22 Feb 2013, BioSpectrum Bureau , BioSpectrum
Singapore: Physicians at Weill Cornell Medical College, US, and biomedical engineers at Cornell University, US, have succeeded in building a facsimile of a living human ear that looks and acts like a natural ear. Researchers believe that their bioengineering method will finally succeed in the long quest by scientists and physicians to provide normal looking "new" ears to thousands of children born with a congenital ear deformity.
In their PLOS ONE study, the researchers demonstrate how 3D printing and new injectable gels made of living cells can be used to fashion ears that are identical to a human ear. Over a three-month period these flexible ears steadily grew cartilage to replace the collagen that was used to help mold them.
They injected animal-derived collagen into that ear mold, and then added nearly 250 million cartilage cells. The collagen served as a scaffold upon which cartilage could grow. This high-density collagen gel, which Cornell researchers developed, resembles the consistency of flexible Jell-O when the mold is removed. Previous bioengineered ears have not been able to maintain their shape or dimensions over time, and the cells within them did not survive.
Dr Jason Spector, director, Laboratory for Bioregenerative Medicine and Surgery (LBMS); associate professor of plastic surgery in the Department of Surgery at Weill Cornell Medical College; and an adjunct associate professor in the Department of Biomedical Engineering at Cornell University, said that, "I believe this will be the novel solution reconstructive surgeons have long wished for to help children born with absence or severe deformity of the ear."
"A bioengineered ear replacement like this would also help individuals who have lost part or all of their external ear in an accident or from cancer. This surgical option is very challenging and painful for children, and the ears rarely look totally natural or perform well. All other attempts to 'grow' ears in the lab, including one 1997 study widely publicized by photos of ears implanted on the backs of mice, have failed in the long term," he added.
The deformity that both Dr. Spector and Dr. Bonassar seek to remedy is
microtia, a congenital deformity in which the external ear is not fully
developed. Although the causes for this disorder are not entirely
understood, research has found that microtia can occur in children whose
mothers took an acne medication during pregnancy. Typically, only a single
ear is affected.
Other co-authors of the study are Dr Alyssa J Reiffel, Dr Karina A
Hernandez, and Dr Justin L Perez from the Laboratory for Bioregenerative
Medicine and Surgery at Weill Cornell Medical College; and Mr Concepcion Kafka, Ms Samantha Popa, Ms Sherry Zhou, Ms Satadru Pramanik, Dr Bryan N. Brown and Won Seuk Ryu, from the Department of Biomedical Engineering at Cornell University.