Good results from a trial (on animals for now) run by the Tissue Engineering Laboratory of La Sapienza University of Rome. A “mix” was created of muscle stem cells and other types of cells, which were treated in the laboratory and then inserted into the damaged heart, restoring cardiac function.
A real biological patch to quickly repair damage caused by a heart attack: the idea, already attempted by various research groups around the world (almost never with satisfactory results), has finally found a practical application that works well, at least in animals. How does it work? This is reported in the journal Scientific Reports (Nature group) by researchers at the Tissue Engineering Laboratory of La Sapienza University of Rome, headed by Professor Antonio Musarò.
The team created an innovative experimental “tool” called X-MET (an acronym for eX-vivo Muscle Engineered Tissue). X-MET is made up of stem cells from the “normal” muscles in animals' legs (therefore not from cardiac muscle), as well as endothelial cells (those that normally line the inner walls of blood vessels) and fibroblasts (connective tissue cells).
This extremely thin “mix” formed a three-dimensional structure, even though the researchers had not added support elements (known as scaffolds). Subjected to mechanical stimulation (in practice, stretched by 60% for 15 days), X-MET triggered a functional remodeling, transforming into a structure similar to the muscle tissue of the heart, and therefore capable of interacting with cardiomyocytes (heart cells).
X-MET was then used as a real patch and transplanted into the hearts of laboratory mice that had had severe heart attacks (chronic myocardial ischemia). "Well,” explains Marianna Cosentino, first author of the study, “thanks to X-MET, the animals' hearts exhibited a robust recovery, restoring cardiac function and significantly increasing survival rates, without showing the negative side effects that other experimenters had reported. In particular, X-MET enabled the animals to live up to 100 days. The mice that did not receive this treatment died after 25-30 days, on average."
The study was supported by the Pasteur Italia Institute, Fondazione Roma, and Afm-Telethon, while Marianna Cosentino is one of the winners of the 2021 Fellowship from the IBSA Foundation for Scientific Research.
Studies on humans as well
Will it also be possible to trial this technique on humans as well?
"We are working on it," says Marianna Cosentino. “As with animals, the idea is to use the skeletal muscle stem cells from the patients themselves, to avoid the risk of rejection, removing them using biopsies and then combining them with other types of stem cells (the ones known as mesenchymal stem cells). The hardest part, as was the case with animals, will be to combine them with other elements to recreate the X-MET model, with a three-dimensional structure, but without a support ".
Without “scaffolding” (usually very thin polymers are used, formed by molecules that are all the same), and with a structure enriched by various types of cells, the biological patch takes hold much better and does not lead to “disorders”, such as arrhythmias and fibrillations.
How long before it is available for clinical use on humans as well, which would revolutionize the treatment of heart attacks? Marianna Cosentino smiles: “We can't say yet, but we really will do everything we can to make it happen.”
