Scientists used red blood cells to smuggle healthy mitochondria into Parkinson’s-damaged brain cells
Parkinson’s disease begins in the power plants of cells. Researchers have now found a way to deliver healthy versions of those power plants directly into diseased neurons — packaged inside an unexpected…
Mitochondria are the structures that generate energy inside cells. In Parkinson’s disease, they become damaged or dysfunctional, causing the death of dopamine-producing neurons in the brain. That loss of cells and energy drives the disease’s hallmark symptoms: tremors, rigidity, and progressive difficulty with movement. Existing treatments compensate for the resulting dopamine deficiency — they do not address the underlying mitochondrial damage.
The choice of red blood cells as a delivery vehicle is counterintuitive: red blood cells don’t actually contain mitochondria themselves. But that is precisely what makes them useful. They are biologically inert, not flagged as threats by the immune system, and can be stripped of their contents and repurposed as empty shells. The researchers extracted the cell membranes of red blood cells and used them to encapsulate functional mitochondria, then injected these capsules into disease models.
Improvements across multiple models
The approach was tested in several Parkinson’s models — both cell cultures and living animals. In each case, improvements were observed: the delivered mitochondria reached diseased cells, were taken up, and measurably restored energy production. In animal models, this translated into improvements in motor function — the movement impairments characteristic of Parkinson’s decreased.
Mitochondrial dysfunction is not unique to Parkinson’s. It is implicated in a range of neurodegenerative diseases and in aging more broadly. A reliable method for delivering healthy mitochondria to specific cells could therefore have wide applications, at least in principle.
The blood-brain barrier problem
The method faces a fundamental challenge that has not yet been resolved: how do you ensure the encapsulated mitochondria reach the brain specifically, rather than dispersing throughout the body? The blood-brain barrier — a tightly regulated boundary between the bloodstream and brain tissue — is notoriously difficult to cross for large molecules and structures. The researchers describe the delivery method as promising, but whether it can effectively reach human brain tissue remains unanswered.
The study was also conducted in mouse models of Parkinson’s, which only partially replicate the human disease. Parkinson’s in people is complex, slow-moving, and highly variable between patients. Whether the mitochondrial damage seen in human Parkinson’s is actually reversible if healthy mitochondria are supplied — and at what stage of disease intervention would need to happen — is still unknown.