Cellulose nanocrystals reinforced highly stretchable thermal-sensitive hydrogel with ultra-high drug loading

Hydrogels often have poor mechanical properties which limit their application in load-bearing tissues such as muscle and cartilage. In this work, a near-infrared light-triggered stretchable thermal-sensitive hydrogel with ultra-high drug loading was developed by a combination of natural polymeric nanocrystals , a network of synthetic thermo-responsive polymer, and magnetic Fe 3 O 4 nanoparticles . The hydrogels comprise cellulose nanocrystals (CNCs) decorated with Fe 3 O 4 nanoparticles (Fe 3 O 4 /CNCs) dispersed homogeneously in poly(N-isopropylacrylamide) (PNIPAm) networks. The composite hydrogels exhibit an extensibility of 2200%. Drug loading of vancomycin (VCM) reached a high value of 10.18 g g −1 due to the dispersion of Fe 3 O 4 /CNCs and the interactions between the CNCs and the PNIPAm network. Importantly, the hydrogels demonstrated a thermo-response triggered by NIR, with the temperature increasing from 26 to 41 °C within 60 s. The hydrogels have high biocompatibility evidenced by cell proliferation tests, illustrating that these hydrogels are promising as dressings for wound closure, and wound healing.