All-natural and biocompatible cellulose nanocrystals films with tunable supramolecular structure.

Herein, nanocomposites films were prepared via the facile casting method by incorporating cellulose nanocrystals (CNCs) with arabinogalactan (AG), galactomannan (GM) or konjac glucomannan (KGM) respectively. The introduced polysaccharides maintained the transparency of CNCs films and promoted the UV blocking properties. In addition, mechanical strength of the nanocomposite films was greatly improved after the combination of polysaccharides. The interactions of hydroxyl-abundant macromolecules, smoother and tighter morphological structures, as well as the disturbed crystal structure were proved to be responsible for the improved properties. Hydrophilic lattice planes of cellulose crystallites were determined to interact with polysaccharides resulting in lower crystallite sizes and crystallinity. The cell culture assay revealed that the films had no cytotoxicity and presented a satisfactory cytocompatibility, because of the polysaccharides from plant cell walls introduced into the films. Therefore, the biocompatible nanocomposites films can be tuned by the addition of polysaccharides, which show great potentials for materials modification in optical, packaging and biomedical fields.