Recirculation--a novel approach to quantify interstitial analytes in living tissue by combining a sensor with...

Area of Science:

• Analytical Chemistry
• Biomedical Engineering
• Physiology

Background:

• Quantifying analytes in interstitial fluid (ISF) is crucial for understanding physiological processes and disease states.
• Existing methods for in vivo analyte measurement often face challenges with accuracy, real-time monitoring, and simultaneous detection.
• Direct access to ISF for continuous analysis remains a significant hurdle in biomedical research.

Purpose of the Study:

• To develop and validate a novel approach for quantifying interstitial analytes in living tissue.
• To enable real-time, simultaneous measurement of multiple compounds within the ISF.
• To establish a robust method for in vivo analyte determination with potential applications in various research fields.

Main Methods:

• Combining open-flow microperfusion (OFM) with a sensor and a re-circulation method for direct ISF access.
• Utilizing macroscopic perforations for unrestricted molecular exchange between ISF and a perfusion medium.
• Monitoring analyte concentration changes in re-circulated perfusate using sensors to calculate absolute ISF concentrations.

Main Results:

• Successfully validated the novel concept by quantifying the absolute electrical conductivity of ISF in six subjects.
• Achieved a robust measurement with a coefficient of variation (CV) of 6% (1.33 ± 0.08 S/m).
• Demonstrated the capability for simultaneous monitoring of multiple analytes by employing different sensors.

Conclusions:

• The developed OFM-based approach provides a robust and accurate method for quantifying interstitial analytes in vivo.
• Simultaneous monitoring of multiple compounds opens new avenues for in vivo analytical chemistry and pharmacological studies.
• This technique holds significant promise for advancing clinical experimental research and personalized medicine.