Background

Drug-induced cardiotoxicity is a primary cause of late-stage drug attrition because conventional 2D models lack physiological relevance. The study aimed to generate a 3D co-culture system that closely mimics the in vivo cardiac microenvironment to improve the functional performance and predictive capacity of toxicity assessments.

Key Challenges

• 2D Immaturity: Cardiomyocytes in 2D systems often exhibit relative immaturity and altered electrophysiological behavior.
• Structural Limitations: Standard models lack the extracellular matrix organization and electro-mechanical integration provided by cardiac fibroblasts.

Our Approach

• Co-Culture Integration: Researchers combined iPSC-derived cardiomyocytes (YBLiCardio) with human cardiac fibroblasts.
• 3D Architecture: Cells were organized into 3D spheroids and cardiac rings.
• Functional Analysis: The SMARTX 2.0 software used machine learning to track parameters such as contraction amplitude, strain, speed, and stress.

Results

• Structural Expression: Immunocytochemistry confirmed the expression of cardiac and fibroblast markers within the 3D structures.
• Functional Activity: Calcium flux assays using Fluo-4 AM demonstrated active calcium influx and efflux during contraction and relaxation phases.
• Predictive Power: High-risk CiPA compounds showed dose-dependent Torsades de Pointes (TdP) effects in the model.

Impact

• Enhanced Prediction: Preliminary observations indicate that integrating the 4D system with specialized software enhances the predictive potential of in vitro cardiac models.
• Improved Maturation: The 3D culture environment promotes enhanced cellular maturation and more physiologically relevant contractile properties compared to 2D models.
• Drug Discovery: The findings support the continued use of this platform for drug discovery, safety assessment, and disease modeling.