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Tissue classification by rapid evaporative ionization mass spectrometry (REIMS): comparison between a diathermic knife and CO2 laser sampling on classification performance
摘要： The increasing need for rapid, in situ, and robust tissue profiling approaches in the context of intraoperative diagnostics has led to the development of a large number of ambient ionization-based surface sampling strategies. This paper compares the performances of a diathermic knife and a CO2 laser handpiece, both clinically approved, coupled to a rapid evaporative ionization mass spectrometry (REIMS) source for quasi-instantaneous tissue classification. Several fresh meat samples (muscle, liver, bone, bone marrow, cartilage, skin, fat) were obtained from different animals. Overall, the laser produced cleaner cuts and more reproducible and higher spectral quality signals when compared with the diathermic knife (CV laser = 9–12%, CV diathermic = 14–23%). The molecular profiles were subsequently entered into a database and PCA/LDA classification/prediction models were built to assess if the data generated with one sampling modality can be employed to classify the data generated with the other handpiece. We demonstrate that the correct classification rate of the models increases (+ 25%) with the introduction of a model based on peak lists that are tissue-specific and common to the two handpieces, compared with considering solely the whole molecular profile. This renders it possible to use a unique and universal database for quasi-instantaneous tissue recognition which would provide similar classification results independent of the handpiece used. Furthermore, the laser was able to generate aerosols rich in lipids from hard tissues such as bone, bone marrow, and cartilage. Combined, these results demonstrate that REIMS is a valuable and versatile tool for instantaneous identification/classification of hard tissue and coupling to different aerosol-generating handpieces expands its field of application.
关键词： Bioanalytical methods,Tissue analysis,Laser ablation,Mass spectrometry,REIMS,Lipids
更新于2025-09-12 10:27:22
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AIP Conference Proceedings [AIP Publishing 15th International Conference on Concentrator Photovoltaic Systems (CPV-15) - Fes, Morocco (25–27 March 2019)] 15th International Conference on Concentrator Photovoltaic Systems (CPV-15) - Solid lipid nanoparticles made of self-emulsifying lipids for efficient encapsulation of hydrophilic substances
摘要： In the last decades, most attention has been paid to solid lipid nanoparticles (SLN) as nanocarriers for pharmaceutical purposes due to their low toxicity, possible production on large scale and delivery of active principles by several administration routes. For example, lung delivery will necessitate direct administration, e.g. by aerosolisation, to maximize deposition into the airways and minimize systemic side effects. However, SLN based on common solid lipids preferentially incorporate lipophilic drugs, while the hydrophilic ones are loaded in low amount. To overcome this drawback, it seemed interesting to evaluate SLN based on self-emulsifying (SE) lipids, which are mixtures of lipids, surfactant and cosurfactants able to form emulsions in contact with aqueous media. Thus, we evaluated the preparation of SLN based on Gelucire? 50/13, selected as a SE lipid model, encapsulating glutathione (GSH) or proanthocyanidins occurring in grape seed extract (GSE), as hydrophilic model substances according to the melt-emulsification method. The encapsulation efficiency of such GSH- or GSE-SLN resulted satisfactory for both the hydrophilic compounds examined. However, to draw definitive conclusions on the scope and limitations of this approach based on SE lipids, further studies are necessary. Moreover, GSH-SLN were investigated for their performance in delivering the antioxidant peptide to immunocompetent fish cells, while GSE-SLN were evaluated for their possible application in the treatment of pulmonary diseases. It was found that GSH-SLN were not internalized by fish cells, while GSE-SLN showed favorable properties for lung delivery.
关键词： lung delivery,proanthocyanidins,solid lipid nanoparticles,self-emulsifying lipids,hydrophilic substances,encapsulation,glutathione
更新于2025-09-11 14:15:04
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X-ray irradiation effects on nuclear and membrane regions of single SH-SY5Y human neuroblastoma cells investigated by Raman micro-spectroscopy
摘要： Raman micro-spectroscopy was performed in vitro on nuclear and membrane regions of single SH-SY5Y human neuroblastoma cells after irradiation by graded X-ray doses (2, 4, 6, 8 Gy). The acquired spectra were analyzed by principal component analysis (PCA) and interval-PCA (i-PCA) methods. Biochemical changes occurring in the different regions of single cells as a consequence of the radiation exposure were observed in cells fixed immediately after the irradiation. The most relevant effects arose from the analysis of the spectra from the cell nucleus region. The observed changes were discussed in terms of the modifications in the cell cycle, resulting in an increase in the DNA-related signal, a protein rearrangement and changes in lipid and carbohydrates profiles within the nucleus. Potential markers of an apoptotic process in cell population irradiated with 6 and 8-Gy X-ray doses could have been singled out. No significant effects were found in spectra from cells fixed 24 h after the irradiation, thus suggesting the occurrence of repairing processes of the X-ray induced damage.
