Breakthrough nanotechnology could help reverse Alzheimer’s damage

Scientists in Spain and China have successfully reversed Alzheimer's-like symptoms in mice using specially designed nanoparticles that help the brain clear toxic proteins linked to the disease.

The study, led by the Institute for Bioengineering of Catalonia (IBEC) and West China Hospital of Sichuan University, represents a new direction in Alzheimer's research. Instead of targeting neurons, the treatment repairs the blood–brain barrier (BBB) - a protective layer that keeps harmful substances out of the brain. The results were published in Signal Transduction and Targeted Therapy, says Medical Xpress.

Repairing the brain's waste system

In Alzheimer's disease, the BBB often becomes damaged, disrupting the brain's ability to remove amyloid-beta (Aβ) - a protein that accumulates and forms plaques linked to memory loss. The researchers found that restoring the barrier's function reactivated the brain's natural cleaning process, allowing it to flush out toxic molecules.

"Once the brain's vasculature starts working properly again, it clears out amyloid-beta and other harmful substances, allowing the system to recover its balance," said Giuseppe Battaglia, a research professor at IBEC and leader of the study.

A new kind of nanomedicine

Most nanomedicines use nanoparticles as delivery vehicles for drugs. The IBEC–Sichuan team instead created "supramolecular drugs" - nanoparticles that act as the drug themselves. When injected into mice genetically engineered to develop Alzheimer's-like symptoms, these particles reduced amyloid-beta levels in the brain by 50–60% within one hour, according to co-author Junyang Chen of West China Hospital and University College London.

Mice given just three doses not only cleared the toxic proteins but also showed restored memory and learning ability months later. One 12-month-old mouse - roughly equivalent to a 60-year-old human - regained normal behavior six months after treatment.

How it works

In a healthy brain, a protein called LRP1 acts as a molecular gatekeeper, moving amyloid-beta from the brain into the bloodstream for disposal. When overwhelmed, this transport system breaks down, leading to toxic buildup.

The nanoparticles mimic LRP1's natural partners, helping it recognize and carry amyloid-beta across the BBB. "The nanoparticles act like a switch that reactivates the brain's ability to clean itself," Battaglia said.

Wider implications

Researchers say the results point to the importance of brain blood vessels in dementia and could open a new front in treatment research.

"The long-term effect comes from restoring vascular function," Battaglia said. "That's what allows the brain to recover, not just temporarily but in a sustained way."

Lorena Ruiz Perez, co-author and researcher at IBEC, said the precision of the nanoparticles is key: "They engage with specific receptors on cell surfaces, allowing us to fine-tune how the brain regulates waste clearance."

Early but encouraging results

While the findings are limited to animal studies, they highlight a potential way to tackle Alzheimer's by repairing the brain's vascular system rather than directly targeting neurons. Experts say this approach could complement or even outperform current therapies, which often struggle to cross the blood–brain barrier effectively.

The project involved collaboration between institutions in Spain, China, and the United Kingdom, including the University of Barcelona, University College London, and the Chinese Academy of Medical Sciences.

Alzheimer's affects more than 55 million people worldwide, and effective treatments remain elusive. If the nanoparticle therapy proves safe and effective in humans, it could mark a major step toward helping the brain heal itself.