Biosensors and Wearables for Health Insights

In a recent Medical Design Briefs podcast, Rob Batchelor, head of biosensors at Australia-based Nutromics, joined us to talk about continuous monitoring and biosensors for health insights. This article presents excerpts from that podcast.

Aptamers, often described as the DNA equivalent of antibodies, are central to the innovative technologies being developed by several startups he has worked with. These companies focus on using aptamers for electrochemical-based sensing within the body, which ultimately led him to Nutromics. Founded seven years ago, Nutromics is now a team of approximately 50 people, operating in Melbourne, Australia, and San Diego, CA.

Nutromics aims to tackle a fundamental challenge in medicine: the lack of timely information about molecular activities within the human body. Many clinical decisions hinge on understanding biomarkers, metabolites, and drug dynamics, yet current methods often rely on outdated technologies, such as blood draws or urine tests, which can be painful, time-consuming, and involve delays of 45 minutes or more. To solve this, Nutromics is developing a revolutionary coin-sized patch, about the size of a U.S. half-dollar, designed to sit on a patient’s arm. Using painless, bloodless microneedles, the patch continuously monitors molecular activity within the interstitial fluid of the skin. This real-time data is wirelessly transmitted to provide critical insights, enabling physicians to make informed, timely decisions — such as adjusting drug dosages or monitoring metabolite levels.

Nutromics conducted clinical trials in collaboration with Monash University in Melbourne to test its prototype device, specifically designed to monitor vancomycin levels. Vancomycin is a powerful antibiotic used to treat life-threatening conditions like sepsis, a severe bacterial infection of the bloodstream. Sepsis requires immediate and effective treatment, and vancomycin plays a critical role in combating the infection. However, the challenge lies in its narrow therapeutic range, says Batchelor. If the drug concentration falls below the required threshold, it fails to treat the infection effectively. Conversely, if the concentration exceeds the safe limit, it can lead to an overdose, causing acute kidney injury (AKI). Often described as a “heart attack for the kidneys,” AKI is a severe condition that can result in long-term kidney damage or even death.

This critical challenge — managing vancomycin’s delicate balance — is precisely the problem Nutromics’ device aims to solve. By providing real-time monitoring of vancomycin levels, the sensor is designed to enable precise dosing, improving patient outcomes and minimizing the risk of severe complications.

MDB: How are aptamer-based biosensors enabling real time diagnostic and therapeutic drug monitoring?

Rob Batchelor: On the backside of our coin-size patch are the microneedles. And so, the microneedles are just barely going into the skin, about half a millimeter into the skin. And then code it on the outside of these microneedles.

The microneedles are also electrodes and on the outside of these microneedles are the aptamers. Those aptamers are sort of the DNA version of antibodies, and just like antibodies, they give specificity. This allows us to get specificity for a particular drug, say, vancomycin, and then the way that this happens is you have one end of the aptamer. An aptamer is a single stranded bit of DNA, so one end of the DNA is attached to the electrode on the microneedle surface. The other end has a redox tag, and this redox tag is a certain distance away from the surface of the electrode so you can interrogate that electrochemically in the absence of the target, say vancomycin, and you get a certain amount of current. Then, in the presence the vancomycin, you get the change and the distance of that redox tag either moves further away — or more likely — it moves closer to the electrode, and you get an increase of current.

This increase in current can be measured using electrochemistry, and we can say we’ve got a certain amount of amps. Now we’ve got more amps for micro amps as it were, and then we can convert that into a drug concentration. So that way we can see the rise and fall of the vancomycin as it goes up and down. And so, the physician changes the drug concentration in the body. This is binding a molecular physical change into an electrical current, which then we can measure and then put on an output to like a wireless device. That’s the real power of this.

MDB: What are the potential applications going forward for these DNA-based sensors?

RB: Therapeutic drug monitoring is the first application. Relatively dangerous antibiotics can really affect the patient’s kidneys or other parts of the body. Clinicians are really excited about being able to measure those in real time, but that’s the just sort of the first cohort. Then other metabolites such as creatinine or lactates, or potentially glucose, would allow you to measure those very interesting, clinical, clinically interesting metabolites in time. That way you can see the rise and fall, and so you’re not just getting a snapshot, say, every five or six hours or however often you take a blood draw or urine sample. You can see these every few minutes.

Instead of a single data point, Nutromics’ patch tracks multiple, crucial targets continuously and in real time, giving clinicians critical, personalized insights. (Credit: Nutromics)

And then you can also start to think about the back of the patch before you get sort of the bed-of-nails effect. You can put dozens of different electrodes on there. With different microneedles, you can start to think about measuring dozens of different biomarkers or drugs over time. Now the first in the first case, we’re interested in just looking every 24 hours, but you can imagine if we can get to the length of time that the continuous glucose monitors have, say, you know two weeks or even three weeks, so then you can see the rise and fall of dozens of analytes going up and down for two or three weeks.

MDB: How is the Nutromics patch different from other existing technologies?

RB: It really is that by having this real-time continuous data, it allows you to find sort of the rise and falls. Current technology is at best maybe every 30 minutes every 60 minutes. The nice thing is that you’re moving away from the chemical reactivity that’s required. Now there are many other technologies that allow you to do sort of the point of care. Lateral flow assays are great technology if you’re looking for a binary answer. But for drugs — in particular — from metabolites, it’s very interesting to see the rise and fall of those over time. Snow you’re talking about nerve cells talking to each other on a subsecond time scale that would be really powerful, and then you can see how those modulate by different drugs or by performance. It allows you to personalize it.

MDB: How are DNA-based or aptamer-based sensors going to transform the diagnostics landscape and the future?

RB: It is really about two things. One, it’s giving people more information, and that’s both the clinicians and then also the patient themselves. And top of that, it’s giving them better information. As opposed to getting a once every few hours or once every day, it’s going to allow you to see what’s going on. A really good case in point that is for people that have organ transplants.

The current state-of-the-art is that they go in, every few months and they get a blood draw to monitor whether they have been taking their immunosuppressants, but who knows what’s going on for those other few months? It’s having better data and then that is going to allow people to make the choices that they want for the lifestyle they want. And it is moving from the reactive medicine to proactive medicine. We’ve already looked at a handful of those particular biomarkers. I’m sure there are dozens if not hundreds, of other biomarkers that would be very interesting to see and that would give us better predictive ability better health performance characteristics.

To listen to the entire podcast, go here . Listen to more MDB podcasts here, or on Spotify or Apple podcasts. To learn more about Nutromics, visit here .