What Are The Advantages Of Nano Silver Particles In The Development Of Influenza Virus Drugs

Influenza virus is an orthomyxovirus. Its infection can cause severe respiratory diseases, which is not only a threat to human health as a result of serious individual infection or even death, but also a potential threat of rapid transmission between animals and humans, and between humans because the influenza virus can undergo frequent mutations and mutate into highly pathogenic strains. In ta huge economic he 20th century, there were several influenza pandemics in the world. All previous influenza outbreaks caused huge human and material losses to the world. Due to influenza worldwide, the number of direct deaths each year is 10,000 to 15,000, and the number of indirect deaths from influenza-related diseases is 200,000 to 500,000. Once the global pandemic of influenza, 20% to 40% of the population will be infected by the influenza virus, and the mortality will be significantly increased. The worldwide influenza A HIN1 pandemic that broke out in 2009 has spread rapidly and widely. Lethality of the influenza A H1N1 virus strain was low this time, but it still caused burden on the world.

Influenza virus infection is difficult to control, mainly due to two glycoproteins on the surface of the influenza virus, namely hemagglutinin (HA) and neuraminidase (NA) proteins. These two proteins are weakly antigenic and prone to antigenic variation and drug resistance mutations, leading to the emergence of new subtypes. Existing vaccines lack specificity for the prevention of new virus strains, resulting in a poor clinical prevention or treatment effect on influenza viruses. After the influenza virus is mutated, the infection caused by the new subtype is not easy to be effectively controlled, which can lead to a local outbreak of influenza or a global pandemic. At present, in order to prevent influenza virus infection, the most effective strategy is to administer an annual influenza virus vaccine. Vaccination can also reduce the morbidity and mortality of patients with known influenza viruses. However, when an influenza outbreak occurs, the production of specific influenza virus vaccines still cannot meet the urgent global demand, and the use of influenza virus drugs for antiviral treatment is particularly important. There are currently four approved clinical anti-influenza virus drugs, including neuraminidase inhibitors (oseltamivir, zanamivir) and amantadine (amantadine and amantadine ethylamine), which can play a broad-spectrum role in prevention and treatment against mutant strains. However, the resistance of mutated influenza A virus to oseltamivir is becoming more and more common. Both the seasonal influenza virus and 2009 H1N1 were insensitive to neuraminidase inhibitors and resistant to adamantane to a certain extent. Therefore, it is of great academic significance and practical application value to actively develop safe and effective broad-spectrum non-specific anti-influenza virus drugs or materials for mucosal surface application worldwide.

In the field of biomedicine, nanotechnology and nanomedicine research have found that nanotechnology has broad application prospects in the field of drug development. And Silver-NPs perform particularly well. In drug development, Silver NPs not only show good drug delivery properties, but also have a long-lasting and highly effective anti-environmental pathogen function as a carrier. Therefore, using Silver NPs as a drug carrier for influenza virus can serve multiple functions. The experimental data verified that Silver-NPs also had a significant inhibitory effect on influenza virus.

At present, the anti-viral mechanism of nano-silver is not very clear, and may be related to the following mechanisms: 1. The mechanical adsorption and immobilization of viruses by nano-silver. The surface of nano-ultrafine particles is covered with a layer of 5-10 nm thick polymer and can fix a large number of proteins and enzymes, especially polysaccharides, and many polysaccharides may prevent the virus from adsorbing to the host cell, thereby showing strong antiviral activity; at the same time, due to the colloidal stability and strong adsorption of nanomaterial particles, the virus lose its living conditions and die.  2. Nano-silver can prevent the virus from entering the host cell, inhibit the virus from binding to cell receptors, and thus prevent the virus from infecting the host cell. Some small nanomolecules can bind to the conserved spatial structure of virus surface proteins to inhibit the interaction between the virus and the receptor, thereby preventing the virus from entering the cell. In addition, direct inactivation of the virus may be similar to its ability to kill bacteria. For example, nano-silver particles combine with -SH on the surface protein of the virion to form a -SAg complex, which inactivates the enzyme protein, interferes with the invasion of the virus, or kills the virus, resulting in virus inactivation. 3. Nano-silver can be combined with viral nucleic acid to change the structure of viral DNA or RNA, affect the replication of DNA or RNA, and make the virus inactive. 4. Ag + released by nano-silver has a direct damaging effect on the virus.