By Diane Ivey
Anyone who’s ever been through a breakup probably wishes they could grow a new heart. (If you’ve never been through a breakup, congratulations; if you’ve also found yourself sobbing in the cheese aisle of the grocery store less than 24 hours after being dumped, maybe we can hang out on Valentine’s Day.) As you may have heard, science is already moving in this direction. The use of stem cells to repair human organs, including the heart, is being explored. According to the National Institutes of Health, “A few small studies have also been carried out in humans, usually in patients who are undergoing open-heart surgery. Several of these have demonstrated that stem cells that are injected into the circulation or directly into the injured heart tissue appear to improve cardiac function and/or induce the formation of new capillaries.”
Since the beginning of stem cell research, scientists have been trying to grow organs in a lab using different types of stem cells. This process is called “organ gardening,” which makes me think of a person in a lab coat carefully watering a heart growing out of the ground like a flower. (Wait a minute, wasn’t that how The Powerpuff Girls were made? At the very least, they were definitely lab-created.) Last month, researchers at Children’s Hospital Los Angeles published a paper about the lab’s attempts to grow a small intestine from stem cells in order to help babies with intestinal problems.
We’ve discussed organ gardening on the AAPS Blog before, and there’s a lot to say with regards to methods and ethics, but how will the future of this technology affect drug discovery?
According to an article by Phil Taylor on PMLive, lab-created organs could be beneficial for pharmaceutical research and development. Organ gardening could make clinical trials easier, Taylor writes. “Assays used to test activity against a drug target tend to involve isolated cells—in other words a two-dimensional (2D) system that is a poor reflection of the three-dimensional (3D) environment within the human body.”
A 3D environment could reduce animal testing as well, the article says. This could cut costs in drug development, Taylor writes, as there are often discrepancies between human and animal physiology. He goes on to discuss the work of Meritxell Huch, who studies growing liver organoids from adult mouse stem cells.
“Typically a study to investigate one potential drug compound to treat one form of liver disease would require up to 50 live animals per experiment, so testing 1,000 compounds would need 50,000 mice,” said Huch. “By using the liver culture system I developed, we can test 1,000 compounds using cells that come from only one mouse, resulting in a significant reduction in animal use.”
Organ gardening can also be used to create models of diseased tissue, Taylor said, which could also aid drug discovery by giving drugmakers examples of diversity and genetic mutations within a disease.
While we have a long way to go before you can just grow your own heart (or really, your own brain, because isn’t that the real source of heartache anyway?), it’s exciting to see all these developments and to consider the possibilities for the future. It’s interesting to know that we live in a world where, someday, the tin man’s predicament could be solved from a few cells.