- While hemodialysis is a unique therapy for treating chronic kidney failure, the application of extracorporeal blood processing presents the opportunity for treating a wider range of bloodborne diseases. The objective of the i-Blood research team is to develop a blood processing device that utilizes microscale-based technology as a platform for incorporating novel bioconjugation mechanisms to remove/degrade undesired solutes in the blood or administer drugs. The development of treatment mechanisms for hyperuricemia (high concentrations of uric acid in the blood) and iron overload (high concentrations of iron in the blood) have been the focus for other individuals on the research team. During preliminary development of the device, one concern that came up was the potential for mechanically induced hemolysis due to the foreign flow conditions imposed by the geometry of the device. While red blood cells (RBCs) are especially adept at modifying their shape to endure high pressures in arteries and small orifices in capillaries, the concern remains that the flow through the foreign materials of the device could inflict enough shear stress to break the cell membrane of RBCs. In order to provide a therapeutic benefit, it is essential that the team can identify flow conditions that minimize risks to the patient (i.e. minimized blood damage and coagulation) while simultaneously maintaining the intended functionality of the device for a given disease.
The primary objective of this project was to characterize the degree of blood damage in a novel microchannel-based blood processing device by quantifying the hemolytic effects of various flow parameters. A nuanced methodology of measuring the plasma-free hemoglobin concentrations via a hemoglobin detection assay and absorbance spectroscopy was developed. The effects of fluid velocity and number of passes through the device were investigated using a syringe pump apparatus. Experimental results indicated that velocity had an insignificant effect on the hemolytic effects of the device for a single pass while increasing the number of passes at a constant flow rate caused an increase in hemolysis. No specific plate geometry recommendations can be made based on the current results, though recommended next steps and identified concerns for future investigation are discussed in detail. Ultimately, the research project was successful at developing a reliable methodology for quantifying blood damage which can be used throughout the design process.