Demystifying and unravelling the molecular structure of the biopolymer sporopollenin.

Rationale: We report the unsolved molecular structure of the complex biopolymer sporopollenin exine extracted from Lycopodium clavatum pollen grains.

Methods: TOF-SIMS and CID-MS/MS, MALDI-TOF-MS and CID-TOF/TOF-MS/MS were used for the analysis of this complex biopolymer sporopollenin exine extracted from Lycopodium clavatum pollen grains. Solid-state H- and C-NMR, 2D H- H NOESY, Rotor-synchronized C{ H} HSQC, and C{ H} multi CP-MAS NMR experiments were used to confirm the structural assigments revealed by MS and MS/MS studies.

Time-of-flight secondary ion tandem mass spectrometry depth profiling of organic light-emitting diode devices for elucidating the degradation process.

Rationale: Organic light-emitting diode (OLED) products based on display applications have become popular in the past 10 years, and new products are being commercialized with rapid frequency. Despite the many advantages of OLEDs, these devices still have a problem concerning lifetime. To gain an understanding of the degradation process, the authors have investigated the molecular information for deteriorated OLED devices using time-of-flight secondary ion mass spectrometry (TOF-SIMS).

Mass Spectrometric Imaging Reveals Temporal and Spatial Dynamics of Bioactive Lipids in Arteries Undergoing Restenosis.

Restenosis, or renarrowing of the arterial lumen, is a common recurrent disease following balloon angioplasty and stenting treatments for cardiovascular disease. A major technical barrier for deciphering restenotic mechanisms is the dynamic, spatial profiling of bioactive lipids in the arterial wall, especially in small animals. Here, applying matrix-assisted laser desorption/ionization mass spectrometric imaging (MALDI-MSI), we conducted the first lipidomic study of temporal-spatial profiling in a small animal model of angioplasty-induced restenosis.

Biosynthetic investigation of γ-lactones in Sextonia rubra wood using in situ TOF-SIMS MS/MS imaging to localize and characterize biosynthetic intermediates.

Molecular analysis by parallel tandem mass spectrometry (MS/MS) imaging contributes to the in situ characterization of biosynthetic intermediates which is crucial for deciphering the metabolic pathways in living organisms. We report the first use of TOF-SIMS MS/MS imaging for the cellular localization and characterization of biosynthetic intermediates of bioactive γ-lactones rubrynolide and rubrenolide in the Amazonian tree Sextonia rubra (Lauraceae). Five γ-lactones, including previously reported rubrynolide and rubrenolide, were isolated using a conventional approach and their structural characterization and localization at a lateral resolution of ~400 nm was later achieved using TOF-SIMS MS/MS imaging analysis.

Identification and High-Resolution Imaging of α-Tocopherol from Human Cells to Whole Animals by TOF-SIMS Tandem Mass Spectrometry.

A unique method for identification of biomolecular components in different biological specimens, while preserving the capability for high speed 2D and 3D molecular imaging, is employed to investigate cellular response to oxidative stress. The employed method enables observing the distribution of the antioxidant α-tocopherol and other molecules in cellular structures via time-of-flight secondary ion mass spectrometry (TOF-SIMS (MS)) imaging in parallel with tandem mass spectrometry (MS) imaging, collected simultaneously. The described method is employed to examine a network formed by neuronal cells differentiated from human induced pluripotent stem cells (iPSCs), a model for investigating human neurons in vitro.

Tandem Mass Spectrometry Imaging and in Situ Characterization of Bioactive Wood Metabolites in Amazonian Tree Species Sextonia rubra.

Driven by a necessity for confident molecular identification at high spatial resolution, a new time-of-flight secondary ion mass spectrometry (TOF-SIMS) tandem mass spectrometry (tandem MS) imaging instrument has been recently developed. In this paper, the superior MS/MS spectrometry and imaging capability of this new tool is shown for natural product study. For the first time, via in situ analysis of the bioactive metabolites rubrynolide and rubrenolide in Amazonian tree species Sextonia rubra (Lauraceae), we were able both to analyze and to image by tandem MS the molecular products of natural biosynthesis.

Observation of endoplasmic reticulum tubules via TOF-SIMS tandem mass spectrometry imaging of transfected cells.

Advances in three-dimensional secondary ion mass spectrometry (SIMS) imaging have enabled visualizing the subcellular distributions of various lipid species within individual cells. However, the difficulty of locating organelles using SIMS limits efforts to study their lipid compositions. Here, the authors have assessed whether endoplasmic reticulum (ER)-Tracker Blue White DPX, which is a commercially available stain for visualizing the endoplasmic reticulum using fluorescence microscopy, produces distinctive ions that can be used to locate the endoplasmic reticulum using SIMS.

Characterization of natural photonic crystals in iridescent wings of damselfly Chalcopteryx rutilans by FIB/SEM, TEM, and TOF-SIMS.

The iridescent wings of the Chalcopterix rutilans damselfly (Rambur) (Odonata, Polythoridae) are investigated with focused ion beam/scanning electron microscopy, transmission electron microscopy, and time-of-flight secondary ion mass spectrometry. The electron microscopy images reveal a natural photonic crystal as the source of the varying colors. The photonic crystal has a consistent number and thickness (∼195 nm) of the repeat units on the ventral side of the wing, which is consistent with the red color visible from the bottom side of the wing in all regions.

