From Nanoparticles to Neurotech: Tetiana Aleksandrova on Subsense

When people think about brain–computer interfaces (BCIs), they often picture invasive ‘brain chips’ and surgical implants. Subsense is taking a different route: A bi-directional BCI concept designed to deliver high accuracy without surgery, using nanoparticles delivered intranasally and a head-worn device that can read and write neural signals.

In this conversation, Tetiana Aleksandrova, Co-founder & CEO of Subsense, shares why she moved beyond non-invasive BCIs, how plasmonic and magnetoelectric nanoparticles work in simple terms, what her team is proving in preclinical work, and why she believes BCIs will become one of the biggest technological revolutions of our time.

Interview by Chay Carter, founder of Carter Sciences.

Tetiana Aleksandrova, Co-founder and CEO of Subsense.

What inspired you to found Subsense?

The short answer is I was lucky enough to start my first BCI company (Neiry) about seven years ago. Subsense is my second BCI company. The first one was completely non-invasive, and I was also lucky to meet a co-founder who, like me, wanted to build something truly revolutionary — the kind of project that could change the world in a real way. We started that company together and it’s still very successful today.

But over time, I realised something important: If we’re talking about a real ‘sci-fi’ BCI — the kind you imagine in Black Mirror or 3 Body Problem — then a completely non-invasive BCI isn’t what will take us there.

When I moved to the US, I knew I wanted to keep building BCIs, but this time with everything I’d learned from the first company. I wanted to build something with accuracy closer to classic invasive systems, like Neuralink or Blackrock — but without surgery. The long-term plan has always included healthy individuals too, and surgery is a huge limitation for that. Healthy people would probably prefer not to do surgery. I definitely don’t want to.

So the question became: How do you get invasive-level accuracy, but non-surgically? For us, the answer was nanoparticles.

At the beginning, we spent a lot of time proving to ourselves we weren’t breaking any laws of physics. We spoke to an enormous number of labs around the world — professors and experts in nanoparticles, chemistry, neurology, physics — everything. And we realised: Hypothetically, it’s possible. Then the question became: What kind of nanoparticles should we use?

We realised we could build a bi-directional BCI using two types of nanoparticles: plasmonic nanoparticles and magnetoelectric nanoparticles. That’s what we’re building now.

And if I zoom out for a second, I think this is connected to who I’ve always been. I remember being ten years old and when people asked me what I wanted to be when I grew up, I’d say, “I don’t want to choose”. I wanted to live ten parallel lives — be a chemist, an astronaut, a president. I even had this strange wish that I could be frozen and woken up hundreds of years later, just to see how technology evolves. It’s probably a weird thing for a ten-year-old girl to say — but I’ve always been a dreamer in the best sense.

I genuinely believe the future isn’t something we enter. It’s something we create — and we’re creating it here.

“ How do you get invasive-level accuracy, but non-surgically? For us, the answer was nanoparticles. ”

What’s been the biggest challenge with a non-surgical nanoparticle approach so far?

We’re not the only ones exploring this in the world. There are academic labs building similar concepts — but I believe we’re doing it in a more advanced way.

There was research recently, for example, showing magnetoelectric nanoparticles could stay in mice for 18 months and the mice were safe — and they could treat Parkinson’s symptoms. That’s an amazing result because it shows that even nanoparticles that are less advanced than ours can be safe and can treat symptoms.

Our focus is to make the nanoparticles much more advanced in terms of biocompatibility and suitability for the human body.

Explain it like I’m five: How does the nanoparticle BCI work?

It’s a two-component system. The first component is the nanoparticles themselves. They get to your brain through your nose (intranasally). So you inhale them, and the nanoparticles end up inside the brain, essentially distributed across it.

The second component is a device you wear on your head — think something like headphones, but with a different form factor. The key point is that the device is what activates and controls the nanoparticles. If you take the headset off, nothing happens. The nanoparticles don’t ‘do’ anything on their own. That’s very important.

And because it’s bidirectional, the system can both read signals from the brain and send signals back.

For reading signals, we use the plasmonic nanoparticles. Imagine the device on your head is sending near-infrared light through the scalp into the brain — that’s not something we invented, it’s a known technology. The plasmonic nanoparticles scatter that near-infrared light back to the device. But when there’s neuronal activity around the nanoparticles, the frequency of the scattered light changes. That’s how we detect that there’s signal — we’re reading changes driven by neural activity around the particles.

For sending signals to the brain, we use the magnetoelectric nanoparticles. Because they work in a completely different way, they don’t interfere with the plasmonic ones. The device sends magnetic fields into the nanoparticles. Because of the piezoelectric effect, the nanoparticles change shape and generate a small electrical effect — and that electrical activity influences the neurons around them.

What stage of development are you at right now?

We’ve already tested the biocompatibility of our nanoparticles with cells and worms. We’ve started tests with mice.

This year, we want to show in mice how we can read the signal from the brain, send the signal back, and treat symptoms of one neurodegenerative disease — we’re choosing which one now. We also want to start trials with pigs.

The Subsense Bioplatform is composed of nanoparticles and a head-worn device.

You launched your lab recently. What are the short, medium, and long-term plans?

We’ve structured our research in a way where we started very early with strong university collaborators, and we still work with them today. We work with UCSC on plasmonic nanoparticles, and we work with ETH Zurich on magnetoelectric nanoparticles — they’re basically the best in the world for that kind of nanoparticles.

