Methodological aspects on microdialysis protein sampling and quantification in biological fluids: an in vitro study...

Area of Science:

• Biomarker Discovery
• Analytical Chemistry
• Neuroscience Research

Background:

• Growing interest in interstitial protein biomarker sampling via high molecular cutoff membrane microdialysis (MD).
• Protein sampling across MD membranes is complex and requires further investigation.
• Challenges include fluid recovery control and protein adsorption.

Purpose of the Study:

• To report three major improvements for microdialysis protein sampling in complex biological matrices.
• Enhance fluid recovery control and precision.
• Reduce protein adsorption and improve quantification.

Main Methods:

• In vitro study using human ventricular cerebrospinal fluid.
• Addition of dextrans to perfusion fluid for fluid recovery optimization.
• Surface modification of MD catheters with self-assembly triblock polymers.
• Quantitative mass spectrometry analysis using isobaric tagged (iTRAQ) proteomics and tandem mass spectrometry.

Main Results:

• Dextrans (250 and 500 kDa) achieved near 100% fluid recovery.
• Surface-modified MD catheters showed improved fluid recovery precision and increased extraction efficiency for some proteins.
• iTRAQ proteomics identified and quantified 48 proteins, enabling analysis of extraction efficiencies.

Conclusions:

• Developed methodology significantly improves microdialysis protein sampling, detection, and quantification.
• Findings provide a foundation for understanding and addressing challenges in protein microdialysis.
• Further optimization and in vivo validation of the developed methodology are warranted.