Self-healable nanocellulose composite hydrogels combining multiple dynamic bonds for drug delivery.

Herein, we developed two nanocomposite polysaccharide hydrogels TPP-CNC and TPP-CNF via simple mixing method, which were constructed with multiple dynamic bonds. The microstructural features, mechanical properties, rheological properties, healable ability and biocompatibility of the complex hydrogels were evaluated. The TPP-CNC and TPP-CNF complex hydrogels exhibited higher tensile strength than pure polysaccharide hydrogel, from ~259 KPa to ~890 KPa and ~910 KPa, respectively, that was attributed to the contribution of ionic crosslinked network and hydrogen bonds. In addition, the hydrogels indicated superior fatigue resistance and high energy dissipation ratio during loading-unloading tests because of the physical sacrifice bonds, which also decreased the self-healing time at room temperature (~15 min). More importantly, the drug loaded nanocomposite hydrogels showed sustained release, reduction burst release, increased release under acidic environment, and the drug release kinetics belonged to Fickian diffusion mechanism. Therefore, the nanocellulose polysaccharide hydrogels have the highly promising to explore as biomaterials for drug delivery.