A Scalable Approach Reveals Functional Responses of iPSC Cardiomyocyte 3D Spheroids

Area of Science:

• Biomedical Engineering
• Cardiovascular Research
• Stem Cell Biology

Background:

• Induced pluripotent stem cells (iPSCs) generate cardiomyocytes (CMs) for in vitro human myocardium models.
• 3D scaffolded cultures enhance iPSC-CM maturity but reduce throughput.
• Scalable, high-throughput methods for mature iPSC-CMs are needed for drug discovery.

Purpose of the Study:

• To develop a novel, scalable, label-free 96-well plate system for 3D iPSC-CM spheroid models.
• To enable simultaneous measurement of contractility and extracellular field potentials (EFPs) from iPSC-CM spheroids.
• To investigate factors influencing iPSC-CM spheroid function and pharmacological responses.

Main Methods:

• Developed a magnetic nanoparticle approach for precise spheroid positioning on electrodes.
• Utilized a 96-well plate format for label-free impedance and EFP measurements.
• Investigated effects of co-culture, buffer composition, and electrical pacing on spheroid function.

Main Results:

• Successfully detected contractility (impedance) and EFPs from beating iPSC-CM spheroids.
• Co-culture with fibroblasts increased beat amplitudes over 15-fold.
• Optimized conditions promoted physiological responses to inotropic agonists, enhancing force over rate.

Conclusions:

• Demonstrated a novel, scalable, label-free 96-well plate system for 3D iPSC-CM spheroid analysis.
• This method allows for label-free assessment of pharmacological responses in iPSC-CM spheroids.
• The system has potential applications in cardiovascular drug efficacy and safety screening, improving assay predictivity.