Visualizing molecular distributions for biomaterials applications with mass spectrometry imaging: a review.

Mass spectrometry imaging (MSI) is a rapidly emerging field that is continually finding applications in new and exciting areas. The ability of MSI to measure the spatial distribution of molecules at or near the surface of complex substrates makes it an ideal candidate for many applications, including those in the sphere of materials chemistry. Continual development and optimization of both ionization sources and analyzer technologies have resulted in a wide array of MSI tools available, both commercially available and custom-built, with each configuration possessing inherent strengths and limitations.

Sequencing and Identification of Endogenous Neuropeptides with Matrix-Enhanced Secondary Ion Mass Spectrometry Tandem Mass Spectrometry.

Matrix-enhanced secondary ion mass spectrometry (ME-SIMS) has overcome one of the biggest disadvantages of SIMS analysis by providing the ability to detect intact biomolecules at high spatial resolution. By increasing ionization efficiency and minimizing primary ion beam-induced fragmentation of analytes, ME-SIMS has proven useful for detection of numerous biorelevant species, now including peptides. We report here the first demonstration of tandem ME-SIMS for de novo sequencing of endogenous neuropeptides from tissue in situ (i.

The Composition of Poly(Ethylene Terephthalate) (PET) Surface Precipitates Determined at High Resolving Power by Tandem Mass Spectrometry Imaging.

We present the first demonstration of a general method for the chemical characterization of small surface features at high magnification via simultaneous collection of mass spectrometry (MS) imaging and tandem MS imaging data. High lateral resolution tandem secondary ion MS imaging is employed to determine the composition of surface features on poly(ethylene terephthalate) (PET) that precipitate during heat treatment. The surface features, probed at a lateral resolving power of<200 nm using a surface-sensitive ion beam, are found to be comprised of ethylene terephthalate trimer at a greater abundance than is observed in the surrounding polymer matrix.

ToF-SIMS Parallel Imaging MS/MS of Lipid Species in Thin Tissue Sections.

Unambiguous identification of detected species is essential in complex biomedical samples. To date, there are not many mass spectrometry imaging techniques that can provide both high spatial resolution and identification capabilities. A new and patented imaging tandem mass spectrometer, exploiting the unique characteristics of the nanoTOF II (Physical Electronics, USA) TOF-SIMS TRIFT instrument, was developed to address this.

Three-Dimensional Image of Cleavage Bodies in Nuclei Is Configured Using Gas Cluster Ion Beam with Time-of-Flight Secondary Ion Mass Spectrometry.

Structural variations of DNA in nuclei are deeply related with development, aging, and diseases through transcriptional regulation. In order to bare cross sections of samples maintaining sub-micron structures, an Ar2500(+)-gas cluster ion beam (GCIB) sputter was recently engineered. By introducing GCIB sputter to time-of-flight secondary ion mass spectrometry (TOF-SIMS), we analyzed the 3D configuration and chemical composition of subnuclear structures of pyramidal cells in the CA2 region in mouse brain hippocampus.

Three-dimensional time-of-flight secondary ion mass spectrometry imaging of a pharmaceutical in a coronary stent coating as a function of elution time.

Three-dimensional (3D) chemical images reveal the surface and subsurface distribution of pharmaceutical molecules in a coronary stent coating and are used to visualize the drug distribution as a function of elution time. The coronary stent coating consists of 25% (w/w) sirolimus in a poly(lactic-co-glycolic acid) (PLGA) matrix and is spray-coated onto metal coupons. Information regarding the 3D distribution of sirolimus in PLGA as a function of elution time was obtained by time-of-flight secondary ion mass spectrometry (TOF-SIMS) imaging using a Au(+) ion beam for analysis in conjunction with a C(60)(+) ion beam for sputter depth profiling.

TOF-SIMS evidence of intercalated molecular gases and diffusion-limited reaction kinetics in an alpha particle-irradiated PTFE matrix.

The chemical evolution of poly(tetrafluoroethylene) (PTFE) that is brought about by increasing levels of irradiation with alpha particles is accompanied by the emergence and proliferation of functionalized moieties. Families of reaction products specifically identified in the alpha-irradiated polymer matrix include hydride-, hydroxide-, and oxide-functionalized fluorocarbons. The data also indicate the emergence of hydrogen peroxide (H2O2) and hydrazine (N2H4), but no distinct evidence suggesting the formation of perfluorinated amines, amides, or cyanogens is found.

Bond insertion, complexation, and penetration pathways of vapor-deposited aluminum atoms with HO- and CH(3)O-terminated organic monolayers.

The interaction of vapor-deposited Al atoms with self-assembled monolayers (SAMs) of HS-(CH(2))(16)-X (X = -OH and -OCH(3)) chemisorbed at polycrystalline Au[111] surfaces was studied using time-of-flight secondary-ion mass spectrometry, X-ray photoelectron spectroscopy, and infrared reflectance spectroscopy. Whereas quantum chemical theory calculations show that Al insertion into the C-C, C-H, C-O, and O-H bonds is favorable energetically, it is observed that deposited Al inserts only with the OH SAM to form an -O-Al-H product. This reaction appears to cease prior to complete -OH consumption, and is followed by formation of a few overlayers of a nonmetallic type of phase and finally deposition of a metallic film.