TOKYO — 
 
 The University of Tokyo and Kyoto University said Friday they have succeeded in creating human ear cartilage from iPS cells. 
 
 The University of Tokyo released photos of a rat with cartilage in the shape of a human ear implanted on its back. The researchers hope they can use the new technology in treating patients born without ears or with small ears, with a clinical study involving humans expected to start in five years. 
 
 The researchers at the two state-run universities cultured human induced pluripotent stem cells into cartilage cells, which were then made into numerous tiny balls. 
 
 They filled a plastic tube with the diameter of about 3 millimeters with the balls. Using three such tubes, the researchers shaped a human ear and implanted it onto the back of a rat. 
 
 In about two months, the tubes dissolved, leaving behind on the animal’s back what looks like a 5-centimeter human ear. 
 
 Induced pluripotent stem cells could grow into various human tissues and they are considered promising in the field of regenerative medicine. 
 
 © KYODO ||||| Bioengineers print ears that look and act like the real thing 
 
 Lindsay France/University Photography 
 
 Lindsay France/University Photography Cornell bioengineers and physicians have created an artificial ear that looks and acts like a natural ear, giving new hope to thousands of children born with a congenital deformity called microtia. In a study published online Feb. 20 in PLOS One, Cornell biomedical engineers and Weill Cornell Medical College physicians described how 3-D printing and injectable gels made of living cells can fashion ears that are practically identical to a human ear. Over a three-month period, these flexible ears grew cartilage to replace the collagen that was used to mold them. "This is such a win-win for both medicine and basic science, demonstrating what we can achieve when we work together," said co-lead author Lawrence Bonassar, associate professor of biomedical engineering. The novel ear may be the solution reconstructive surgeons have long wished for to help children born with ear deformity, said co-lead author Dr. Jason Spector, director of the Laboratory for Bioregenerative Medicine and Surgery and associate professor of plastic surgery at Weill Cornell. "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," Spector said. Replacement ears are usually constructed with materials that have a Styrofoam-like consistency, or sometimes, surgeons build ears from a patient's harvested rib. This option is challenging and painful for children, and the ears rarely look completely natural or perform well, Spector said. To make the ears, Bonassar and colleagues started with a digitized 3-D image of a human subject's ear and converted the image into a digitized "solid" ear using a 3-D printer to assemble a mold. They injected the mold with collagen derived from rat tails, and then added 250 million cartilage cells from the ears of cows. This Cornell-developed, high-density gel is similar to the consistency of Jell-O when the mold is removed. The collagen served as a scaffold upon which cartilage could grow. The process is also fast, Bonassar added: "It takes half a day to design the mold, a day or so to print it, 30 minutes to inject the gel, and we can remove the ear 15 minutes later. We trim the ear and then let it culture for several days in nourishing cell culture media before it is implanted." The incidence of microtia, which is when the external ear is not fully developed, varies from almost 1 to more than 4 per 10,000 births each year. Many children born with microtia have an intact inner ear, but experience hearing loss due to the missing external structure. Bonassar and Spector have been collaborating on bioengineered human replacement parts since 2007. Bonassar has also worked with Weill Cornell neurological surgeon Dr. Roger Härtl on bioengineered disc replacements using some of the same techniques demonstrated in the PLOS One study. The researchers specifically work on replacement human structures that are primarily made of cartilage -- joints, trachea, spine, nose -- because cartilage does not need to be vascularized with a blood supply in order to survive. They are now looking at ways to expand populations of human ear cartilage cells in the laboratory so that these cells can be used in the mold, instead of cow cartilage. "Using human cells, specifically those from the same patient, would reduce any possibility of rejection," Spector said. He added that the best time to implant a bioengineered ear on a child would be when they are about 5 or 6 years old. At that age, ears are 80 percent of their adult size. If all future safety and efficacy tests work out, it might be possible to try the first human implant of a Cornell bioengineered ear in as little as three years, Spector said. ##
– Cool—and/or creepy—news out of Japan, where researchers at the University of Tokyo and Kyoto University have created a human ear ... on the back of a rat. The researchers used stem cells that grew into ear cartilage, shaping the cells into an ear by putting them in "biological tubing," Discovery News reports. More specifically, they used "induced pluripotent stem cells," which the National Institutes of Health explains are "adult cells that have been genetically reprogrammed to an embryonic stem cell-like state." The ear-shaped cartilage was implanted under a rat's skin, where it was allowed to grow for two months; the tubing dissolved and a 2-inch-long ear was left behind. The researchers believe this technology could be used to treat people who are born with no ears or with smaller-than-normal ears, Japan Today reports. It could also be used to repair ears disfigured in accidents, Discovery adds. In the case of a child born with a missing or misshapen ear, the researchers note that the ear they created is "living," and thus would develop and grow along with the child. A clinical trial involving humans is expected to start in five years. In 2013, researchers in Boston used sheep cells, bovine collagen, and an ear-shaped titanium wire frame to grow an ear on the back of another rat, Discovery notes. (These creatures can grow the heads and brains of other species.)