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Platelet Adhesion and Aggregation Under Flow using Microfluidic Flow Cells
Published on: October 27, 2009
The Role of Platelet-Derived Microparticles in Platelet Adhesion and Aggregation to Immobilized Extracellular Matrix
Tatiana Mencarini1, Yana Roka-Moiia2, Eleonora Puce1
1Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milano, MI Italy.
Introduction:
Platelet adhesion and aggregation on exposed vascular extracellular matrix (ECM) is critical for haemostasis, with dysregulation and inappropriate thrombus formation associated with cardiovascular disease. While collagen is recognised as vital in these processes, the role of other ECM proteins is less understood. Platelet-derived microparticles (PDMPs), small vesicles released by activated platelets, similarly influence haemostasis, though their modulatory effect on ECM substrates is also unclear. We investigated platelet adhesion and aggregation on various ECM proteins-collagen, fibrinogen, fibronectin, and laminin-and examined the modulatory role of PDMPs under physiologic and pathologic flow conditions.
Methods:
Whole blood, alone or enriched with PDMPs, was perfused through microfluidic channels coated with ECM substrates at varying shear rates. Fluorescence imaging assessed platelet behaviour measuring surface coverage, number of thrombi, mean thrombus area and thrombus height.
Results:
Collagen exhibited greatest overall thrombus formation, versus the other ECM substrates, with platelet adhesion and aggregation increasing at higher shear rates. Addition of PDMPs significantly reduced thrombus area (p < 0.01) and height (p < 0.05-0.01) at all shear rates. Fibrinogen supported stable but smaller thrombi, with PDMP addition resulting in increased platelet adhesion (23% increase) at low shear. Both fibronectin and laminin demonstrated weak platelet adhesion, with thrombus formation decreasing as shear rate increased, and PDMP addition slightly increasing platelet adhesion, though without influence on thrombus dimensions.
Conclusion:
Collagen exerts a dominant effect in platelet adhesion and aggregation across a wide range of shear, compared to fibrinogen, fibronectin and laminin. PDMPs alter platelet adhesion and resultant thrombus formation across all ECM proteins tested, likely through competitive occupation of platelet binding sites. Our findings underscore the complex interactions between ECM proteins, PDMPs, and shear forces under flow conditions.
Supplementary Information:
The online version contains supplementary material available at 10.1007/s12195-026-00920-2.
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