Gold nanoparticles could be a safe tool for improving the effectiveness of vaccines and other medicines that need to target the B cells of the immune system, according to new research.

 

The number of medical uses for nanoparticles has grown steadily over the past 20 years. However, doctors and scientists remain concerned about their safety and how they might affect the immune system.

 

The human body tolerates gold well, and the metal is easy to manipulate. In the form of nanoparticles, gold offers the potential to target cells in very specific ways. This makes drug delivery in precision medicine a particularly promising area of research.

 

Previous studies have already shown that gold nanoparticles can interact safely with larger immune cells, such as macrophages, in biocompatible ways.

 

Now, for the first time, scientists have investigated how gold nanoparticles interact with B lymphocytes — a type of white blood cell that is smaller and more difficult to manage.

 

The new study was conducted by researchers from Switzerland and the United Kingdom and was published in the journal ACS Nano.

 

B cells are largely responsible for producing antibodies in the immune system.

 

“Nanoparticles can form a protective vehicle for vaccines — or other drugs — to specifically deliver them where they can be most effective while sparing other cells,” explains co-senior study author Carole Bourquin, a professor in the faculties of medicine and science at the University of Geneva in Switzerland.

 

Bourquin and her colleagues investigated the interactions between different forms of gold nanoparticles and freshly isolated human B lymphocytes.

 

The researchers conducted experiments in which they exposed B cells to both coated and uncoated gold nanoparticles in rod-shaped and spherical forms.

 

By observing activation markers on the surface of the B cells, the scientists were able to determine how different nanoparticle types either activated or inhibited immune responses.

 

None of the tested gold nanoparticle types produced harmful side effects. However, the nanoparticles varied in their ability to trigger an immune response.

 

The researchers discovered that both the surface coating and the shape of the gold nanoparticles had a significant effect on how they interacted with B cells.

 

Uncoated spherical gold nanoparticles were found to be unsuitable because they tended to form clumps.

 

The best-performing particles were polymer-coated spherical gold nanoparticles. These particles remained stable and did not interfere with normal B cell function.

 

Rod-shaped gold nanoparticles, however, were not effective because they reduced the immune response instead of activating it. Researchers believe this may be because the heavier rod-shaped particles interfered with processes occurring in the cell membranes.

 

For vaccines to work effectively, they must reach B cells before the body destroys them. Gold nanoparticles could serve as protective carriers that help deliver vaccine drugs safely to their intended targets.

 

B cells can also be targets for medications used to treat other diseases, including cancer and autoimmune disorders.

 

The researchers believe that the gold nanoparticles developed in this study could serve as an effective vehicle for delivering drugs directly to B cells.

 

Such a targeted delivery system could potentially reduce the required drug dosage and minimize unwanted side effects.

 

Gold nanoparticles may also be ideal carriers for brain cancer treatments because they are small enough to pass through the blood-brain barrier. Research into using nanoparticles to treat brain tumors is already underway.

 

Another interesting property of gold nanoparticles is their ability to absorb light and release that energy as heat.

 

This characteristic could make them useful tools for precision cancer therapy. Doctors could guide gold nanoparticles into tumors and then apply light to heat the particles, selectively destroying cancer cells.

 

An important feature of the study is that the researchers developed a systematic method for investigating the safety and compatibility of nanoparticles with B cells.

 

No previous study had used this methodology, and it could become particularly valuable for future research as scientists continue exploring the medical use of nanoparticles and develop clearer safety guidelines.