Dr. W. T. Green, a pediatric orthopedist at Children's Hospital in Boston, Massachusetts, made one of the first attempts at tissue engineering. He tried to grow cartilage in laboratory mice. Although unsuccessful, his work set the stage for later attempts by suggesting that, once suitable materials were invented, cells would grow on configured scaffolds.
Joseph Vacanti, a transplant surgeon, and Robert Langer (b. 1948), an engineer, created an engineered, biosynthetic, biodegradable scaffold in 1987. The scaffolds they developed provided access to nutrients as well as waste removal for the growing cells. The final structure can resemble a natural organ.
A famous development was the "auriculosaurus," a mouse with a human-shaped ear growing on its back. The "ear" was a biodegradable scaffold seeded with bovine cartilage cells. The mouse was a nude animal specifically bred not to reject foreign proteins. The auriculosaurus, filmed by a BBC video crew, became the image of tissue engineering worldwide.
In 1998 a factory worker was presented to the University of Massachusetts Medical Center after the last bone in his thumb was ripped off in machinery, leaving just the flesh. Vacanti ground a piece of coral into the shape of the missing bone. The coral was then seeded with bone cells, and eventually implanted. As the coral dissolved, the bone replaced the structure.
These two examples were grown inside organisms. Engineered tissue is more commonly grown in bioreactors—vessels designed to provide nutrients and remove waste more efficiently than could be done in a petri dish.
