Doctors raised new ears for five children with underdeveloped auricles based on their own cells. The auricles were formed from a biodegradable material and then colonized with cartilage cells. Two and a half years of patient follow-up showed that this approach is promising. The results of clinical trials are described in an article in the journal EBioMedicine.
Congenital underdevelopment of the auricle (microtia) occurs, depending on the region, with a frequency of 1 to 17 cases per 10 thousand children. In addition to causing everyday inconveniences - for example, people with microtia cannot wear glasses - it can seriously impair hearing and negatively affect self-esteem in childhood. Usually, the problem is solved with the use of ear prostheses made of polymer materials or rib cartilage, but such ears do not function as hearing organs, or cause additional inconvenience associated with the need for rib surgery.
As early as 1997, researchers showed that the human ear could be successfully grown from cartilage cells in the mouse. Since then, this possibility has been repeatedly confirmed in animal models, but the case has not come to use in humans. Chinese scientists conducted the first successful clinical trials on the transplantation of five children with microtia of the auricles, artificially grown from the patients' own cartilage cells on a 3D matrix.
Using computed tomography, the researchers took an impression of a healthy ear in children with unilateral microtia and 3D printed a mirror copy of it from biodegradable polymers of polyglycolic acid and polylactate with the addition of polycaprolactone. A biopsy of the ear cartilage was taken from the patient, the cells of the cartilage tissue were isolated and the matrix was populated with them in vitro. Cultivation of the auricle took three months, after which the organ was transplanted to the patient while preserving the ear canal.
A child with microtia before and after surgery (top panel). Below are photographs of the implant 1, 6, 9, 12, 24 and 30 months after surgery. Guangdong Zhou et al / EBioMedicine 2018.
After the operation, the patients were followed up for a long time. For the very first test subject (a six-year-old girl), this period was two and a half years. All this time, the organ retained its shape and elasticity, no inflammation and signs of rejection were observed. Magnetic resonance imaging has confirmed that the polymer base of the ear degrades over time, leaving only cartilage.
Experts say that it will be possible to talk about the full success of the tests in a few more years, when the patients grow up. The researchers themselves argue that they specially selected participants who were at least six years old - the age by which the ear is already fully formed, and intend to continue working with the inclusion of adult patients. In addition, the authors are considering the possibility of completely switching to 3D printing of the auricles - for this you need to use tissue cells as a "refueling" for the printer.
Daria Spasskaya
Promotional video: