Abstract

3D Printing Complex Biological Scaffolds using Freeform Reversible Embedding of Suspended Hydrogels (FRESH)

Adam Feinberg, Associate Professor, Carnegie Mellon University

3D printing of hydrogels is an additive fabrication approach that has the potential to create complex construct architectures not possible using other tissue engineering methods. While there have been a number of advances, the 3D printing of soft hydrogels such as alginate, collagen and fibrin remains challenging because these materials typically have an elastic modulus <100 kPa and deform during the layer-by-layer printing process in air. To address this we have developed a Bingham plastic support bath into which these hydrogels can be printed with high fidelity and subsequently released, using a process we term freeform reversible embedding of suspended hydrogels (FRESH). Using FRESH we demonstrate (i) a biocompatible support material that prevents print deformation during and after gelation, (ii) non-destructive removal of the support material after printing, and (iii) maintaining sterile conditions and temperature, pH, and osmolality within the physiologic range. Example prints of arteries and hearts and dimensional analysis compared to original 3D models validates the fabrication of complex 3D structures with high fidelity while using inexpensive open-source technologies.  Future work is focused on cellularizing these constructs to create functional tissues.