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Paust, N.

Publications and source records attributed to Paust, N..

2 recordsLinked to original sources
bioRxiv2025

MR-SP2: A Microreactor for Upward Pressure-Catapulting Laser Microdissection for Mass Spectrometry-Based Spatial Proteomics at Single-Cell Resolution

Laser capture microdissection (LCM) combined with liquid chromatography-tandem mass-spectrometry (LC-MS/MS) enables spatially resolved proteomics at few-cell scale, yet losses from minute LCM-cut specimens, particularly with upward pressure-catapulting systems and subsequent processing, limit depth and reproducibility. We present MR-SP{superscript 2} (Microreactor-based Sample Preparation for Spatial Proteomics), a one-pot-in-solution workflow that integrates reproducible LCM-cut specimen capture, processing with minimized adsorptive losses, and pipetting-free transfer with Evotip disposable precolumns. The workflow is demonstrated on a formalin-fixed paraffin-embedded (FFPE) murine kidney using upward pressure-catapulting LCM for targeted isolation of defined tissue specimens. Across 50,000 {micro}m3 regions (22 cells), MR-SP{superscript 2} modestly improved proteome coverage (3,381 {+/-} 80 versus 3,174 {+/-} 59 proteins). Decreasing sample input further accentuated the advantage of MR-SP{superscript 2} in maintaining higher identification rates, highlighting the successful reduction of adsorptive losses of the MR-SP{superscript 2} workflow. At 12,500 {micro}m3 (5-6 cells), identifications increased to 1,145 {+/-} 188 versus 302 {+/-} 126. At 3,125 {micro}m3 (1-2 cells), identifications reached 695 {+/-} 112 versus 206 {+/-} 51. MR-SP{superscript 2} improves identification depth for few-cell FFPE samples nearly threefold and provides an LCM-compatible preparation that expands the robustness, applicability of upward pressure-catapulting LCM within the spatial proteomics toolkit.

cancer biology↗
bioRxiv2025

VDisk: Microfluidic Cartridge for Multimodal High-Yield, High-Purity Isolation of Extracellular Vesicles from up to 1 mL of Plasma

Blood-derived extracellular vesicles (EVs) hold strong diagnostic potential, yet conventional isolation methods such as ultracentrifugation and size-exclusion chromatography (SEC) involve manual handling steps and show substantial run-to-run variability, hindering clinical translation. This study presents the Vesicle Disk (VDisk), a centrifugal microfluidics-based EV purification platform that combines cation-exchange chromatography, sequential filtration, and multimodal chromatography for automated, label-free EV isolation from up to 1 mL of plasma. VDisk configurations differing in filter membrane and plasma volume (0.1-1.0 mL) are benchmarked against SEC for yield, purity, reproducibility and robustness. VDisk matches SEC in EV yield and exceeds it in EV/contaminant ratios at reduced input volumes, while achieving greater reproducibility (intra-donor CV < 5% for CD9 and CD81, versus up to 16% for SEC) and maintaining consistent yield and contaminant removal under both fasting and postprandial sampling conditions. The platform is application-tunable: processing up to 1 mL of plasma maximizes EV yield and concentration, whereas processing 0.5 mL achieves approximately 2-3-fold higher EV/total protein ratios than SEC. These findings establish the VDisk as an automated, robust and adaptable alternative to existing EV isolation methods for both research and clinical translation.

bioengineering↗