Should the device prove effective, it could replace invasive point-of-care blood draws for clinical laboratory testing during patient drug therapy monitoring

What if it were possible to perform therapeutic drug monitoring (TDM) without invasive blood draws using breath alone? Patients fighting infections in hospitals certainly would benefit. Traditional TDM can be a painful process for patients, one that also brings risk of bloodline infections. Nevertheless, regular blood draws have been the only reliable method for obtaining viable samples for testing.

One area of critical TDM is in antibiotic therapy, also known as personalized antibiotherapy. However, for antibiotic therapy to be successful it typically requires close monitoring using point-of-care clinical laboratory testing.

Now, a team of engineers and biotechnologists from the University of Freiburg in Germany have developed a biosensor that can use breath samples to measure antibiotic concentrations present in blood, according to a University of Freiburg press release.

The team’s non-invasive collection method requires no needle sticks and can allow for frequent specimen collections to closely monitor the levels of an antibiotic prescribed for a patient. The biosensor also provides physicians the ability to tailor antibiotic regimens specific to individual patients, a core element of precision medicine.

The researchers published their findings in the journal Advanced Materials, titled, “Biosensor-Enabled Multiplexed On-Site Therapeutic Drug Monitoring of Antibiotics.”

Can Dincer, PhD
 
“Until now researchers could only detect traces of antibiotics in the breath,” said Can Dincer, PhD (above), Junior Research Group Leader at the University of Freiburg, and one of the authors of the study, in the press release. “With our synthetic proteins on a microfluid chip, we can determine the smallest concentrations in the breath condensate and [how] they correlate with the blood values.” Should the breath biosensor prove effective in clinical settings, painful blood draws for clinical laboratory testing at the point of care could become obsolete. (Photo copyright: Conny Ehm/University of Freiburg.)

Can a Breath Biosensor Be as Accurate as Clinical Laboratory Testing?

The University of Freiburg’s biosensor is a multiplex, microfluid lab-on-a-chip based on synthetic proteins that react to antibiotics. It allows the simultaneous measurement of several breath samples and test substances to determine the levels of therapeutic antibiotics in the blood stream.

To perform their research, the University of Freiburg team tested their biosensor on blood, plasma, urine, saliva, and breath samples of pigs that had been given antibiotics. The results the researchers achieved with their device using breath samples were as accurate as standard clinical laboratory testing, according to the press release.

The microfluidic chip contains synthetic proteins affixed to a polymer film via dry film photoresist (DFR) technology. These proteins are similar to proteins used by drug-resistant bacteria to sense the presence of antibiotics in their environment. Each biosensor contains an immobilization area and an electrochemical cell which are separated by a hydrophobic stopping barrier. The antibiotic in a breath sample binds to the synthetic proteins which generates a change in an electrical current. 

“You could say we are beating the bacteria at their own game,” said Wilfried Weber, PhD, Professor of Biology at the University of Freiburg and one of the authors of the research paper, in the press release.

Rapid Monitoring at Point-of-Care Using Breath Alone

The biosensor could prove to be a useful tool in keeping antibiotic levels stable in severely ill patients who are dealing with serious infections and facing the risk of sepsis, organ failure, or even death. Frequent monitoring of therapeutic antibiotics also could prevent bacteria from mutating and causing the body to become resistant to the medications.

“Rapid monitoring of antibiotic levels would be a huge advantage in hospital,” said H. Ceren Ates, PhD, scientific researcher at the University of Freiburg and one of the authors of the study in the press release. “It might be possible to fit the method into a conventional face mask.”

Along those lines, the researchers are also working on a project to create wearable paper sensors for the continuous measurement of biomarkers of diseases from exhaled breath. Although still in the development stages, this lightweight, small, inexpensive paper sensor can fit into conventional respiratory masks, according to a University of Freiburg press release.

Other Breath Analysis Devices Under Development

Devices that sample breath to detect biomarkers are not new. Dark Daily has regularly reported on similar developments worldwide.

In “NIST Scientists Enhance Frequency Comb Breathalyzer Enabling It to Detect Multiple Disease Biomarkers,” we reported on research conducted at JILA, a research center jointly operated by the National Institutes of Standards and Technology (NIST) and the University of Colorado Boulder, that could pave the way for real-time, noninvasive breath analysis to detect and monitor diseases, and potentially eliminate the need for many blood-based clinical laboratory tests.

And in “Will Blowing in a Device Be Useful in Screening for COVID-19? FDA Grants Its First EUA for a Breathalyzer SARS-CoV-2 Screening Test,” Dark Daily covered the FDA’s first ever emergency use authorization (EUA) for a portable breath test device designed to screen for SARS-CoV-2 infection. Developed by InspectIR Systems, the COVID-19 Breathalyzer identifies a chemical signature associated with SARS-CoV-2 in about three minutes with 91.2% sensitivity and 99.3% specificity.

Thus, University of Freiburg’s non-invasive lab-on-a-chip biosensor is worth watching. More research is needed to validate the effectiveness of the biosensor before it could be employed in hospital settings, however, monitoring and managing antibiotic levels in the body via breath samples could prove to be an effective, non-invasive method of providing personalized antibiotic therapy to patients.

Clinical trials on human breath samples are being planned by the University of Freiburg team. This type of precision medicine service may give medical professionals the ability to maintain proper medication levels within an optimal therapeutic window.

JP Schlingman

Related Information:

Antibiotic Levels Measurable in Breath for the First Time

Biosensor-Enabled Multiplexed On-Site Therapeutic Drug Monitoring of Antibiotics

A Breath of Fresh Information

NIST Scientists Enhance Frequency Comb Breathalyzer Enabling It to Detect Multiple Disease Biomarkers

Will Blowing in a Device Be Useful in Screening for COVID-19? FDA Grants Its First EUA for a Breathalyzer SARS-CoV-2 Screening Test

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