Differentiated skeletal myotubes coupled with bimodal biosensing for dynamic functional evaluation of inflammatory...

Inflammatory skeletal muscle atrophy is a growing clinical challenge, driven by chronic inflammatory conditions and life-threatening illnesses that cause progressive muscle loss. This condition leads to premature muscle fatigue and a decline in muscle function, highlighting the necessity for highly sensitive diagnostic methods to detect impairment prior to the occurrence of structural damage. Conventional diagnostic methods, including electromyography, serum biomarker assays, and medical imaging, often fail to detect early and subtle alterations in myotube electrophysiological responsiveness because of limited temporal accuracy and insufficient target specificity. Furthermore, these techniques are limited in resolving dynamic electrophysiological fluctuations as well as characterizing the coupling between electrical signaling and intracellular calcium dynamics. Herein, we have developed an integrated bimodal biosensing platform that combines microelectrode array (MEA)-based electrophysiological recording with high-resolution, fluorescence-based calcium imaging. This platform performs coordinated and real-time tracking of extracellular field potentials and intracellular calcium transients across networks of differentiated C2C12 myotubes. Using an in vitro model of LPS-induced inflammatory skeletal muscle atrophy, LPS exposure progressively disrupted spontaneous electrical firing, field potential amplitude, and intracellular calcium transients in a concentration- and time-dependent manner. Diclofenac, a clinically applied anti-inflammatory agent, effectively maintained both electrophysiological function and calcium homeostasis in myotubes under inflammatory stress. Therefore, our bimodal platform functions as a robust, real-time preclinical tool for the detection of incipient inflammatory myopathy. Its integrated capabilities enable the precise quantification of drug responses and the scalable screening of therapeutic candidates, thereby establishing a versatile, translationally-oriented platform for the investigation of skeletal muscle atrophy mechanisms and interventions.