Stroke remains one of the leading causes of disability worldwide because brain cells begin to die within minutes after their blood supply is blocked.
Even when doctors successfully remove the clot, many patients are left with permanent damage because lost brain tissue cannot naturally grow back.
Scientists at Duke University have now developed an innovative injectable biomaterial that could help the injured brain repair itself. Their findings were published in Cell Biomaterials.
Current stroke treatment focuses on restoring blood flow as quickly as possible. However, once brain tissue has died, restoring circulation alone cannot reverse the damage. Large strokes often leave an empty cavity that becomes a major obstacle to healing, as there is little structure to support the growth of new cells and blood vessels.
To solve this problem, the researchers created a tiny porous scaffold made from hydrogel particles. After injection, the particles connect to form a three-dimensional framework that allows cells to enter and communicate.
Rather than acting as an artificial brain, the scaffold provides a temporary home where natural repair processes can take place.
The team combined this scaffold with extracellular vesicles collected from astrocytes. Astrocytes are important support cells in the brain that release these microscopic packages to send signals to nearby cells. The researchers anchored the vesicles to the scaffold so their biological messages stayed where they were most needed.
They also discovered that adding two signalling molecules, IL-4 and C1q, attracted beneficial immune cells into the damaged region.
This changed the local environment from one dominated by injury to one that supported healing. Surprisingly, neutrophils, which are often considered harmful after stroke, became important partners in rebuilding damaged tissue.
When the researchers removed these neutrophils, far fewer blood vessels formed and the scaffold was remodelled less effectively. This finding suggests that immune cells can play very different roles depending on the timing of their arrival and the signals they receive. The engineered material appeared to guide these cells toward repair instead of inflammation.
The treated mice developed healthier blood vessel networks and showed increased growth of axons, the long fibres that carry signals between nerve cells. They also regained movement more successfully than untreated mice during walking tests. Delivering extracellular vesicles without the scaffold failed to produce the same benefits, demonstrating that the material itself was essential.
The researchers are now investigating ways to produce extracellular vesicles from human stem-cell-derived astrocytes, which may provide a practical source for future therapies. Before this treatment can move into human clinical trials, scientists must confirm its safety, understand how each immune cell contributes to healing, and test it in larger animal models.
The study offers an exciting glimpse into the future of regenerative medicine for stroke. Instead of relying only on rehabilitation after brain injury, doctors may one day be able to reshape the damaged area so the body’s own repair systems can rebuild blood vessels and nerve connections.
Although this work is still several years away from clinical use, it represents an important scientific advance and provides strong evidence that engineering the brain’s healing environment could become a powerful new approach for stroke recovery.
If you care about stroke, please read studies that diets high in flavonoids could help reduce stroke risk, and MIND diet could slow down cognitive decline after stroke.
For more health information, please see recent studies about antioxidants that could help reduce the risk of dementia, and tea and coffee may help lower your risk of stroke, dementia.
Source: Duke University.
