| Oct 08, 2025 |
Gold nanoparticle nasal spray delivers lithium safely to the brain
A new gold nanoparticle nasal spray delivers lithium directly to the brain, targeting Alzheimer's and bipolar disorder while avoiding harmful side effects.
(Nanowerk News) A new nasal spray packed with gold nanoparticles could make lithium therapy safer and more effective for treating neurological and psychiatric disorders. The device delivers lithium directly to the brain, targeting an enzyme linked to Alzheimer’s disease, bipolar disorder, and other brain conditions.
|
|
The treatment, described in Advanced Materials ("Lithium‐Charged Gold Nanoparticles: A New Powerful Tool for Lithium Delivery and Modulation of Glycogen Synthase Kinase 3 Activity") and now patented, uses lithium-loaded gold nanoparticles that can reach the brain through the nasal passages. Lithium has long been prescribed for bipolar disorder, but when taken orally, it spreads through the bloodstream and can cause kidney and thyroid problems. By using gold nanoparticles as carriers, researchers found a way to direct lithium precisely where it is needed, allowing for much lower doses.
|
|
The team showed that these nanoparticles can inhibit glycogen synthase kinase-3 beta (GSK-3β), an enzyme involved in multiple neurological diseases. In experiments on mice with Alzheimer’s-like symptoms, the treatment restored memory function without causing side effects.
|
|
“Our challenge was to develop a device that would allow us to exploit the therapeutic potential of lithium without causing adverse effects and that could be delivered in a site-specific manner, avoiding systemic administration,” said Professor Piacentini.
|
|
Professor Buonerba explained that gold nanoparticles are ideal for this kind of targeted therapy. “They can be functionalized with glutathione, which promotes the formation of aggregates that easily enter cells and allows molecules or ions, such as lithium, to bind. Once the aggregates enter the cells, they are broken down, releasing lithium and achieving effective therapeutic concentrations with low doses.”
|
|
The intranasal route proved especially effective. “It directly targets the brain and bypasses the systemic circulation, thus optimizing the safety of our nanodevice,” said Professor Piacentini. He added that gold is inert and naturally expelled by the body, which reduces the risk of accumulation over time.
|
|
Professor Buonerba highlighted the flexibility of the technology. “The nanoparticles developed can be loaded with different pharmacological active ingredients and are able to evade biological cellular defenses, allowing their targeted transport to specific physiological sites.”
|
|
The experiments revealed that just five days of treatment with lithium-coated gold nanoparticles, known as LiG-AuNPs, significantly inhibited GSK-3β activity in the hippocampus of mice. Two months of treatment reversed memory deficits in animals with Alzheimer’s-like symptoms.
|
|
Professor Claudio Grassi said this targeted approach could improve the safety of lithium therapy. “Taken orally, lithium reaches the brain through the bloodstream and exerts toxic effects on other organs such as the kidneys and thyroid. Delivering low doses directly to nerve cells through a brain-targeted system is an important step toward safer treatment.”
|
|
He added that this nanotechnological tool could be adapted for other brain disorders, including those linked to viral infections where the same enzyme plays a role.
|
|
Professor Alfonso Grassi noted that the nanoparticles are easy to synthesize, making large-scale production feasible. “That simplifies manufacturing and could keep costs low for future pharmaceutical applications.”
|
|
The study’s findings open the door to clinical trials aimed at testing the safety and broader therapeutic use of this nasal spray. Researchers are now exploring how the same system might carry other drugs for neurodegenerative and viral diseases that affect the brain.
|
