Researchers at the Massachusetts Institute of Technology have developed a novel approach to support liver function using injectable “mini-livers” that integrate with the body’s blood supply and perform key tasks normally carried out by natural liver cells. This technique aims to address the significant challenges associated with traditional liver transplants, including organ shortages, the complexity of surgery, and the inability of some patients to withstand the operation.

The experimental treatment, tested so far only in mice, involves creating small tissue grafts composed of human liver cells (hepatocytes) combined with hydrogel microspheres and fibroblasts—cells that aid tissue structuring. The hydrogel acts as a scaffold, allowing the transplanted cells to remain cohesive and connect to the bloodstream after being injected. Using ultrasound to guide the placement, the team injected this mixture into the abdominal fat of immune-suppressed mice. The grafts remained viable and continued producing essential liver proteins and enzymes for the eight-week duration of the study, as reported in the journal Cell Biomaterials.

This research, led by MIT professor Sangeeta Bhatia, represents a potential shift in regenerative medicine, enabling liver support through minimally invasive procedures rather than major surgery. The authors suggest that such injectable patches could be administered as a temporary measure for patients awaiting a full transplant, potentially with repeated booster injections to maintain liver functions like blood clotting, detoxification, and drug metabolism.

Despite the promising results, experts caution that the technology is still in early stages. Patricia Lalor, professor of experimental hepatology at the University of Birmingham, noted the importance of developing new treatment options for those on transplant waiting lists but emphasized that the current mini-livers only replaced a fraction of normal liver volume in mice. She pointed out the complexity of replicating the full range of cell types found in an intact liver and raised issues including the sourcing of cells without relying on donated organs and the risks of immune rejection. Future directions could involve generating hepatocytes from patients’ own stem cells to mitigate rejection concerns.

The MIT team has not given a timeline for clinical trials in humans and indicated further research is needed to determine the maximum feasible size for a single injectable graft and its longevity.

While this approach offers an innovative alternative to transplantation, the procedure pioneered in the mid-20th century remains a transformative medical achievement. In her 2024 book, “The Story of A Heart,” physician and author Rachel Clarke highlights transplantation as a profound act of altruism, underscoring the human compassion at its core, as donor families provide life-saving hope to others during moments of profound loss.