Every year, millions of people around the world suffer an ischemic stroke, which happens when a blood clot blocks blood flow to part of the brain.
Doctors can sometimes remove the clot or dissolve it with medicine if treatment begins quickly.
These treatments save brain tissue that is still alive, but they cannot replace tissue that has already died. A new study from Duke University offers hope by showing that a specially designed injectable material may help the damaged brain begin repairing itself. The research was published in Cell Biomaterials.
Large strokes often leave behind a hollow cavity where brain tissue has been destroyed. Rehabilitation helps people regain some movement by teaching the healthy parts of the brain to adapt, but it cannot rebuild the missing tissue. Researchers have long searched for ways to create an environment where healing can occur inside this empty space.
The Duke University team designed a biomaterial called a microporous annealed particle scaffold, or MAP scaffold. It is made from tiny hydrogel particles that join together after being injected into the damaged area. Instead of replacing brain tissue directly, the scaffold creates a supportive structure where the body’s own cells can move in and begin repair.
The researchers also used tiny biological packages called extracellular vesicles, or EVs. These natural particles are released by astrocytes, star-shaped brain cells that help support nerve cells and respond quickly after injury. EVs carry proteins, fats and genetic material that allow cells to communicate with one another.
Rather than injecting the EVs alone, the scientists attached them to the scaffold so they remained inside the injured area. They also added signalling molecules called IL-4 and C1q, which attracted helpful immune cells into the damaged brain. This combination encouraged the repair process to begin.
One of the biggest surprises involved neutrophils, a type of white blood cell. Neutrophils are usually linked with inflammation and early tissue damage after a stroke. However, the study found that when these cells arrived later and within the specially engineered scaffold, they helped build new blood vessels and supported healing instead of causing harm.
The treated mice developed many new blood vessels inside the stroke cavity. The researchers also found more growing nerve fibres around the damaged region, suggesting that the brain was beginning to rebuild important connections. These changes were not seen when the extracellular vesicles were given without the scaffold, showing that the biomaterial itself played a critical role.
The improvements were not limited to the microscope. Mice receiving the treatment also performed much better on movement tests that measured how accurately they placed their front paws while walking. After eight weeks, their performance was similar to healthy mice, and these gains remained throughout the study.
Although the findings are exciting, this research is still at an early stage. The treatment has only been tested in mice, and many more studies will be needed before it can be tested safely in people. Researchers also plan to use human stem-cell-derived astrocytes to produce extracellular vesicles that may be more suitable for future clinical use.
This study highlights a new way of thinking about stroke recovery. Instead of trying to replace lost brain tissue directly, the researchers focused on rebuilding the environment needed for healing.
The results suggest that guiding the body’s own immune cells, blood vessels and nerve cells to work together may become an important strategy in future stroke treatment. While the study remains preclinical, the improvements in brain repair and movement make it a promising advance that deserves further investigation.
If you care about health, 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.
