P78: Detection of Platelet-Derived Microparticles via Dynamic Light Scattering

Abstract

Purpose: Implantable cardiac devices, while effective therapeutically, often generate supraphysiologic shear forces which activate platelets and generate platelet-derived microparticles (PDMPs), all increasing overall thrombotic risk. While a variety of methods exist to measure platelet activation, limited methods exist for ready detection and quantitation of PDMPS. Identifying a core methodology that is useful for translation and development of a portable PDMP assay system will aid in the management of implanted patients reducing both thrombotic and bleeding risks. Here we examine laser light scattering as a method of microparticle detection. Methods: Spherical polystyrene latex microparticles (100-1000 nm in diameter) were suspended in saline and exposed to 520 nm laser light. An avalanche photodiode was used as a light/scatter detector. Signals were processed as to frequency and amplitude. Intensity signals were processed using an autocorrelation function to create calibration curves that vary with particle size. Calibration curves were used to size and quantify the microparticles within the sample, with particle size and concentration displayed on a GUI. The entire system is housed in a dark enclosure to ensure a reliable environment for optical analysis. Results: This system configuration successfully detected particle-induced light scattering. A change in light intensity over time was measured between samples of differing microparticle sizes and concentrations. An autocorrelation function is useful to create different calibration curves that are unique to size and concentration. Conclusion: Laser light scattering is effective as a method for microparticle detection. Our initial system demonstration reveals that both concentration and particle size may be measured via comparison to reference calibration curves. Further advancement and translation of this approach is targeted to yield a portable instrument for clinical utility.