Scientists achieve 3D-printed human ears in the body

artificial ears can be 3D printed under the skin Photo: SEBASTIAN KAULITZKI / SCIENCE PHOTO LIBRARY / GETTY IMAGES
3D printing technology is increasingly being used to customize new "parts" of the human body, such as jaws, ribs and spines. But these tissues or organs must be printed in vitro and then surgically implanted, which poses a risk of infection.
new study published in Scientific Progress suggests that Goma Ling and colleagues at Sichuan University in China have shown that these body tissues can be 3D-printed in the body , at least in mice, and therefore do not require surgery. The technique has the potential to create new ears or other parts of the body without surgery.
study, scientists first injected a "biological ink" of hydrogel particles and cartilage cells into the back of mice. Next, they used near-infrared light to project the shape of their ears on the ink. Light sticks hydrogel particles together and layers develop into ear-like structures.
over the next month, cartilage cells grow around the hydrogel structure, eventually forming cartilage structures similar to those of real human ears. During this time, the mice did not show significant inflammation or other side effects.
The famous "Wakanti Rat" experiment of the 1990s also allowed a "human ear" to grow on the back of a mouse, but it was achieved by implanting a pre-crafted plastic stent under the skin carrying cartilage cells, rather than directly on-site 3D-printed stents.
researchers hope the new technology could be used to rebuild new ears for those with congenital small ear deformities, a condition that hinders the normal development of the ears. "We are working to improve this technology so that we can treat ear defects in the future." Ms Goo said.
non-surgical 3D printing technology could also be used to repair damaged cartilage in the nose, fingers, toes or elbows, said Derek Rosenzweig of McGill University in Canada. In contrast, hip and knee deep cartilage defects can be more difficult to repair, he said, because near-infrared light can usually penetrate only about 2 cm of human skin.
team hopes to eventually use the technology to repair other damaged organs, such as the heart or lungs. However, Rosenzweig believes that
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