Freeform Vertical and Horizontal Fabrication of Alginate-Based Vascular-Like Tubular Constructs Using Inkjetting

Organ printing, among different tissue engineering innovations, is a freeform fabrication approach for making three-dimensional (3D) tissue and organ constructs using cellular spheroids or bioinks as building blocks. The capability to fabricate vascular-like tubular constructs is an important indicator of the overall feasibility of envisioned organ printing technology. In this study, vascular-like alginate tubes, which mimic typical vascular constructs, are fabricated both vertically and horizontally using drop-on-demand (DOD) inkjetting. Manufacturing-related challenges are different for the vertical and horizontal printing configurations. In general, the vertical printing configuration has instability or collapse/buckling problems and may experience some difficulty in fabricating complex constructs such as Y- or K-shaped constructs if there is no supporting material. The horizontal printing configuration may easily result in a deformed hollow cross section and may require extra effort to mitigate the undesired deformation. It is envisioned that the combination of vertical and horizontal printing provides an efficient and effective way to fabricate complex tubular constructs with both vertical and horizontal branching features.