Search Results (72)

Plant gums have long served as essential binding media in polychrome cultural heritage, contributing to pigment adhesion, surface cohesion, and long-term stability. This review evaluates recent advances in analytical technologies, including FTIR, Raman spectroscopy, GC-MS, LC-MS/MS, MALDI-TOF MS, hyperspectral imaging, and immunological assays, for the identification of gums such as gum arabic, peach gum, and tragacanth in diverse cultural contexts. Drawing on case studies from 19th-century watercolours, ancient Egyptian coffins, and Maya murals, the paper demonstrates how these methods enable precise chemical characterization even in complex, aged, and mineral-rich matrices. Such information directly aids conservators in selecting compatible restoration materials, tailoring treatment protocols, and assessing deterioration mechanisms. Persistent challenges remain, including gum degradation, spectral interference from pigments and restoration materials, sample heterogeneity, and limited reference libraries, particularly for non-European species. Future research directions emphasize multi-modal, non-invasive workflows that integrate hyperspectral imaging with spectroscopic and chromatographic methods, drone-assisted micro-Raman for inaccessible surfaces, machine learning-assisted spectral databases, and bio-inspired adhesives replicating historical rheology. By linking molecular identification to conservation decision-making, plant gum analysis not only deepens our understanding of historical material practices but also strengthens the scientific basis for sustainable heritage preservation strategies. Full article

Ovarian cancer is the most lethal gynecological cancer. Up to 75% of cases are high-grade serous ovarian cancer (HGSOC) that have high chemosensitivity to first-line platinum-based therapies. However, 75% of patients will become chemoresistant following relapse. The underlying mechanism for developing resistance to chemotherapy in HGSOC is poorly understood. In this study, we employed Matrix-Assisted Laser Desorption/Ionization–Mass Spectrometry Imaging (MALDI-MSI) on matching formalin-fixed paraffin-embedded (FFPE) HGSOC tissues at the time of diagnosis and following relapse with chemotherapy-resistant disease (n = 4). We identified m/z values that were differentially abundant in the matching diagnosis and relapse HGSOC tissues. These were matched to proteins using nano-liquid chromatography tandem mass spectrometry (LC-MS/MS). We identified upregulated proteins in the HGSOC relapse tissues, including COL12A1, FUBP1, PLEC, SLC4A1, and TKT. These proteins were validated by immunohistochemistry (IHC) and gene expression using online databases. IHC showed COL12A1, FUBP1, PLEC, SLC4A1, and TKT protein abundance were significantly elevated in HGSOC relapse tissues compared to matching tissues at diagnosis. COL12A1, FUBP1, PLEC, and TKT mRNA expression levels were significantly increased in HGSOC compared to normal ovary and associated with poor prognosis in HGSOC. We confirmed that higher protein abundance of both COL12A1 and PLEC correlated with reduced progression-free survival in HGSOC patients. Furthermore, both COL12A1 and PLEC mRNA and protein levels were significantly associated with chemotherapy resistance. In summary, using MALDI-MSI, we have identified proteins, including COL12A1 and PLEC, associated with chemotherapy resistance to be further evaluated as HGSOC biomarkers and/or therapeutic targets. Full article

Pollen is a cornerstone of life for plants. Its durability, adaptability, and complex design are the key factors to successful plant reproduction, genetic diversity, and the maintenance of ecosystems. A detailed study of its chemical composition is important to understand the mechanism of pollen–pollinator interactions, pollination processes, and allergic reactions. In this study, a multimodal approach involving Fourier transform infrared spectrometry (FTIR), direct mass spectrometry with an atmospheric solids analysis probe (ASAP), matrix-assisted laser desorption/ionization (MALDI) and ultra-high-performance liquid chromatography–mass spectrometry (UHPLC-MS) was applied for metabolite profiling. ATR-FTIR provided an initial overview of the present metabolite classes. Phenylpropanoid, lipidic, and carbohydrate structures were revealed. The hydrophobic outer layer of pollen was characterized in detail by ASAP-MS profiling, and esters, phytosterols, and terpenoids were observed. Diacyl- and triacylglycerols and carbohydrate structures were identified in MALDI-MS spectra. The MALDI-MS imaging of lipids proved to be helpful during the microscopic characterization of pollen species in their mixture. Polyphenol profiling and the quantification of important secondary metabolites were performed by UHPLC-MS in context with pollen coloration and their antioxidant and antimicrobial properties. The obtained results revealed significant chemical differences among Magnoliophyta and Pinophyta pollen. Additionally, some variations within Magnoliophyta species were observed. The obtained metabolomics data were utilized for pollen differentiation at the taxonomic scale and provided valuable information in relation to pollen interactions during reproduction and its related applications. Full article

