Properties of silver nanoparticles
- Silver nanoparticles (AgNPs) are increasingly used in various fields, including medical, food, health care, consumer, and industrial purposes, due to their unique physical and chemical properties. These include optical, electrical, and thermal, high electrical conductivity, and biological properties
Silver nanoparticles have mainly been studied for their antimicrobial potential against bacteria, but have also proven to be active against several types of viruses including human imunodeficiency virus, hepatitis B virus, herpes simplex virus, respiratory syncytial virus, and monkey pox virus . Depending on the specific surface area of the nanoparticles, silver ions are released with high efficiency. In addition to their bactericidal activity, small Ag NPs (<10 nm in diameter) affect viruses although the microbicidal effect of silver mass is weak.
Virus infections pose significant global health challenges, especially in view of the fact that the emergence of resistant viral strains and the adverse side effects associated with prolonged use continue to slow down the application of effective antiviral therapies. This makes imperative the need for the development of safe and potent alternatives to conventional antiviral drugs. In the present scenario, nanoscale materials have emerged as novel antiviral agents for the possibilities offered by their unique chemical and physical properties. Silver nanoparticles have mainly been studied for their antimicrobial potential against bacteria, but have also proven to be active against several types of viruses including human imunodeficiency virus, hepatitis B virus, herpes simplex virus, respiratory syncytial virus, and monkey pox virus.
The use of metal nanoparticles provides an interesting opportunity for novel antiviral therapies. Since metals may attack a broad range of targets in the virus there is a lower possibility to develop resistance as compared to conventional antivirals. The present review focuses on the development of methods for the production of silver nanoparticles and on their use as antiviral therapeutics against pathogenic viruses.
Viruses represent one of the leading causes of disease and death worldwide. Thanks to vaccination programmes, some of the numerous diseases that used to kill many and permanently disable others have been eradicated
Emerging and re-emerging viruses are to be considered a continuing threat to human health because of their amazing ability to adapt to their current host, to switch to a new host and to evolve strategies to escape antiviral measures .
Viruses can emerge because of changes in the host, the environment, or the vector, and new pathogenic viruses can arise in humans from existing human viruses or from animal viruses. Several viral diseases that emerged in the last few decades have now become entrenched in human populations worldwide. The best known examples are: SARS , coronavirus, West Nile virus, monkey pox virus, Hantavirus, Nipah virus, Hendravirus, Chikungunya virus, and last but not least, the threat of pandemic influenza viruses, most recently of avian or swine origin. Unfortunately the methodological advances that led to their detection have not been matched by equal advances in the ability to prevent or control these diseases. There have been improvements in antiviral therapy, but with a wide margin of ineffectiveness, therefore new antiviral agents are urgently needed to continue the battle between invading viruses and host responses.
Technological advances have led to the discovery and characterization of molecules required for viral replication and to the development of antiviral agents to inhibit them. Most viruses are, indeed, provided by an extraordinary genetic adaptability, which has enabled them to escape antiviral inhibition and in certain cases to regain advantage over the host by mutagenesis that create new viral strains with acquired resistance to most of the antiviral compounds available
Due to the outbreak of the emerging infectious diseases caused by different pathogenic viruses and the development of antiviral resistance to classical antiviral drugs, pharmaceutical companies and numerous researchers are seeking new antiviral agents. In the present scenario, nanoscale materials have emerged as novel “antimicrobial agents” due to their high surface area to volume ratio and their unique chemical and physical properties
Nanotechnology is an emerging field of applied science and cutting edge technology that utilizes the physico-chemical properties of nanomaterials as a means to control their size, surface area, and shape in order to generate different nanoscale-sized materials. Among such materials, metal-based ones seem the most interesting and promising, and represent the subject of the present review. Nanotechnology is directly linked with physics, chemistry, biology, material science and medicine. In fact, it finds application in multiple aspects of research and in everyday life such as electronics and new material design. However, its use in medical research is probably one of the fastest growing areas in which the functional mechanisms of nanoparticles and especially metal-based nanoparticles are just beginning to be exploited. Nanotechnologies have been used to develop nanoparticle-based targeted drug carriers [6,7], rapid pathogen detection [8,9], and biomolecular sensing , as well as nanoparticle-based cancer therapies [11,12]. The use of nanoparticles can be extended to the development of antivirals that act by interfering with viral infection, particularly during attachment and entry.