UMN research team fixes broken hearts with 3D-printed tissue patch

A team of University of Minnesota researchers uses 3D-printed tissue to heal scar tissue.

Associate Professor Brenda Ogle places a 3D printed biopatch on a mouse heart in Nils Hasselmo Hall on Tuesday, April 25, 2017. Her research team induces heart attacks in mice, which causes a dead area of cardiac cells. The patch is placed in this dead zone and mimics the cells of the native heart that aren't able to be replenished on their own.

Ellen Schmidt

Associate Professor Brenda Ogle places a 3D printed biopatch on a mouse heart in Nils Hasselmo Hall on Tuesday, April 25, 2017. Her research team induces heart attacks in mice, which causes a dead area of cardiac cells. The patch is placed in this dead zone and mimics the cells of the native heart that aren’t able to be replenished on their own. “A defining moment was when the [mouse] heart started to beat, and we realized human heart pacing could be possible too,” Ogle said.

Olivia Johnson

A research team at the University of Minnesota found a way to heal broken hearts.

Researchers used a 3D printer to create protein patches that mimic heart tissue to treat post-heart attack scars. The research is in collaboration with the University of Wisconsin-Madison and the University of Alabama-Birmingham.

Brenda Ogle, a University biomedical engineering professor and lead researcher for the project, said she and her team have investigated proteins that surround cells in the body for 15 years. The team has been studying how the proteins — also called the extracellular matrix — influence stem cell behavior.

“For many years, we’ve been trying to develop optimum formulation that can support … stem cells in new cardiac [cell] types,” Ogle said, adding that they’ve focused on cardiac cell types to figure out a way to strengthen them after the muscle cells are damaged and die during a heart attack. “It’s one of the cell types in the body that can’t be recovered.”

The team successfully treated mice with the patches and is now planning to test the method on larger animals.

Molly Kupfer, a doctoral student who is part of Ogle’s team, said a heart attack occurs when there is a blockage in a primary blood vessel that delivers oxygen and nutrients to the heart.

“When that happens, you have cell death in the area of the heart that doesn’t receive the appropriate oxygen and nutrients,” Kupfer said. “Those cells that die aren’t able to recover.”

Typically, after a heart attack, the blood clot in the heart is removed at a hospital, and if the heart has not been damaged too badly, doctors monitor the heart long-term, prescribe medicine and regularly check for signs of heart failure, Ogle said.

“What you get instead after a heart attack is scar tissue forming, and that scar tissue ultimately fails,” Ogle said.

Kupfer said she worked with Paul Campagnola and his lab at the University of Wisconsin to print the patches; the cells were prepared at the University of Minnesota.

Campagnola, a biomedical engineering professor, said he initially developed the underlying printing technology in 2000.

“The idea of the patch is it could actually behave like native cardiac tissue and assist the function of the heart,” Kupfer said, adding that the method used to print the patches results in extremely high resolution structures.

Ogle said before applying the patch to the animal hearts they’re currently testing on, they take a scan of the scarred tissue and create a digital template for the 3D-printer to follow and print the proteins in the same pattern.

Campagnola said the patch provides a stable space for cells to grow and be implanted in damaged areas.

Cardiac cells are also added to the patch when it covers a damaged area. Ogle said it not only provides a support structure, but transplants healthy cells that will eventually become integrated into the heart, stabling it structurally and functionally.

“A huge … ‘aha’ moment was when [the cardiac cells] started to beat on this patch synchronously and spontaneously,” she said. “When that happened, we realized that this could be a viable therapy for the heart, a way to replace those lost muscle cells.”

Through the research group at the University of Alabama, Ogle said a study was conducted where the patch was tested on dead or dying tissue in mice hearts and the group saw improvement in the mice after four weeks.

The project was funded through a series of grants from the National Institutes of Health, the National Science Foundation with support from the University, she said.

The group has since received larger funds from the NIH to run a study using the patch on larger animals within the next year.

Ogle said it would take about 10 years until the patch can be used on human patients in a clinical setting.