This was an expected result since this ink formulation flowed (Figure ) and formed droplets when extruded. Our data indicates that the influence of CBP concentration on printability was considerably stronger than that of GelMA. Varying the CBP concentration from 0.1 to 0.5% resulted in inks that were not printable (0.1%) to ones that presented outstanding printability (0.5%). This trend was also observed in the rheological characterizations of the inks and confirmed that CBP concentration is critical to achieve good printability and shape fidelity through extrusion 3D bioprinting.