关键词： X-ray effects on DNA, lipids, proteins and carbohydrates,Single SH-SY5Y human cancer cells,Raman micro-spectroscopy,Cellular nucleus and membrane,Multivariate analysis
更新于2025-09-11 14:15:04
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Very long-chain fatty acids support synaptic structure and function in the mammalian retina
摘要： Elongation of Very Long chain fatty acids-like 4 (ELOVL4) is a fatty acid elongase responsible for the biosynthesis of very long chain (VLC; ≥ C26) fatty acids in the retina, brain, skin, Meibomian gland, and testes. Heterozygous inheritance of mutant ELOVL4 causes juvenile macular degeneration in autosomal dominant Stargardt-like macular dystrophy (STGD3). Retinal photoreceptors are enriched with VLC polyunsaturated fatty acids (VLC-PUFAs), which have been shown by our group and others to be necessary for the survival of rod photoreceptors. Our group performed a series of studies using mice conditionally depleted of retinal Elovl4 (KO) aimed at understanding the role of VLC-PUFAs in long-term retinal health and function, focusing on the role of these fatty acids in mediating synaptic function between the photoreceptors and the rest of the neural retina. The absence of VLC-PUFA from the retina of KO mice resulted in a marked decrease in retinal b-wave responses of the electroretinogram as well as a decrease in the amplitude of the oscillatory potentials mediated by the neural retina. Although there were no measureable di?erences between KO and wild type (WT) mice in either pre-synaptic rod calcium channel function or post-synaptic bipolar cell glutamate receptor responses, ultrastructural analysis revealed a marked decrease in the diameter of synaptic vesicles in rod terminals. Recent quanti?cation suggests that this decrease in synaptic vesicle size due to the absence of VLC-PUFAs in KO mice, and the consequent decrease in glutamate content, could account for the decrease in b-wave response amplitudes that were previously measured in these animals.
关键词： very long chain fatty acids,Stargardt-like macular dystrophy,Lipids in retinal structure and function,ELOVL4,very long chain polyunsaturated fatty acids
更新于2025-09-09 09:28:46
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ATR FTIR Spectroscopic Study on Insect Body Surface Lipids Rich in Methylene-Interrupted Diene
摘要： To protect themselves, insects cover their bodies with what is called cuticular lipid. The cuticular lipid of American cockroach has a unique lipid content; the most abundant is a cis-alkadiene, cis, cis-6, 9-heptacosadiene amounting to about 70%, which is followed by a branched alkane 3-methylpentacosane. In order to clarify the structural features of the unique lipid composition below the critical temperature, the cuticular lipid was studied by Fourier Transform Infrared (FTIR) spectroscopy in combination with attenuated total reflection (ATR) sampling technique. The infrared spectra measured on an extracted lipid sample at 20°C suggested that the lipid keeps an appreciable level of conformational and lateral packing regularity, in spite of high cis-unsaturated lipid content and also a highly disordered condition around the methyl terminals and cis-olefin groups. The CH2 scissoring and the CH2 rocking regions showed the characteristics of the O⊥ subcell. The same characteristics were observed also by in-situ measurements on a forewing of American cockroach. Combining the spectral features of these bands and the physicochemical properties of each component, it can be inferred that saturated lipids form highly ordered domains within the liquid containing the cis, cis-diene as main component. For comparison, the cuticular lipid of male cricket, which consisted many different hydrocarbons including 15 percent of unsaturated hydrocarbons, showed a lower regularity both in the conformation and in the lateral packing of hydrocarbon chains. These results imply that not only the degree of cis-unsaturation but also the chemical structure diversity of hydrocarbons is the important factor to determine the physicochemical properties of cuticular lipid.
关键词： cuticular lipid,American cockroach,FTIR spectroscopy,lateral packing,methylene-interrupted diene,cis-unsaturated lipids,ATR sampling technique,hydrocarbon chains,conformational order
更新于2025-09-04 15:30:14