Amyloid-β (Aβ) plaque deposits in the brain are a hallmark of Alzheimer’s disease (AD) neuropathology. Plaques consist of complex mixtures of peptides like Aβ_1–42 and characteristic lipids such as gangliosides, and they are targeted by reactive microglia and astrocytes. Background: In pharmaceutical research and development, it is a formidable challenge to contextualize the different biomolecular classes and cell types of the Aβ plaque microenvironment in a coherent experimental workflow on a single tissue section and on a benchtop imaging reader. Methods: Here, we developed a workflow that combines lipid MALDI mass spectrometry imaging using a vacuum-stable matrix with histopathology stains and with the MALDI HiPLEX immunohistochemistry of plaques and multiple protein markers on a benchtop imaging mass spectrometer. The three data layers consisting of lipids, protein markers, and histology could be co-registered and evaluated together. Results: Multimodal data analysis suggested the extensive co-localization of Aβ plaques with the peptide precursor protein, with a defined subset of lipids and with reactive glia cells on a single brain section in APPPS1 mice. Plaque-associated lipids like ganglioside GM2 and phosphatidylinositol PI38:4 isoforms were readily identified using the tandem MS capabilities of the mass spectrometer. Conclusions: Altogether, our data suggests that complex pathology involving multiple lipids, proteins and cell types can be interrogated by this spatial multiomics workflow on a user-friendly benchtop mass spectrometer. Full article

EFNA1 (ephrinA1), a highly expressed tyrosine kinase receptor-ligand in healthy cardiomyocytes, is reduced following myocardial infarction (MI). A single intramyocardial injection of chimeric EFNA1-Fc at the time of ischemia mitigates the injury in both reperfused and non-reperfused mouse myocardium by reducing apoptosis, necrosis, and inflammation. Recently, we have successfully imaged and qualitatively identified endogenous EFNA1 pre- and post-MI using matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI) coupled with a time-of-flight mass spectrometer (MALDI/TOF MS). Building on our previous work, we are currently focused on understanding and characterizing EFNA1’s role in cardiac tissue by developing an integrated quantitative method to determine endogenous levels of EFNA1 using MALDI-MSI technologies. Herein, we have optimized a method for the relative quantitation of endogenous tryptic EFNA1 peptides detected in the murine heart as compared with routine western blotting. In healthy myocardium, there was approximately 50 ng of endogenous EFNA1 per section of 9.43 mm³ tissue, or roughly 12 pg/µg of homogenized tissue. MALDI-MSI thus provides a tool for determining the anatomical distribution and relative quantitation of endogenous EFNA1 in cardiac tissue. Future applications of these tools will allow us to investigate the dynamic changes in EFNA1 expression profile that occur in pathological states such as myocardial infarction and upon therapeutic treatments. Full article

Background: Angelicae Dahuricae Radix (ADR) is used as both a traditional Chinese medicine and a food ingredient in China and East Asian countries. ADR is generally sun-dried post-harvest but is sometimes sulfur-fumigated to prevent decay and rot. Although there are some studies on the effect of sulfur fumigation on ADR, they are not comprehensive. Methods: This study used HPLC fingerprinting, matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI), in vitro anti-inflammatory assays, and metabolite analysis in blood based on UPLC-MS/MS to assess the impact of sulfur fumigation on the active ingredients of ADR. Results: There were significant decreases in specific coumarins and amino acids, particularly byakangelicol, oxypeucedanin, L-proline, and L-arginine, following sulfur fumigation. Among the 185 metabolites in blood, there were 30 different compounds, and oxypeucedanin was the most obvious component to decrease after sulfur fumigation. ADR showed anti-inflammatory activity regardless of sulfur fumigation. However, the effects on the production of cytokines in LPS-induced RAW264.7 cells were different. Conclusions: Chemometric analysis and in vitro anti-inflammatory studies suggested that byakangelicol and oxypeucedanin could serve as potential quality markers for identifying sulfur-fumigated ADR. These findings provide a chemical basis for comprehensive safety and functional evaluations of sulfur-fumigated ADR, supporting further research in this field. Full article

