Frontiers in Chemistry

Our medical research library holds 7 studies published in Frontiers in Chemistry (2022–2025). Each entry links to the study's record on PubMed and, where there is one, to the publisher's page and a free full text. 7 have an abstract, the authors' own summary as PubMed records it: open "Abstract" to read it.

About the journal

• Publisher: Frontiers Media S.A
• Published: 2013 to the present, Switzerland
• Language: English
• ISSN: 2296-2646 (electronic)
• Its record in the NLM Catalog

2020s

• Manganese-doped nanotheranostic system for MRI-guided photothermal therapy of malignant pleural mesothelioma: in vivo study. L. Lei, H. Zi, S. Kang, et al. 2025;13:1659283. PubMed · Publisher · Free full text

  Abstract

  Introduction: Magnetic Resonance Imaging (MRI)-guided photothermal therapy (PTT) holds significant promise for the treatment of solid tumors, however, its diagnostic and therapeutic efficacy in malignant pleural mesothelioma (MPM) remains underexplored. To address the limitations of traditional gadolinium (Gd)-based MRI contrast agents, such as intolerance in patients with renal insufficiency and T1 signal attenuation at high field strengths, as well as oxidative stress damage caused by manganese ion leakage from manganese-based materials, this study aims to develop highly chelated and stable manganese polydopamine (Mn-PDA) multifunctional nanoprobes for MRI monitoring and PTT treatment of MPM.

  Methods: Mn2+ and dopamine were chelated into Mn-PDA NP nanospheres in an ethanol-water system. The physicochemical properties were characterized using Transmission Electron Microscopy (TEM), Dynamic Light Scattering (DLS), zeta potential, Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Photoelectron Spectroscopy (XPS), and Electron Paramagnetic Resonance (EPR). The photothermal performance under 808 nm laser irradiation was also evaluated. The MRI imaging performance (longitudinal/transverse relaxation rates, r1/r2) and manganese ion deposition quantification of Mn-PDA NPs were evaluated in vitro and in vivo at 3.0 T MR scanner. Additionally, the PTT efficacy of Mn-PDA NPs was evaluated in MSTO-211H cells and xenograft tumor models. Biocompatibility was assessed through H&E staining of major organs and blood biochemical analyses.

  Results: Mn-PDA NPs exhibited a spherical morphology with uniform size (~200 nm), along with high photothermal conversion efficiency, favorable T1-weighted MRI contrast enhancement and low cytotoxicity. At 8 hours post-injection in vivo, Mn-PDA NPs resulted in a 42.9% enhancement in T1-weighted MRI signals within MPM tumors, accompanied by specific tumor accumulation. Under 808 nm laser irradiation, Mn-PDA NPs inhibited MPM tumor growth, as evidenced by reduced tumor volume, expanded areas of tumor necrosis (H&E staining), and downregulated Ki-67 expression. Moreover, stable body weight, normal histological features of major organs, and unaltered blood biochemical parameters were observed in the animals.

  Discussion: These findings indicate that Mn-PDA NPs are effective dual-functional agents, serving as both MRI contrast agents and photothermal therapeutics. They exhibit good tumor targeting ability, excellent imaging performance, potent therapeutic efficacy, and high biosafety, thereby offering a promising therapeutic strategy for MPM management.

  Copyright © 2025 Lei, Zi, Kang, Duan, Zhang, Gao, Xu and Han.

• Validation of freeze-drier/plasma asher method for analysis of asbestos in the lung tissue. A.B. Somigliana. 2025;13:1581910. PubMed · Publisher · Free full text

  Abstract

  Introduction: The analysis of asbestos fibers in lung tissue is complex due to both the biological matrix and the analyte. Lung tissue preparation techniques for asbestos burden analysis require the removal of organic matter to make the inorganic mineral components visible. The method's validation is challenging due to the analyte's inherent variability. This study outlines a procedure for validating an asbestos fiber analysis method in lung tissue.

  Methods: At the Electron Microscopy Laboratory of ARPA Lombardia, a method using a plasma asher for freeze-dried lung tissue digestion was developed. The analysis is carried out with a scanning electron microscope equipped with an energy-dispersive x-ray spectrometer. Problems associated with interferences, instrument calibration and resolution, analytical sensitivity, recovery were described in detail. The trueness and precision of the analytical method were evaluated using certified reference materials in accordance with ISO 33403:2024 standard.

  Results And Conclusion: The developed method underwent a rigorous validation process to ensure metrological traceability of the results. Using validated analytical methods with consistent counting rules ensures comparability of data across laboratories while guaranteeing traceable results.

