A study published in ACS Biomaterials Science & Engineering details the development of a 3D-printed, full-size model of a human heart, that could be used to train surgeons preparing for surgical procedures in the heart. Authored by Eman Mirdamadi and colleagues from the Department of Biomedical Engineering, Carnegie Mellon University (Pittsburgh, USA), the study details the use of Freeform Reversible Embedding of Suspended Hydrogels (FRESH) bioprinting to develop a human heart model from patient-derived magnetic resonance imaging (MRI) datasets.
FRESH printing involves the ability to embed soft biomaterials in a thermoreversible support bath at sizes ranging from several millimetres to centimetres.
The study team’s first step was to show that alginate, an inexpensive material made from seaweed, has similar material and mechanical properties as cardiac tissue. Next, the researchers placed sutures in a piece of alginate, which held even when stretched—suggesting that surgeons could practice stitching up a heart model made from the material.
In preparation for making the heart model, the team modified their FRESH 3D printer to make larger objects. They used this device and MRI scans from a patient to model and print a full-size adult human heart, as well as a section of coronary artery that they could fill with simulated blood.
The heart model was structurally accurate, reproducible and could be handled outside of the gelatin bath. The method could also be applied to printing other realistic organ models, such as kidneys or liver, the researchers say.
The study team writes: “In addition to achieving high print fidelity on a low-cost printer platform, FRESH-printed alginate proved to create mechanically tunable and suturable models. This demonstrates that large-scale 3D bioprinting of soft hydrogels is possible using FRESH and that cardiac tissue constructs can be produced with potential future applications in surgical training and planning.”