Anti-fatigue, highly resilient photocrosslinkable gellan gum hydrogels reinforced by flexible nanoparticulate polyurethane multi-crosslinkers

In this study, multifunctional polyurethane nanoparticles (MPUNs) were embedded into the methacrylated gellan gum (MGG) to prepare stimuli-responsive hydrogels with improved mechanical properties including remarkable fatigue resistance and excellent self-recoverability. The photocurable MPUNs/MGG nanocomposite hydrogels with different formulations were synthesized through a facile and green solution mixing method. The result obtained from mechanical analysis displayed an excellent improvement in compression strength (120 6 +/- 83.7 kPa) and ultimate strain (94.2 +/- 2.7%) in the optimized formulation. Furthermore, the optimized formulation could restore approximately its original shape after continuous loading-unloading compression tests over 100 cycles which might result from its favorable crosslinked structure. These reinforced hydrogels exhibited a dual physical and chemical crosslinking mechanism based on the hydrogen bonding formation and photocrosslinking of methacrylate functional groups, respectively. Interestingly, the nanocomposite hydrogels exhibited no significant cytotoxicity to human dermal fibroblast cells which made them suitable as the appropriate biomaterials for the engineering of soft tissues. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

In this study, multifunctional polyurethane nanoparticles (MPUNs) were embedded into methacrylated gellan gum to prepare stimuli-responsive hydrogels with improved mechanical properties. The optimized formulation showed excellent compression strength and ultimate strain, as well as the ability to restore its original shape after repeated compression tests. The hydrogels exhibited a dual physical and chemical crosslinking mechanism and were found to be non-toxic to human dermal fibroblast cells, making them suitable for soft tissue engineering applications.