Biomedical engineers from Carnegie Mellon University have created a full-size 3D bioprinted human heart model using their newly developed technique, Freeform Reversible Embedding of Suspended Hydrogels (FRESH). The model was created from MRI data using a specially built CD printer, which is capable of realistically mimicking the elasticity of cardiac tissue and sutures.
The FRESH technique was created to fill a demand for 3D printed soft polymers, which are unable to stand unsupported due to their lack of rigidity. FRESH 3D printing uses a needle to inject the bioink into a bath of soft hydrogel, supporting the object as it prints. Once completed, heat is then applied, causing the hydrogel to melt away, leaving only the 3D bioprinted model. The milestone here was printing a human heart at full scale. This required a specially built 3D printer capable of holding a gel support bath large enough to print the desired size.
Many hospitals utilize 3D bioprinting for models of a patient’s body to help surgeons educate patients prior to a procedure; however, the tissues and organs can only be printed in a hard plastic or rubber. The teams bioprinted heart is made of a soft, natural polymer, giving it properties like real cardiac tissue. This allows surgeons to have access to models they can cut, suture, and manipulate in ways close to a real heart.
