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Antimony-doped tin oxide nanoparticles (ATO NPs) have emerged as a promising tool in biomedical applications, namely robust photothermal effects upon near-infrared (NIR) light exposure, enabling controlled thermal dynamics to induce spatial cell death. This study investigated the interplay between ATO NPs and macrophages, understanding cellular uptake and cytokine release. ATO NPs demonstrated biocompatibility with no impact on macrophage viability and cytokine secretion. These findings highlight the potential of ATO NPs for inducing targeted cell death in cancer treatments, leveraging their feasibility, unique NIR properties, and safe interactions with immune cells. ATO NPs offer a transformative platform with significant potential for future biomedical applications by combining photothermal capabilities and biocompatibility.

Generation of amplified stimulated emission inside mammalian cells has paved the way for a novel bioimaging and cell sensing approach. Single cells carrying gain media (e.g., fluorescent molecules) are placed inside an optical cavity, allowing the production of intracellular laser emission upon sufficient optical pumping. Here, we investigate the possibility to trigger another amplified emission phenomenon (i.e., amplified spontaneous emission or ASE) inside two different cell types, namely macrophage and epithelial cells from different species and tissues, in the presence of a poorly reflecting cavity. Furthermore, the resulting ASE properties can be enhanced by introducing plasmonic nanoparticles. The presence of gold nanoparticles (AuNPs) in rhodamine 6G-labeled A549 epithelial cells results in higher intensity and lowered ASE threshold in comparison to cells without nanoparticles, due to the effect of plasmonic field enhancement. An increase in intracellular concentration of AuNPs in rhodamine 6G-labeled macrophages is, however, responsible for the twofold increase in the ASE threshold and a reduction in the ASE intensity, dominantly due to a suppressed in and out-coupling of light at high nanoparticle concentrations., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)

The approval of new nanomedicines requires a deeper understanding of the interaction between cells and nanoparticles (NPs). Silica (SiO 2 ) and gold (Au) NPs have shown great potential in biomedical applications, such as the delivery of therapeutic agents, diagnostics, and biosensors. NP-cell interaction and internalization can trigger several cellular responses, including gene expression regulation. The identification of differentially expressed genes in response to NP uptake contributes to a better understanding of the cellular processes involved, including potential side effects. We investigated gene regulation in human macrophages and lung epithelial cells after acute exposure to spherical 60 nm SiO 2 NPs. SiO 2 NPs uptake did not considerably affect gene expression in epithelial cells, whereas five genes were up-regulated in macrophages. These genes are principally related to inflammation, chemotaxis, and cell adhesion. Nuclear receptor NR4A1, an important modulator of inflammation in macrophages, was found to be up-regulated. The expression of this gene was also increased upon 1 h of macrophage exposure to spherical 50 nm AuNPs and 200 nm spherical SiO 2 NPs. NR4A1 can thus be an important immediate regulator of inflammation provoked by NP uptake in macrophages.

The share of non-exhaust particles, including tire wear particles (TWP), within the airborne dust and particularly within PM10 has increased in recent years due to a significant reduction of other particles including exhaust road traffic emissions. However, the quantification of TWP is a demanding task due to the non-specificity of tracers, and the fact that they are commonly contained in analytically challenging low concentrations (e.g. Zn, styrene, 1,3-butadiene, vinylcyclohexene). This difficulty is amplified by the chemical and morpho-textural heterogeneity of TWP resulting from the interaction between the tires and the road surface. In contrast to bulk techniques, automated single particle SEM/EDX analysis can benefit from the ubiquitous heterogeneity of environmental TWP as a diagnostic criterion for their identification and quantification. For this purpose, we follow a machine-learning (ML) approach that makes use of an extensive number (67) of morphological, textural (backscatter-signal based) and chemical descriptors to differentiate environmental particles into the following classes: TWP, metals, minerals and biogenic/organic. We present a ML-based model developed to classify airborne samples (trained by >100,000 environmental particles including 6841 TWP), and its application within a one-year monitoring campaign at two Swiss sites. In this study, the mass concentrations of TWP in the airborne fractions PM80-10, PM10-2.5 and PM2.5-1 were determined. Furthermore, the particle size distribution and shape characteristics of 5621 TWP were evaluated. A cut through a TWP by means of FIB-SEM evidences that the mineral and metal particles typically found in TWP are not only present on the particle surface but also throughout the complete TWP volume. At the urban background site, the annual average mass fraction of TWP and micro-rubber in PM10 was 1.8% (0.28 μg/m 3 ) and 0.9%, respectively. At the urban kerbside site, the corresponding values were 6 times higher amounting to 10.5% (2.24 μg/m 3 ) for TWP, and 5.0% for micro-rubber., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)