"The addition of fibroblasts in our experiments provided signals that we believe are present in a developing embryo," Liau said. The need for helper cells is not uncommon in mammalian development. For example, he explained, nerve cells need "sheathe" cells known as glia in order to develop and function properly.
Bursac believes that the latest experiments represent a proof-of-principle advance, but said there are still many hurdles to overcome before such patches could be implanted into humans with heart disease.
"While we were able to grow heart muscle cells that were able to contract with strength and carry electric impulses quickly, there are many other factors that need to be considered," Bursac said. "The use of fibrin as a structural material allowed us to grow thicker, three-dimensional patches, which would be essential for the delivery of therapeutic doses of cells. One of the major challenges then would be establishing a blood vessel supply to sustain the patch."
The researchers plan to test their model using non-embryonic stem cells. For use in humans, this is important for many reasons, both scientifically and ethically, Bursac said. Recent studies have demonstrated that some cells from human adults have the ability to be reprogrammed to become similar to embryonic stem cells.
"Human cardiomyocytes tend to grow a lot slower than those of mice," Bursac said. "Since it takes nine months for the human heart to complete development, we need to find a way to get the cells to grow faster while maintaining the same essential properties of native cells."
If they could use a patient's own cells, the patch would also evade an immune system reaction, Bursac added.
'/>"/>
| Contact: Richard Merritt richard.merritt@duke.edu 919-660-8414 Duke University Source:Eurekalert |