Plant-derived Nanocellulose as Structural and Mechanical Reinforcement of Freeze-Cast Chitosan Scaffolds for Biomedical Applications

Despite considerable recent interest in micro- and nanofibrillated cellulose as constituents of lightweight structures and scaffolds for applications that range from thermal insulation to filtration, few systematic studies have been reported to date on structure-property-processing correlations in freeze-cast chitosan-nanocellulose composite scaffolds, in general, and their application in tissue regeneration, in particular. Reported in this study are the effects of the addition of plant-derived nanocellulose fibrils (CNF), crystals (CNC) or a blend of the two (CNB) to the biopolymer chitosan on structure and properties of the resulting composites. Chitosan-nanocellulose composite scaffolds were freeze cast at 10°C/min and 1°C/min, and their microstructures were quantified in both the dry and fully-hydrated states using scanning electron and confocal microscopy, respectively. The modulus, yield strength, toughness (work to 60% strain) were determined in compression parallel and the modulus also perpendicul...