Researchers have developed a new technique that allows them to grow, then inject healthy nerve cells into the brain. By converting stem cells into neurons on tiny 3D scaffolds, the team was able to replace diseased cells in mouse brains. The findings, published in Nature Communications this week, may one day help patients with ALS, Parkinson’s, Alzheimer’s, and other brain-related conditions. 

Neurodegenerative diseases and traumatic brain injuries happen when the central nervous system loses functional neurons. Treatments that involve cell transplants are promising, but they suffer from poor cell survival rates in animal studies. In recent years, researchers have turned to stem cells that can be reprogrammed into neurons. These stem cells can be taken from the patients themselves. "If you can transplant cells in a way that mimics how these cells are already configured in the brain, then you're one step closer to getting the brain to communicate with the cells that you're now transplanting," Prabhas Moghe of Rutgers says in a statement. 

Together with Zhiping Pang from Rutgers Robert Wood Johnson Medical School, Moghe and colleagues reprogrammed adult tissue-derived stem cells into human neurons, and then they loaded hundreds of these healthy cells onto islands of tiny, synthetic polymer fibers. These so-called microtopographic scaffolds are 100 micrometers wide, about the width of a single strand of human hair. Once they attach to the fibers, the cells rapidly branch out into networks and start sending out signals. 

"We take a whole bunch of these islands and then we inject them into the brain of the mouse," Moghe explains. "These neurons that are transplanted into the brain actually survived quite miraculously well. In fact, they survived so much better than the gold standard in the field." Compared to other methods, this 3D scaffold technology resulted in a 100-fold increase in cell survival. 

Next, the team wants to improve the scaffold biomaterials to increase the number of implanted neurons in the brain. They’re also working on developing better control over a dense circuitry of highly functioning neurons. While trials using mice with Parkinson’s is already underway, it’ll be another decade or two before the technology can be tested in humans.