Rehydration of ready-to-use gel powder to construct self-healing and injectable hydrogel for protein delivery

Storage and transportation of dynamic hydrogel in ambient conditions is challenging. At present, cold-chain management is the most suitable option but it requires substantial infrastructure and energy. Moreover, the raw materials for preparing dynamic hydrogels often require chemical modification and purification, making the process cumbersome and time-consuming. This poses challenges for the practical applications of dynamic hydrogels. Here, we have developed a dynamic micron-sized (DMS) gel powder that can be packed, stored, and transported in a freeze-dried powdered form and rehydrated into a dynamic hydrogel before use. The dynamic hydrogel obtained by rehydrating the DMS gel powder stored under ambient conditions for 7 months can achieve properties similar to the original hydrogel, including stable protein delivery, mechanical properties, injectability, self-healing and remodeling. We propose a novel strategy for preparing a long-term storable DMS gel powder that can maintain properties similar to those of the original hydrogel after rehydration. Considering the advantages in terms of convenience and commercialization for practical applications in the biomedical fields, this unique ready-to-use DMS powder offers a practical, scalable, and simple solution to enable mass production, cold-chain free, and low cost off-the-shelf dynamic hydrogel.