Three research groups from multiple institutions in Brazil, China, and the US collaborated to publish a study on how to increase vaccine efficacy. The team has used "handedness" in chiral gold nanoparticles that act as an adjuvant to enhance the immune response of mice to the influenza virus.
The research groups involved in this study include the University of Michigan in the US, Jianggan University in China, and the Federal University of São Carlos (UFSCar) led by Professor André Farias de Moura.
Vaccine Efficacy Can Be Increased to More Than 25% Using Left-Handed Chiral Gold Nanoparticles, Study Claims
Chirality of Gold Nanoparticles
According to PR Newswire, the sophisticated shape and surface chemistry of the protein molecules plays an important role in how they interact with each other. It allows the fine tunes of the physiology of organisms, such as their immune system. Their shapes have a special property in which they are chiral.
Nano-Magazine reported that chirality refers to the asymmetry of the structure that gives them handedness, like human hands. They may look similar, but chiral objects are not identical to their mirror image. One of them is called right, and the other is called left.
It is a ubiquitous property of any living organism, like the helical structure of DNA, that serves a good purpose. For instance, the transfer of signals between cells relies on the lock-and-key interaction of mirror-symmetrical molecules.
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Left-Handed Chiral Gold Particles Enhance Immune Response
In his previous study, Professor Nicholas Kotov from the University of Michigan found that nanoparticles can be imparted from chiral photons' local shapes. He used this technology to create gold nanoparticles that become left-handed when illuminated with left-handed helical light and becomes right-handed when light has a right-hand twist.
These nanoparticles are perfect mirror images of each other that are established by a mathematical measure and optical parameter known as the g-factor. According to Phys.org, it is on a scale from minus two (-2) to plus two (+2), but the procedure the team used allowed them to exceed 0.4 and resulted in the original achiral gold, right-handed enantiomer, and left-handed enantiomer.
They then tested how they could use this customization to impact nanoparticles when exposed to macrophages or dendritic cells, which play key roles in recognizing foreign proteins in the body that signal an infection.
They found that left-handed chiral gold nanoparticles greatly enhanced the efficacy of vaccines at a 25.8% increase compared to the right-handed chiral gold nanoparticles, and even greater than the original achiral nanoparticle.
Moura emphasized that the findings are made public and available to all so those who want to develop vaccines can use the knowledge and create highly effective vaccines against novel variants of SARS-CoV-2, influenza, or any type of viruses.
They described the findings of their study, titled "Enantiomer-Dependent Immunological Response to Chiral Nanoparticles," in the journal Nature.
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