Matrix Assisted Laser Desorption/Ionisation-Mass Spectrometry Imaging (MALDI-MSI) is a well-established spatial omic technique which enables the untargeted mapping of various classes of biomolecules, including tryptic peptides, directly on tissue. This method relies on the use of matrices for the ionisation and volatilisation of analytes, and α-Cyano-4-hydroxycinnamic acid (CHCA) represents the most widespread matrix for tryptic peptides analysis. However, CHCA also presents certain limitations that foster the quest for novel matrix compounds. 6-aza-2-thiothymine (ATT), traditionally used in MALDI mass spectrometry (MS) for oligonucleotides, small molecules and oxidised phospholipids, has not been thoroughly investigated as a potential matrix for tryptic peptide analysis in MALDI-MS or MALDI-MSI. Therefore, this study addresses this gap by evaluating the capability of ATT to ionise tryptic peptides from Bovine Serum Albumin (BSA) and map in situ-digested peptides from formalin-fixed paraffin-embedded (FFPE) tissue sections in these respective applications. Comparative analysis with CHCA demonstrated the complementary strengths of these matrices for detecting tryptic peptides, establishing ATT as a feasible alternative to CHCA in the MALDI-MSI field and paving the way for future advancements in spatial proteomics. Full article

The attachment of sugar to proteins and lipids is a basic modification needed for organismal survival, and perturbations in glycosylation cause severe developmental and neurological difficulties. Here, we investigated the neurological consequences of N-glycan populations in the spinal cord of Wt AB and mgat1b mutant zebrafish. Mutant fish have reduced N-acetylglucosaminyltransferase-I (GnT-I) activity as mgat1a remains intact. GnT-I converts oligomannose N-glycans to hybrid N-glycans, which is needed for complex N-glycan production. MALDI-TOF MS profiles identified N-glycans in the spinal cord for the first time and revealed reduced amounts of complex N-glycans in mutant fish, supporting a lesion in mgat1b. Further lectin blotting showed that oligomannose N-glycans were more prevalent in the spinal cord, skeletal muscle, heart, swim bladder, skin, and testis in mutant fish relative to WT AB, supporting lowered GnT- I activity in a global manner. Developmental delays were noted in hatching and in the swim bladder. Microscopic images of caudal primary (CaP) motor neurons of the spinal cord transiently expressing EGFP in mutant fish were abnormal with significant reductions in collateral branches. Further motor coordination skills were impaired in mutant fish. We conclude that identifying the neurological consequences of aberrant N-glycan processing will enhance our understanding of the role of complex N-glycans in development and nervous system health. Full article

Carbendazim (CBZ) residues in food are a severe threat to food safety, and their detection is a challenging problem in food science. We introduce here a new method based on laser desorption postionization mass spectrometry imaging (LDPI-MSI) for detecting CBZ residues in carrots. In the novel LDPI-MSI method, two distinct laser beams simultaneously exert dissociation and ionization, which offers several advantages over traditional techniques based on single-photon matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI), including simplified sample preparation, streamlined operation workflow, and a lower limit of detection (LOD). The LOD, in the proposed method, has been lowered to 0.019 ppm. Coupled with mass spectrometry imaging (MSI), the LDPI-MS method enabled in situ detection of small molecular compounds, such as chemical pesticides, and provided comprehensive and accurate results. The image obtained from the characteristic mass spectrometric signature of CBZ at m/z 191 illustrated that most of the CBZ could not enter the carrot tubers directly, but a small amount of CBZ entered the carrot root and was mainly concentrated in the central xylem. The results suggest that the proposed method could potentially be used in pesticide analysis. Full article

