Cow cartilage has been printed out by scientists in a move that could fix worn joints.
The special 3D printing technique could one day be used to print out special patches that will help people with worn joints. 
To create the organic ink, researchers grew cells in thin tubes that were just three hundredths of an inch wide, made from algae.
They then took that cartilage out and pushed it through a special nozzle, which means that it can be printed out in rows in any pattern that’s needed.
Once the ‘ink’ had been left for about half an hour, it could be moved into a laboratory dish. There, the different stands attached and fused together.
Scientists hope to be able to print out such pieces of cartilage so that they can patch up worn out joints.