Functionalized Cellulose Nanofibers as Crosslinkers to Produce Chitosan Self-Healing Hydrogel and Shape Memory Cryogel

Cellulose nanofibers functionalized with multiple aldehyde group were synthesized as the crosslinker to produce composite self-healing hydrogel and shape memory cryogel from chitosan. The hydrogel possessed effective self-healing (similar to 100% efficiency) and shear-thinning properties. The cryogel had macroporous structure, large water absorption (>4300%), and high compressibility. Both hydrogel and cryogel were injectable. In particular, the cryogel (nanocellulose/chitosan 1:6) revealed thermally induced shape memory, the mechanism of which was elucidated by in situ small-angle X-ray scattering (SAXS) and wide-angle X-ray scattering (WAXS) as changes in orientation of the induced crystalline structure during the shape memory program. The shape memory cryogel with a large size (15 mm x 10 mm x 1.1 mm) injected through a 16 G syringe needle was recoverable in 37 degrees C water. Moreover, the cryogel was cytocompatible and promoted cell growth. The nanocellulose-chitosan composite hydrogel and cryogel are injectable and degradable biomaterials with adjustable mechanical properties for potential medical applications.

Automated summary

Functionalized cellulose nanofibers were used as a crosslinker to synthesize composite self-healing hydrogel and shape memory cryogel. Both hydrogel and cryogel exhibited excellent properties such as injectability, tunable mechanical properties, self-healing ability, and shape memory effect. In addition, the cryogel showed cytocompatibility and promoted cell growth.