Phytophthora parasitica is an oomycete pathogen that infects a broad range of crops of worldwide economic interest; among them are citrus species. In general, some Citrus and the rootstocks of related genera offer considerable resistance against P. parasitica; therefore, understanding the mechanisms involved in the virulence of this pathogen is crucial. In this work, P. parasitica secondary metabolite production was studied using matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) and ultrahigh-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UHPLC/ESI-Q-TOF-MS) combined with chemometric tools, and its metabolic profile was evaluated under the influence of Citrus sunki (a highly susceptible host) and Poncirus trifoliata (a resistant genotype) extracts. The root extracts of Citrus sunki had an influence on the growth and hyphae morphology, and the root extracts of P. trifoliata had an influence on the zoospore behavior. In parallel, the spatial distribution of several metabolites was revealed in P. parasitica colonies using MALDI-MSI, and the metabolite ion of m/z 246 was identified as the protonated molecule of Arg-Ala. The MALDI-MSI showed variations in the surface metabolite profile of P. parasitica under the influence of the P. trifoliata extract. The P. parasitica metabolome analysis using UHPLC-ESI-Q-TOF-MS resulted in the detection of Arg-Gln (m/z 303.1775), as well as L-arginine (m/z 175.1191) and other unidentified metabolites. Significant variations in this metabolome were detected under the influence of the plant extracts when evaluated using UHPLC-ESI-Q-TOF-MS. Both techniques proved to be complementary, offering valuable insights at the molecular level when used to assess the impact of the plant extracts on microbial physiology in vitro. The metabolites identified in this study may play significant roles in the interaction or virulence of P. parasitica, but their functional characterization remains to be analyzed. Overall, these data confirm our initial hypotheses, demonstrating that P. parasitica has the capabilities of (i) recognizing host signals and altering its reproductive programing and (ii) distinguishing between hosts with varying responses in terms of reproduction and the production of secondary metabolites. Full article

Canine osteosarcoma (OSA) is an aggressive bone neoplasia with high metastatic potential. Metastasis is the main cause of death associated with OSA, and there is no current treatment available for metastatic disease. Proteomic analyses, including matrix-assisted laser desorption/ionisation-time of flight mass spectrometry (MALDI TOF/TOF MS), are widely used to select molecular targets and identify proteins that may play a key role in primary tumours and at various steps of the metastatic cascade. The main aim of this study was to identify proteins differently expressed in canine OSA cell lines with different malignancy phenotypes (OSCA-8 and OSCA-32) compared to canine osteoblasts (CnOb). The intermediate aim of the study was to compare canine OSA cell migration capacity and assess its correlation with the malignancy phenotypes of each cell line. Using MALDI-TOF/TOF MS analyses, we identified eight proteins that were significantly differentially expressed (p ≤ 0.05) in canine OSA cell lines compared to CnOb: cilia- and flagella-associated protein 298 (CFAP298), general transcription factor II-I (GTF2I), mirror-image polydactyly gene 1 protein (MIPOL1), alpha-2 macroglobulin (A2M), phosphoglycerate mutase 1 (PGAM1), ubiquitin (UB2L6), ectodysplasin-A receptor-associated adapter protein (EDARADD), and leucine-rich-repeat-containing protein 72 (LRRC72). Using the Simple Western technique, we confirmed high A2M expression in CnOb compared to OSCA-8 and OSCA-32 cell lines (with intermediate and low A2M expression, respectively). Then, we confirmed the role of A2M in cancer cell migration by demonstrating significantly inhibited OSA cell migration by treatment with A2M (both at 10 and 30 mM concentrations after 12 and 24 h) in a wound-healing assay. This study may be the first report indicating A2M’s role in OSA cell metastasis; however, further in vitro and in vivo studies are needed to confirm its possible role as an anti-metastatic agent in this malignancy. Full article

