An international research team has reported that they have made remarkable progress against Alzheimer’s disease in mice using specially designed nanoparticles that go beyond just delivering drugs. These microscopic particles act as drugs in themselves, helping the brain restore its own natural cleaning systems and dramatically reducing the buildup of toxic proteins associated with Alzheimer’s disease.
The research was led by scientists from the Institute of Biotechnology of Catalonia (IBEC) and the West China Hospital of Sichuan University (WCHSU), together with UK collaborators. Their discovery is Signal transduction and targeted therapy.
Rather than focusing directly on damaged neurons, the researchers targeted the blood-brain barrier (BBB), a protective network of cells and blood vessels that controls what goes in and out of the brain. In Alzheimer’s disease, this system gradually breaks down, allowing harmful proteins to build up and damage brain function over time.
Researchers have designed bioactive nanoparticles called “supramolecular drugs” that can help repair this barrier and restart the brain’s ability to remove waste.
Repair the brain purification system
The human brain consumes a huge amount of energy. In adults, it consumes about 20% of the body’s total energy supply, but in children, the figure can reach 60%. To meet these demands, the brain relies on an extremely dense vascular network. Scientists estimate that there are approximately 1 billion capillaries in the brain, and nearly every neuron is connected to its own blood supply.
Growing evidence suggests that these blood vessels play a much larger role in dementia than previously thought. Many researchers now believe that vascular damage is not just a side effect of Alzheimer’s disease, but may actively promote its progression. Recent studies have also linked disruption of the blood-brain barrier to early cognitive decline and increased accumulation of toxic proteins.
In health, the blood-brain barrier helps remove waste from the brain while blocking harmful substances such as toxins and pathogens. One of the most important waste proteins is amyloid beta (Aβ), a sticky substance that forms the plaques associated with Alzheimer’s disease.
In Alzheimer’s patients, the brain’s waste disposal system begins to fail. As amyloid-beta accumulates, it damages neurons and worsens memory loss.
Alzheimer’s plaques diminish within hours
To test the new treatment, researchers used genetically engineered mice that develop high levels of amyloid-beta and progressive cognitive decline similar to Alzheimer’s disease in humans.
Animals received only three doses of nanoparticles. The effects were immediate.
“Just one hour after injection, we observed a 50-60% reduction in Aβ content in the brain,” explains the study’s lead co-author Junyang Chen, a researcher at Sichuan University West China Hospital and a PhD student at University College London (UCL).
The long-term results were even more dramatic. Scientists followed the animals for several months using behavioral and memory tests covering different stages of the disease’s progression.
In one experiment, researchers treated 12-month-old mice (equivalent to a 60-year-old human) and evaluated them six months later. At that point, the animal was roughly equivalent to a 90-year-old human. Despite their advanced age, the mice behaved like healthy animals and showed no signs of deterioration associated with Alzheimer’s disease.
“Long-term effects come from the restoration of the brain’s vasculature. We think it works like a cascade. As toxic species such as amyloid beta (Aβ) accumulate, the disease progresses. But once the vasculature is able to function again, Aβ and other harmful molecules, allowing the overall balance of the system to be restored. What is noteworthy is that our nanoparticles appear to act as a drug and activate a feedback mechanism that restores this removal pathway to normal levels,” said Giuseppe Battaglia, IBEC’s ICREA Research Professor and principal investigator in the Molecular Bionics Group.
How nanoparticles work
The main focus of the study was a protein called LRP1, which acts like a molecular transport system at the blood-brain barrier. Normally, LRP1 recognizes and binds to amyloid beta, moving it from the brain to the bloodstream for disposal.
However, the process is delicate. When LRP1 binds too tightly to amyloid β, the transport machinery becomes overloaded and becomes dysfunctional. If the interaction is too weak, waste removal will not be efficient enough. In either case, amyloid-beta begins to accumulate in the brain.
Supramolecular nanoparticles were designed to mimic natural molecules that interact with LRP1. This allows the particles to “reset” the transport system, allowing amyloid-beta to move out of the brain again.
Researchers say this strategy differs from many traditional Alzheimer’s treatments because it focuses on repairing the brain’s own infrastructure, rather than simply attacking plaques directly.
That idea has been gaining momentum in recent years. Scientists are increasingly viewing Alzheimer’s disease as both a neurological and vascular disease, with impaired blood flow and damage to the blood-brain barrier contributing to the spread of toxic proteins.
Different types of nanomedicine
Most nanomedicine approaches use nanoparticles as delivery vehicles to carry drugs into the body. In this case, the nanoparticles themselves are the therapy.
The research team created the particles using a bottom-up molecular engineering process that allows precise control over the size of the particles and the number of ligands on their surface. This precision allowed the particles to interact with receptors on the cell membrane in a highly specific manner.
By influencing the movement and function of these receptors, the nanoparticles improved amyloid-β clearance and helped restore healthier vascular activity in the brain.
Researchers say this approach could eventually complement other Alzheimer’s treatments, including anti-amyloid antibody drugs. One of the biggest challenges facing current treatments is obtaining sufficient quantities of the drug to cross the blood-brain barrier safely and efficiently.
Other experimental techniques are also exploring ways to overcome this challenge, including ultrasound-based delivery systems, “brain shuttle” molecules, and additional nanoparticle platforms designed to cross barriers more effectively.
what happens next
Although this finding is promising, the research is still in the animal testing stage. Many Alzheimer’s disease treatments that worked in mice subsequently failed in human clinical trials.
Still, experts say the study highlights an increasingly important area of Alzheimer’s disease research: restoring the health of the brain’s blood vessels and waste removal system.
“Our study demonstrated remarkable efficacy in achieving rapid Aβ clearance, restoring the healthy functioning of the blood-brain barrier, and leading to a remarkable reversal of Alzheimer’s disease,” concluded Lorena Ruiz Pérez, researcher in the Molecular Bionics Group at the Institute of Biotechnology of Catalonia (IBEC) and Sera Hunter Assistant Professor at the University of Barcelona (UB).
The project involved researchers from the Institute of Biotechnology of Catalonia (IBEC), West China Hospital of Sichuan University, West China Xiamen Hospital of Sichuan University, University College London, Xiamen Key Institute of Psychoradiology and Neuromodulation, University of Barcelona, the Chinese Academy of Medical Sciences, and the Institute for Advanced Research of Catalonia (ICREA).
