A technique previously pioneered at Carnegie Mellon University to enable 3D bioprinting of tissue scaffolds based on collagen has been successfully demonstrated to produce the first full-size 3D bioprinted human heart model.

The model realistically simulates the elasticity of cardiac tissues and sutures and was generated with the Freeform Reversible Embedding of Suspended Hydrogels (FRESH) technique, based on MRI data and a specially built 3D printer. FRESH 3D printing uses a needle to inject bioink into a bath of soft hydrogel, which supports A completed 3D printed heart model. Source: Carnegie Mellon Universitythe object as it forms. Once finished, a simple application of heat causes the hydrogel to melt away, leaving only the 3D bioprinted object.

Inexpensive alginate derived from seaweed served as the printing biomaterial to mimic the elastic modulus of cardiac tissue. In addition to achieving high print fidelity on a low-cost printer platform, FRESH-printed alginate proved to create mechanically tunable and suturable models.

Such soft, biocompatible scaffolds may one day provide the structure onto which cells adhere and form an organ system, placing biomedicine one step closer to the ability to repair or replace full human organs. In addition to serving as physical models for surgical training and educational purposes, tissues and organs printed using FRESH have the potential to host living cells and advance bioengineered organ research.