• 3D bioprinting
• accuracy
• artificial muscle
• filaments
• myogenic bioinks
• optimization
• printability
• printing parameters
• sacrificial bioinks

This thesis addresses the challenge of developing an in vitro 3D skeletal muscle construct through 3D bioprinting. In tissue engineering, the fabrication of a large-scale functional tissue is part of one of the greatest challenges particularly due to low cell viability at the innermost part of the construct. Indeed, cell viability is maintained only if the newly formed tissue is featured by a thickness smaller than 400 µm, due to limits in the diffusion of oxygen, nutrients and metabolic wastes. Some strategies, such as the introduction of porosities, have been proposed in the state-of-the-art. In this scenario, 3D bioprinting is an additive manufacturing technique that holds promises. However, so far, this has been possible until an overall size of tens of millimetres. Moreover, in the proposed systems, in vivo neo-angiogenesis occurs with a too slow dynamic to reach the innermost part of the neo-tissue before the arousal of necrotic events. This is due to a sub-optimal production of filaments. A systematic analysis of the effect of temperatures, printing speeds and pressures on the filament size and shape is currently missing, in this field.
This work aims at optimizing the printing conditions to finely control the deposition of bioinks, achieving filaments with a width equal to the nominal diameter of the extrusion tip and as close as possible to 200 µm, considered an optimal size for the future development of 3D macro-scale vascularised muscle constructs.