Intrinsically cryopreservable, bacteriostatic, durable glycerohydrogel inks for 3D bioprinting

Three-dimensional (3D) printing of “bioinks” containing living cells has broad prospects in the fields of in vitro modeling and regenerative medicine. However, existing bioinks lack a number of required properties, including antibacterial characteristics, long-term shape maintenance, and cytoprotection ability during fabrication, cryopreservation, and transportation of 3D bioprinted tissues. In this study, we created a multifunctional glycerohydrogel bioink to address these challenges. The key is using glycerol to regulate the state of water in the bioink. Glycerohydrogels with limited “free water” exhibited significant inhibition of Escherichia coli and mold, outstanding shape maintenance, excellent compatibility with 3T3 mouse fibroblasts and rat adipose-derived stem cells, and an intrinsic ability of cryopreservation at −80°C, which is superior to existing hydrogel-based bioinks. This work provides a design principle for bioinks by regulating molecular interactions and will have broad prospects for practical biomedical applications.