Ultrafast construction of partially hydrogen-bonded metal-hyaluronan networks with multiple biotissue-related features

This paper reports a versatile and dynamic hydrogel system based on ultrafast coordination between partially hydrogen-bonded (PHB) biopolymer hyaluronic acid and a series of transition metal ions at appropriate pH values. It was found that the procedure for the hydrogel synthesis was extremely facile, requiring a simple mixing of the components within 2 s. The hydrogels exhibited high water content, up to 96 %. Even so, the hydrogels can be stretched >50 times and rapidly self-heal from damage within only 10 s without using any healing agents or heating. Furthermore, this dynamic hydrogel network underwent reversible sol-gel transitions as response to multiple disparate stimuli, including pH, temperature, ions, redox, and light. The photo-patterning ability of the hydrogel with a rapid gel-sol transition upon exposure to light was also demonstrated. We disclosed the principle and methodology to use PHB metal-biopolymer systems for constructing dynamic bio-related soft matters.