The body already has the machinery to move things where they need to go.
Deep within nearly every human cell, mitochondria govern the pace of aging — and for decades, their double-membrane fortress has kept medicine at bay. Researchers at Johns Hopkins Medicine have now found a way through, not by force, but by borrowing the cell's own language: fusing a common blood pressure drug to natural transport proteins that mitochondria already trust. Published in PNAS Nexus in August 2022, the work suggests that the long-sought goal of targeting age-related cellular decline may be approached not by inventing new tools, but by listening more carefully to what the body already knows how to do.
- Mitochondrial dysfunction quietly underlies some of humanity's most devastating conditions — heart failure, neurodegeneration, metabolic collapse — yet the organelle's double membrane has made it nearly impossible to treat directly.
- Johns Hopkins researchers fused the blood pressure drug losartan to three natural mitochondrial transport proteins, creating molecular Trojan horses the cell willingly escorts past its own defenses.
- Lab imaging confirmed the fused compounds penetrated the inner mitochondrial membrane at far greater concentrations than free losartan alone, while a scrambled control construct failed entirely — validating the mechanism.
- Two patents have been filed, but the experiments remain in lab-grown cells, leaving the critical leap to living organisms and human trials still ahead.
- If the method scales, it could allow physicians to target the biochemical roots of aging itself with precision — fewer side effects, less systemic drug exposure, and therapies aimed at the cellular machinery that time erodes.
For decades, scientists have watched aging unfold at the cellular level with limited power to intervene. Mitochondria — the tiny energy factories inside nearly every cell — are wrapped in a double membrane that keeps most drugs out. When they falter, organs weaken, inflammation spreads, and the body ages. Getting medicine to the inner sanctum where it could actually do something has remained stubbornly difficult.
Now researchers at Johns Hopkins Medicine say they've found a way in. Rather than forcing a drug through the membrane, they borrowed the cell's own delivery system — the natural transport proteins mitochondria use to move oxygen and other chemicals across that protective barrier. By fusing the common blood pressure medication losartan to these proteins, they created compounds the mitochondria would willingly accept. The three resulting molecules — mtLOS1, mtLOS2, and mtLOS3 — penetrated the inner mitochondrial membrane at concentrations far higher than free losartan could achieve, a difference confirmed through fluorescence imaging. A scrambled control construct failed to cross, proving the transport proteins were doing the essential work.
Associate professor Peter Abadir frames the significance plainly: the body already has the machinery to move things where they need to go. If a drug can reach the mitochondrial core, it can target the biochemical imbalances that drive aging itself — chronic inflammation, organ dysfunction, the slow erosion of cellular energy production. For years, researchers have been hamstrung by delivery; a drug that can't reach its target is useless regardless of its potency.
The work is still early — conducted in lab-grown cells, not living organisms — but two patents have been filed and further research is planned. What makes the approach elegant is its restraint: rather than engineering entirely new delivery systems, the team asked what the cell already knows how to do and built on that. The principle is now proven. Whether it holds in living tissue, whole organisms, and ultimately in people remains the next question — but the door to the mitochondria, it turns out, can be opened from the inside.
For decades, scientists have watched aging unfold at the cellular level and felt powerless to intervene. The culprit sits inside nearly every cell: mitochondria, those tiny energy factories that power everything from thought to heartbeat. When they falter, organs weaken, inflammation spreads, and the body ages. The problem has always been the same. Mitochondria are wrapped in a double membrane—a fortress that keeps most drugs out. Getting a therapeutic molecule to the inner sanctum where it could actually do something has remained stubbornly difficult.
Now researchers at Johns Hopkins Medicine say they've found a way in. In a study published in August in PNAS nexus, they describe a method that essentially tricks the cell into delivering medicine where it's needed most. Instead of forcing a drug through the membrane, they borrowed the cell's own delivery system—the natural transport proteins that mitochondria use to move oxygen and other chemicals across that protective barrier. By fusing a common blood pressure medication called losartan to these transport proteins, they created a Trojan horse that the mitochondria would welcome inside.
