We interact with many useful, tiny particles every day

Let’s be honest: There are so many ways size matters, and for small things, size is beautiful. However, very small things, such as nanoparticles, are sometimes misunderstood.

In recent months, many people have had difficult conversations with friends and family members who were reluctant to take the COVID-19 vaccine. In some cases, this reluctance has arisen because they have been led to believe that vaccines cannot be trusted because they contain nanoparticles. Lipid nanoparticles – called liposomes – carry the messenger RNA molecule in the COVID-19 mRNA vaccines.

Nanoparticles in mRNA vaccines

These liposomes act as compounds that transport the viral protein template to where they can interact with the immune system and stimulate antibody production. Their small size allows them to do the job faster and more effectively.

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Liposomes are tiny droplets of fat that mimic the membranes of our cells. This allows the particles not only to travel to their destination in the body without triggering an immune reaction, but also to integrate with our cells which can then take up the messenger RNA molecule and make the protein it codes for. Once the birth is complete, these lipid nanoparticles are degraded in our bodies like any other fat.

This technology became possible through years of concerted efforts by the scientific community. These types of nanoparticles are a potentially useful medium for all other types of drugs. These include other vaccines, as well as promising cancer treatments.

Read more: COVID-19 Vaccines: How 95% Effective mRNA Shots Work for Pfizer and Moderna

As scholars who Make Nanoparticles, we would hope our loved ones would at least be less afraid of our work. Fortunately, they are all now fully vaccinated, but the reluctance of vaccines caused by the novelty of the terms nanoparticles and nanotechnology leaves us anxious.

With the emergence of COVID cases due to the Omicron variant, efforts to address vaccine frequency worldwide, including information on nanoparticles, must be intensified. The term nanoparticles and nanotechnology may be unfamiliar to many people, but humans have been interacting with nanoparticles for thousands of years, and all of us come into contact with nanotechnology-based products every day.


One of the authors – Keroles Riad – produces large amounts of nanoparticles by setting fire to chemicals (very satisfactory). This process – called flame spray pyrolysis – can produce special nanoparticles called quantum dots, which are used in lithium batteries and gas sensors. But nanotechnology has uses in every aspect of our lives, affecting things like our wine, our guts, and our climate.

Nanoparticles in mRNA vaccines are not the first nanoparticles used in health applications. For example, co-author Sylvie Owlette is currently manufacturing lipid nanodiscs in her lab. This consists of cracking the fatty layer of coli bacteria Bacteria are cut into small pieces, to study the proteins they contain as if they were still in their natural environment. Since these proteins are involved in antibiotic resistance, lipid nanodisks are an important tool in fighting infection.

Selvi also studied gold nanoparticles to assess their usefulness in the diagnosis and treatment of cancer and other health conditions.

Nanoparticles have been used for centuries. In China in the fourth century, nanoparticles were made by flame and used as inks.

Gold nanoparticles have been at the core of Ayurveda, a traditional Indian healing practice, for thousands of years. Although the jury is still out on whether these gold nanoparticles per se confer healing properties, the way in which they are made has paved the way for their use in modern medicine. It is now being studied as a way to target medically active compounds to tissues or cells implicated in various diseases such as cancer.

How small is a nanometer?

The word “nano” comes from a Greek word meaning “dwarf”. In essence, it means “very small”. A nanometer is 70,000 times smaller than the thickness of a human hair. A nanoparticle is anything so small that its size ranges from one to a few hundred nanometers. If you cut a block of wood into pieces about 0.00000001 centimeters (one nanometer) in length, you would have made nanoparticles.

Nanoparticles can be made up of almost anything, from metals to lipids. It can be formed naturally or unintentionally, and it can also be manufactured in research or industrial laboratories.

A set of containers containing different colored powders.
Different colored copper oxide quantum dots from Kerolis lab.
(Andrew Kingsley Girag)And Author introduced

Perhaps one of the most common nanoparticles today is carbon black, which is used to strengthen our tires and improve their wear resistance, and is a $17.5 billion industry in 2018. We paint the walls in our homes with white titanium nanoparticles. The pills we swallow to treat headaches or serious illnesses are usually covered with silica or titanium nanoparticles.

Recently, several brands of anti-aging creams have been touting their higher potency thanks to their active compounds found in liposomes – the same type of nano-sized lipid particles found at the core of COVID vaccines.

Given the wide prevalence and wide variety of nanoparticles, there are also some useless particles. For example, nano-sized soot particles from cigarettes that smokers inhale are very harmful to the lungs.

Other types of soot nanoparticles enter the atmosphere when aircraft and cargo ships burn fuel, where they are the third major contributor to the climate crisis. However, unlike other greenhouse gases, soot remains in the atmosphere only a few weeks (compared to a hundred years in the case of carbon dioxide). This means that if we stopped emitting soot today, the benefits would be immediate.

Read more: The 9 psychological barriers that lead to hesitation and rejection of the COVID-19 vaccine

Small is useful when used advantageously, but nanoparticles can sometimes elicit fear or mistrust. Just like the conversations we have with our families, helping people understand how nanoparticles are part of our daily lives may help dispel some of these concerns.

Do you have a question about COVID-19 vaccines? Email us at ca-vaccination@theconversation.com and vaccine experts will answer questions in upcoming articles.

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