Hyaluronic acid incorporation into hybrid alginate-based bioinks promotes long term viability and controlled release of 3D embedded scaffolds mesenchymal stem cells in absence of Dimethyl Sulfoxide cryoprotectant

Cryopreservation is critical in 3D bioprinting to ensure availability for clinical use and long-term storage. We have studied the incorporation of hyaluronic acid (Ha) into an alginate-nanocellulose bioink to enhance scaffold properties and reduce reliance on dimethyl sulfoxide (DMSO), a traditional, but toxic cryoprotectant. Our findings show that Ha significantly improves biomaterial ink viscoelasticity, even after cryopreservation at ultra-low temperatures. Moreover, scaffolds incorporating Ha exhibited increased roughness and porosity and mechanical testing indicated that cryopreserved scaffolds with Ha were more durable. Interestingly, scaffolds without DMSO maintained high cell viability and metabolic activity, suggesting effective cryoprotection with reduced cytotoxicity. In conclusion, incorporating Ha into bioinks enhances scaffold properties and enables successful cryopreservation without DMSO, paving the way for safer and more efficient bioinks in tissue engineering and regenerative medicine. • Bioink with hyaluronic acid supports safer and efficient tissue engineering cryopreservation. • Cryopreserved scaffolds without DMSO maintain cell viability and long-term release. • Hyaluronic acid preserves porosity and surface roughness of scaffold.