Fall 2005- Research Rotation I
Under the guidance of Drs. Danny Bluestein and Jolyon Jesty, we are trying to determine the shear stress levels at which platelets are activated in order to determine the pathological shear conditions at which thrombus formation is initiated. This relates to conditions where internal blood trauma and not external injury is responsible for setting off the blood coagulation cascade. There are three parts to the study (in vivo, in vitro, and numerical modeling) of which I am responsible for the in vitro study. We utilize a flow loop in a Left Ventricular Assist Device (LVAD) mounted with mechanical heart valves (MHV), connected to a pulsatile pump, as well as a hemodynamic shearing device (HSD) with Couette flow to generate varying types of physiological flow conditions, ranging from laminar flow to pulsatile flow. The program for the HSD allows us to input waveforms that mimic human physiological flow. A Platelet Activation State Assay (PAS), developed by Drs. Bluestein and Jesty, allow us to measure the level of platelet activation by using acetylated prothrombin to generate acetylated thrombin which is blocked from aggregation.
Currently, the project is in its initial stages, where it is my responsibility to prepare the human abdominal aortic endothelial cell (HAAEC) culture for testing with the HSD. We are attempting to pre-treat our endothelial cells with varying levels of shear over various periods of time to orient them in a manner that will allow uniform interaction with platelets. My current responsibilities include:
-Redesigning our cone-and-plate model for optimizing shear distribution
-Optimizing our culturing technique to achieve better and faster cell growth