Magnetoimpedance Sensor-Based In Vitro Real-Time Magnetic Recording System for Drug Screening Application

Historically, in vitro cardiac function assays for drug screening have predominantly utilized electrophysiological techniques, employing electrodes and fluorescence microscopy. However, the patch-clamp technique entails potential cellular trauma and relies heavily on the operator’s proficiency. Microelectrode arrays (MEAs) necessitate specialized culture dishes owing to their sensitivity to cell adhesion on electrodes. In fluorescent imaging application, the loading of fluorescent dyes into cells may elicit stress, inflict damage, and disrupt cellular homeostasis. Compared to electrophysiological assays, magnetic measurements, which are advantageous for yielding vector data and being unaffected by the tissue microenvironment, remain unutilized in high-throughput drug screening in vitro owing to challenges in detecting faint magnetic signals. Therefore, we developed an in vitro noninvasive real-time magnetic recording system based on magneto-impedance (MI) sensors by providing correlated double sampling (CDS) and avoidance from singularity points of sensor noises, in MI sensor as simple, small, and highly sensitive drug screening tool. Our proposed system demonstrates high field detection sensitivity, maintaining excellent linearity and a noise level of approximately 2 pT/Hz1/2 at room temperature. This innovative MI sensor system effectively distinguishes the beat rate alterations of induced pluripotent stem cell-derived cardiomyocytes treated with positive and negative chronotropic drugs from the steady state, correlating with the MEA recordings and fluorescence imaging using standard culture dishes. The presented data suggest that our system has the potential to replace conventional methods, enabling the acquisition of diverse biometric data across cellular, tissue, and organ levels for drug screening and diagnostics.