Microfluidic Dielectric Spectroscopy of Costal Cartilage Chondrocytes

Abstract

Dielectric spectroscopy allows non-invasive probing of biological cells. Information on the cell membrane, cytoplasm, and nucleus can be obtained by dielectric spectroscopy provided that appropriate experimental and numerical tools are used in specific frequency ranges. The focus of this study is to identify bioelectrical characteristics of human costal cartilage cells using a microfluidic device for dielectric spectroscopy. An in house computer program is developed to extract dielectric properties of biological cells from raw cell suspension impedance data. The algorithm utilizes Maxwell-Wagner mixture and double shell models to extract single cell dielectric spectrum and cellular dielectric parameters, respectively. The dielectric parameters of human costal chondrocytes are compared with melanoma, leukemia, and electrically excitable cardiomyoblast cells in order to comparatively assess the electrical nature of chondrocytes. The results suggest that electrical cell membrane characteristics of chondrocyte cells are closer to cardiomyoblast cells than melanoma or leukemia cells. In addition, blocking effects of Gadolinium is tested on chondrocyte, myoblast, and melanoma cells. The significant decreases in cell membrane conductance and capacitance values after treatment with Gadolinium are linked with ion channels activity on chondrocyte cell membranes.