If you were planning to perform open-heart surgery on someone, it would definitely help if you could first do a "dry run" on an exact replica of their heart. Doing so may soon be possible, thanks to a recent advance in 3D printing technology.
First of all, it is already possible to produce a physical replica of a person's heart, based on MRI scans. Such models are typically made of rubber or hard plastic, however, so they lack the texture of the real thing. Doctors can examine them from different angles, but they can't practise the actual surgery on them.
That's where the Freeform Reversible Embedding of Suspended Hydrogels (FRESH) technique comes in.
Developed in the lab of Carnegie Mellon University's Prof. Adam Feinberg, it utilizes a "bioink" made up of a natural polymer known as alginate. That bioink is extruded from a moving needle into a hydrogel bath, which holds the soft polymer in place as the object is printed. Once the printing process is complete, the hydrogel is melted away via the application of heat, leaving only the object behind.
Although the technology has previously been used to create miniature models of organs, this is the first time it's been utilized to print a full-size replica. Among other things, the process required building a new 3D printer that could accommodate a larger hydrogel bath, and tweaking the printing software.
The finished 3D-printed item is claimed to mimic the elasticity of a real human heart, and can be cut and sutured in a similar manner.
"We can now build a model that not only allows for visual planning, but allows for physical practice," says Feinberg. "The surgeon can manipulate it and have it actually respond like real tissue, so that when they get into the operating site they've got an additional layer of realistic practice in that setting."
The process is described in a paper that was recently published in the journal ACS Biomaterials Science and Engineering.
Sources: Carnegie Mellon University, American Chemical Society
