Researchers at Weill Cornell Medicine and Cornell Engineering have utilized cutting-edge tissue engineering methods and 3D printing technology to fabricate a replica of an adult human ear that closely resembles and feels natural. The findings of this study, published online in Acta Biomaterialia on March 16, hold promise for the development of grafts with precise anatomical characteristics and appropriate biomechanical properties, particularly beneficial for individuals with congenital ear malformations or those who have lost an ear later in life.
Dr. Jason Spector, chief of the Division of Plastic and Reconstructive Surgery at NewYork-Presbyterian/Weill Cornell Medical Center and a professor of surgery (plastic surgery) at Weill Cornell Medicine, emphasized the significant impact of this innovative technology on ear reconstruction procedures. He noted that conventional methods often involve multiple surgeries and intricate craftsmanship, while this new approach could potentially offer a realistic option for individuals requiring surgery to correct outer ear deformities.
Traditional techniques for ear reconstruction typically involve harvesting cartilage from a child’s ribs, a procedure associated with pain and scarring. However, the resulting grafts often lack the natural flexibility of the recipient’s original ear. To address this challenge, researchers explored the use of chondrocytes, cartilage-building cells, in conjunction with a collagen scaffold. Previous attempts using animal-derived chondrocytes led to graft contraction and loss of anatomical details over time.
In this study, the research team employed sterilized animal-derived cartilage, processed to eliminate potential immune rejection triggers, which was integrated into intricate plastic scaffolds resembling the shape of a human ear. These cartilage pieces served as internal reinforcements within the scaffold, akin to rebar in concrete, promoting new tissue formation and preventing contraction. Over several months, the scaffold transformed into cartilage tissue closely mirroring the anatomical features of a natural ear.
Biomechanical assessments, conducted in collaboration with Dr. Larry Bonassar, a professor in Biomedical Engineering at Cornell University, confirmed that the replicas exhibited flexibility and elasticity similar to human ear cartilage, albeit with slightly reduced strength. To enhance the biomechanical properties further, Dr. Spector plans to incorporate chondrocytes derived from a small piece of cartilage from the recipient’s unaffected ear. These cells would contribute elastic proteins essential for robust ear cartilage, resulting in grafts more closely resembling the native ear tissue.
