By Kat Procyk
Credit: Laboratory of Adam Feinberg, Carnegie Mellon University
When Alejandro Soto-Gutiérrez was growing up in Latin America, it was nearly impossible for people with organ failure to get transplants. He lost his uncle nearly 25 years ago to liver cirrhosis, shaping his career.
“Only those who could either pay for the immunosuppressants, which are necessary for transplants to prevent rejection, or the very few who could get the treatment for free were the only groups receiving transplants in Mexico at the time,” said Soto-Gutiérrez, Professor of Experimental Pathology and faculty member of the Thomas E. Starzl Transplantation Institute, University of Pittsburgh, School of Medicine. “I knew from that moment on that I wanted to tackle the organ transplant shortage.”
As of January 2026, Soto-Gutiérrez is part of a Carnegie Mellon University-led team that received up to $28.5 million from the Advanced Research Projects Agency for Health (ARPA-H) for Liver Immunocompetent Volumetric Engineering (LIVE), a project aimed at developing a functional, 3D-bioprinted liver for patients with acute liver failure. LIVE is part of ARPA-H's Personalized Regenerative Immunocompetent Nanotechnology Tissue program to create personalized, functional human organs and tissues on demand through 3D bioprinting.
Today, more than 100,000 men, women and children are on the national transplant waiting list in the United States, with 13 people dying each day waiting for a transplant, according to the Health Resources and Services Administration. In continents with far more limited resources and health care disparities, those numbers are even more dire. In Africa, for example, only 286 transplants were recorded in the region in 2022, a sharp decline from the 643 transplants in 2016.
LIVE will leverage Carnegie Mellon’s Freeform Reversible Embedding of Suspended Hydrogels (FRESH) 3D bioprinting to fabricate biological livers made entirely from human cells and structural proteins such as collagen. The idea is that the liver will be able to be placed in patients for about two to four weeks while their own liver regenerates, meaning those patients won’t need a full transplant. Once the patient has recovered, the bioprinted liver is naturally rejected and reabsorbed by the body.
Soto-Gutiérrez's role in the project is to define and measure the cell functions the bioprinted liver must meet for it to have a clinical benefit. The biggest challenge is overcoming the need for immunosuppressive medications, which can damage a patient’s organs or other systems in the body. The livers will be built using hypoimmune cells—engineered to function as universal donor cells so recipients can receive these tissues without needing immune‑suppressing drugs.
“Imagine eliminating immune suppression for life,” said Soto-Gutiérrez. “No medications, no costs and no fear of chronic rejection. That would fundamentally change transplantation forever.”
Soto-Gutiérrez's lab always had a deep interest in fabricating organs that are “customized, available on demand and not dependent on donors,” but the technology needed wasn’t quite ready.
After following clinical trials using implantable devices throughout other parts of the world, Soto-Gutiérrez's lab began studying how stem-cell-derived liver cells function compared to normal cells. They also questioned how many cells could reliably be produced as well as how many liver cell types could be generated. Eventually, that led Soto-Gutiérrez's lab to be the first to grow genetically engineered livers that could be used to emulate disease and test treatments. Soto-Gutiérrez began collaborating with Adam Feinberg, principal investigator and professor of biomedical engineering, Carnegie Mellon, to leverage his lab’s ability to use machine learning and robotics to construct the size of tissue needed for transplants.
“In the past, 3D printing just couldn’t build tissue large or complex enough for transplantation—the printers couldn’t produce thick, vascularized structures that would actually survive and function,” Soto-Gutiérrez said. “Adam’s new FRESH bioprinting system changed that. It finally allows precise, stable printing at a scale that makes real organ‑level fabrication possible, and that breakthrough is what captured our attention.”
Researchers believe they can extend their bioprinting capability to other organs, including the heart and pancreas, using the liver as a blueprint. In the next decade, Soto-Gutiérrez's ambition is building manufacturing facilities that can produce organs on demand, eliminating waiting lists for organ transplantation.
“This can transform medicine,” Soto-Gutiérrez said. “It sounds like science fiction, but it’s actually happening.”
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This publication was supported by the Advanced Research Projects Agency for Health (ARPA-H) under Award Number D25AC00460-00, providing up to $28,520,065 to Carnegie Mellon University for a 60-month period. The content is solely the responsibility of the authors and does not necessarily represent the official views of the Advanced Research Projects Agency for Health.