Mitochondria (artist’s impression) wrapped in red-blood-cell membranes can sneak into cells without being tagged for destruction.Credit: Alfred Pasieka/SPL A well-fitted ‘disguise’ allows transplanted mitochondria to slip into cells whose own mitochondria are defective, scientists reported 18 March in Cell1. Administration of these cloaked mitochondria prolonged the life of mice with a deadly disease caused by abnormal mitochondria. The scientists found that a mitochondrion wrapped in the membrane of a red blood cell can enter a cell without triggering protective mechanisms that would typically destroy the organelle. The technique “hugely” increased the efficiency of the treatment compared with previous methods, says Mike Devine, a neurobiologist at the Francis Crick Institute in London, who was not involved in the study. The difference is like “night and day”, he says. But scientists also expressed scepticism about some aspects of the study.…