing feed rate and increasing nozzle-collector distance led to lower average particle size. Voltage did not show a practically significant effect on the average particle size. The average size of the electrosprayed keratin nanoparticles fabricated in this work lies in the range of 36–72 nm. Fourier transform infrared Fourier transform infrared (FTIR) spectra showed that electrosprayed keratin nanoparticles contain –SO2–S– and –SO–S– linkages. Copyright © 2014 John Wiley & Sons, Ltd.