A research team at Columbia University, funded by the National Institutes of Health (NIH) in the US, has used electric and mechanical stimulation to make a human adult-like cardiac muscle model from induced pluripotent stem cells (iPSCs).
When stimulated at an early stage, the iPSCs were able to form the model, which can be used to test drugs and toxic substances because of its similarities to the actual organ.
iPSCs are created by extracting cells from humans and altering them into a stem-cell state. Chemicals and physical stimuli can be used to induce these cells into other cell types.
The researchers said that while iPS-derived cardiomyocytes (iPS-CMs) were in use for a long time, engineering them to accurately mimic human heart cells has not been achieved so far.
In the latest study, the team cultured heart muscle from early-stage iPS-CMs and electrically induced contractions in order to speed up the cell development from the foetal-to-postnatal stage.
The resulting tissue from four weeks of growth is reported to feature adult-like gene expression and organised ultrastructure with several functions that are characteristic to mature heart muscle.
Columbia University Biomedical Engineering professor Gordana Vunjak-Novaković said: “Human cardiac tissues grown in the lab that displays the behaviour of native heart muscle would be transformative for biomedical research.”
After experimentation with various scenarios, the researchers observed that gradual increase in electrical stimuli levels at an early stage had a better effect on the cells.
NIH National Institute of Biomedical Imaging and Bioengineering Tissue Chips programme director Seila Selimovic said: “The resulting engineered tissue is truly unprecedented in its similarity to functioning human tissue.
“The ability to develop mature cardiac tissue in such a short time is an important step in moving us closer to having reliable human tissue models for drug testing.”