Non-invasive maturity assessment of iPSC-CMs based on optical maturity characteristics using interpretable AI.

Human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) are an important resource for identifying novel therapeutic targets and cardioprotective drugs. However, a key limitation of iPSC-CMs is their immature, fetal-like phenotype. Cultivation of iPSC-CMs in lipid-supplemented maturation media (MM) enhances the structural, metabolic and electrophysiological properties of iPSC-CMs. Nevertheless, they face substantial limitations as there are labor-intensive, time consuming and go in line with cell damage or loss of the sample. To address this issue, we have developed a non-invasive approach for automated classification of iPSC-CM maturity through interpretable artificial intelligence (AI)-based analysis of beat characteristics derived from video-based motion analysis. In a prospective study, we evaluated 230 video recordings of early-state, immature iPSC-CMs on day 21 after differentiation (d21) and more mature iPSC-CMs cultured in MM (d42, MM). For each recording, 10 features were extracted using Maia motion analysis software and entered into a support vector machine (SVM). The hyperparameters of the SVM were optimized in a grid search on 80 % of the data using 5-fold cross-validation. The optimized model achieved an accuracy of 99.5 ± 1.1 % on a hold-out test set. Shapley Additive Explanations (SHAP) identified displacement, relaxation-rise time and beating duration as the most relevant features for assessing iPSC-CM maturity. Our results suggest the use of non-invasive, optical motion analysis combined with AI-based methods as a tool to assess iPSC-CMs maturity and could be applied before performing functional readouts or drug testing. This may potentially reduce the variability and improve the reproducibility of experimental studies.