Fourier transform infrared microspectroscopy (FTIRM) is a recent technique that, over the last de... more Fourier transform infrared microspectroscopy (FTIRM) is a recent technique that, over the last decade, has become more popular for the study of biological systems. It is the result of the union between FTIR spectroscopy and optical microscopy. The use of synchrotron radiation offers a significant gain in terms of brightness but recent developments on optics (ATR) and detectors (FPA) allow as well an important expansion of the technique in laboratories. In both cases, micrometric resolution can be reached. The generated optical image allows studying a particular area and uses the mid-infrared radiation (2.5 to 15 µm/ 4000 to 650 cm-1) to detect vibrational movements from the molecular groups present in biological samples. FTIRM results allow us to observe the biochemical state of a sample, and provide us with information about all molecules present therein, allowing identification, semi-quantification and precise localization of one or more relevant molecules. In this way it is possible to identify cells from different species or in different metabolic stages, or to analyze the biochemical changes generated in the samples under diverse experimental conditions. This review aims to inform about FTIRM, giving a general prospect of the technique and citing several studies made with it in various biological systems. www.relaquim.com
... Marine Cotte*ab, Jean Susinib, V. Armando Soléb, Yoko Taniguchic, Javier Chillidad, Emilie Ch... more ... Marine Cotte*ab, Jean Susinib, V. Armando Soléb, Yoko Taniguchic, Javier Chillidad, Emilie Checroune and Philippe Walter ... On the other hand, some analyses focus on the better understanding of alteration mechanisms (pigment whitening or blackening, apparition of cracks, ...
Amyloid peptides are the main component of one of the characteristic pathological hallmarks of Al... more Amyloid peptides are the main component of one of the characteristic pathological hallmarks of Alzheimer's disease (AD): senile plaques. According to the amyloid cascade hypothesis, amyloid peptides may play a central role in the sequence of events that leads to neurodegeneration. However, there are other factors, such as oxidative stress, that may be crucial for the development of the disease. In the present paper, we show that it is possible, by using Fourier tranform infrared (FTIR) microscopy, to co-localize amyloid deposits and lipid peroxidation in tissue slides from patients affected by Alzheimer's disease. Plaques and lipids can be analyzed in the same sample, making use of the characteristic infrared bands for peptide aggregation and lipid oxidation. The results show that, in samples from patients diagnosed with AD, the plaques and their immediate surroundings are always characterized by the presence of oxidized lipids. As for samples from non-AD individuals, those ...
Synchrotron-based Fourier transform infrared micro-spectroscopy (SR-μFTIR) was used to map photo-... more Synchrotron-based Fourier transform infrared micro-spectroscopy (SR-μFTIR) was used to map photo-oxidative degradation of acrylonitrile-butadiene-styrene (ABS) and to investigate the presence and the migration of additives in historical samples from important Italian design objects. High resolution (3×3 μm(2)) molecular maps were obtained by FTIR microspectroscopy in transmission mode, using a new method for the preparation of polymer thin sections. The depth of photo-oxidation in samples was evaluated and accompanied by the formation of ketones, aldehydes, esters, and unsaturated carbonyl compounds. This study demonstrates selective surface oxidation and a probable passivation of material against further degradation. In polymer fragments from design objects made of ABS from the 1960s, UV-stabilizers were detected and mapped, and microscopic inclusions of proteinaceous material were identified and mapped for the first time.
The complexity and heterogeneity of artistic materials make their chemical characterization uneas... more The complexity and heterogeneity of artistic materials make their chemical characterization uneasy. Micro-imaging techniques are commonly applied to attain full 2D descriptions of fragments cross-sections. At the European Synchrotron Radiation Facility (ESRF), Grenoble, France, the ID21 beamline is primarily designed for scanning X-ray microscopy. Since 2004, it also hosts a Fourier Transform Infrared (FTIR) end-station. The combined access (fig. 1) on a single beamline to both X-ray and FTIR micro spectroscopies has become a main asset in the characterization of very complex heterogeneous samples at the micron scale in several research fields, such as Cultural Heritage Sciences with a particular focus on paintings. At the ID21 beamline, the X-ray microscope is devoted to micro X-ray fluorescence and micro X-ray Absorption Near-Edge Spectroscopy (XANES) in the tender X-ray domain (2-9 keV). Therefore, it is very well suited to reveal the chemical state of pigments with a very high l...
