»ΖΙ«Φ±²₯

»ΖΙ«Φ±²₯ researchers integrate crucial immune cells onto heart-on-a-chip platform

The immune cells, known as primitive macrophages, were found to enhance heart tissue function and vessel stability
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L-R: »ΖΙ«Φ±²₯ post-doctoral fellow Shira Landau, PhD alum Yimu Zhao and Professor Milica Radisic are three of the primary authors of a study that could lead to advancements in the creation of more stable and functional heart tissues (supplied images)

Researchers at the »ΖΙ«Φ±²₯ have discovered a novel method for incorporating primitive macrophages – crucial immune cells – into heart-on-a-chip technology, in a potentially transformative step forward in drug testing and heart disease modeling.

In a study , an interdisciplinary team of scientists describe how they integrated the macrophages – which were derived from human stem cells and resemble those found in the early stages of heart development – onto the platforms. These macrophages are known to have remarkable abilities in promoting vascularization and enhancing tissue stability.

Corresponding author Milica Radisic, a senior scientist in the University Health Network's Toronto General Hospital Research Institute and professor in the Institute of Biomedical Engineering at »ΖΙ«Φ±²₯’s Faculty of Applied Science & Engineering, says the approach promises to enhance the functionality and stability of engineered heart tissues.

β€œWe demonstrated here that stable vascularization of a heart tissue in vitro requires contributions from immune cells, specifically macrophages. We followed a biomimetic approach, re-establishing the key constituents of a cardiac niche,” says Radisic, who holds a Canada Research Chair in Functional Cardiovascular Tissue Engineering

β€œBy combining cardiomyocytes, stromal cells, endothelial cells and macrophages, we enabled appropriate cell-to-cell crosstalk such as in the native heart muscle.”

Milica Radisic lab
Professor Milica Radisic's research team have worked on developing a miniaturized version of cardiac tissue on heart-on-a-chip platforms for a decade (photo by Nick Iwanyshyn)

A major challenge in creating bioengineered heart tissue is achieving a stable and functional network of blood vessels. Traditional methods have struggled to maintain these vascular networks over extended periods, limiting their effectiveness for long-term studies and applications.

In their study, researchers demonstrated that the primitive macrophages could create stable, perfusable microvascular networks within the cardiac tissue, a feat that had previously been difficult to achieve.

Furthermore, the macrophages helped reduce tissue damage by mitigating cytotoxic effects, thereby improving the overall health and functionality of the engineered tissues.

β€œThe inclusion of primitive macrophages significantly improved the function of cardiac tissues, making them more stable and effective for longer periods,” says Shira Landau, a post-doctoral fellow in Radisic’s lab and one of the study’s lead authors.

The breakthrough has far-reaching implications for the field of cardiac research. By enabling the creation of more stable and functional heart tissues, researchers can better study heart diseases and test new drugs in a controlled environment.

Researchers say this technology could lead to more accurate disease models and more effective treatments for heart conditions.

Donnelly