In what appears to be a world first, a patient’s own cells were expanded and used to 3D print tissue—an ear—that was then implanted under the patient’s skin, The New York Times reports. The milestone, also announced today in a press release by 3DBio Therapeutics, the company that developed the technology, has not yet been reported in a peer-reviewed journal. But experts say it is a step toward one day producing more complex tissues, and potentially even organs, for transplantation using similar techniques. 

“It’s definitely a big deal,” Adam Feinberg, a biomedical engineer at Carnegie Mellon University who is not affiliated with 3DBio, tells the Times. “It shows this technology is not an ‘if’ anymore, but a ‘when.’” Feinberg cofounded FluidForm, another company working toward 3D printing replacement tissues.  

See “On the Road to 3-D Printed Organs” 

According to 3DBio’s announcement, the implantation was part of a clinical trial of the technology that includes 11 patients with microtia, a condition in which the outer part of the ear doesn’t develop normally. According to the Times, the company did not provide details on the procedure, but it involved harvesting a small sample of the patient’s cartilage cells, which were then expanded and incorporated with other ingredients to make a bio-ink containing collagen. A 3D printer shaped that ink into a structure matching the patient’s normal ear, and the printed ear was then implanted by Arturo Bonilla of the Microtia-Congenital Ear Deformity Institute in San Antonio, who regularly performs reconstructive surgeries on patients with microtia.

“This is so exciting, sometimes I have to temper myself a little bit,” Bonilla, who is not affiliated with 3DBio, tells the Times. “If everything goes as planned, this will revolutionize the way this is done.” Currently, reconstructive surgery for microtia is commonly performed with a piece of a patient’s rib that has been shaped into an ear—a far more invasive procedure—or synthetic materials. Reconstructions of this type don’t affect hearing but can aid patients’ self-esteem and head off bullying, Bonilla tells CBS News.

Speaking to the Times, Feinberg cautions that there’s still a long way to go before organs could be 3D printed. For now, the microtia clinical trial is still ongoing.