We present a microfluidic device for separating platelet-rich plasma (PRP) from whole blood, addressing key limitations in current sedimentation-based technologies. Unlike existing methods that rely on a single sedimentation trench-limiting plasma yield and processing speed-our device incorporates a novel multi-trench design, allowing the processing of 1 mL of whole blood in 40 minutes, yielding ∼250 μL of PRP with at least a 2-fold increase in platelet concentration. The device is fabricated using a CO2 laser cutter on acrylic layers and bonded with a pressure-sensitive adhesives, offering a cost-effective and simple alternative to more complex manufacturing processes. To ensure reliable PRP separation and minimize bubble formation, we applied a hydrophilic coating at the trench bottoms. We analyzed three trench geometries to optimize PRP yield and quality. Flow simulations optimized shear rates to improve sedimentation. Our approach effectively removes red and white blood cells with purities of 98% and 96%, respectively, only 8.2% of the total platelets were activated post-processing, compared to 31% with conventional centrifugation. This combination of a novel multi-trench layout, simplicity, cost-efficiency, and effective platelet preservation enables a low-cost device for obtaining high-quality PRP for clinical research and therapy.

Introduction: Alzheimer's disease (AD) and aging are associated with platelet hyperactivity. However, the mechanisms underlying abnormal platelet function in AD and aging are yet poorly understood. Methods: To explore the molecular profile of AD and aged platelets, we investigated platelet activation (i.e., CD62P expression), proteome and transcriptome in AD patients, non-demented elderly, and young individuals as controls. Results: AD, aged and young individuals showed similar levels of platelet activation based on CD62P expression. However, AD and aged individuals had a proteomic signature suggestive of increased platelet activation compared with young controls. Transcriptomic profiling suggested the dysregulation of proteolytic machinery involved in regulating platelet function, particularly the ubiquitin-proteasome system in AD and autophagy in aging. The functional implication of these transcriptomic alterations remains unclear and requires further investigation. Discussion: Our data strengthen the evidence of enhanced platelet activation in aging and provide a first glimpse of the platelet transcriptomic changes occurring in AD.
Copyright © 2023 de Sousa, Poupardin, Villeda, Schroer, Fröhlich, Frey, Staffen, Mrowetz, Altendorfer, Unger, Iglseder, Paulweber, Trinka, Cadamuro, Drerup, Schallmoser, Aigner and Kniewallner.

h4>Summary/h4> The classical hematopoietic hierarchy, which is mainly built with fluorescence-activated cell sorting (FACS) technology, proves to be inaccurate in recent studies. Single cell RNA-seq (scRNA-seq) analysis provides a solution to overcome the limit of FACS-based cell type definition system for the dissection of complex cellular hierarchy. However, large-scale scRNA-seq is constrained by the throughput and cost of traditional methods. Here, we developed Microwell-seq, a high-throughput and low-cost scRNA-seq platform using extremely simple devices. Using Microwell-seq, we constructed a single-cell resolution transcriptome atlas of human hematopoietic differentiation hierarchy by profiling more than 50,000 single cells throughout adult human hematopoietic system. We found that adult human hematopoietic stem and progenitor cell (HSPC) compartment is dominated by progenitors primed with lineage specific regulators. Our analysis revealed differentiation pathways for each cell types, through which HSPCs directly progress to lineage biased progenitors before differentiation. We propose a revised adult human hematopoietic hierarchy independent of oligopotent progenitors. Our study also demonstrates the broad applicability of Microwell-seq technology.