Magnetic nanoparticles could help rejuvenate damaged hearts

Myocardial Infarction occurs when cardiac perfusion is interrupted, leading to damage and functional impairment. Current treatment strategies aim to preserve as much tissue as possible to preserve cardiac function with few complications.

Attempts have been made to rejuvenate the damaged areas of the heart with replacement cells, however most are flushed away when injected. An interdisciplinary team led by researchers from the University of Bonn has been investigating a new approach using replacement cells that contain magnetic nanoparticles, allowing the cells to be held in place.

Cardiac muscle replacement cells obtained from foetal mouse hearts or mouse stem cells expressing fluorescent markers were loaded with magnetic nanoparticles and injected into the infarct zone. When a magnet was placed a few millimetres away from the heart around 60% of the cells remained in place compared to 25% in the control group. After 2 weeks and 2 months, 7 and 4 times as many replacement cells survived respectively, a significant achievement according to the researchers as mice only have a 2 year lifespan. Just 10 minutes with the magnet in place improved cell retention for several days after the procedure, allowing them to gradually attach to the existing tissue.

Professor Röll, from the Department of Cardiac Surgery at University Hospital Bonn, states that the cell attachment is particularly surprising because the area of damaged tissue has a relatively poor blood supply. The replacement cells had a greater level of cell survival, retention and multiplication, believed to have been caused by the increased cell density which facilitated improved cell-to-cell interactions. Many genes that promote survival such as those related to cellular respiration also showed greater activity.

The researchers are confident that this technique can be used in humans in a clinical setting, however there are many years of research ahead before potential human application.