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Silver nanoparticles (AgNPs) have become increasingly popular in the biomedical field over the last few decades due to its proven antibacterial property. Previous scientific studies have reported that one of the major organs responsible for detoxification of AgNPs is the liver. The liver is also the primary organ responsible for secretion of angiotensinogen (AGT), a key signaling molecule involved in the renin-angiotensin system (RAS), which plays an important role in maintaining cardiac output and vascular pressure. The aim of this study was to assess any potential changes in the RAS-associated gene signaling, inflammatory response, and hepatocellular toxicity resulting from AgNP exposure. To do this, 6-week-old, male Wistar rats were exposed to a subacute inhalation exposure of AgNP (200 ppb/days over 4 h/days exposure, for 5 d) and their livers were analyzed for alterations in RAS components, inflammation, and oxidative stress. Real time qPCR analysis showed that AgNP-exposure resulted in a significant increase in hepatic AGT, angiotensin converting enzyme (ACE)-1, and ACE-2 mRNA expression. Expression of inflammatory markers interleukin (IL)-6, IL-1β, and tumor necrosis factor (TNF)-α were also upregulated with AgNP-exposure, compared to controls. Furthermore AgNP-exposure mediated a significant increase in hepatic expression of catalase, and superoxide dismutase, and oxidative stress, as assessed via 8-Oxo-2'-deoxyguanosine staining. Increased oxidative stress was associated with increased monocyte/macrophage-2 staining in the liver of AgNP-exposed rats. Such findings indicate that subacute inhalation exposure to AgNPs mediate increased hepatic RAS signaling, associated with inflammation, macrophage infiltration, and oxidative stress., (© 2021 Wiley Periodicals LLC.)

Silver nanoparticles (AgNPs) have become crucial players in the field of medicine and various other industries. AgNPs have a wide array of applications, which includes production of electronic goods, cosmetics, synthesis of dyes, and printing inks, as well as targeted delivery of drugs to specialized cells inside the body. Even though humans readily come in contact with these particles, the organ-specific accumulation and resulting mechanisms of toxicity induced by inhaled AgNPs are still under investigation. The goal of this study was to determine the organ distribution of inhaled AgNPs and investigate the resulting systemic toxicity. To do this, male Wistar rats were exposed by inhalation to AgNPs for 4 hr/day (200 parts per billion/day) for five consecutive days. The nanoparticles were generated using a laser ablation technique using a soft-landing ion mobility (SLIM) instrument. Inductively coupled plasma mass spectrometric (ICP-MS) analysis showed organ-specific accumulation of the nanoparticles, with the highest concentration present in the lungs, followed by the liver and kidneys. Nanoparticle distribution was characterized in the organs using scanning electron microscopy (SEM) and matrix-assisted laser desorption/ionization mass spectrometric (MALDI-MS) imaging. Bone marrow cytotoxicity assay of the cells from the femur of rats showed micronuclei formation and signs of cellular cytotoxicity. Moreover, rats displayed increased levels of circulating lactate and glutathione disulphide (GSSG), as determined by liquid chromatography-mass spectrometry (LC-MS) analysis. Collectively, our observations suggest that inhaled subacute exposure to AgNP results in accumulation of AgNPs in the lungs, liver, and kidneys, preferentially, as well as mediates induced systemic toxicity., (© 2020 John Wiley & Sons, Ltd.)

Matrix-assisted laser desorption ionization (MALDI) imaging is gaining popularity, but matrix effects such as mass spectral interference and damage to the sample limit its applications. Replacing traditional matrices with silver particles capable of equivalent or increased photon energy absorption from the incoming laser has proven to be beneficial for low mass analysis. Not only can silver clusters be advantageous for low mass compound detection, but they can be used for imaging as well. Conventional matrix application methods can obstruct samples, such as fingerprints, rendering them useless after mass analysis. The ability to image latent fingerprints without causing damage to the ridge pattern is important as it allows for further characterization of the print. The application of silver clusters by soft-landing ion mobility allows for enhanced MALDI and preservation of fingerprint integrity.