New Advances in Bioprinting Promise More Natural Breast Reconstruction

“Our Bodies, Ourselves.” The title of the popular book rings true because as human beings, our physical form helps define who we are. For a breast cancer patient who undergoes a mastectomy, the loss is not only physical but powerfully psychological—and it cuts even deeper in a culture in which breasts are intimately connected to self-esteem.

Reconstructive surgery after breast removal has come a long way since it was first tried in 1895. While today’s implants mimic nature quite well in some ways, it’s the nipple, or nipple-areola complex (NAC), that has stumped surgeons. 

Now a team of University of Maryland researchers led by Professor John Fisher, director of the Tissue Engineering and Biomaterials Lab in the Fischell Department of Bioengineering, is applying modern bioprinting techniques to this tissue-engineering challenge; it's 3D-printing NACs that can be tailored to each patient and promise to perfectly match the real thing.

Nearly 300,000 women are diagnosed with invasive breast cancer each year in the United States, and about a third of them lose one or both breasts when they opt for mastectomy as treatment or prevention of recurrence. While most surgeons today try to spare nipples for later reattachment, sometimes the NAC can’t be saved. 

“The standard options have been to build a skin flap over the area, to tattoo it, or, in many cases, to do nothing at all,” said Fisher. When one of his former Ph.D. students, Sarah Van Belleghem Ph.D. ’20, pitched bioprinting as a possible solution, “we realized we could do something better for these patients,” he said. 

Fisher had an additional personal incentive to consider the NAC problem: His wife underwent a double mastectomy in 2024 after a breast cancer diagnosis. He and his students were attracted not just to the tissue engineering feat but to how their work could ultimately affect patients’ emotional well-being. 

“After cancer—already a traumatic experience—it’s really important to the psychological health of women to have a natural looking result,” said postdoc Sahar Vakili Ph.D. ’25, who joined Fisher’s lab early this year. “That our NACs are customizable makes them a bigger engineering challenge, but it lets us give patients back something aesthetically important that hasn’t been a priority before now.”

Fisher enlisted surgical collaborators, including University of Maryland School of Medicine researchers, “for input on our ideas from the real world,” and the team then designed its NACs using a computer-aided design program, sending the blueprints to an extrusion-based printer to bring the parts to life. 

Each NAC is 3D-printed from a combination of structural materials that remain in the patient after implantation, along with living cell populations transferred to the body via collagen—a protein that degrades over time as host tissue grows and replaces it. Matching one engineered NAC to its counterpart isn’t difficult, by “flipping” the design for side II. Pigmentation is also easy to adjust and match, the researchers said.

What makes natural NAC tissue complex is that it is tied into the nervous system (“innervated”) and suffused with blood vessels (“vascularized”). The newly designed implants can’t quite match their natural counterparts in those aspects yet, but the scientists are now creating a population of smooth muscle cells with an innervated component that should let the tissue contract in response to stimuli, as natural tissue does. It may even be possible down the line, Fisher said, to print nipples that can function well enough for breast feeding.

In the future, the team’s bioprinting process could be applied to build other complex body parts that share with NACs a well-defined architecture and the need for personalization. “Noses and ears come to mind,” Fisher said. Having recently completed their pilot study showing proof of concept, the engineers are now focused on improving the NAC’s functionality. They’re also partnering with a company in Baltimore to produce the implants and beginning the long process of getting Food and Drug Administration approval for their product. 

With success within reach, Vakili recalls the thrill of seeing tissue growth 14 days after first implanting one of the team’s NACs in a mouse. “There was kind of a ‘wow’ feeling to know it was working, that the vascularization was actually happening,” she said. But the biggest boost for her has been something subtler and more personal. “Working on NACs has let us get closer to patients and have a real impact on their lives when they need it most,” she said.