Applications of nanoparticles in the health sciences have seen progress in the past several years.

What is a nanoparticule

Nanoparticles have invaded our daily lives over the past few decades: basic ingredients in components for mass-market electronics (particularly those ensuring the capacitor function), sunscreens (and other cosmetics), colorants including food colorings, paints, fillers in many composite materials (including tires), construction materials, etc.

These particles are characterized by the fact that at least one of their three dimensions is less than 100 nm, thus leading to nano-objects of various shapes: more or less spherical nanopowders, nanotubes, nanoribbons, etc.

Due to their size, isolated metal nanoparticles exhibit specific properties compared to those of the bulk material. In particular they are the site of electronic oscillations at optical frequencies, called plasmons.

Made of gold, silver, or copper, they can be functionalized by adding a molecule (H2O, antibody, etc.), a semiconductor (TiO2, etc.), a quantum emitter (CdSe, etc.), or a catalyst (Pd, Pt, etc.), via a chemical bond, covalent or otherwise. They then become hybrid nanoparticles (or nanohybrids).

Within nanohybrids, complex mechanisms can lead to various phenomena such as:

the localized generation of light or electron-hole pairs

heat release from the absorbed radiation

the formation of a reactive oxygen species (singlet) or hydrogen

These properties open the door to applications in photonics and microelectronics (sensors), as well as nanomedicine. In particular, the release of heat or reactive oxygen types by gold nanorods illuminated with an infrared laser could help treat cancerous tumors.

Gold nanoparticules explained

Gold nanoparticles are one of many nanoplatforms developed for pharmaceutical or biomedical use in a field known as nanomedicine.

These Gold nanoparticles can take various shapes and sizes and are composed of a gold core and a ring of organic molecules called ligands, which can be Active Pharmaceutical Ingredients (API). Combining gold nanoparticles with an API can enhance its physicochemical or biological properties, leading to an improvement in its pharmacological effect.

Gold nanoparticles characterization is essential. It is performed using a range of complementary analytical techniques. Some techniques provide size information (nucleus or whole particle), while others characterize the corona. All techniques must be optimized for a specific compound, while being designed to ensure maximum versatility.

Very Promising Initial Results on Several Viruses

To carry out their research aimed at inventing a strategy that effectively eliminates viruses from the body while remaining non-toxic to humans, some twenty international researchers specializing in the fields of virology and nanomaterials have succeeded in creating gold-based nanoparticles (particles with a diameter of around a nanometer, or 1,000,000 times smaller than a millimeter).

In this process developed by the researchers, the virus binds to the gold nanoparticle, which it mistakenly identifies as a human cell. Its immediate bond with the particle causes pressure that deforms and splits it. Once opened, the virus becomes harmless.

The ingenuity of this discovery? In this case, virus destruction occurs through mechanical pressure, which is non-toxic to human cells, unlike other previously tested solutions that used a chemical process to destroy the virus.

The advantages of broad-spectrum antiviral treatment

Like broad-spectrum antibiotics, which act against a range of bacteria, the development of antivirals that eradicate multiple viruses simultaneously remains a very promising therapeutic strategy.

The advantages of such antiviral therapy would:

offer a single solution to combat viral infections for which there is no treatment

enable developing countries, which have limited human and material resources to establish accurate diagnoses, to opt for non-specific treatment

fight against growing viral mutations

This is promising to prevent viral infections and epidemics. It now remains to conduct very in-depth studies on animal models, then on humans, to prove the effectiveness of these gold nanoparticles in the fight against viruses.