Cell encapsulation in gelatin bioink impairs 3D bioprinting resolution

Recent advances in three-dimensional (3D) bioprinting technologies have enabled precise patterning of cellular components along with biomimetic constructs for tissue engineering and regenerative medicine. The viscoelasticity of bioinks regulate printability and the smallest feature size in 3D bioprinted constructs. The impact of cellular components is typically neglected when choosing 3D bioprinting parameters. In this short communication, we quantified the effect of cell densities on the printability of hydrogel bioinks. Unexpectedly, our results show that encapsulated cells reduced the steady shear viscosity of gelatin-based bioinks by approximately 50% and the minimum force for onset of flow by approximately 30%. These results may justify the lower spatial resolution in 3D bioprinted cell-laden hydrogels.