Silver nanoparticles of 70 nm and 20 nm affect differently the biology of human neutrophils

Abstract

The influence of size of nanoparticles (NP), especially in regard to pulmonary toxicity, has been widely investigated. In general, NP with smaller diameters are more pro-inflammatory in vivo, at least in terms of neutrophil influx. Nevertheless, the influence of size of NP on polymorphonuclear neutrophil (PMN) cell biology is poorly documented. In the study here, it was decided to determine if AgNP with a diameter of 70 nm (AgNP70) will alter the biology of human PMN similarly to AgNP20 previously reported to induce apoptosis and inhibit de novo protein synthesis. The results here indicated that, in contrast to AgNP20, AgNP70 delayed PMN apoptosis. However, both AgNP20 and AgNP70 inhibited de novo protein synthesis. Both forms of AgNP did not significantly increase reactive oxygen species (ROS) production, but AgNP20 significantly increased the cell production of the CXCL8 chemokine (IL-8). In addition, AgNP20, but not AgNP70, induced the release of albumin and matrix metalloproteinase-9 (MMP-9/gelatinase B) into culture supernatants. Consistent with this latter observation, gelatinase activity was increased by AgNP20, as assessed by zymography. From these outcomes, it is concluded that two NP with different initial diameters can possess similar - as well as distinct - biological properties in modulating human PMN functions. These outcomes are testimony to the complexity of the modes of action of NP at the cellular level.

Silver nanoparticle immunomodulatory potential in absence of direct cytotoxicity in RAW 264.7 macrophages and MPRO 2.1 neutrophils

“…release of pro-inflammatory cytokines, neutrophil extracellular traps, cell death, etc.) in response to AgNP exposure in primary neutrophils (Poirier et al 2014(Poirier et al , 2016Soares et al 2016). However, those studies never attempted to study the consequences of exposure to sub-(cyto)toxic concentrations of the AgNPs.…”

Mechanistic understanding of nanoparticles’ interactions with extracellular matrix: the cell and immune system

“…Both forms of AgNPs do not significantly affect ROS production, but AgNP20 significantly increases the CXCL8 chemokine (IL-8) generation. In addition, AgNP20, but not AgNP70, induce the release of albumin and MMP-9/gelatinase B [102]. When treated with AgNP20, the size of the neutrophils increase and transmission electronic microscopy results indicate that within 1 day of exposure, AgNP20 can rapidly interact with the cell membrane, penetrate into neutrophils, localize in vacuole-like structures, and are randomly distributed in the cytosol [103].…”

Activation of human AML14.3D10 eosinophils by nanoparticles: Modulatory activity on apoptosis and cytokine production

“…The presence of large aggregates in AgNP 20 is not without any precedent since, as previously documented for human neutrophils (Poirier et al 2014), and as for these cells, we cannot rule out here the possibility that such aggregates can induce the observed effect in 3D10 cells. Interestingly, we recently documented that AgNP 70 and AgNP 20 alter differently the biology of human neutrophils (Poirier et al 2016). The fact that AgNP 20 were more potent than AgNP 70 could be related to their ability to penetrate more easily inside cells.…”

“…3D10 cells were incubated for up to 24 h in the presence or absence of 100 lg/ml of TiO 2 , CeO 2 , ZnO, AgNP 20 , or AgNP 70 and cell viability was then determined by trypan blue exclusion at 6, 12, 18, and 24 h. The concentration of 100 lg/ml was selected based on previous studies performed with human granulocytes (Goncalves et al 2010;Babin et al 2013;Goncalves & Girard 2014;Poirier et al 2014Poirier et al , 2016. For apoptosis, cells were incubated for 24 h and apoptosis then evaluated by flow cytometry by counting the numbers of FITC-Annexin-V-positive cells.…”