A method of delivering genetic material into the body is being tested as a way to repair damaged heart muscle after a heart attack. The groundbreaking research is presented today in Frontiers in Cardiovascular Biomedicine 2022, a scientific congress of the European Society of Cardiology (ESC).1
COVID-19 messenger RNA (mRNA) vaccines2 Use lipid nanoparticles (small fat droplets) to deliver mRNA to the body’s cells. This mRNA instructs cells to make a dummy spike protein on their surface to mimic the protein on the virus causing COVID-19. The body then mounts an immune response by making antibodies that can be used if the person is infected with the virus.
A similar method was used for mRNA delivery in the present study. However, rather than the target of the immune response, the researchers’ ultimate goal is to instruct heart cells to repair themselves after a heart attack.
This preliminary study was conducted to determine whether the mRNA in lipid nanoparticles could be successfully delivered to heart muscle. Researchers injected different formulations into the left ventricular wall of mouse hearts during open chest surgery under general anesthesia. Twenty-four hours after administration, mice were sacrificed and the site of mRNA translation was examined.
The researchers found that the mRNA successfully reached the heart cells 24 hours after the injection. However, despite injection into the heart, the highest levels of mRNA translation were found in the cells of the liver and spleen.
Study author Dr Clara Labonia, from the University Medical Center Utrecht, The Netherlands, said: “High expression was expected in the liver, as it metabolizes lipid nanoparticles. Nevertheless, it was encouraging to see that there was mRNA translation in heart tissue which means that lipid nanoparticles can serve as delivery systems for mRNA therapy.
She concluded: “The next phase of this research is to test more formulations and choose one that most efficiently targets the heart tissue. We will then assess whether the delivery of mRNA to mice with ischemic heart (heart). have no therapeutic effect.