  Copyright © 2025 Somigliana.

• Detection of PD-L1 expression levels in malignant pleural mesothelioma with a targeted MRI nanoprobe in vivo. Z. Zhang, Y. Tian, W. Gao, et al. 2024;12:1508912. PubMed · Publisher · Free full text

  Abstract

  Objectives: Immune checkpoint inhibitors (ICIs) have demonstrated potential in inhibiting the growth of malignant pleural mesothelioma (MPM), and their efficacy is associated with the expression of programmed death-ligand 1(PD-L1). This study evaluated a PD-L1-targeted nanoprobe for detecting PD-L1 expression in a nude mouse model of malignant pleural mesothelioma (MPM).

  Methods: A PD-L1-binding peptide (WL-12) was conjugated with superparamagnetic iron oxide nanoparticles (SPIONs) to create the nanoprobe WL-12@Fe₃O₄. The nanoprobe's stability, biotoxicity, targeting ability, and in vivo magnetic resonance (MR) imaging effects were assessed and compared to non-targeted Fe₃O₄ nanoparticles. ΔT2 values and PD-L1 expression were measured in H226 and MSTO-211H tumor tissues over 4 weeks to analyze correlations.

  Results: The WL-12@Fe₃O₄ nanoprobe demonstrated uniform distribution and a spherical shape, with a larger size (43.82 nm) and lower surface potential (-9.34 ± 0.54 mV) compared to Fe₃O₄ (32.67 nm, -20.20 ± 0.88 mV, P < 0.05). The XPS and FT-IR analysis results indicate the successful coupling of WL-12 with Fe3O4. It was well dispersed in serum and saline and showed no cytotoxicity or organ damage in vivo. The probe selectively accumulated in PD-L1-expressing MPM cells, especially MSTO-211H, and exhibited significantly higher uptake in high PD-L1-expressing H460 cells (930.22 ± 11.75 ng/mL) compared to low PD-L1-expressing A549 cells (254.89 ± 17.33 ng/mL, P < 0.05). Tumor iron levels in the WL-12@Fe₃O₄ group were significantly elevated (141.02 ± 17.33 μg/g) compared to controls (36.43 ± 3.56 μg/g, P < 0.05), with no significant differences in other organs (P > 0.05). The T2 values of H226 and MSTO-211H tumors decreased after probe injection, with ΔT2 values significantly higher in the targeted group than the nontargeted group (P < 0.05). ΔT2 values increased over 4 weeks, correlating strongly with PD-L1 expression (P < 0.05).

  Conclusion: The PD-L1-targeted nanoprobe with MRI is a promising tool for noninvasive, real-time assessment of PD-L1 expression in MPM.

  Copyright © 2024 Zhang, Tian, Gao, Hu, Luo, Lei, Shen and Han.

• A new approach to deposit homogeneous samples of asbestos fibres for toxicological tests in vitro. G. Della Ventura, A. Rabiee, A. Marcelli, et al. 2023;11:1116463. PubMed · Publisher · Free full text

  Abstract

  In this paper we describe the results obtained with a novel method to prepare depositions of asbestos fibres for toxicological tests in vitro. The technique is based on a micro-dispenser, working as an inkjet printer, able to deposit micro-sized droplets from a suspension of fibres in a liquid medium; we used here a highly evaporating liquid (ethanol) to reduce the experimental time, however other solvents could be used. Both the amount and spatial distribution of fibres on the substrate can be controlled by adjusting the parameters of the micro-dispenser such as deposition area, deposition time, uniformity and volume of the deposited liquid. Statistical analysis of images obtained by optical and scanning electron microscopy shows that this technique produces an extremely homogeneous distribution of fibers. Specifically, the number of deposited single fibres is maximized (up to 20 times), a feature that is essential when performing viability tests where agglomerated or untangled fibrous particles need to be avoided.

  Copyright © 2023 Della Ventura, Rabiee, Marcelli, Macis, D’Arco, Iezzi, Radica and Lucci.

