A simple, minimally invasive patch can make the use of powerful antibiotics such as vancomycin significantly safer and more effective. Researchers at the University of New South Wales (UNSW), together with international partners and the Australian diagnostics company Nutromics, have developed a sensor patch that measures the concentration of the antibiotic in the body every five minutes.
Vancomycin is often used as a last resort in severe, antibiotic-resistant infections or blood poisoning. However, the dosage must be carefully monitored: too low a dose is ineffective, while too high a dose can lead to serious kidney damage or even death. Up to 40 per cent of patients receiving vancomycin develop acute kidney damage. Currently, dosages are monitored through repeated blood samples, a burdensome and time-consuming process that does not always provide sufficient information in a timely manner.
“Lab-on-a-patch”
The new patch offers an alternative. The system uses synthetic DNA-based sensors, known as aptamers, which bind specifically to target molecules such as vancomycin. These sensors are integrated into microneedles that sample body fluids just under the skin. Patients reported that wearing the patch is virtually painless and much more comfortable than repeated blood samples.
‘This is a remarkable breakthrough,’ says Justin Gooding, professor at the UNSW School of Chemistry. ‘We can now measure on the timescale needed to give patients the most effective and safest treatment.’ Continuous measurements enable doctors to adjust dosages more quickly and accurately, which can prevent complications and improve treatment outcomes. The results of a clinical study have been published in Nature Biotechnology.
Broader applicability
An important advantage of aptamer technology is its flexibility. The sensors can be adapted to measure other drugs or disease indicators. Nutromics is already working on applications for sepsis, among other things, a condition that is difficult to recognise but requires rapid intervention.
‘The symptoms of sepsis are very similar to those of other infections,’ says Gooding. ‘If we can measure biomarkers of sepsis in real time, we can treat it more quickly and effectively. That can save lives. In principle, this technology is suitable for virtually any drug or small molecule.’
Towards clinical practice
Although the potential of aptamers had long been known from animal studies, the step towards a practical, producible medical device was complex. The collaboration with Nutromics proved crucial in this regard. ‘Academics come up with and test ideas,’ says Gooding. ‘But to really bring something to market, you need partners who know how to develop a product.’
Nutromics CEO Peter Vranes also emphasises the importance of this collaboration. ‘For a world first, you need both scientific discovery and translation into practice. Together, we can develop solutions that truly improve healthcare.’
Next steps
The patch is currently being tested in intensive care units in Australia. Nutromics hopes to receive approval from US regulators next year. At the same time, the company is working on applications for other areas, such as cardiology and rapid triage in emergency departments.
If the technology is widely adopted, real-time medication monitoring could become a new standard tool in clinical care, with fewer complications, less burden on patients and better-informed treatment decisions.
Computer-controlled dosing
Several years ago, Dr Eveline Wallenburg, who was then a researcher at Radboudumc, developed computer models (in Dutch) that can be used to calculate the correct dosage of antibiotics to be administered for each patient and situation. A major problem is that the standard dosage of antibiotics has been tested in practice on healthy subjects or patients who were not in the ICU. Both too high and too low a dose carries risks.
In order to be able to administer antibiotics in the ICU more precisely, Wallenburg investigated three commonly used types of antibiotics in the ICU. Among other things, she determined the blood levels of these antibiotics in patients during their stay in the ICU and collected data on the age, gender and kidney function of the patients.
