Microfluidics in Haemostasis: A Review.

Haemostatic disorders are both complex and costly in relation to both their treatment and subsequent management. As leading causes of mortality worldwide, there is an ever-increasing drive to improve the diagnosis and prevention of haemostatic disorders. The field of microfluidic and Lab on a Chip (LOC) technologies is rapidly advancing and the important role of miniaturised diagnostics is becoming more evident in the healthcare system, with particular importance in near patient testing (NPT) and point of care (POC) settings.

3D Printing of Metallic Microstructured Mould Using Selective Laser Melting for Injection Moulding of Plastic Microfluidic Devices.

A new method, a 3D printing technique, in particular, selective laser melting (SLM), has been used to fabricate moulds for the injection moulding of thermoplastic microfluidic chips that are suitable for prototyping and early stage scale-up. The micro metallic patterns are printed on to a pre-finished substrate to form a microstructured mould. The dimensional accuracy, surface morphology, bonding strength between the printed patterns and substrate, as well as the microstructure of micro features were all characterized.

Self-Powered Microfluidic Device for Rapid Assay of Antiplatelet Drugs.

We report the development of a microfluidic device for the rapid assay in whole blood of interfacial platelet-protein interactions indicative of the efficacy of antiplatelet drugs, for example, aspirin and Plavix, two of the world's most widely used drugs, in patients with cardiovascular disease (CVD). Because platelet adhesion to surface-confined protein matrices is an interfacial phenomenon modulated by fluid shear rates at the blood/protein interface, and because such binding is a better indicator of platelet function than platelet self-aggregation, we designed, fabricated, and characterized the performance of a family of disposable, self-powered microfluidic chips with well-defined flow and interfacial shear rates suitable for small blood volumes (≤200 μL). This work demonstrates that accurate quantification of cell adhesion to protein matrices, an important interfacial biological phenomenon, can be used as a powerful diagnostic tool in those with CVD, the world's leading cause of death.

Effective hydrodynamic shaping of sample streams in a microfluidic parallel-plate flow-assay device: matching whole blood dynamic viscosity.

We report the development of an aqueous buffer system tailored to the fluidic and hemodynamic requirements of our recently reported microfluidic platelet dynamic assay device, which uses hydrodynamic focusing to "shape" a blood sample into a thin flowing layer adjacent to its protein-functionalized surface. By matching the dynamic viscosity of whole blood (3.13 ± 0.

Shear-mediated platelet adhesion analysis in less than 100 μl of blood: toward a POC platelet diagnostic.

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.

Development of a fluorescent method for detecting the onset of coagulation in human plasma on microstructured lateral flow platforms.

Microfluidic devices and microsystems have been used to develop blood coagulation monitoring devices for point of care diagnostic use. However, many of them suffer from inherent variability and imprecision, partly due to the fact that they only detect changes in bulk clotting properties and do not reflect the microscopic nature of blood coagulation. This work demonstrates microstructured lateral flow platforms used in combination with fluorescently labelled fibrinogen to detect microscopic clot formation.

Microfluidic device to study arterial shear-mediated platelet-surface interactions in whole blood: reduced sample volumes and well-characterised protein surfaces.

We report a novel device to analyze cell-surface interactions under controlled fluid-shear conditions on well-characterised protein surfaces. Its performance is demonstrated by studying platelets interacting with immobilised von Willebrand Factor at arterial vascular shear rates using just 200 μL of whole human blood per assay. The device's parallel-plate flow chamber, with 0.

Integrated system investigating shear-mediated platelet interactions with von Willebrand factor using microliters of whole blood.

We report an integrated platelet translocation analysis system that measures complex dynamic platelet-protein surface interactions in microliter volumes of unmodified anticoagulated whole blood under controlled fluid shear conditions. The integrated system combines customized platelet-tracking image analysis with a custom-designed microfluidic parallel plate flow chamber and defined von Willebrand factor surfaces to assess platelet trajectories. Using a position-based probability function that accounts for image noise and preference for downstream movement, outputs include instantaneous and mean platelet velocities, periods of motion and stasis, and bond dissociation kinetics.