Robust chitin films with good biocompatibility and breathable properties.

Chitin is the second abundant polysaccharide after cellulose, and has been demonstrated to possess various applications in the fields of the biomaterials, water treatment, etc. Here, mechanically strong chitin films were successfully fabricated from chitin solution in NaOH/urea aqueous system with cooling by chemical crosslinking with epichlorohydrin (ECH). The results indicated that tensile strength and elongation at break of the chitin film prepared by using the weight ratio of ECH to chitin solution of 6:100 enhanced significantly to achieve 139 MPa and 43%, respectively, showing highly strong strength and elongation. The cell assay results confirmed that the chitin films were non-toxicity. Water vapor transmittance rate testing indicated that the chitin films had better breathable properties than commercial product. The robust chitin films with high transmittance, biocompatibility and breathability have great potentials in the wide applications such as biomedical, food packaging, wound healing, garments fields, etc.