Wool cortical cell-based porous films

Abstract

The aim of this work is to improve the select mechanical properties of keratin films for biomedical application by exploiting the hierarchical cell structure of wool fibers in a simple and green process. Bio-composite keratin films were prepared by ultrasonic irradiation of wool fibers soaked in clean water, have previously been swollen in mild alkali. The disruption of the fiber cell structure produced a suspension of cortical cells that was centrifuged and rinsed to remove part of the hydrolyzed keratin matrix, then cast into micro-structured porous films made of randomly oriented cortical cells stuck to each other by solidification of the matrix. The chemical and physical properties of the porous films were compared with those of compact films produced using the entire hydrolyzed keratin matrix. Reduction of the keratin matrix amount leads to an even micro-porous structure and improves the mechanical properties (ultimate tensile strength: 11.36 MPa; elongation at break: 3.18%), the moisture uptake and the thermal stability of the films. These properties, associated with other properties of wool keratin, which is naturally hydrophilic, non-burning, biodegradable and biocompatible, make the porous bio-composite keratin films simple and low-cost candidates for biomedical and biotechnology applications.