“Out‐of‐the‐box” Granular Gel Bath Based on Cationic Polyvinyl Alcohol Microgels for Embedded Extrusion Printing

Embedded extrusion printing provides a versatile platform for fabricating complex hydrogel‐based biological structures with living cells. However, the time‐consuming process and rigorous storage conditions of current support baths hinder their commercial application. This work reports a novel “out‐of‐the‐box” granular support bath based on chemically crosslinked cationic polyvinyl alcohol (PVA) microgels, which is ready to use by simply dispersing the lyophilized bath in water. Notably, with ionic modification, PVA microgels yield reduced particle size, uniform distribution, and appropriate rheological properties, contributing to high‐resolution printing. Following by the lyophilization and re‐dispersion process, ion‐modified PVA baths recover to its original state, with unchanged particle size, rheological properties, and printing resolution, demonstrating its stability and recoverability. Lyophilization facilitates the long‐term storage and delivery of granular gel baths, and enables the application of “out‐of‐the‐box” support materials, which will greatly simplify experimental procedures, avoid labor‐intensive and time‐consuming operations, thus accelerating the broad commercial development of embedded bioprinting. This study develops an “out‐of‐the‐box” granular support bath that is ready to use by simply dispersing the lyophilized bath in a solvent. Re‐dispersed bath displays same physicochemical property, shear‐thinning and self‐healing properties, and printing resolution with the fresh one. The lyophilized bath facilitates long‐term storage and delivery, thereby simplifying experimental procedures, saving time and money, and enabling the construction of scale‐up tissue‐like structures.