Digital light processing-based 3D bioprinting of κ-carrageenan hydrogels for engineering cell-loaded tissue scaffolds

The demand to regenerate biological tissues and organs in patients as an alternative to transplants has motivated the tissue engineering field. Digital light processing (DLP)-based three-dimensional (3D) bioprinting technology enables the rapid fabrication of complex 3D cell-laden scaffolds for tissue engineering applications. Herein, we demonstrate the outstanding printability of photocurable methacrylate-κ-carrageenan (MA-κ-CA) using DLP 3D printing. 3D printed hydrogels with varying concentrations (1-5% w/v) of MA-κ-CA were thoroughly characterized for their swelling, degradation, mechanical, and rheological properties, and suitability for bioprinting with living cells. Viscosity and shear thinning behavior of MA-κ-CA faithfully recapitulate the biomechanical properties of soft human tissues. Encapsulated NIH-3T3 cells show high viability and good proliferation over several days. Furthermore, highly complex 3D hydrogel scaffolds of MA-κ-CA were printed to recapitulate the biological complexity of tissues and organs. This work presents a polysaccharide bioink for preparing tissue scaffolds by DLP 3D bioprinting.