Reconstituted Keratin Biomaterial with Enhanced Ductility

Halleh Atri,David Dunstan,Elham Bidram

doi:10.3390/ma8115392

Abstract

Nowadays the waste from protein fibres represents an important renewable source for a new generation of biomaterials and promising competitors for carbohydrate based biomaterials. Regenerated keratin biomaterials are biodegradable in vivo and in vitro, biocompatible, and support cell attachment and proliferation; however, their major drawback has been their weak mechanical properties such as ductility. The following study was conducted in an attempt to improve the ductility of reconstituted keratin films obtained from Australian merino wool fibres. Keratin was extracted from wool fibres according to an established protocol proposed by Yamauchi, and then dialyzed and desalted by multiple diafiltration wash cycles. The resulting keratin film was transparent, biodegradable, and, opposite to its predecessors, mechanically durable, possessing a Young modulus about 12.5 MPa with 35% extensibility. The polypeptide chains were found to rearrange themselves in the β-sheet state in this keratin film, which was shown to be semi-crystalline. This film, unlike its predecessors, did not support human cell proliferation. These properties of the diafiltered keratin film have led us to think that diafiltration resulted in producing a totally new keratin film, which is envisaged to find applications in various areas.

Highlights

The demand for eco-friendly products has increased significantly in different sectors in recent years [1,2,3]
Dialysis with cellulose tubing has been recommended as an efficient purification method for keratin [29,30,31,32,33,34,35], this study revealed the necessity of further filtration of the sample with double distilled water as many times as it was desired to remove all impurities including the salts used for keratin extraction—14 cycles of diafiltration was performed in this study; this number depends on the amount of salts and quality of the membrane
Keratin extract was obtained in a chemical reaction from wool fibres, and subsequently it was purified by conventional dialysis followed by multiple diafiltration against a 10 kDa membrane with double distilled water

Summary

Introduction

The demand for eco-friendly products has increased significantly in different sectors in recent years [1,2,3]. Proteins have emerged as potentially suitable candidates for a new generation of biomaterials due to their inherent properties such as biodegradability, natural abundance and durability [3] Some of these proteins—which have been used to develop new biomaterials—are collagen [4], albumin [5], gelatine [6,7], fibroin [8,9], and keratin [10,11,12]. Earlier research has shown that keratin biomaterials are biodegradable in vivo and in vitro, biocompatible, commercially abundant and of consistent quality [10] These new materials can find applications in textile and non-textile areas, compostable packaging, disposables, agricultural films, membranes and coatings [27,28]. ESEM(environmental scanning electron microscopy) imaged the keratin films, and the films were used in human cell culture experiments to study their toxicity as well as their effect on cell growth and proliferation

Results and Discussion

Cell Culture Experiments

Conclusions