The team synthesized three different transport proteins and attached losartan to each one, creating compounds they labeled mtLOS1, mtLOS2, and mtLOS3. When they introduced these fused molecules into lab-grown cells, something remarkable happened. The drug penetrated the inner mitochondrial membrane at concentrations far higher than free losartan could achieve on its own—a difference visible under a microscope through fluorescence imaging. To prove the mechanism worked, they also tested a scrambled version of the same construct, which failed to cross the membrane, confirming that the transport protein was doing the heavy lifting.
Peter Abadir, an associate professor of geriatric medicine at Johns Hopkins, frames the significance plainly: the body already has the machinery to move things where they need to go. "We can use the body's natural mitochondrial transport system to deliver drugs much more precisely," he says. The implication is profound. If you can get a drug into the mitochondrial core, you can target the biochemical imbalances that drive aging itself—chronic inflammation, organ dysfunction, the slow erosion of cellular energy production that characterizes growing old.
This is not theoretical. Mitochondrial decline is woven into the biology of aging. It's also central to many diseases: heart failure, neurodegeneration, metabolic disorders. For years, researchers have tried to develop therapies that could reverse or slow this decline, but they've been hamstrung by delivery. A drug that can't reach its target is useless, no matter how potent it is in theory. By hijacking the cell's own transport system, Abadir and his colleagues may have solved that problem—at least in principle.
The work is still early. The experiments were done in lab-grown cells, not in living organisms. The team has filed two patents and plans further research, but they're explicit about the goal: to use this transport method or similar natural pathways to deliver medicines that directly counteract mitochondrial decline while minimizing side effects. The appeal is obvious. If you can target the organelle precisely, you avoid flooding the whole body with a drug, which means fewer unwanted effects, both immediate and long-term.
What makes this work elegant is its simplicity. Rather than engineering new delivery systems from scratch, the researchers asked what the cell already knows how to do and built on that. It's a reminder that sometimes the most powerful innovations come not from inventing something entirely new, but from understanding and repurposing what's already there. The next phase will determine whether this approach works in living tissue, in whole organisms, and ultimately in people. But the principle is now proven: the door to the mitochondria can be opened from the inside.
Notable Quotes
We can use the body's natural mitochondrial transport system to deliver drugs much more precisely.— Peter Abadir, associate professor of geriatric medicine, Johns Hopkins University School of Medicine
Scientists have been trying to get therapies directly into the organelle to counteract mitochondrial decline for decades. This approach uses the body's natural systems, which may greatly reduce negative side effects.— Peter Abadir
The Hearth Conversation Another angle on the story
Why has getting drugs into mitochondria been so hard for so long?
The double membrane is the core problem. It's a barrier that evolved to protect the organelle, but it also keeps out most molecules we'd want to send in. You can't just force a drug through—it doesn't work that way at the cellular level.
So what changed with this approach?
They stopped trying to break through the barrier and instead asked: what does the mitochondria already let through? The answer was transport proteins. The cell uses these all the time to move things across membranes. The researchers essentially attached the drug to one of these proteins, so the mitochondria treated it as cargo it was supposed to accept.
That sounds almost too simple.
It is simple, which is part of why it's elegant. But getting there required understanding the system deeply enough to know which proteins to use and how to fuse them to the drug without breaking either one. The lab work was meticulous.
Why does this matter for aging specifically?
Because mitochondrial decline is one of the core drivers of aging. As you get older, these organelles produce less energy and accumulate damage. That ripples through everything—your organs weaken, inflammation rises, you become frail. If you could deliver a drug directly to the mitochondria to counteract that decline, you'd be addressing aging at its root.
Is this going to work in people?
That's the open question. This was done in cells grown in a dish. The next steps are animal models, then eventually human trials. But the principle is proven. They showed the drug gets where it needs to go at much higher concentrations than it would otherwise.
What's the real significance here—is it just about this one blood pressure drug?
No. Losartan was the proof of concept. The real significance is the method itself. If this transport system works for one drug, it could work for many others. It opens a whole new category of therapies that were previously impossible to deliver.