Non-planar embedded 3D printing for complex hydrogel manufacturing

Abstract

Embedded bioprinting as a tissue engineering method has expanded the ability to bioprint complex geometry of native tissue. Print bath support in these methods allows the biomaterial to solidify in place, mitigating the possibly negative effects of low viscosity and gravity. This material stability also permits for non-planar deposition of the biomaterial. Here, we developed a non-planar 3D print slicer for non-planar embedded bioprinting. We quantified the changes in ink deposition properties with respect to non-planar movement to understand printability in the system. Alginate prints in a FRESH support bath were used to quantify the capability of the slicer to create tunable mechanical properties. Mechanical testing reveals that geometric changes to the printed models can tune stiffness, failure stress and strain, and Poisson's ratio. These results demonstrate that using non-planar manufacturing can produce mechanically tunable properties with a homogeneous biomaterial. This may strengthen our ability to precisely match mechanical properties of native tissues to improve tissue engineering outcomes.