Stem-cell organoids injected directly into the blood vessels of a pig’s lung can successfully graft themselves onto the organ's deep tissue.

Lung diseases like emphysema are currently impossible to reverse because the damage happens deep in the air sacs where medicine cannot reach. Most attempts to deliver cells through the windpipe fail because the cells are coughed out or stuck. By using the pulmonary artery as a highway, researchers delivered mini-organs that anchored themselves and started growing new tissue. This method turned the blood system into a delivery service for organ repair. It brings us one step closer to repairing damaged lungs from the inside out without a transplant.