Sodium Alginate Printability Using a Developed Extrusion-Based Coaxial Nozzle for Biofabrication

Sodium alginate (SA), cross-linked by calcium ions, is widely used as bioink in 3D bioprinting. The coaxial printing method integrating with the extrusion-based method offers the merit for simultaneously printing multi-materials such as SA and calcium chloride (CaCl2). A design of an adapter based on coaxial printing is developed and evaluated to crosslink the SA solution immediately after deposition through the nozzle. The printability of SA solution at different flow rates and concentrations of SA and CaCl2 is investigated by computational simulation and experimental method to figure out the optimal printing condition. The results show that the concentration of SA and the flow rate of solutions have significant effects on the printed line width while the concentration of CaCl2 only affects the adhesion of the printed line on the substrate.