• Waterborne asbestos: Good practices for surface waters analyses. C. Avataneo, S. Capella, M. Luiso, et al. 2023;11:1104569. PubMed · Publisher · Free full text

  Abstract

  Asbestos occurrence has been mainly monitored in air so far and only limitedly considered in other matrices, such as water. Waterborne asbestos could originate from natural or anthropogenic sources, leading to non-conventional exposure scenarios. It could be a secondary source of airborne asbestos in case of water-to-air migration, particularly in case of surface moving water, such as in rivers and streams. The scarce attention dedicated to waterborne asbestos has led to a considerable fragmentation in regulatory approaches regarding the study of water samples possibly contaminated by mineral fibres. In this context, this study has been designed to test the reliability of an existing analytical method devoted to natural waters investigations. Following the operational protocol issued by the Piedmont (Italy) Environmental Protection Agency, Scanning Electron Microscopy analyses have been performed on a standard sample of waterborne chrysotile, mimicking stream water. The investigations have been performed by different operators and using different analytical setups, to verify whether the method applied has a good interlaboratory reproducibility and which could be the most error-prone analytical steps. Three data sets have been obtained on the same sample, showing a low reproducibility among each other. Possible reasons causing this discrepancy have been discussed in detail and good practices to perform reliable analyses on surface water samples containing asbestos have been proposed to help the regulatory organs to better define analytical protocols.

  Copyright © 2023 Avataneo, Capella, Luiso, Marangoni, Lasagna, De Luca, Bergamini, Belluso and Turci.

• Global geological occurrence and character of the carcinogenic zeolite mineral, erionite: A review. J.P. Patel, M.S. Brook, M. Kah, et al. 2022;10:1066565. Review PubMed · Publisher · Free full text

  Abstract

  As with the six regulated asbestos minerals (chrysotile, amosite, crocidolite, anthophyllite, tremolite, and actinolite), the zeolite mineral, erionite, can exhibit a fibrous morphology. When fibrous erionite is aerosolized and inhaled, it has been linked to cases of lung cancers, such as malignant mesothelioma. Importantly, fibrous erionite appears to be more carcinogenic than the six regulated asbestos minerals. The first health issues regarding erionite exposure were reported in Cappadocia (Turkey), and more recently, occupational exposure issues have emerged in the United States. Erionite is now classified as a Group 1 carcinogen. Thus, identifying the geological occurrence of erionite is a prudent step in determining possible exposure pathways, but a global review of the geological occurrence of erionite is currently lacking. Here, we provide a review of the >100 global locations where erionite has been reported, including: 1) geological setting of host rocks; 2) paragenetic sequence of erionite formation, including associated zeolite minerals; 3) fiber morphological properties and erionite mineral series (i.e., Ca, K, Na); and 4) a brief overview of the techniques that have been used to identify and characterize erionite. Accordingly, erionite has been found to commonly occur within two major rock types: felsic and mafic. Within felsic rocks (in particular, tuffaceous layers within lacustrine paleoenvironments), erionite is disseminated through the layer as a cementing matrix. In contrast, within mafic (i.e., basaltic) rocks, erionite is typically found within vesicles. Nevertheless, aside from detailed studies in Italy and the United States, there is a paucity of specific information on erionite geological provenance or fiber morphology. The latter issue is a significant drawback given its impact on erionite toxicity. Future erionite studies should aim to provide more detailed information, including variables such as rock type and lithological properties, quantitative geochemistry, and fiber morphology.

  Copyright © 2022 Patel, Brook, Kah and Hamilton.

• Reanalysis of historic elemental speciation filters to investigate the presence of fibrous mineral particles using microscopy techniques. N. Talbot, K.N. Dirks, W. Fan, et al. 2022;10:1032624. PubMed · Publisher · Free full text

  Abstract

  A case is presented for the value of archiving air quality filters to allow for retrospective analysis of emerging contaminants, that is filter constituents not considered to be harmful (and thus not identified or quantified specifically) at the time of collection but subsequently considered to be of interest. As an example, filters from a 20-year historical archive consisting of 16,000 filters from three sites across Auckland are re-examined for the presence of elongated mineral fibres known to be present in rock across the city. Originally collected for the purpose of the source apportionment of particulate matter, 10 filters from each of the three sites were chosen for reanalysis based on their high silica and aluminium content, and thus considered more likely to contain fibre-like particles (FLP). These filters were analysed using various microscopic methods, including phase contrast microscopy (PCM), scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDS). The results show that although the commonly used fibrous polytetrafluoroethylene (PTFE) material of the filters may hamper the visual identification of any fibre-like particles under a certain length, their key components are able to be identified using a combination of PCM and SEM when they are of a suitable dimension and have settled in a certain orientation on the filter. In this case, the use of EDS confirmed the silicon content of the fibres and also revealed elemental spectra. Although the exact identification of the mineral fibre is uncertain, the EDS scan is consistent with hazardous zeolites such as erionite, known to be present in the rock found in Auckland. This study highlights the value in maintaining filter archives for the purpose of investigating the historical evolution of emerging atmospheric pollutants.

  Copyright © 2022 Talbot, Dirks, Fan, Patel, Costello, Brook and Davy.

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