Episode 6: Injury therapies tested on human spinal cord organoid

In this podcast episode, MRS Bulletin’s Sophia Chen interviews Samual Stupp from Northwestern University about his group’s research on developing treatments for spinal cord injuries by use of an organoid. The researchers fabricated the human spinal cord organoid by including microglial cells, which are the immune cells in the central nervous system. They mimicked various kinds of spinal injuries, then applied different injury treatments to see how the organoid responded best. This work was published in a recent issue of Nature Biomedical Engineering.

Transcript

SOPHIA CHEN: Welcome to MRS Bulletin’s Materials News Podcast, providing breakthrough news & interviews with researchers on hot topics in materials research. My name is Sophia Chen. At Samuel Stupp’s laboratory at Northwestern University, he and his colleagues are developing ways to treat spinal cord injuries. Spinal cord injuries are the leading cause of permanent disability in children and adults. It can lead to permanent paralysis. It can also lead to health problems related to involuntary body processes such as breathing, urination and heart rate, Stupp says.

SAMUEL STUPP: It’s a devastating injury, because, of course, your brain is functioning perfectly well, but you lose one of the most fundamental things that we need for our daily existence, being able to move from one place to another.

SOPHIA CHEN: Some 15 million people worldwide live with the health consequences of a spinal cord injury, with around 1,000,000 new cases globally each year. Stupp, who is a materials scientist, and his colleagues are developing treatments for spinal cord injuries. In a recent study, they have put human stem cells in a dish and grown them into a small piece of tissue over several weeks. This millimeters-sized piece of tissue is a lab-grown version of human spinal cord tissue, known as a human spinal cord organoid. They can test therapies on these organoids, which reduces their need for animal models, he says.

SAMUEL STUPP: We will be able to test modifications on our biomaterials, using this organoid model to try to accelerate the pace of discovery, to create the perfect therapy.

SOPHIA CHEN: Their organoid is a more realistic replica of actual human tissue than previous versions because it is the first to include microglial cells. Microglial cells are the immune cells in the central nervous system.  

SAMUEL STUPP: They are cells that respond to injury and to inflammatory processes that go with the injury.

SOPHIA CHEN: They injured the organoid and studied how the biomaterial responded to the injuries. In one type of injury, they cut the organoid with a scalpel. In another, they dropped a weight on the organoid.

SAMUEL STUPP: So sort of mimicking what might happen when you have an accident. You have a big blow, you know, mechanical force that damages your spinal cord, which is what's going to paralyze you.

SOPHIA CHEN: Then, they studied how the injured organoid responded to a therapy for treating spinal cord injury. This therapy was a long time in the making. Stupp’s group first discovered the molecule used in the therapy, a type of peptide amphiphile, in 2001. In 2021, Stupp’s group found that applying these peptide amphiphiles could reverse paralysis in mice with acute spinal cord injuries. The injured organoid responded to the therapy similarly to the mouse model. 

SAMUEL STUPP: We could regenerate the axons that had been severed by the injury. And that's also something we saw in the animal model. So it's very exciting to see that. 

SOPHIA CHEN: The therapy also suppressed scar formation in the organoid. They plan to perform clinical trials for the spinal cord therapy in the next year, pending FDA approval.

SAMUEL STUPP: That therapy will treat the acute injury, which means it's a fresh injury. So if you have an accident, you know, a car accident, a bullet injury, a sports injury, an explosion, a fall, then you are treated within 24 hours of that injury, or say, a few days, that will prevent you from becoming paralyzed.

SOPHIA CHEN: In future work, Stupp would like to develop different types of organoids to find therapies for other diseases, such as for strokes. This work was published in a recent issue of Nature Biomedical Engineering. My name is Sophia Chen from the Materials Research Society. For more news, log onto the MRS Bulletin website at mrsbulletin.org and follow us on X, @MRSBulletin. Don’t miss the next episode of MRS Bulletin Materials News – subscribe now. Thank you for listening.