Xyloglucan-cellulose nanocrystal multilayered films: effect of film architecture on enzymatic hydrolysis.

Understanding the hydrolysis process of lignocellulosic substrates remains a challenge in the biotechnology field. We aimed here at investigating the effect of substrate architecture on the enzymatic degradation process using two different multilayered model films composed of cellulose nanocrystals (CNCs) and xyloglucan (XG) chains. They were built by a spin-assisted layer-by-layer (LbL) approach and consisted either of (i) an alternation of CNC and XG layers or of (ii) layers of mixed (CNC/XG) complexes alternated with polycation layers. Neutron reflectivity (NR) was used to determine the architecture and composition of these films and to characterize their swelling in aqueous solution. The films displayed different [XG]/[CNC] ratios and swelling behavior. Enzymatic degradation of films was then performed and investigated by quartz crystal microbalance with dissipation monitoring (QCM-D). We demonstrated that some architectural features of the substrate, such as polysaccharide accessibility, porosity, and cross-links, influenced the enzymatic degradation.