MACRAMÉ - Advanced characterisation methodologies to assess and predict the health and environmental risks of advanced materials.

Ensuring the safety and sustainability of advanced materials (AdMas) is critical for fostering innovation while protecting human health and the environment. As industries integrate AdMas into commercial products to innovate in the next stage of the value chains, there is an urgent need for robust methodologies to detect, characterize, and assess their potential risks throughout their life cycle. The MACRAMÉ Project addresses this challenge by advancing standardized testing and regulatory frameworks, supporting the EU's vision for a toxic-free environment.

Reliable Surface Analysis Data of Nanomaterials in Support of Risk Assessment Based on Minimum Information Requirements.

The minimum information requirements needed to guarantee high-quality surface analysis data of nanomaterials are described with the aim to provide reliable and traceable information about size, shape, elemental composition and surface chemistry for risk assessment approaches. The widespread surface analysis methods electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and secondary ion mass spectrometry (SIMS) were considered. The complete analysis sequence from sample preparation, over measurements, to data analysis and data format for reporting and archiving is outlined.

Evaluation of Time-of-Flight Secondary Ion Mass Spectrometry Spectra of Peptides by Random Forest with Amino Acid Labels: Results from a Versailles Project on Advanced Materials and Standards Interlaboratory Study.

We report the results of a VAMAS (Versailles Project on Advanced Materials and Standards) interlaboratory study on the identification of peptide sample TOF-SIMS spectra by machine learning. More than 1000 time-of-flight secondary ion mass spectrometry (TOF-SIMS) spectra of six peptide model samples (one of them was a test sample) were collected using 27 TOF-SIMS instruments from 25 institutes of six countries, the U. S.

Distribution of Paramagnetic Fe₂O₃/SiO₂⁻Core/Shell Nanoparticles in the Rat Lung Studied by Time-of-Flight Secondary Ion Mass Spectrometry: No Indication for Rapid Lipid Adsorption.

Amorphous silica nanoparticles comprise a class of widely used industrial nanomaterials, which may elicit acute inflammation in the lung. These materials have a large specific surface to which components of the pulmonary micro-milieu can bind. To conduct appropriate binding studies, paramagnetic Fe₂O₃/SiO₂ core/shell nanoparticles (Fe-Si-NP) may be used as an easy-to-isolate silica surrogate, if several prerequisites are fulfilled.

Detection of ZrO₂ Nanoparticles in Lung Tissue Sections by Time-of-Flight Secondary Ion Mass Spectrometry and Ion Beam Microscopy.

The increasing use of nanoparticles (NP) in commercial products requires elaborated techniques to detect NP in the tissue of exposed organisms. However, due to the low amount of material, the detection and exact localization of NP within tissue sections is demanding. In this respect, Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) and Ion Beam Microscopy (IBM) are promising techniques, because they both offer sub-micron lateral resolutions along with high sensitivities.

Detection of SiO nanoparticles in lung tissue by ToF-SIMS imaging and fluorescence microscopy.

The direct detection of nanoparticles in tissues at high spatial resolution is a current goal in nanotoxicology. Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) is widely used for the direct detection of inorganic and organic substances with high spatial resolution but its capability to detect nanoparticles in tissue sections is still insufficiently explored. To estimate the applicability of this technique for nanotoxicological questions, comparative studies with established techniques on the detection of nanoparticles can offer additional insights.

Structural and photosensitizing features of phthalocyanine--zeolite hybrid nanomaterials.

In this work, we have quantified for the first time the fluorescence and singlet oxygen quantum yields of a silicon(IV) phthalocyanine bound to the surface of zeolite L nanocrystals. The photophysical properties were correlated with the absorption spectra and the morphology of the nanoparticles, and most importantly, with the fraction of photoactive chromophores. By comparison with the fluorescence and singlet oxygen quantum yields of the free phthalocyaninate in dilute solution (ΦF = 0.

Bioimaging TOF-SIMS: High resolution 3D imaging of single cells.

The distribution of phosphocholine ions (m/z 184, m/z 86), sodium ions, and potassium ions in thyroid tumor cells was analyzed by imaging TOF-SIMS. Repeated sputtering with a C(60) (+) source and subsequent analysis with a Bi(3) (+) gun produced a series of 138 images that were stacked to make a 3D display of the chemistry of cells. Phosphocholine was seen in the plasma membrane (m/z 184) and intracellular membranes (m/z 86).

Localization of fatty acids with selective chain length by imaging time-of-flight secondary ion mass spectrometry.

Localization of fatty acids in biological tissues was made by using TOF-SIMS (time-of-flight secondary ion mass spectrometry). Two cell-types with a specific fatty acid distribution are shown. In rat cerebellum, different distribution patterns of stearic acid (C18:0), palmitic acid (C16:0), and oleic acid (C18:1) were found.

Localization of lipids in the aortic wall with imaging TOF-SIMS.

Time-of-flight secondary-ion-mass-spectrometry (TOF-SIMS) was utilized to address the issue of localization of lipids and inorganic ions in healthy rat aorta and human atherosclerotic plaque. Pieces of rat aorta were high pressure frozen, freeze-fractured and freeze dried. The samples were analyzed by imaging TOF-SIMS equipped with a Bi(1-7)(+)-source.

Distribution of cholesterol and galactosylceramide in rat cerebellar white matter.

White matter and the inner granular layer of rat cerebellum was analysed by imaging time-of-flight secondary-ion mass spectrometry (TOF-SIMS) equipped with a Bi+ ion cluster gun. Samples were prepared by high pressure freezing, freeze-fracturing and freeze drying or by plunge freezing and cryostat sectioning. The identified and localized chemical species were: sodium, potassium, phosphocholine, cholesterol and galactosylceramide (GalC) with carbon chain lengths C18:0 (N-stearoyl-galactosylceramide) and C24:0 (N-lignoceroylgalactosylceramide) with CH24:0 (hydroxy-lignoceroylgalactosylceramide).

Imaging TOF-SIMS of rat kidney prepared by high-pressure freezing.

Phosphocholine, potassium ions, and sodium ions were localized in rat kidney with imaging TOF-SIMS. Tissue preparation was performed with high-pressure freezing, freeze-fracturing and freeze-drying. The distribution of sodium ions was visualized by imaging the signal at m/z 23 of positively charged secondary ions, and the distribution of potassium ions was visualized by imaging the signal at m/z 39.

Localization of cholesterol, phosphocholine and galactosylceramide in rat cerebellar cortex with imaging TOF-SIMS equipped with a bismuth cluster ion source.

Time-of-flight secondary-ion-mass-spectrometry (TOF-SIMS) was utilized to address the issue of co-localization of cholesterol, phosphocholine and galactosylceramide in rat cerebellar cortex. Rat cerebellum was fixed, freeze-protected by sucrose, frozen and sectioned by cryoultramicrotomy and dried at room temperature. The samples were analyzed in an imaging TOF-SIMS instrument equipped with a Bi(1-7)+-source.

Tissue molecular ion imaging by gold cluster ion bombardment.

The use of gold cluster focused ion beams produced by a liquid metal ion gun in a TOF-SIMS mass spectrometer is shown to dramatically enhance secondary ion emission of phospholipids and peptides. The method has been successfully tested with cells grown onto plastic slips and with mouse brain slices, without any treatment of the samples. Very reliable time-of-flight mass spectra are acquired with a low primary ion dose of a few 10(7) ions, and high lateral resolution molecular ion images are obtained for heavy ions of great biological interest.