How was the laboratory-grown rat leg made in 2015?

In 2015, researchers reported the development of the first laboratory-grown bioartificial limb, a rat leg, as a significant advancement in regenerative medicine and tissue engineering.12

The limb was created using the following process:

• Scaffold Preparation: Scientists utilized a decellularized scaffold derived from a dead donor rat, which provided the necessary structural framework.1
• Cell Seeding and Incubation: The scaffold was seeded with muscle and vein cell precursors. These cells were then incubated in a bioreactor, where they matured and expanded to populate the structure.1
• Final Assembly: Skin was grafted over the limb to complete the structure.1

When tested, the limb demonstrated functional potential: the muscles contracted in response to electrical stimulation, and when transplanted onto a living rat, the newly grown vascular tissue successfully perfused with blood. This achievement highlights the complex challenge of engineering limbs, which require multiple tissue types to work in coordination to perform biological functions.1