Silver nanoparticles (AgNPs) are widely available as consumer goods, and over-the-counter or nutraceutical products used for alleged therapeutic and antibacterial properties. Among these products, AgNP topical therapy is proposed for treating patients with upper airway bacterial rhinosinusitis. While silver ion release from AgNPs in biological systems is well known, limited investigations actually characterize this silver ion release and their subsequent biological effects distinct from delivered particulate metallic silver. This is in part due to the analytical complexity and difficulty involved in distinguishing silver ion release from metallic AgNPs in biological media. Therefore, this study compared intranasal administration of AgNPs versus soluble silver ion (AgNO3) control to examine their transport and biological differences in tissues. First, we compared bactericidal activities of AgNPs and AgNO3 in those bacteria commonly associated with clinical rhinosinusitis in vitro. Next, we evaluated silver residence time in the sinus cavity after intranasal delivery of AgNPs and AgNO3 to mice, and characterized tissue distribution of silver in the sinonasal mucosal epithelium. We found that AgNPs show reduced bactericidal activity compared to AgNO3 (i.e., MBC of 15ppm compared to 5ppm), and significantly lower residence times in the sinus cavity (AgNP concentrations of 3.76ppm after 3h compared to 9ppm for AgNO3). AgNPs were not readily taken up into or through respiratory epithelium, with very low silver levels found in blood and no detectable silver measured in the olfactory bulb and brain. Results indicate that limited tissue distribution of silver detected from AgNPs is due to AgNP dissolution to silver ion. AgNPs therefore demonstrate adequate safety through limited penetration and absorption, but limited potential therapeutic efficacy as antimicrobials in nasal applications, as concentrations of silver in the sinus cavity drop below the minimum bactericidal concentration within 3h.
Pharmacology, Toxicology and Pharmaceutical Science
15
22%
Biochemistry, Genetics and Molecular Biology
6
9%
Immunology and Microbiology
4
6%
Chemistry
4
6%
Medicine and Dentistry
4
6%
Other
17
25%
Unknown
17
25%
Attention Score in Context
Attention Score in Context
This research output has an Altmetric Attention Score of 2. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 28 October 2017.
All research outputs
#16,725,651
of 25,382,440 outputs
Outputs from Journal of Controlled Release
#7,062
of 9,727 outputs
Outputs of similar age
#204,785
of 338,242 outputs
Outputs of similar age from Journal of Controlled Release
#75
of 133 outputs
Altmetric has tracked 25,382,440 research outputs across all sources so far. This one is in the 32nd percentile – i.e., 32% of other outputs scored the same or lower than it.
So far Altmetric has tracked 9,727 research outputs from this source. They typically receive a little more attention than average, with a mean Attention Score of 5.9. This one is in the 23rd percentile – i.e., 23% of its peers scored the same or lower than it.
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We're also able to compare this research output to 133 others from the same source and published within six weeks on either side of this one. This one is in the 40th percentile – i.e., 40% of its contemporaries scored the same or lower than it.
