Insight into the Keratin Ratio Effect of the Keratin/Cellulose Composite Fiber

In this work, biocompatible composite fibers were prepared from human hair keratin and plant cellulose with different proportions by the wet-spinning method, and their properties and performance, including chemical structures, morphology, mechanical strength, and cell proliferation and attachment, were systematically investigated. It showed that the best proportion of the keratin/cellulose mass ratio was 30:70, and its tensile strength reached 277 MPa (elongation at break can be 27%), which is higher than that of the regenerated cellulose fiber (193 MPa, 12%). Its viability and proliferation of L929 murine fibroblast cells are also better than those of the regenerated cellulose fiber. Atomistic simulations were carried out and demonstrated the formation of hydrogen bonds between keratin and cellulose molecules, clarifying that the ratio of keratin has a significant effect on the aggregation structures in the solution and that the hydrogen bonds formed between keratin and cellulose molecules have a distinct contribution to the biocompatible composites. This work demonstrates the potential of the prepared composite fiber in biomedical applications and provides an innovative way to utilize waste human hair as a high-value raw material.