CBET-0644538 A. Minerick, Mississippi State University
Currently, the medical diagnosis of blood disorders rely on expensive and time consuming procedures that are outsourced to special analytical laboratories. Emerging electrokinetic microdevice technology has the potential to replace off-line lab analysis with point-of-care devices that could provide the patient with positive or negative results, along with quantitative information on disease progression, in less than 5 minutes. One way to diagnose disease is to use a tool such as dielectrophoresis (DEP) to distinguish and quantify abnormal versus normal blood cells. Dielectrophoretic characterization of blood cells has been performed by a handful of researchers, yet no work has been done to ascertain dependencies on blood type and other inherent physiological properties. The purpose of this project is to investigate the dielectrophoretic response of blood cells over the radio frequency range (kHz to MHz) to correct this deficiency. The research aspect of this CAREER program aims to 1) experimentally quantify the response of all eight blood types (A+, B+, AB+, O+, A-, B-, AB-, and O-), 2) definitively determine through antigen modification, the role of ABO antigens in dielectrophoretic polarization, 3) map out blood type membrane instabilities and rupturing for subsequent subcellular analysis, and 4) modify shell models with antigen charges to further understand the mechanics of cell polarizability. Educational activities are interwoven with research activities through the development and dissemination of Desktop Experiment Modules (DEMos) directed to a range of educational levels. Specifically, the DEMo approach will be used to 1) appeal to a variety of learning styles, 2) enrich courses including transport and process controls, 3) develop an advanced elective course in Analytical Microdevice Technology, and 4) develop and implement outreach activities to engage students of traditionally underrepresented minority groups in Science, Technology, Engineering and Math.
Intellectual Merit: The development of baseline data for all blood types would be of intellectual interest to academic, medical, and industrial communities. The eight blood types differ by the expression of a combination of two antigens and two antibodies. Preliminary results by the PI show differences in DEP responses between blood types. In addition, red blood cells are an ideal system with which to further understand how inclusion of molecules can alter effective polarizability and thus dielectrophoretic force on a cell. This work will also develop baseline data from which abnormal cells can be dielectrophoretically distinguished in future blood diagnostic devices. Lastly, DEMos building on these principles will aid in the intellectual development of students from high school to graduate school.
Broader Impacts: If successful, the proposed research would enable eventual determination of an infected / healthy cell ratio with a single drop of blood in under five minutes, representing a revolution in medical diagnostic practice. Outgrowths of the new technology might include portable diagnostic devices for acute diseases or monitoring of chronic diseases, both of which could be conveniently used in remote geographical areas, where traditional diagnostic laboratories are inaccessible. Students from underrepresented minority groups will continue to be recruited with particular attention given to personalized mentoring and retention. Successful research and educational techniques will be broadly disseminated to the academic, medical and industrial communities.
This research demonstrated that ABO-Rh blood types (A+, B+, AB+, O+, A-, B-, AB-, and O-) could be distinguished in a microdevice without antibodies using electric fields. This was accomplished by 1) experimentally quantifying the response of all eight blood types, 2) comparing that response to the response of the same cells without ABO antigens (accomplished with a selective enzyme), 3) examining blood type membrane rupturing which could allow subsequent subcellular protein analysis, and 4) modifying mathematical models to further understand the mechanics of cell polarizability. Two microdevice designs were explored during this project; one batch system and one continuous flow system that was able to test and quantify more cells more rapidly. Statistical analysis revealed some blood types could be distinguished at 99.99% confidence from other blood types. The intellectual merits and implications of this work are that electric fields have the potential to distinguish molecular expression on and through cell membranes. This tool could be used to rapidly discern diseased cells from healthy cells within minutes at a patient's bedside. This project advanced scientific knowledge of the interactions of electric fields with biological cells. Further, this work has revealed a commercially viable alternative to antigen/antibody molecular recognition reactions for medical diagnosis. The broader impacts of this work are evident from the 84 million blood typings per year in the U.S., 16 million donations, and current protocols require 4 or more tests to minimize fatal transfusions. Current technology cost ~$95 per test, while our approach could cost less than $10 per test. This technology has the potential to reduce the cost of health care and enable more cost efficient blood typing checks of the blood supply.
