Chiral gold nanoparticles increase vaccine efficacy by more than 25%, study suggests

A study by an international collaboration shows that left-handed gold nanoparticles can be used to make vaccines 25% more effective. The results are reported in an article in Nature.

Three research groups collaborated on the study, one of which is affiliated with the University of Michigan in the United States. The leader of the Brazilian group was a professor in the Chemistry Department at the Federal University of S&E3;o Carlos.

The study didn't involve the vaccine because it began before the outbreak. The researchers used vaccines to fight the flu. The results can be generalized for any type of vaccine, with case-by-case studies, even if this is not the strain that is currently circulating in Brazil. Left-handed gold nanoparticles are not the active ingredient, but an adjuvant that potentiates the recipient's immune response.

The key to understanding the contribution of these nanoparticles is the concept of chirality, which applies to an object or system that can't be superimposed on its own mirror image.

It is a type of asymmetry. The best example of the difference between left and right hand is derived from the Ancient Greek for hand. When we hold up our hands to a mirror, we can see the same hand on the right and left.

Everything on Earth is not straight. Depending on whether the molecule is left- or right-handed, it can have different properties. The drug thalidomide was prescribed to pregnant women in the late 1950s and 1960s. Babies were born with a range of malformations. One of the enantiomers in the substance had the expected therapeutic effect, but the other atrophied the limbs of the fetus.

There are particles.

The study reported in Nature was based on the fact that scientists could separate one enantiomer completely. They are achiral. He said that they first had them interact with the cysteine and then had them expose them to the light using the phenylalanine as a light-harvesting antenna.

The quotient is measured on a scale from minus two to plus two. The procedure used in the study allowed the scientists to exceed 0.4 and resulted in three nanoparticles: the original achiral gold, the right-handed enantiomer, and the left-handed enantiomer.

We tested the nanoparticles on human immune cells and found that they stimulated the production of substances associated with an immune response even if there was no vaccine. This kind of reaction is what an adjuvant does in a vaccine.

The efficacy of the vaccine was increased by 25.8% with the left-handed enantiomer.

The knowledge is available to anyone who wants to use it. We aren't vaccine developers, but we are offering this basic knowledge as a novel technological platform for those who are.

More information: Liguang Xu et al, Enantiomer-dependent immunological response to chiral nanoparticles, Nature (2022). DOI: 10.1038/s41586-021-04243-2 Journal information: Nature Citation: Chiral gold nanoparticles increase vaccine efficacy by more than 25%, study suggests (2022, April 18) retrieved 18 April 2022 from https://phys.org/news/2022-04-chiral-gold-nanoparticles-vaccine-efficacy.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.