Well, a team of biomedical engineers from Carnegie Mellon University is bringing us closer to that reality. This heart mimics the structure and elasticity of the real thing. The invention promises advances in the medical field, and future iterations may one day save someone’s life.
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The First Life-Size Flexible 3D Human Heart
Additive manufacturing printers are popular, but are typically known for building hard objects using plastic or metal materials.
Rigid plastic parts are not efficient.
These printers could be used with softer materials, such as organic hydrogen to make a heart – but they tend to collapse in the middle of printing.
The 3D printing technique is called Freeform Reversible Embedding of Suspended Hydrogels or FRESH. It can print biological structures with soft, rubberized materials like alginate, a biomaterial made of seaweed that looks like human tissue.
It intelligently solves the problem of collapse by suspending flexible materials inside a gelatin container.
How does it all work?
For this team of researchers, it all starts with a magnetic resonance from a real heart.
The scan is digitally “crushed” into horizontal slices by a program, which then translates them into code that a printer will understand.
A needle-type nozzle moves through the gelatin support bath, extruding thin layers of alginate.
The layers overlap each other to build the shape
When the print is complete, it is placed in an incubator overnight where the temperature is raised to 37°C to gently melt the support structure, leaving only the heart printed in 3D.
In this full-scale test, they were able to reproduce characteristics as thin as two sheets of paper, and in smaller-scale tests, they were able to obtain them as thin as human hair.
The 3D printed hearts have been printed before, but were small, more suitable for a rabbit or mouse than humans.
Full-size 3D printed hearts can also be used as educational tools to help surgeons prepare for surgery.
Older surgical models are made of rigid plastic or rubber, so they are useful for planning, but limited because surgeons cannot interact with them as real tissue.
Now surgeons can use these more realistic models to refine surgical techniques and test their tools before the surgery itself.
One of the most interesting parts is that it could be an impression of your specific heart! This will allow hospitals to customize tissue replacements.
If you have a blocked artery and need a stent inserted into your real heart, the surgeon can test the stent with the heart printed in 3D to make sure it fits properly.
They are starting to use this technology to help design functional parts that have been difficult to correct in the past.
The heart valves printed with collagen can open and close. And the printed coronary arteries help to move the blood around the body.
Ventricles made of heart muscle cells can also visibly contract and begin to synchronize.
But it’s still not a heart beating functionally
Using real human tissue like “Bio-ink” for an organ printer can be expensive in the volumes required.
If you are on a waiting list for this essential organ, you may be willing to pay any price! Time is also a factor:
- Currently, a full-scale FRESH model takes four days to complete
- If we print with live cells at this rate, many cells are lost in the process
- To make a normal sized heart, billions of cells are needed
Although it is not now possible to create a fully functional heart, the Carnegie Mellon team is already working to perfect FRESH technology so that more complex models can be built.
One day, these printed tissues could be used to test more safely:
- Decrease animal testing
- Even replace or repair damaged organs with a new, healthy, 3D printed copy
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