You can’t resurrect a dead cell any more than you can breathe life into a brick, regardless of what you may have gleaned from zombie movies and Dr. Frankenstein.
It’s been a vexing problem, not just for those who yearn to have an army of the “undead” at their beck and call – personally I’d prefer winged monkeys, but to each their own – but for people recovering from heart attacks, who have to replace dead heart muscle cells to heal the damage.
Trouble is, the cell replacement process often proceeds at a less than optimal pace. Researchers have tried various methods of transplanting healthy cells into a damaged heart, but haven’t achieved consistent success in promoting healing.
Ruiz-Lozano and a team of researchers engineered a mesh-like patch made of collagen – the fibrous protein found in connective tissue such as skin, bone, cartilage and tendons.
Instead of replacing the dead muscle cells, the patch replaces the outer layer of the heart, the epicardium, which protects and supports the heart muscle.
The collagen patch – like epicardium – is permeable enough to allow cell migration and proliferation, and let nutrients and cellular waste to pass through the network of blood vessels that grow into the patch.
Mice that had the patch grafted onto the damaged portion of their heart immediately after a surgically induced heart attack significantly outpaced the patch-less control group in their recovery.
The patch is as flexible as embryonic epicardium, which speeds tissue replacement. It’s made with acellular collagen, which contains no cells and thus avoids the rejection issues that often accompany transplants. And over time, it will get absorbed into the organ.
Ruiz-Lozano and her colleagues are already at work on a study to see how the patch performs in larger animals. In the meantime, you can check out the research paper here.