Scientists are closer to creating an "ear from a test tube"

Researchers from ETH Zurich, together with colleagues from Basel and the Cantonal Hospital of Lucerne, have reported progress in creating a "laboratory ear". They were able to grow elastic ear cartilage from human cells andprint blanks from it on a 3D printer. In animal experiments, these blanks remained mould-resistant and quite elastic.

The work is important for people who have lost part of their ear due to trauma or burns, as well as for children with a congenital anomaly of the outer ear - microtia (occurs in about 1-4 out of 10,000 newborns). Now the "gold standard" for reconstruction is to take cartilage from a rib, but this is painful, leaves scarring, and the new ear is often stiffer than the natural ear.

How to make an "ear": scientists took cells of ear cartilage from small fragments of tissue that remain after surgery to correct the shape of the ear. The cells were then multiplied to hundreds of millions, mixed with biochernyls(carrier gel) and printed into the desired shape. After printing, the blanks were "matured" for several weeks in conditions where the tissue was evenly oxygenated and nourished - to make it stronger and more like the real thing.

According to the authors, after about 9 weeks of maturation in the lab, the constructs were implanted under the skin of rats and observed for another 6 weeks. During this time, the "ear" cartilage retained its shape and properties close to the natural one.

But a key component - elastin- is still missing from the fully "real" ear. It's what makes ear cartilage so flexible and "springy". Researchers say that creating elastin is not enough: it needs to line up in the right strong network and remain stable for a long time. This is now the main barrier to clinical application.