TitleContinuous microdialysis of blood proteins during cardiopulmonary bypass
NameFok, Alexander (author), Zahn, Jeffrey (chair), Cai, Li (internal member), Shreiber, David (internal member), Rutgers University, Graduate School - New Brunswick,
DescriptionCardiopulmonary bypass is a procedure that temporarily substitutes a patients’ heart and lung functions with an extracorporeal heart-lung machine. This allows surgeons to operate on motionless heart and lungs, while still providing the body with proper blood circulation. However, the heart-lung machine has been shown to activate the body’s systemic inflammatory response, resulting in short- and long- term organ dysfunction, and even death. The severity of this inflammatory response is strongly correlated to the production levels of specific cytokines and complements found in the bloodstream. Current detection methods require taking discrete blood samples during surgery and waiting at least several hours, but typically one to two weeks when including laboratory queue times in hospitals, for results. I propose a microdialysis device that continuously samples the patient’s blood for biomarkers during surgery. The primary function of this device is to prepare a purified solution, with complement concentrations that closely matches that of the patient’s bloodstream, to be used in a continuous microimmunoassay device.
The microdialysis device was fabricated using photolithography and softlithography techniques to create microfluidic channels and bonded to commercially available semi-permeable membranes with biocompatible epoxy. The device was designed based on computational simulations and fabrication constraints for optimal performance. It was tested for its analyte-recovery capabilities for complements C3a, C4a, and C5a, in human blood continually circulating through a mock heart-lung machine.
Two slightly different designs were tested, one using a membrane pore-diameter of 0.1 µm and the other using 0.4 µm. Both devices operated at a perfusion flowrate of 4.1 µL/min, which is considered to be relatively fast for microdialysis probes. For the 0.1 µm pore membrane device, the relative recoveries were 79%, 75%, and 70% for C3a, C4a, and C5a, respectively. For the 0.4 µm pore membrane device, the relative recoveries were 112%, 135%, and 101% for C3a, C4a, and C5a, respectively. These findings show promising results for the proposed microdialysis device, but further investigation is needed to improve statistical significance.
NoteIncludes bibliographical references (p. 89-94)
Noteby Alexander Fok
CollectionGraduate School - New Brunswick Electronic Theses and Dissertations
Organization NameRutgers, The State University of New Jersey
RightsThe author owns the copyright to this work