Synchrotron-based radiation (SRS) Fourier-transform infrared (FTIR) microspectroscopy potentially... more Synchrotron-based radiation (SRS) Fourier-transform infrared (FTIR) microspectroscopy potentially provides novel biomarkers of the cell differentiation process. Because such imaging gives a "biochemical-cell fingerprint" through a cell-sized aperture, we set out to determine whether distinguishing chemical entities associated with putative stem cells (SCs), transit-amplifying (TA) cells, or terminally-differentiated (TD) cells could be identified in human corneal epithelium. Desiccated cryosections (10 microm thick) of cornea on barium fluoride infrared transparent windows were interrogated using SRS FTIR microspectroscopy. Infrared analysis was performed through the acquisition of point spectra or image maps. Point spectra were subjected to principal component analysis (PCA) to identify distinguishing chemical entities. Spectral image maps to highlight SCs, TA cells, and TD cells of the cornea were then generated. Point spectrum analysis using PCA highlighted remarkable s...
The epithelial-cell layer lining the two morphologically and functionally distinct segments of th... more The epithelial-cell layer lining the two morphologically and functionally distinct segments of the mammalian intestinal tract, small intestine, and colon is constantly being renewed. This renewal is necessitated by a harsh lumen environment and is hypothesized to be driven by a small population of stem cells (SCs) that are believed to reside at the base of intestinal crypts. A lack of specific markers has hampered previous attempts to identify their exact location. We obtained tissue sections containing small intestine and colon crypts derived from normal (benign) or adenocarcinoma (AC) human intestine. The samples were floated onto BaF2 windows and analyzed using synchrotron radiation-based Fourier transform infrared microspectroscopy via an aperture size of 10 × 10 μm. Derived infrared (IR) spectral data was then analyzed using principal component analysis and/or linear discriminant analysis. Hypothesized cell types (as a function of aperture location along the length of individual crypts) within benign crypts were classed based on exploratory unsupervised IR spectral point clustering. Scores plots derived from individual small intestine crypts consistently generated one or two distinct spectra that clustered away from the remaining cell categories; these were retrospectively classed as "distinct base region" spectra. In these plots, a clear progression of locations along crypt lengths designated as from putative stem cells (SCs) to transit-amplifying (TA) cells to terminally differentiated (TD) cells was observed in benign small intestine and colon crypts. This progression of spectral points was crypt specific, pointing away from a unifying cell lineage model in human intestinal crypts. On comparison of AC-derived spectra versus corresponding benign, a subpopulation of AC-derived spectra suggested a putative SC-like spectral fingerprint; remaining IR spectra were classed as exhibiting TA cell-like or TD cell-like spectral characteristics. These observations could point to a cancer SC phenotype; an approach capable of identifying their in situ location has enormous therapeutic applications.
Fourier transform infrared microspectroscopy (FTIRM) is a recent technique that, over the last de... more Fourier transform infrared microspectroscopy (FTIRM) is a recent technique that, over the last decade, has become more popular for the study of biological systems. It is the result of the union between FTIR spectroscopy and optical microscopy. The use of synchrotron radiation offers a significant gain in terms of brightness but recent developments on optics (ATR) and detectors (FPA) allow as well an important expansion of the technique in laboratories. In both cases, micrometric resolution can be reached. The generated optical image allows studying a particular area and uses the mid-infrared radiation (2.5 to 15 µm/ 4000 to 650 cm-1) to detect vibrational movements from the molecular groups present in biological samples. FTIRM results allow us to observe the biochemical state of a sample, and provide us with information about all molecules present therein, allowing identification, semi-quantification and precise localization of one or more relevant molecules. In this way it is possible to identify cells from different species or in different metabolic stages, or to analyze the biochemical changes generated in the samples under diverse experimental conditions. This review aims to inform about FTIRM, giving a general prospect of the technique and citing several studies made with it in various biological systems. www.relaquim.com
... Marine Cotte*ab, Jean Susinib, V. Armando Soléb, Yoko Taniguchic, Javier Chillidad, Emilie Ch... more ... Marine Cotte*ab, Jean Susinib, V. Armando Soléb, Yoko Taniguchic, Javier Chillidad, Emilie Checroune and Philippe Walter ... On the other hand, some analyses focus on the better understanding of alteration mechanisms (pigment whitening or blackening, apparition of cracks, ...
Amyloid peptides are the main component of one of the characteristic pathological hallmarks of Al... more Amyloid peptides are the main component of one of the characteristic pathological hallmarks of Alzheimer's disease (AD): senile plaques. According to the amyloid cascade hypothesis, amyloid peptides may play a central role in the sequence of events that leads to neurodegeneration. However, there are other factors, such as oxidative stress, that may be crucial for the development of the disease. In the present paper, we show that it is possible, by using Fourier tranform infrared (FTIR) microscopy, to co-localize amyloid deposits and lipid peroxidation in tissue slides from patients affected by Alzheimer's disease. Plaques and lipids can be analyzed in the same sample, making use of the characteristic infrared bands for peptide aggregation and lipid oxidation. The results show that, in samples from patients diagnosed with AD, the plaques and their immediate surroundings are always characterized by the presence of oxidized lipids. As for samples from non-AD individuals, those ...
