Capsules loaded with stem cells help repair heart damage in mice

Heart attacks are a leading cause of death, largely because the damage caused by one can lead to more later. Now researchers at Rice University have developed a new way to repair heart tissue and reduce scarring, by implanting capsules loaded with stem cells.

When a person suffers a heart attack, the organ repairs itself as best it can, patching up the damage with scar tissue. The problem is that scarred heart tissue doesn’t beat as well, which throws the rhythm out of whack and eventually leads to further complications down the track, including more heart attacks.

Stem cells are one possible treatment that’s currently being investigated. Unfortunately, loose stem cells don’t stick around for long, because the immune system recognizes that they’re foreign and wipes them out.

So for the new study, the Rice researchers came up with a new way to protect the cells while they did their job. They encased mesenchymal stem cells (MSCs) in alginate hydrogel capsules, a biocompatible material made of brown algae.

About 30,000 MSCs were loaded into each 1.5-mm (0.06-in) alginate capsule, and then implanted in mice, near their damaged hearts. After four weeks, the hearts of the mice that had received these “shielded” stem cells had healed as much as 2.5 times more effectively than those of mice that received non-shielded stem cells.