Mini-Hearts (Serves 12)
A bite-sized model of the human heart: perfect for studying heart disease and testing drug effectiveness. I got this recipe from Jana Hecking, a PhD student at the Applied Stem Cell Technologies research group of the University of Twente. She works on the next generation of miniature hearts.
Ingredients
- Gelatine
- Heart cells
- Cardiomyocytes (the beating cells) derived from Human Pluripotent Stem Cells
- Some supporting cells, like Human Cardiac Fibroblasts, for added structure
- Extracellular matrix
- The biological “glue” (like cornflour) that holds everything together
- Medium
- A nourishing broth for the cells
Tools & Equipment
- A heart-shaped moulding insert and a negative mould
- A multi-heart plate (think 3D printed muffin tray) that works like Legos
- An incubator (your highly controlled “oven”)
- A fridge (for setting the gelatine)
- General lab equipment (pipettes, tubes, sterile technique, and patience)
Instructions
- Warm your base
Heat the gelatine and the medium to exactly 37°C.
We’re making mini-hearts, not mulled wine. - Pour the outer mould
Mix the two solutions and pour half into your muffin tray.
Insert the heart moulding insert to create the shape and place the tray in the fridge. - Build the inner mould
Pour the remaining mixture through the hollow channel into the negative mould.
This will become the inner core.
Cool until firm. - Prepare the living filling
Mix your heart cells into a smooth suspension.
Add the extracellular matrix “glue” and stir until the mixture is uniform.
This is the essence of your future “beating heart”. - Check your moulds
When both gelatine parts wobble like a proper pudding, remove them from their supports.
The jiggle is non-negotiable. - Assemble your heart
Place the inner gelatine mould inside the outer one. - Inject the mix of cells
Using a pipette, carefully dispense the cell–matrix mixture into the space between the two moulds.
This is the moment where biology meets baking and all the magic comes together. - Let it rest
Allow 10 minutes at room temperature.
Then place the whole setup in the incubator at 37°C to set. - Finished!
After ten minutes, your mini-hearts are ready. Store in an incubator for up to a month.
They’re not for eating, but they are perfect for research into heart disease, drug effectiveness, and understanding how the human heart works at a cellular level.
Why do we cook mini-hearts?
These tiny 3D heart models beat, respond to drugs, and mimic human heart tissue without using animals and without the risks of testing directly on patients. They help us study disease in a controlled, human-relevant way. In the future, these mini-hearts might be made from stem cells from a patient, so you can personalise a treatment for heart disease. Would you like to see the hearts in action? Then watch this video.
