In situ monitoring of mitochondrial redox dynamics during cardiac reprogramming using a poly-l-lysine/Matrigel-coated gold nanostructured composite platform

Cardiac regeneration via the direct reprogramming of fibroblasts into chemically induced cardiomyocyte-like cells (CiCMs) offers a potential therapeutic avenue for heart failure. Nonetheless, the absence of non-invasive techniques for evaluating CiCM maturation and functionality while maintaining therapeutic viability poses a considerable challenge. We present poly-l-lysine, and Matrigel double layer–coated gold nanostructured (PMGN) composite platform coupled with an electrochemical (EC) method that effectively monitors mitochondrial redox dynamics in CiCMs. Based on the metabolic transition from glycolysis to oxidative phosphorylation (OXPHOS), this EC method provides precise measurement of fibroblast-to-CiCM conversion in a completely non-destructive manner. Moreover, the PMGN composite platform facilitates the early detection of functional alterations induced by drugs, such as isoproterenol and carbachol, which conventional cell viability assays fail to detect, and exhibits exceptional sensitivity in identifying drug-induced cardiotoxicity. This in situ method offers real-time feedback and rapid quality control during cell preparation, significantly enhancing the safety and efficacy of stem-cell-based therapies for cardiac regeneration.