Mass Spectrometric Determination of the Effect of Surface Deactivation on Membranes Used for In-Situ Sampling of Cerebrospinal Fluid (CSF)

In this paper, a strategy for structured monitoring of surface modifications to control protein adsorption to membrane structures is presented. The already established on-surface enzymatic digestion (oSED) method combined with nano-liquid chromatography and tandem mass spectrometry (LC-MS/MS) analysis was employed for the analysis of proteins in ventricular cerebrospinal fluid (vCSF) from neurointensive care patients. Protein adsorption was studied by in-situ sampling in a temporally resolved manner on both immobilized native and Pluronic-deactivated membranes. Deactivation was significantly reducing the protein adsorption but it also induced novel selective properties of the surface. The proposed versatile strategy will facilitate protein-biomaterial, protein-polymer, protein-protein interaction studies in the future.