Nanotechnology has long promised to change medicine by delivering therapies with greater precision. But turning nanoscale science into reliable, scalable products has proved difficult. NurExone Biologic is among the companies hoping to bridge that gap with exosome-based therapeutics: biological nanoparticles designed to carry defined therapeutic cargo to damaged tissues.
The company’s lead candidate, ExoPTEN, uses exosomes loaded with siRNA targeting PTEN, a gene linked to pathways that regulate axonal growth and regeneration. The goal is to support nerve repair in conditions such as acute spinal cord injury and optic nerve damage, where patients currently have few options.
Here, NurExone CEO Lior Shaltiel discusses the promise of exosome therapeutics, the challenges of manufacturing and regulation, and whether the next decade will see nanomedicine reach its potential.
Please introduce NurExone’s approach to nanotechnology therapeutics and the vision behind your exosome platform?
For many years, nanomedicine was defined by efforts to engineer very small delivery vehicles: liposomes, lipid nanoparticles, and other artificial carriers. Earlier in my career, I worked directly on some of these liposomal delivery systems, so I saw both their promise and their limitations up close.
But nature already has its own nanomedicine. Exosomes are nanosized vesicles that cells use to communicate with each other. They can carry biological signals, move through the body, and interact with tissues in ways that are impossible to reproduce artificially.
That is the idea behind NurExone. We use exosomes as a natural therapeutic delivery platform. Our goal is to load naïve exosomes with defined therapeutic cargo and use their biological properties to help reach damaged tissues, particularly in the central nervous system.
One of the most interesting features of exosomes is that they are not just passive drug carriers. I like to think of them as a kind of biological coast guard: small natural messengers that respond to distress signals from damaged tissue and carry therapeutic cargo into difficult environments when needed.
So for me, the vision is simple: instead of trying to convince the body to accept an artificial delivery vehicle, we use a natural nanosized messenger and turn it into a regenerative medicine platform.
Your lead platform, ExoPTEN, targets nerve regeneration. What is the underlying mechanism, and what makes this such a challenging therapeutic area?
The central nervous system is one of the hardest areas in medicine because adult nerve cells in the brain, spinal cord, and optic nerve do not regenerate easily after injury. If you damage skin, it heals. If you break a bone, it can repair. But when the spinal cord or optic nerve is damaged, the body does not naturally regenerate and rewire those connections in a meaningful way.
Part of the problem is that the environment after injury becomes hostile to regeneration. You have inflammation, cell death, scar formation, and inhibitory signals that prevent new axons from growing and reconnecting.
ExoPTEN is designed to address one of the key biological brakes on nerve repair. It uses exosomes loaded with siRNA targeting PTEN, a gene involved in pathways that regulate axonal growth, cell survival, and regeneration. By temporarily reducing PTEN activity, the goal is to support the injured neuron in moving into a more regenerative state.
The way I think about it is as a one-two punch. The exosome provides the natural biological carrier along with their own biological “goodies.” The siRNA payload targets and inhibits PTEN, one of the major internal brakes on regeneration. So we are combining a natural nanosized delivery system with a targeted regenerative signal. Importantly, we are also developing ExoPTEN with minimally invasive administration in mind, because in CNS injury the route of delivery matters. A therapy for nerve damage has to be biologically powerful, but it also has to be practical enough to reach patients in real clinical settings.
In preclinical models, this approach has repeatedly shown encouraging evidence of functional recovery in acute spinal cord injury and optic nerve injury. For me, that is what makes ExoPTEN so exciting. One product candidate has shown activity across more than one high-value market where patients have very few real options today. The biology is powerful, and the real value will come from turning that into a reproducible, scalable, safe product.
Nanotechnology has long promised clinical impact but struggled with translation. Where have previous approaches fallen short?
Nanomedicine has historically produced important products. A classic example is Doxil, the liposomal form of doxorubicin, which was one of the first FDA-approved nanomedicines. It showed that you can take a known drug and change its behavior by packaging it in a nanoscale carrier.
That was a major step for the field and big pharma. But it also taught us that nanomedicine is not automatically simple just because a particle is small. Artificial carriers can solve one problem and create another. They can change distribution, reduce some toxicities, introduce different toxicities, accumulate in certain tissues, or behave differently than expected in living systems.
Exosomes offer a different starting point because they are not synthetic particles designed to imitate biology. They are biological vesicles produced by cells and used by the body for communication.
They also reflect an important lesson from the stem cell field. Years ago, much of the focus was on direct administration of stem cells themselves. Over time, the field began to understand that much of the therapeutic effect may come from what the cells secrete including exosomes. This means we may be able to capture some of the biological signaling potential associated with stem cells without administering living cells.
The beauty of an acellular approach is that it may be easier to develop as an off-the-shelf product, with lower concerns regarding patient rejection and broader applicability across patients – potentially even in urgent-care settings where timing matters.
From your perspective, what are the biggest manufacturing challenges in developing exosome-based therapies at scale?
The biggest challenge is consistency. With exosomes, you are working with a biological system. Small changes in the cells, the culture conditions, the timing, the temperature, the flow, the scaffold, the purification process, or the handling can influence the final product.
To make this type of therapy viable, you need to be able to produce comparable batches again and again. That requires defined starting material, optimized culture conditions, reliable purification, analytical methods, and release criteria that tell you whether the batch is acceptable.
