Injectable and biodegradable double-network nanocomposite hydrogel with regulable sol-gel transition process and mechanical properties

Alginate hydrogels have the most extensively explored injection system among natural molecular. The injectable alginate hydrogel has special physical and biological properties without toxicity, therefore, it has been served as minimally invasive treatments to treat various irregular defects. However, the inconvenient truth is low formability and poor mechanical properties of injectable alginate hydrogels; besides, there are little relevant studies about controlling, measurement and analysis of the sol-gel transition and degradation process. We synthesized an injectable nanocomposite alginate hydrogel, used specific methods and equipment to regulate and evaluate the sol-gel transition of the hydrogel, moreover, we researched the degradation behaviour using scanning electron microscope, nano-indenter and titration analysis. The results showed that gelation time and mechanical properties could be regulated and effectively described. Compression properties of the hydrogels increased to 150%–300% compared with common alginate hydrogels, in addition, the degradation behaviour with ions release could be regulated by the formula. The results will be propitious to solve problems in quality control of hydrogel manufacturing engineering and the nanocomposite hydrogels with good biocompatibility will have great potential for multifunctional biological scaffolds and tissue engineering.