Synchrotron-based Fourier transform infrared micro-spectroscopy (SR-μFTIR) was used to map photo-... more Synchrotron-based Fourier transform infrared micro-spectroscopy (SR-μFTIR) was used to map photo-oxidative degradation of acrylonitrile-butadiene-styrene (ABS) and to investigate the presence and the migration of additives in historical samples from important Italian design objects. High resolution (3×3 μm(2)) molecular maps were obtained by FTIR microspectroscopy in transmission mode, using a new method for the preparation of polymer thin sections. The depth of photo-oxidation in samples was evaluated and accompanied by the formation of ketones, aldehydes, esters, and unsaturated carbonyl compounds. This study demonstrates selective surface oxidation and a probable passivation of material against further degradation. In polymer fragments from design objects made of ABS from the 1960s, UV-stabilizers were detected and mapped, and microscopic inclusions of proteinaceous material were identified and mapped for the first time.
The complexity and heterogeneity of artistic materials make their chemical characterization uneas... more The complexity and heterogeneity of artistic materials make their chemical characterization uneasy. Micro-imaging techniques are commonly applied to attain full 2D descriptions of fragments cross-sections. At the European Synchrotron Radiation Facility (ESRF), Grenoble, France, the ID21 beamline is primarily designed for scanning X-ray microscopy. Since 2004, it also hosts a Fourier Transform Infrared (FTIR) end-station. The combined access (fig. 1) on a single beamline to both X-ray and FTIR micro spectroscopies has become a main asset in the characterization of very complex heterogeneous samples at the micron scale in several research fields, such as Cultural Heritage Sciences with a particular focus on paintings. At the ID21 beamline, the X-ray microscope is devoted to micro X-ray fluorescence and micro X-ray Absorption Near-Edge Spectroscopy (XANES) in the tender X-ray domain (2-9 keV). Therefore, it is very well suited to reveal the chemical state of pigments with a very high l...
Synchrotron-based radiation (SRS) Fourier-transform infrared (FTIR) microspectroscopy potentially... more Synchrotron-based radiation (SRS) Fourier-transform infrared (FTIR) microspectroscopy potentially provides novel biomarkers of the cell differentiation process. Because such imaging gives a "biochemical-cell fingerprint" through a cell-sized aperture, we set out to determine whether distinguishing chemical entities associated with putative stem cells (SCs), transit-amplifying (TA) cells, or terminally-differentiated (TD) cells could be identified in human corneal epithelium. Desiccated cryosections (10 microm thick) of cornea on barium fluoride infrared transparent windows were interrogated using SRS FTIR microspectroscopy. Infrared analysis was performed through the acquisition of point spectra or image maps. Point spectra were subjected to principal component analysis (PCA) to identify distinguishing chemical entities. Spectral image maps to highlight SCs, TA cells, and TD cells of the cornea were then generated. Point spectrum analysis using PCA highlighted remarkable s...
The epithelial-cell layer lining the two morphologically and functionally distinct segments of th... more The epithelial-cell layer lining the two morphologically and functionally distinct segments of the mammalian intestinal tract, small intestine, and colon is constantly being renewed. This renewal is necessitated by a harsh lumen environment and is hypothesized to be driven by a small population of stem cells (SCs) that are believed to reside at the base of intestinal crypts. A lack of specific markers has hampered previous attempts to identify their exact location. We obtained tissue sections containing small intestine and colon crypts derived from normal (benign) or adenocarcinoma (AC) human intestine. The samples were floated onto BaF2 windows and analyzed using synchrotron radiation-based Fourier transform infrared microspectroscopy via an aperture size of 10 × 10 μm. Derived infrared (IR) spectral data was then analyzed using principal component analysis and/or linear discriminant analysis. Hypothesized cell types (as a function of aperture location along the length of individual crypts) within benign crypts were classed based on exploratory unsupervised IR spectral point clustering. Scores plots derived from individual small intestine crypts consistently generated one or two distinct spectra that clustered away from the remaining cell categories; these were retrospectively classed as "distinct base region" spectra. In these plots, a clear progression of locations along crypt lengths designated as from putative stem cells (SCs) to transit-amplifying (TA) cells to terminally differentiated (TD) cells was observed in benign small intestine and colon crypts. This progression of spectral points was crypt specific, pointing away from a unifying cell lineage model in human intestinal crypts. On comparison of AC-derived spectra versus corresponding benign, a subpopulation of AC-derived spectra suggested a putative SC-like spectral fingerprint; remaining IR spectra were classed as exhibiting TA cell-like or TD cell-like spectral characteristics. These observations could point to a cancer SC phenotype; an approach capable of identifying their in situ location has enormous therapeutic applications.
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