Cellulose nanofibril reinforced functional chitosan biocomposite films

Recently, chitosan has become attractive due to being biodegradable, biocompatible and renewable. However, the weak mechanical properties of chitosan films limit their large-scale application. In this work, a strategy of blending TEMPO, oxidized CNF (TOCN) and chitosan was developed to fabricate nanocomposite films in order to improve the mechanical properties and maintain biocompatibility. The TOCN/chitosan nanocomposite films exhibited excellent optical transmittance (>85%) and extremely high tensile strength of 235 MPa. The good compatibility of TOCN and chitosan chains, good dispersion of chitosan aggregates and the presence of stiff TOCN crystal domains are the main reasons for getting improved mechanical strength of composite films. The films showed good biocompatible properties based on the cell activity assay results. Furthermore, they were stable in PBS buffer for more than 6 months without significant degradation. The TOCN/chitosan nanocomposite films with these excellent properties could be employed in medical applications.

Automated summary

A strategy of blending TEMPO oxidized cellulose nanofibers (TOCN) and chitosan was developed to fabricate nanocomposite films with improved mechanical properties and biocompatibility. The TOCN/chitosan nanocomposite films exhibited excellent optical transmittance (>85%) and extremely high tensile strength (235 MPa). The good compatibility of TOCN and chitosan chains, good dispersion of chitosan aggregates, and the presence of stiff TOCN crystal domains were the main reasons for the improved mechanical strength of the composite films. These nanocomposite films showed good biocompatible properties and stability in PBS buffer for more than 6 months, making them suitable for medical applications.