Monitoring the Effects Brought By a Drug on Myocardial Cells Using Field Effect Transistor (FET) Based Sensing Platform

Abstract

: Ion channels are the membrane proteins that modulate the active flow of ions between cellular environment. These therapeutic targets are expressed in every active cell and can be used as important targets for cellular changes. The ion channels play an important role in different physiological processes including blood regulation, cell proliferation, nerve relaxation, etc. Various cardiac and neurological diseases have been reported to be related to ion channel regulation. They are brought through by the ion channel mutations. Several techniques are currently deployed for monitoring drug effectiveness of ion channels. Among these techniques, patch clamp technology is considered as a golden standard for monitoring the ion channel function. Unfortunately, the conventional patch clamp technologies are not enough to be employed in the early stages of drug discovery. Similarly, serval fluorescence detection methods and combination technologies have been developed for calcium ion channel detection. These assays are not suitable for large scale detection due to less selectivity and sensitivity.At present, field-effect transistor-based biosensors (BioFETs) have been widely employed in various applications due to their non-invasive detection, and high sensitivity. In this work, we adopted an extended gated EDL-FET platform for rapid drug screening on myocardial cell lines (H9c2). The drug effectiveness was studied by tested nifedipine on myocardial cells which were mounted over an EDL-FET platform. Two different surface conditions were studied using Ca2+ treatment and the capability the of EDL-FET sensor as a drug screening platform was discussed.Surface functionalization and Measurements An extended gate chip was used as the sensor array. Before probe immobilization, the sensor electrode was treated with oxygen plasma. Cell attachment over the sensor platform was facilitated using a glycoprotein- Fibronectin. Traut’s reagent was used to modify fibronectin to initiate the covalent attachment to the sensor surface. Optical images and electrical readings were taken to ensure proper functionalization of the fibronectin-attached surface before the cells were seeded over it. Myocardial cells (H9c2 cells), removed from their culture media, were incubated over the functionalized electrodes for ~2 hours following which, electrical measurements were taken to establish a baseline reading using the BioFET device. Different concentrations of nifedipine [0 to 50 μM] and calcium ions [18 μM to 1.8 mM] were used to make testing solutions, which were used for monitoring various changes occurring on the ion channels of the myocardial cells. Figure 1