Urinary tract cancers, including those of the bladder, the kidneys, and the prostate, represent over 12% of all cancers, with significant global incidence and mortality rates. The continuous challenge that these cancers present necessitates the development of innovative diagnostic and prognostic methods, such as identifying specific biomarkers indicative of cancer. Biomarkers, which can be genes, proteins, metabolites, or lipids, are vital for various clinical purposes including early detection and prognosis. Mass spectrometry (MS), particularly soft ionization techniques such as electrospray ionization (ESI) and laser desorption/ionization (LDI), has emerged as a key tool in metabolic profiling for biomarker discovery, due to its high resolution, sensitivity, and ability to analyze complex biological samples. Among the LDI techniques, matrix-assisted laser desorption/ionization (MALDI) and surface-assisted laser desorption/ionization (SALDI) should be mentioned. While MALDI methodology, which uses organic compounds as matrices, is effective for larger molecules, SALDI, based on the various types of nanoparticles and nanostructures, is preferred for smaller metabolites and lipids due to its reduced spectral interference. This study highlights the application of LDI techniques, along with mass spectrometry imaging (MSI), in identifying potential metabolic and lipid biomarkers for urological cancers, focusing on the most common bladder, kidney, and prostate cancers. Full article

Fungal keratitis is a relatively rare yet severe ocular infection that can lead to profound vision impairment and even permanent vision loss. Rapid and accurate diagnosis plays a crucial role in the effective management of the disease. A patient’s history establishes the initial clinical suspicion since it can provide valuable clues to potential predisposing factors and sources of fungal exposure. Regarding the evaluation of the observed symptoms, they are not exclusive to fungal keratitis, but their timeline can aid in distinguishing fungal keratitis from other conditions. Thorough clinical examination of the affected eye with a slit-lamp microscope guides diagnosis because some clinical features are valuable predictors of fungal keratitis. Definitive diagnosis is established through appropriate microbiological investigations. Direct microscopic examination of corneal scrapings or biopsy specimens can assist in the presumptive diagnosis of fungal keratitis, but culture remains the gold standard for diagnosing fungal keratitis. Advanced molecular techniques such as PCR and MALDI-ToF MS are explored for their rapid and sensitive diagnostic capabilities. Non-invasive techniques like in vivo confocal microscopy (IVCM) and optical coherence tomography (OCT) are useful for real-time imaging. Every diagnostic technique has both advantages and drawbacks. Also, the selection of a diagnostic approach can depend on various factors, including the specific clinical context, the availability of resources, and the proficiency of healthcare personnel. Full article

In the present work, cholesterol (Chol)-substituted zinc phthalocyanine (Chol-ZnPc) and its composite with graphene oxide (GO) were prepared for photodynamic therapy (PDT) applications. Briefly, Chol-substituted phthalonitrile (Chol-phthalonitrile) was synthesized first through the substitution of Chol to the phthalonitrile group over the oxygen bridge. Then, Chol-ZnPc was synthesized by a tetramerization reaction of Chol-phthalonitrile with ZnCl₂ in a basic medium. Following this, GO was introduced to Chol-ZnPc, and the successful preparation of the samples was verified through FT-IR, UV–Vis, ¹H-NMR, MALDI-TOF MS, SEM, and elemental analysis. Regarding PDT properties, we report that Chol-ZnPc exhibited a singlet oxygen quantum yield (${\Phi }_{∆}$) of 0.54, which is slightly lower than unsubstituted ZnPc. Upon introduction of GO, the GO/Chol-ZnPc composite exhibited a higher ${\Phi }_{∆}$, about 0.78, than that of unsubstituted ZnPc. Moreover, this enhancement was realized with a simultaneous improvement in fluorescence quantum yield (${\Phi }_F$) to 0.36. In addition, DPPH results suggest low antioxidant activity in the composite despite the presence of GO. Overall, GO/Chol-ZnPc might provide combined benefits for PDT, particularly in terms of image guidance and singlet oxygen generation. Full article

In this paper, a new type of borasilsesquioxanes was synthesized through a condensation process, and its reactivity in catalytic hydrosilylation reactions with silanes, siloxanes, and silsesquioxanes was investigated. The obtained compounds were mostly obtained in >90% yield. They were fully characterized using spectroscopic (¹H, ¹³C, ²⁹Si NMR) and spectrometric (MALDI-TOF-MS) methods. The next stage of the research involved studying the thermogravimetric properties of the borasilsesquioxanes. By analyzing the different stages of decomposition using spectroscopic techniques (NMR, ATR-FTIR, Raman) and microscopic imaging, it was found that the structure of the borasilsesquioxanes changed during the pyrolysis process and polymer compounds were formed. Full article