Advances in Engineered Cardiac Tissues Aid Disease Modeling and Drug Testing

Researchers have developed new methods for creating and studying advanced three-dimensional (3D) heart tissue models, known as cardiac organoids and heart-on-a-chip (HOC) platforms. These innovations aim to address limitations in traditional research models for cardiovascular disease, the leading cause of death globally, by offering more accurate and human-relevant systems for understanding cardiac development, disease mechanisms, and drug responses.

These innovations offer more accurate and human-relevant systems for understanding cardiac development, disease mechanisms, and drug responses.

Background on Cardiac Research Limitations

Heart disease continues to be a major global health concern. Existing experimental models, such as animal models, often do not fully replicate human-specific cardiac biology. Meanwhile, conventional two-dimensional (2D) cell cultures lack the structural and functional complexity of native heart tissue. These limitations have hindered progress in both understanding and treating cardiac disorders.

Magnetic Torque Stimulation Enhances Cardiac Organoids

A team of researchers led by Professor Yongdoo Park from Korea University, Republic of Korea, investigated the application of magnetic torque stimulation (MTS) to 3D cardiac organoids. This approach aimed to mimic the mechanical forces present during early heart development, which are often absent in conventional organoid systems. The absence of these forces can lead to developmental immaturity and poor vascularization.

The researchers differentiated human embryonic stem cells into 3D cardiac organoids that incorporated surface-bound magnetic particles. A custom magnetic torque was applied during an early developmental phase. Analyses, including gene and protein expression profiling, immunofluorescence imaging, and functional measurements, indicated that MTS significantly enhanced cardiac organoid maturation.

According to Professor Park, the stimulation activated mechanotransduction pathways, leading to improvements in cardiac differentiation, maturation, and vascularization.

This study was published in Acta Biomaterialia in December 2025.

Dual-Sensing Heart-on-a-Chip Platform Developed

Separately, scientists from multiple Canadian institutions developed a 3D "heart-on-a-chip" (HOC) platform designed to advance cardiovascular disease research. This engineered heart tissue exhibits autonomous beating, calcium mobilization, and predictable responses to certain drugs. A key feature of this HOC is its dual-sensing platform, which enables real-time activity tracking from the tissue level down to individual cells.

To construct these HOCs, researchers harvested cardiac muscle and connective tissue cells from rats. These cells were embedded in a protein-rich gel matrix and seeded onto flexible silicon-based chips.

Two types of sensors were integrated into the HOC platform:

• Macro-scale sensors: Elastic pillars positioned on either side of the engineered heart tissues deform with each heartbeat, providing data on the overall contractile strength.
• Micro-scale sensors: Flexible, hydrogel-based microsensors, approximately 50 micrometers in size, were immersed within the tissue to capture local mechanical stresses at the cellular level.

This cellular-level sensing is considered relevant because many cardiovascular diseases are associated with dysfunction in cardiomyocytes, the contractile cells of the heart. The research was published in the journal Nano Micro Small.

Applications and Future Directions

Both advancements offer significant potential applications in various areas of cardiovascular research and medicine:

• Drug Screening and Safety Testing: The MTS-enhanced cardiac organoids provide a platform for cardiotoxicity screening and drug safety testing. The HOCs demonstrated their capability for drug screening by responding as predicted to compounds like norepinephrine and blebbistatin.
• Personalized Medicine: These models could facilitate patient-specific disease modeling and the development of personalized treatment strategies. The HOCs may allow for testing medications on a patient's own cells before administering treatment.
• Understanding Cardiac Development and Disease: The organoids offer a platform for elucidating interactions between mechanical, molecular, and cellular cues in early human cardiac development. The HOCs could be used to simulate specific disorders by developing heart tissues from patients with conditions such as dilated cardiomyopathy and arrhythmias.
• Reduction in Animal Studies: Both platforms aim to reduce the reliance on animal models by providing more accurate, human-relevant in vitro systems.
• Extensibility: The magnetic torque stimulation platform may be extensible to other organoid systems where mechanical cues play a regulatory role.