Insulator-based dielectrophoretic diagnostic tool for babesiosis

Abstract

Babesia species are obligate intraerythrocytic tick-borne protozoan parasites that are the etiologic agents of babesiosis, a potentially life-threatening, malaria-like illness in humans and animals. Babesia-infected people have been known to suffer from complications including liver problems, severe hemolytic anemia, and kidney failure. As reported by the Food and Drug Administration, 38% of mortality cases observed in transfusion recipients were associated with transfusion transmitted diseases of which babesiosis is the chief culprit. As of now, no tests have been licensed yet for screening blood donors for babesiosis. Current diagnostic tools for babesiosis including enzyme-linked immunosorbent assay, fluorescence in situ hybridization, and polymerase chain reaction are expensive and burdened with multifarious shortcomings. In this research, a low-cost, high-specificity, quick, and easy-to-use insulator-based dielectrophoretic diagnostic tool is developed for characterizing and concentrating Babesia-infected cells in their homogenous mixture with healthy cell population. In this work, a mixture of Babesia-infected (varying parasitemia) and healthy red blood cells (RBCs or erythrocytes) was exposed to non-uniform electric fields in a fabricated microfluidic platform to manipulate and sort the Babesia-infected cells within a minute. At DC voltage configurations of 10 V and 0/6 V in the inlet and the two outlet channels, respectively, the diseased cells were seen to flow in a direction different from the healthy RBCs. Bright field and fluorescence microscopy were utilized to present qualitative differentiation of the healthy erythrocytes from the infected cells. The proposed micro device platform was able to enrich RBCs from 0.1% to ∼70% parasitemia. This device, when finally developed into a point-of-care diagnostic chip, would enhance the detection of Babesia-infected erythrocytes and as well serve as a precursor to babesiosis vaccine development.

Insulator Based Dielectrophoresis: Micro, Nano, and Molecular Scale Biological Applications

“…For example, Chen et al [ 83 ] and Bhattacharya et al [ 84 ] manipulated Hela and breast cancer (MDA-MB-231) mammalian cells, respectively, using iDEP for cancer diagnostics. More recently, Adekanmbi et al [ 37 ] developed a low-cost, high-specificity, iDEP diagnostic tool detecting, concentrating, and separating healthy red blood cells (RBCs) from those infected with the apicomplexan Babesia , a haemoprotozoan parasite that is tick-borne. In their device, electrodes with embedded insulated saw-tooth geometry was employed to generate nonuniformity in the electric field.…”

“…Since the earliest report of iDEP by Masuda et al [ 36 ], it has been generally applied at the micron scale, but there is a growing body of work being carried out at smaller scales. One such example of such a small scale application is biomarker screening [ 37 ] and cell response to the drug [ 13 ]. Since iDEP can maintain cell viability over extended periods, it is a good candidate to investigate the manipulation of subcellular biology [ 33 ].…”

Dielectric Characterization and Separation Optimization of Infiltrating Ductal Adenocarcinoma via Insulator-Dielectrophoresis

“…The DEP suspending medium (dextrose solution) was prepared and characterized as described in our previous article [38]. The prepared 100 mL suspending medium was divided into five separate beakers.…”

“…As a result, the radius of the constrictions was varied keeping the number (#) of constrictions fixed at 5 at a given time thus resolving the Laplace equation each time using different applied potential without varying the mesh conditions ( Figure 7). The number of constrictions was fixed as an optimization test constraint with respect to the length of the device as well as the exploration of the possibility of initiating cellular separation with minimal insulating constrictions as previously demonstrated by Adekanmbi et al [38].…”

Preface to Special Topic: Selected Papers from the 2015 Annual Meeting of the AES Electrophoresis Society in Salt Lake City, Utah

“…Examples include electrodes manufactured from platinum black threads 1 to carbonized SU8, 2 novel geometries such as the nanoslit, 3 and new applications such as the detection of Babeosis in blood cells. 4 Finally, Mata-Gomez and colleagues 5 report on a DEP-based device for capturing macromolecules. Interestingly, many of these papers use yeast as a model organism-just as in the 1966 paper.…”