Results
Validation and Characterization
The concept was assessed to test initial printability using a 6 % (w/v) sodium alginate (dissolved in sterile double distilled water) (see Appendix 1 for a detailed protocol). Cell-free bioprinting experiments were performed initially using an 18G syringe needle as the nozzle. Subsequent analysis on optimal parameters were then carried out. All materials used were purchased from Sigma-Aldrich Pty. Ltd. (South Africa), unless otherwise specified.
Proof of concept: does the extrusion mechanism work as intended and is it capable of printing geometrically complex constructs?
The computer aided design (CAD) software SketchupMake2017 (v.17.2.2555) was used to design a grid-like structure for initial printability tests. Dimensions include: Height = 19.80 mm
Width = 19.80 mm, Layer height = 2 layers (0.2 mm). Cura (v.15.04.2) was used as the slicing software as well as for the parametrization of the printing process. The printing parameters include Layer height (1 layer = 0.1 mm), Shell thickness (0.4 mm), No retraction, Bottom/Top thickness (0.4 mm), Fill density (100%), Print speed (10mm/s), Flow rate (150%), Nozzle diameter (18G needle).