Microneedle biosensor ‘detects patient’s antibiotic levels in real time’

Small, non-invasive patches worn on the skin can detect the levels of medication in a patient’s system, scientists say.

Press Association
Last updated: 30 September 2019 - 11.40pm

Scientists have used skin sensors to accurately detect antibiotic levels in patients.

They say the method, which uses microneedle biosensors, has the potential to help the sickest of patients by identifying how they are responding to their treatment.

Researchers at Imperial College London say they have shown for the first time how the sensors can be used to monitor the changing concentration of antibiotics.

The small, non-invasive patches worn on the skin can detect the levels of medication in a patient’s system, matching the accuracy of current clinical methods.

Dr Timothy Rawson, from Imperial’s department of infectious disease led the research, and said: “Microneedle biosensors hold a great potential for monitoring and treating the sickest of patients.

“When patients in hospital are treated for severe bacterial infections the only way we have of seeing whether antibiotics we give them are working is to wait and see how they respond, and to take frequent blood samples to analyse levels of the drugs in their system – but this can take time.

“Our biosensors could help to change that.

“By using a simple patch on the skin of the arm, or potentially at the site of infection, it could tell us how much of a drug is being used by the body and provide us with vital medical information, in real time.”

The findings of a small-scale clinical evaluation, published in The Lancet Digital Health journal, suggest the sensors enable real-time monitoring of changes in antibiotic concentration in the body, with similar results to those obtained from blood tests.

Scientists believe the technology could change how patients with serious infections are treated by showing how quickly their bodies ‘use up’ medications they are given.

They add that if future development and testing proves successful and the technology reaches the clinic, it could help to cut costs for the NHS and reduce drug-resistant infections.

It could also improve treatment for patients with life-threatening infections and improve the management of less serious ones.

The biosensors also have the potential to reduce the need for blood sampling and analysis.

Microneedle biosensors use a series of microscopic ‘teeth’ to penetrate the skin and detect changes in the fluid between cells.

The teeth can be coated with enzymes which react with a drug of choice, altering the local pH of the surrounding tissue if the drug is present.

While the technology has been used for continuous monitoring of blood sugar, the Imperial group says it has shown, for the first time, its potential for use in monitoring changes to drug concentrations.

In a small proof-of-concept trial, they trialled the sensors in 10 healthy people who were given penicillin.

The 1.5cm sq patches were placed on their forearms and connected to monitors, with frequent measurements taken from 30 minutes before receiving oral penicillin, to four hours afterwards.

Blood samples were taken at the same time points for comparison.

Data from nine patients indicated the sensors could accurately detect the changing concentration of penicillin in patients’ bodies.

While penicillin concentrations varied from patient to patient, the overall readings from the biosensors were similar to those from blood samples – showing a marked decrease in drug concentration over time.

Professor Tony Cass, from the department of chemistry said: “This small, early-stage trial has shown that the sensor technology is as effective as gold standard clinical analysis in detecting changes to the concentrations of penicillin in the human body.

“When further developed, this technology could prove critical for the monitoring and treatment of patients with severe infections.

“More widely it could be used to monitor many other drugs and personalise treatment in many diseases.”

However, the researchers acknowledge their study was limited by the small sample size, and was only tested on a single antibiotic, in healthy patients.

They say that along with further testing in larger patient groups to strengthen the initial findings, they will look to see how the sensors could help to optimise the dosing of penicillin and similar antibiotics.

The technology was developed through research supported by funding from the National Institute for Health Research (NIHR) and Fondation Merieux.

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