title: Shear-mediated platelet adhesion analysis in less than 100 μl of blood: toward a POC platelet diagnostic.
abstract: We report a microfluidic chip-based hydrodynamic focusing approach that minimizes sample volume for the analysis of cell-surface interactions under controlled fluid-shear conditions. Assays of statistically meaningful numbers of translocating platelets interacting with immobilized von Willebrand factor at arterial shear rates (∼1500 s(-1)) are demonstrated. By controlling spatial disposition and relative flow rates of two contacting fluid streams, e.g., sample (blood) and aqueous buffer, on-chip hydrodynamic focusing guides the cell-containing stream across the protein surface as a thin fluid layer, consuming ∼50 μL of undiluted whole blood for a 2-min platelet assay. Control of wall shear stress is independent of sample consumption for a given flow time. The device design implements a mass-manufacturable fabrication approach. Fluorescent labeling of cells enables readout using standard microscopy tools. Customized image-analysis software rapidly quantifies cellular surface coverage and aggregate size distributions as a function of time during blood-flow analyses, facilitating assessment of drug treatment efficacy or diagnosis of disease state.
authors.affiliation: Biomedical Diagnostics Institute, Dublin City, Glasnevin, Dublin 9, Ireland. nigel.kent@dit.ie
authors.forename: Nigel J
authors.initials: NJ
authors.lastname: Kent
authors.forename: Sinead
authors.initials: S
authors.lastname: O'Brien
authors.forename: Lourdes
authors.initials: L
authors.lastname: Basabe-Desmonts
authors.forename: Gerardene R
authors.initials: GR
authors.lastname: Meade
authors.forename: Brian D
authors.initials: BD
authors.lastname: MacCraith
authors.forename: Brian G
authors.initials: BG
authors.lastname: Corcoran
authors.forename: Dermot
authors.initials: D
authors.lastname: Kenny
authors.forename: Antonio J
authors.initials: AJ
authors.lastname: Ricco
mesh_terms: D001792:Blood Platelets / Q000737:chemistry / Q000166:cytology* / Q000378:metabolism; D006801:Humans; D007091:Image Processing, Computer-Assisted; D055767:Immobilized Proteins / Q000737:chemistry / Q000378:metabolism; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D010973:Platelet Adhesiveness / Q000502:physiology*; D010979:Platelet Function Tests / Q000295:instrumentation / Q000379:methods; D019095:Point-of-Care Systems; D033081:Shear Strength; D014841:von Willebrand Factor / Q000737:chemistry / Q000378:metabolism
chemical_list: D055767:Immobilized Proteins; D014841:von Willebrand Factor