• 3D bioprinting
• crosslinking protocol
• dissolution
• sacrificial ink
• methacrylate gelatin
• fibrinogen

Aim of this thesis is to develop a new bioink for 3D-printed and vascularized constructs for the treatment of volumetric muscle loss (VML). The ink consists of ingredients with high myogenic potential, such as fibrinogen (1% w/v) and GelMA (5% w/v). A sacrificial bioink, Pluronic F127 (40%w/v), was used to create the inner channels that mimic the vasculature. A detailed protocol of myogenic ink preparation was developed by identifying parameters that may influence this process: solvent, fibrinogen concentration, and stirring speed. The ink was then rheologically characterized to gain insights into its potential printability. An optimal temperature range for printing was identified, thus obtaining the final temperature at which the material exhibits shear thinning behavior and good shape retention. Next, different crosslinking protocols were tested to obtain stable constructs over time under cell culture conditions. Finally, tests were performed to optimize the printing parameters of the first layer of the construct, obtaining continuous filaments with a defined thickness, using an extrusion-based bioprinting technique. The bioink shows good potential for future 3D-printing of a cellular construct for VML treatment.