MIT scientists have developed injectable "mini livers" that could one day help patients with failing livers without the need for full organ transplants. In a recent study on mice, these mini livers remained functional for at least two months, continuing to produce essential enzymes and proteins typically made by the liver. The research was led by Sangeeta Bhatia, a professor at MIT, and Vardhman Kumar, a postdoctoral researcher. The injectable material consists of liver cells, hydrogel microspheres, and supportive fibroblast cells. The hydrogel microspheres act as a scaffold, helping the liver cells stay together and connect with nearby blood vessels. Fibroblast cells, which are a type of connective tissue cell, help the liver cells survive and support the growth of new blood vessels. The injectable material can be delivered through a syringe and solidifies once inside the body, forming a stable structure. The researchers used ultrasound imaging to monitor the implants and ensure their stability over time. In the study, the mini livers were implanted into the fatty tissue of mice’s abdomens. The grafts successfully integrated with the surrounding tissue, and blood vessels formed around them, providing the necessary nutrients for the liver cells to function. This technology could potentially be used in humans by implanting the mini livers near the spleen or kidneys, areas with rich blood supplies. The researchers suggest that this injectable approach could serve as an alternative to traditional surgery or as a temporary solution while waiting for a liver transplant. The study was supported by several funding organizations, including the National Institutes of Health and the National Science Foundation. This research marks a significant step toward developing less invasive treatments for liver disease, offering hope for patients who may not have access to timely transplants.