The idea is: Our collaborators help us develop what we call the basic science; the fundamental science. Then we bring that research into our own lab and enhance the nanoparticles in-house. That’s where we focus on things like biocompatibility, toxicology, histology, and all of that. And over time, as we keep progressing, we’ll bring more and more of the research fully in-house.

We launched our lab a few months ago, and it already feels like years ago — I can’t imagine how we lived without it. It’s full of equipment and people and activity. But the funniest part is: We’ve recently expanded our lab capabilities, because the original one was already not enough for us.

Given the complexity of brain signals, how do you think about decoding cognitive functions?

You know, it’s very interesting — the product pipeline, because I think what’s happening right now is two parallel things, and it’s not just in our company, it’s in basically all BCI companies in the world.

From one perspective, the technology is evolving — BCI technology itself, and the way we interact with the brain. From the other perspective, there’s this other scientific area where we’re learning more and more about how the brain works itself… because we still don’t understand the brain completely, right? And the more advanced our tools become, the faster we learn.

So yes, we have a product roadmap, actually for the next 15 years — but it’s still very preliminary, because it will depend on how quickly our understanding of the brain evolves. If we want to enhance cognitive abilities, or affect the brain in a meaningful way, first we need to understand how it works and we need to decode the signals.

And this is where nanoparticles make things much more efficient.

With classic invasive BCIs, you have electrodes attached to a certain area of the brain, so you’re limited to that area. You can decode that part very well with advanced software, but covering the whole brain with electrodes is basically impossible.

With nanoparticles, it becomes much easier. Nanoparticles can cover the whole brain, and we can move them from one area to another. We already have navigation concepts depending on the area and the depth of nanoparticles inside the brain — and based on that, you can build different applications.

So for us, it’s not the main issue to apply nanoparticles to a certain area. Like every BCI company, we’re more dependent on understanding how the brain works. But as soon as we can decode certain signals, we can build the models that will enhance that part of the brain.

“ If we want to affect the brain in a meaningful way, first we need to understand how it works. ”

Which clinical indications are you prioritising first and why?

We haven’t finalised the decision yet, but we’re very close.

When a BCI company is considering applications, especially if you need to go to the FDA, you also have to think about how people are treating the problem today, and where your technology can bring meaningful additional value.

For us, neurodegenerative disease is one of those places. The current methods either don’t work as well as you want them to work, or they’re incredibly invasive and require surgery — like deep brain stimulation, for example. It’s a terrible and very risky surgery. And when you compare DBS surgery to just inhaling nanoparticles through your nose… it’s two completely different stories.

And many patients who need treatment aren’t eligible for DBS because of the risks. If you can replace that approach, it could expand eligibility significantly.

Right now, we’re focusing on neurodegenerative diseases like Parkinson’s or epilepsy, because we can bring a lot of value there, and it connects to our future product roadmap too.

What do you expect the regulatory pathway to look like?

I think it’s different for every BCI company.

Right now, most of what I call ‘real BCI’ — the invasive, semi-invasive, more traditional interfaces — are going for Breakthrough Device Designation and aiming for a Class III device pathway. But it really depends on the application.

For us, we started FDA communications in December 2025. And that’s exactly why we hired an extremely experienced VP of regulatory and clinical trials — someone who’s been through this process many times.

When I hired for this role, I spoke to 20+ senior regulatory leaders and heard the same thing: The FDA used to feel like they were trying to prove you wrong — now it’s increasingly collaborative, with teams that actually work with you.

So that’s my hope. And honestly… ask me in a couple of years, and I’ll tell you how it went.

Beyond clinical use, what excites you most about cognitive enhancement?

This is honestly my favourite part — it’s one of the main reasons I’m doing this.

I see Subsense as a platform for a huge number of applications, and cognitive enhancement is one of the most exciting. My favourite example is external memory. I forget things all the time, so imagine having a direct link from your brain to an external cloud, where experiences are recorded and stored. Every conversation, every negotiation, everything you’ve seen. And when you need something back, you just send a signal and it returns exactly as it was — not what you think you remember.

That changes learning too: languages, new skills, speed of recall. And more broadly, it’s the idea that you can start ‘hacking’ your brain — your brain doesn’t control you; you control your brain and can build tools that support the life you actually want.

“ You have to think about how people are treating a [clinical] problem today, and where your technology can bring meaningful additional value. ”

Finally, where do you see the future of neurotechnology heading?

I believe brain–computer interfaces will be the next big revolution — and I think it happens in our lifetime. Maybe not in five years, but in ten to fifteen years, easily.

Think about how many people couldn’t imagine life with the internet, and now it’s impossible to go without. Or how quickly tools like large language models became part of daily work. Each revolution increases the stakes.

Right now, AI also creates uncertainty, because every generation of smarter AI can widen the gap between humans and machines. But if we unite the brain and technology, each generation of smarter AI makes us smarter too — and that gap doesn’t really exist anymore.

And I’m not even talking about what that does to interfaces. We won’t always need phones or computers as these external tools. If the connection is in the brain, and we can communicate and access the digital world directly, the whole ‘peripheral layer’ changes. I think it becomes a huge revolution — probably the biggest one we’ve ever had.

Also published on Medium via NeuroTechX

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Specialisms include: Neurotechnology, Neuromodulation/Stimulation, Brain-Computer Interfaces, Wearable Devices, Neurosurgical Technology, and Private Equity/Venture Capital.

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