Stock solutions of the block polyanion (sulfonate functionalized bPEs), block polycation (guanidinium functionalized bPEs), GelMA precursor, and photoinitiator Irgacure 2959 or LAP were prepared in DBPS. GelMA/DbPE and GelMA/TbPE inks were prepared by mixing the block polyanion with an aqueous solution of GelMA precursor and photoinitiator, followed by the addition of the block polycation. Each addition step was followed by thorough mixing to ensure homogeneity of the sample. The bPEs were mixed in such a proportion that the molar charge ratio of cationic and anionic moieties was 1:1.