Ultrafast gelation of hyaluronan hydrogels via alternate compression-decompression

High pressure-induced inter/intra-hydrogen bonds are strong enough to sustain microassemblies. Here, for the first time, we demonstrate a rapid route (several minutes) for dynamic pressure to enable effective gel formation from hyaluronic acid (HA). The HA hydrogels prepared in such an alternate compression-decompression procedure exhibit a layered structure and high yield of as-made gels. Compared to conventional freeze-thawed hydrogels, the gels via alternate compression-decompression (ACD) have an enhanced intermolecular interaction as well as improved mechanical properties. This method is fast, simple, and safe. Furthermore, the present results provide new ideas for obtaining physical gels and contribute to the development of HA-based materials that can be used in biomedical and agricultural applications.