Electric Impedance Spectroscopy for on-chip Analysis of Human Trabecular Meshwork Endothelium

摘要

It is reported the investigation of in vitro cultured human trabecular meshwork (TM) using electric impedance spectroscopy (EIS).TM is a critical determinant of intraocular pressure (IOP),the increase of which is the main cause of glaucoma.An array of interdigitated microelectrodes (IMEs) was fabricated for electric impedance sensing.Equivalent electric circuit model was proposed to study the cellular activities on the IMEs,showing the impedance of extracellular matrix (ECM) and the cell coverage ratio have distinct signatures on the spectrum.The utility of the EIS was demonstrated by treating TM cells during their proliferation with dexamethasone (DEX).The impedance measurement at 40 kHz showed that a higher DEX concentration can induce more severe inhibition of cell proliferation.The measurement was validated by AlamarBlue assay.The measurement provided a reasonable explanation of glucocorticoid induced glaucoma,where the glucocorticoid alters the metabolic and physiological functions of TM cells by inhibiting normal cell growth and proliferation.