Chaotic bioprinting enables the fabrication of microstructured hydrogel fibers with co-extruding permanent and fugitive inks using a kenics static mixer (KSM) printhead. However, these fibers degrade completely after 7 days of static culture. Survival of hydrogel constructs for prolonged periods is critical for tissue maturation. Therefore, in this project, chaotic bioprinting was optimized to reinforce multichannel hollow fibers, thereby extending the culture time to enable skeletal muscle tissue maturation. A KSM printhead equipped with eight inlets and two mixing elements was used to print hydrogel fibers with three materials: a bioink suitable to load cells, a sacrificial material to create hollow channels, and a structural material to provide mechanical stability (without cells). Each bioink layer was placed 62.5 µm apart from a hollow channel. Furthermore, the optimal ratio for ea...