Silver Nanoparticle Cytotoxic Mechanism

- Oct 13, 2017 -

"Nano silver" is short for "silver nanoparticles," or "silver nanoparticles," or "silver nanoparticles," or "silver nanoparticles," or "silver nanoparticles". Large silver of material surface has bacteriostatic properties have already known, its mechanism is silver atoms can be present on the surface of the material environment, slow oxidation and oxygen in the release of free silver ion (Ag +), the silver ions through combined with bacterial walls of sulphur, blocking bacteria respiratory chain, eventually kill the bacteria adhesion in the material surface. For large silver materials, the oxidation process is extremely slow, and the amount and rate of release of silver ions are very low.

"Nano silver" is short for "silver nanoparticles," or "silver nanoparticles," or "silver nanoparticles," or "silver nanoparticles," or "silver nanoparticles". Large silver of material surface has bacteriostatic properties have already known, its mechanism is silver atoms can be present on the surface of the material environment, slow oxidation and oxygen in the release of free silver ion (Ag), the silver ions through combined with bacterial walls of sulphur, blocking bacteria respiratory chain, eventually kill the bacteria adhesion in the material surface. For large silver materials, the oxidation process is extremely slow, and the amount and rate of release of silver ions are very low.

Like large silver materials, the nanosilver surface is also oxidized to release free silver ions. However, because nanoparticles of small size effect and surface effect, with the decrease of the particle size, the surface of the silver nanoparticles atomic number instead of a sharp increase in the proportion of inner atomicity, eventually lead to the silver ion release rate increased significantly; At the same time, due to its large particle surface release silver ions, and the particle size is smaller than viruses, silver ions on the surface of the silver nanoparticles can through its cause direct damage to the cell membrane and into a variety of cells, cause apoptosis or necrosis. Due to the above characteristics, the sterilization effect of silver nanoparticles was significantly higher than that of silver ions, but, at the same time, the nano silver into the cells and stop them, cause local high concentration of silver ion distribution, cause definite toxicity to the cells, tissues and organs and injury.

Nano silver cytotoxic mechanism mainly includes the following aspects: (1) whether itself or its silver ions on the surface of the silver nanoparticles can be applied to membrane protein of the cell membrane, activate the signal transduction pathways, inhibition of cell proliferation. (2) by the high concentration of silver ions on the surface of a particle caused by the oxidation of the cell membrane permeability of cell membrane changes, results in a flow in the calcium ion and overload, cause oxidative stress and mitochondrial membrane change; (3) distribution within the cytoplasm of nano silver lead to partial release silver ions concentration, caused by acting on mitochondrial respiratory chain function is impaired, resulting in ROS, cause oxidative stress and ATP synthesis disorder, cause DNA damage. (4) nanosilver in the cytoplasm causes cell cycle arrest and apoptosis. (5) nanosilver can induce the structural changes of a variety of proteins by adsorbing protein molecules, such as inhibiting the activity of creatine kinase in the brain and muscle cells. (6) due to the continuous release of silver ions from the nano-silver in the cytoplasm, the DNA damage caused by it cannot be fully repaired.

A large number of studies have confirmed that, regardless of exposure pathway, nanometer silver can lead to significant increases in the level of silver elements in organs and tissues, and can accumulate for months. In the liver and spleen, the accumulation is the most, followed by the kidney, thus causing obvious liver, renal toxicity and immunotoxicity. Second, nanosilver can span multiple biological barriers including the blood brain, blood testis, placenta and intestinal mucosa, causing clear central neurotoxicity, reproductive system toxicity and genetic toxicity.

Therefore, before considering the application of nanometer silver components research and development of medical supplies, need to fully understand cytotoxicity of silver nanoparticles, and the necessity of its clinical application, safety and efficacy, fully considering the impact on public health product.


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