Our Master Cell Bank gives us an excellent starting point. It helps make sure we are not beginning each batch from a different biological source. In addition, our proprietary 3D production technique is intended to create a more natural and controlled production environment than standard 2D methods, with the goal of generating exosomes that are more consistent, potent and biologically active.
You’ve recently reached a key manufacturing milestone. What has that enabled, and how close are you now to first-in-human trials?
The manufacturing milestone matters because it moves the program from promising science toward clinical readiness.
A controlled source of cells and a repeatable production process allow us to build the next parts of the development package: GMP-aligned production, analytical validation, toxicology studies, and regulatory submission work.
For ExoPTEN, the remaining work is focused on closing the key items required for the IND pathway, including GMP manufacturing and toxicology. We already have encouraging preclinical efficacy data, including objective functional readouts in spinal cord injury and optic nerve injury models. Now we need to complete the IND-enabling package and continuing engagement with regulators which we started early in the process.
Regulatory pathways for novel modalities can be complex. What hurdles do exosome-based therapeutics face, and how are you navigating them?
The main regulatory challenge is that exosome therapeutics are still a new modality. Regulators understand biologics, cell therapies, gene therapies, and drug products, but exosomes sit in an area where the field is still learning what the best standards should be.
That creates practical questions. How do you define the product? What attributes matter most for safety and activity? Which potency assays are meaningful? How should biodistribution be studied? What is the right way to evaluate a product that has both a biological carrier and a defined therapeutic cargo?
Our approach is to be proactive rather than wait for the field to become fully standardized. We want to bring regulators a package that is clear, organized, and scientifically justified. That includes explaining the product, the mechanism, the planned clinical use, the safety work, and the assays we believe are relevant.
In a novel modality, you have to help the reviewer understand what the product is, why it is controlled, why the testing strategy makes sense, and why the proposed clinical path is responsible.
I actually think this is healthy for the field. The companies that can explain their products clearly and generate the right data will help define the standards for everyone else.
More broadly, what is driving renewed interest and investment in nanotechnology therapeutics right now?
I think the renewed interest comes from the fact that nanotechnology in medicine is becoming more practical. Today, we have better tools to design, measure, manufacture, and control nanoscale systems, and that makes the field much more investable.
Drug delivery is an important part of this. We understand that the nanoscale format can completely change how a therapeutic behaves: where it goes, how long it lasts, how cells take it up, and whether it can reach tissues that are difficult for conventional drugs to access.
And the broader opportunity is not limited to drug delivery. There is a lot of interest in technologies that connect the human body with hardware and software, including devices, sensors, and neural interfaces. Today, many of those approaches are still driven mainly by electronics and software. Over time, I believe the deeper opportunity will be at the biological interface: technologies that do not just read or stimulate the body from the outside, but interact with biology at the level of cells, tissues, and repair.
That is why I think investors and pharmaceutical companies are looking at nanotechnology differently today. It is about creating a new layer of medicine that can communicate with the body, repair the body, and connect biology with advanced technologies.
Are we starting to see a genuine shift from promising lab science to viable clinical products in this space?
Yes, I think we are, but it is not happening equally across every part of the field.
Some areas of nanotechnology therapeutics have already made the transition. Liposomes and lipid nanoparticles, for example, showed that nanoscale systems can become real medicines, not just laboratory concepts. That changed the way people think about the field. It proved that if you can control the product, manufacture it properly, and show clinical benefit, nanotechnology can reach patients at very large scale.
Exosomes are at an earlier stage, but I believe they are moving in the same direction. The conversation has changed. A few years ago, people were mainly excited by the biology of exosomes. Today, the focus is shifting toward clinical translation: how to produce them consistently, how to define their activity, how to test them, and how to move them through a regulatory pathway.
So yes, I do think there is a genuine shift. The winners will be technologies that can move from scientific excitement to disciplined development. In the end, the field will not be judged by how elegant the particles are. It will be judged by whether they become safe, effective, reproducible products that physicians can use and patients can access.
Finally, what will it take for nanotechnology-based therapies to truly reach patients at scale over the next decade?
I think the answer is discipline. The science is exciting, but science alone does not reach patients. To reach patients at scale, nanotechnology-based therapies will need the same things every serious medicine needs: controlled manufacturing, strong quality systems, clear regulatory pathways, and clinical studies that show meaningful benefit.
For exosomes specifically, this means building the product correctly from the beginning. You need a reliable biological source, a reproducible production process, strong characterization, and potency assays that connect the product to its intended biological effect. Companies will need to show what they are, how they work, how consistently they can be produced, and why regulators and clinicians should trust them.
The other major issue is practicality. A therapy can be scientifically impressive, but if it cannot be manufactured, stored, shipped, priced, and administered in real clinical settings, it will remain a niche product. For conditions like acute spinal cord injury or optic nerve trauma, timing may also matter, so the long-term goal has to be a product that is not only effective, but also accessible and administrable when and where patients need it.
For me, that is the real test for the coming years. The companies that succeed will not be the ones with the most interesting nanoparticles. They will be the ones that can turn complex biology into reliable medicine: something physicians can use, regulators can evaluate, and payers can understand the value. And of course, the goal is to make them useful for patients, especially in areas where conventional medicine has not been able to restore what was lost.
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