Methodological Aspects on Microdialysis Protein Sampling and Quantification in Biological Fluids: An In Vitro Study on Human Ventricular CSF

Citations Over TimeTop 10% of 2010 papers

Abstract

There is growing interest in sampling of protein biomarkers from the interstitial compartment of the brain and other organs using high molecular cutoff membrane microdialysis (MD) catheters. However, recent data suggest that protein sampling across such MD membranes is a highly complex process that needs to be further studied. Here, we report three major improvements for microdialysis sampling of proteins in complex biological matrixes. The improvements in this in vitro study using human ventricular cerebrospinal fluid as the sample matrix include increased fluid recovery control, decreased protein adsorption on the microdialysis membrane and materials, and novel quantitative mass spectrometry analysis. Dextrans in different concentrations and sizes were added to the perfusion fluid. It was found that dextrans with molecular mass 250 and 500 kDa provided a fluid recovery close to 100%. An improved fluid recovery precision could be obtained by self-assembly triblock polymer surface modification of the MD catheters. The modified catheters also delivered a significantly increased extraction efficiency for some of the investigated proteins. The final improvement was to analyze the dialysates with isobaric tagged (iTRAQ) proteomics, followed by tandem mass spectrometric analysis. By using this technique, 48 proteins could be quantified and analyzed with respect to their extraction efficiencies. The novel aspects of microdialysis protein sampling, detection, and quantification in biological fluids presented in this study should be considered as a first step toward better understanding and handling of the challenges associated with microdialysis sampling of proteins. The next step is to optimize the developed methodology in vivo.

Related Papers

• → In VivoAssessment of Brain Interstitial Fluid with Microdialysis Reveals Plaque-Associated Changes in Amyloid-β Metabolism and Half-Life(2003)410 cited
• → Microdialysis methodology for the measurement of dermal interstitial fluid in humans(1996)82 cited
• → A Modified in vivo Flow Variation Technique of Microdialysis for Sampling Uremic Toxins in the Subcutaneous Interstitial Compartment(2011)11 cited
• → P2‐458: NPT001 reduces Aβ plaque without altering brain interstitial fluid Aβ levels in aged Tg2576 mice(2011)
• → Microdialysis in Metabolic Research(2012)