A revolutionary procedure involving a patient’s own stem cells has allowed British researchers to grow artificial body parts in their lab, including noses, ears, tear ducts, and blood vessels, which they can then reattach to the patient’s body.

Researchers at the University College London have developed a technique they say is similar to baking a cake — only their oven is a little more sophisticated. They’ve already developed smaller organs, such as blood vessels and windpipes, although they hope to be the first scientists to transplant a nose made partly of stem cells. Last year, team leader Alexander Seifalian and his colleagues attached a lab-grown nose onto the arm of a British man who’d lost his own nose to cancer. The skin has engulfed the nose, accepting it; all that remains is the approval to transplant it.

The body parts are made of a polymer material that includes a scaffolding mold and stem cell samples taken from patients’ fat. To get the desired spongy texture for the man’s artificial nose, the team added a mixture of salt and sugar to the mold. Seifalian holds a patent on the polymer used to make noses and hopes to extend it to include other organs. Currently, he and his team are working on building coronary arteries, although ears are admittedly the most challenging.

"Ears are harder to make than noses because you have to get all the contours right and the skin is pulled tight so you see its entire structure," Dr. Michelle Griffin, a plastic surgeon who’s made handfuls of ears and noses as part of Seifalian’s team, told The Associated Press. The challenge with building ears also lies in the cartilage that’s used for them, which must come from a patient’s ribs and is highly invasive to extract, Griffin added.

If the scientists working on the project reach a consistent level of success, their next hope is to conquer larger, more sophisticated organs. These include kidneys, lungs, and livers. In the meantime, however, there are still details that need ironing out. Invasiveness is one glaring hurdle. Another is cost. Seifalian has already put approximately $16 million into the research. He hopes one day the procedure will only burden patients by a few hundred dollars.

Suchitra Sumitran-Holgersson, a professor of transplantation biology at the University of Gothenburg in Sweden, echoed Seifalian’s optimism. "I'm convinced engineered organs are going to be on the market soon,” she told the AP.

Of course, there is always the battle of getting patients onboard. Stem cells aren’t exactly uncontroversial. They cut to the heart of many people’s discomforts with modern science, as the initial tests of embryonic stem cells in 2009 forced people to decide whether the technique destroyed life or effectively extended it. Since then, scientists have used adult stem cells to mimic embryonic growth, grow mini-organs, and “cut out” the human immunodeficiency virus (HIV) from mice.

Seifalian has high hopes that the technique will be well-received. "If people are not that fussy, we could manufacture different sizes of noses so the surgeon could choose a size and tailor it for patients before implanting it," he told the AP. "People think your nose is very individual and personal but this is something that we could mass produce like in a factory one day."