Researchers from Weill Cornell Medicine and Cornell Engineering have replicated an adult human ear using a combination of 3D printing and tissue engineering.

Designed to look and feel like the real thing, the researchers believe the development will pave the way for future grafts with well-defined anatomy and the correct biomechanical properties for those born with outer-ear deformities or who lose an ear later in life.

Pictured is the left-ear plastic scaffold that was created on a 3D printer based on data from a person’s ear, anterior view (left) and posterior view (right). Source: Spector LabPictured is the left-ear plastic scaffold that was created on a 3D printer based on data from a person’s ear, anterior view (left) and posterior view (right). Source: Spector Lab

To accomplish this, the researchers used sterilized cartilage obtained from animals, which had been treated to reduce the chance of infection and thus the likelihood of rejection by the recipient’s immune system.

The sterilized cartilage was placed on ear-shaped plastic scaffolds created on a 3D printer, featuring the dimensions and curves of the person’s ear. The researchers explained that the small pieces of cartilage served as internal reinforcements to encourage new tissue growth within the scaffold.

Over a period of three to six months, the end result was an ear graft featuring the physical characteristics of the human ear, including the helical rim, the rim-inside-the-rim and the middle conchal bowl.

Further, a series of biomechanical tests revealed that the ear felt like a human ear and had the flexibility and elasticity similar to human ear cartilage.

Yet, despite the natural look and feel of the ear, the researchers reported that the replica’s material was not as strong as natural cartilage and could tear. The researchers intend to rectify this going forward by adding chondrocytes to the mix — ideally ones taken from a small piece of cartilage removed from the recipient’s other ear.

The research is detailed in the article, “Bioengineering Full-scale auricles using 3D-printed external scaffolds and decellularized cartilage xenograft,” which appears in the journal Acta Biomaterialia.

To contact the author of this article, email mdonlon@globalspec.com