Human hearts are in high demand. Even in the US, 15% of patients on the wait list will die before a heart is found. Living on that list is not fun, either. It is exactly this grim reality that makes the work of BIOLIFE4D really important. This US-based company made headlines back when they announced that they had 3D-printed a small model of the human heart. Could this be the first step to an artificial heart patients can actually receive?
3D-printing hearts isn’t simple
Standard 3D-printing is a simple process: Hot plastic is laid in a computer generated pattern. To print a living, beating heart is a lot harder. The scientists at BIOLIFE4D use this recipe:
- First, create pluripotent stem cells from white blood cells.
- Then, convince stem cells to transform to muscle cells (cardiomyocytes), vascular cells and cells that produce connective tissue.
- You then need a scaffold for them to lay on.
- After you “print” the cells, each in the right place, they need time to grow. By the way, placing each cell in the right spot is much harder than it sounds.
- Once they mature, the scaffold needs to disappear without hurting them.
- During this whole process, cells need to stay fed. The temperature can’t get too high, either.
The magic ingredient is still out there
If you follow this impossible recipe to the letter, you’ll end up with something that looks a lot like a heart. The problem is, there’s no pulse. For a heart to contract in a coordinated way, muscle cells need to have the right connections. It seems our recipe doesn’t produce that.
Making use of a tiny heart
Unlike most prototypes, the heart model produced by BIOLIFE4D is of actual use, right now. Scientists can find out which drugs harm actual human hearts, using this tiny heart as a model. Patients may benefit from this work soon, as some parts of the heart don’t need to beat in order to be fully functional. If BIOLIFE4D can create replacement valves from patients’ own tissue, that’ll be a revolution all on its own!
Take-home messages
- BIOLIFE4D printed a tiny replica of a human heart, complete with muscle, arteries and veins.
- The only thing they took from the patient was a blood sample.
- Although the heart is really small and can’t beat yet, this was a big step in organ 3D-printing.
- We hope that the know-how from this project quickly leads to novel therapies for patients. Still, creating hearts for patients that need transplantation is not happening anytime soon.