Photosensitizer effects on cancerous cells: A combined study using synchrotron infrared and fluorescence microscopies

Biochemical assay and spectroscopic analysis of oxidative/antioxidative parameters in the blood and serum of substance use disorders patients. A methodological comparison study

Substance abuse such as opioids, cannabis, and alcohol causes activation on the immune system and the release of reactive oxygen species (ROS) into the blood and serum. These substances cause an effect on oxidant and antioxidant status in patients with substance abuse. Mainly, wide-open to the ROS are lipids and proteins included blood, which suffers peroxidation. In this study, for the first-time differentiation of the effects of cannabis, alcohol and other synthetic substances on blood and serum samples, were performed. For this purpose, the level of the malondialdehyde (MDA) and glutathione (GSH) in serum and red blood cells, was measured using biochemical assay methods and Fourier Transform InfraRed spectroscopy (FTIR). The results showed, that peroxidation which is dignified as the production of MDA was increased for substance use disorder (SUD) patients (18.01 ± 2.97) compared to the control group (10.75 ± 2.28) (p < 0.001) and for antioxidant capacity, GSH level were significantly increased for SUD patients (p < 0.001). For the discrimination of protein and lipid region obtained from FTIR spectroscopy, we extracted features by principal component analyze (PCA) of protein (1800 cm^-1 to 900 cm^-1) and lipid (3200 cm^-1 to 2800 cm^-1) regions for blood and serum samples collected from patients with different types of SUD and healthy control (HC) participants. For the consideration of lipid oxidation, lipid saturation, lipid desaturation and protein aggregation the peak heights at 1740 cm^-1 to 2960 cm^-1, 2920 cm^-1 to 2960 cm^-1, 3012 cm^-1 to 2960 cm^-1, and 1630 cm^-1 to 1650 cm^-1 regions were studied for SUD and HC. Moreover, more visible changes were noticed for proteins region, than for lipids. The most notice structural changes were observed in amide II in serum spectra. Then we classified protein and lipid region's PCA results of blood and serum by Linear discriminant analysis (LDA) and Support vector machine (SVM). Confidence of the specificity, sensitivity and accuracy of blood and serum were obtained as 100%, 100% and 100% individually. This is the first comparative study on the spectrochemical tool and biochemical assay on SUD. Our results presented 100% discrimination of disorder region compared to healthy subjects.

Imidazole and beta-carotene photoprotection against photodynamic therapy evaluated by synchrotron infrared microscopy

In order to better understand the role of β-carotene and imidazole on the Photodynamic Therapy (PDT) mechanism, synchrotron infrared microscopy was used to detect the associated intracellular biochemical modifications following the visible light irradiation of HeLa cells incubated with these compounds as typical hydrophobic and hydrophilic singlet oxygen quenchers, respectively. For this purpose, PDT was performed employing the hydrophilic sensitizer 5,10,15,20-Tetrakis (1-methyl-4-pyridinio) porphyrin tetra (p-toluenesulfonate), TMPyP, and the hydrophobic sensitizer 5-(4-Methoxycarboxyphenyl)-10,15,20-triphenyl-21H,23H-porphyrin. The single cell IR spectra of PDT-treated, PDT plus quencher-treated and control HeLa cells were recorded at the SOLEIL Synchrotron Infrared SMIS beamline targeting specifically the cell nucleus. Principal Component Analysis (PCA) was used to assess the IR spectral changes. PCA revealed that there is a frequency shift of the protein Amide I vibrational band for the assays with the TMPyP sensitizer, indicating changes in the protein secondary structures of the PDT-treated cancer cells compared to the controls. In addition, the scores in those cells treated with both quenchers appear to be similar to the controls indicating a photoprotective effect. Comparative experiments carried out with SKMEL-28 and HaCat cells showed non- significant photoprotective effects of β-carotene and imidazole.

Infrared Spectroscopy as a Tool to Study the Antioxidant Activity of Polyphenolic Compounds in Isolated Rat Enterocytes

The protective effect of different polyphenols, catechin (Cat), quercetin (Qc) (flavonoids), gallic acid (GA), caffeic acid (CfA), chlorogenic acid (ChA) (phenolic acids), and capsaicin (Cap), against H2O2-induced oxidative stress was evaluated in rat enterocytes using Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) Spectroscopy and Fourier Transform Infrared Microspectroscopy (FTIRM), and results were compared to standard lipid peroxidation techniques: conjugated dienes (CD) and Thiobarbituric Acid Reactive Substances (TBARS). Analysis of ATR-FTIR and FTIRM spectral data allowed the simultaneous evaluation of the effects of H2O2 and polyphenols on lipid and protein oxidation. All polyphenols showed a protective effect against H2O2-induced oxidative stress in enterocytes, when administered before or after H2O2. Cat and capsaicin showed the highest protective effect, while phenolic acids had weaker effects and Qc presented a mild prooxidative effect (IR spectral profile of biomolecules between control and H2O2-treated cells) according to FTIR analyses. These results demonstrated the viability to use infrared spectroscopy to evaluate the oxidant and antioxidant effect of molecules in cell systems assays.

Use of infrared microspectroscopy to elucidate a specific chemical signature associated with hypoxia levels found in glioblastoma

Detection of the chemical signature associated with hypoxia in single glioblastoma cells by synchrotron infrared microspectroscopy.

Fourier transform infrared (FT-IR) spectromicroscopy to identify cell organelles: correlation with fluorescence staining in MCF-7 breast cancer cells

Biomolecules display specific vibrational signatures in the infrared (IR) range, and organelles that concentrate these biomolecules can be identified by these IR signatures. Subcellular identification and location of cell organelles using IR signatures is attractive as it does not require the use of any specific trackers and is thus non-invasive and non-destructive. We show here that endogenous IR absorptions are relevant to detecting and imaging the nucleus, the cytoplasm, and the Golgi apparatus/endoplasmic reticulum in MCF-7 breast cancer cells, and we compare these results with our previous work on the HeLa cell line. We correlate maps of fixed and dried cells obtained by synchrotron radiation Fourier transform infrared (SR FT-IR) spectromicroscopy with epifluorescence images using fluorescent trackers for Golgi apparatus and nucleus, namely BODIPY TR C5-ceramide complexed to BSA and DAPI, respectively. Interestingly, the ratios of the IR bands CH2 : CH3 (both asymmetric and symmetric) and CO((ester)):amide I were shown to be reliable gauges of the lipidic character of a cellular compartment, the -CH2 and the CO((ester)) absorptions increasing with the presence of inner membranes like in the Golgi apparatus.

Oral cancer diagnostics based on infrared spectral markers and wax physisorption kinetics

Infrared microspectroscopy is an emerging approach for disease analysis owing to its capability for in situ chemical characterization of pathological processes. Synchrotron-based infrared microspectroscopy (SR-IMS) provides ultra-high spatial resolution for profiling biochemical events associated with disease progression. Spectral alterations were observed in cultured oral cells derived from healthy, precancerous, primary, and metastatic cancers. An innovative wax-physisorption-based kinetic FTIR imaging method for the detection of oral precancer and cancer was demonstrated successfully. The approach is based on determining the residual amount of paraffin wax (C(25)H(52)) or beeswax (C(46)H(92)O(2)) on a sample surface after xylene washing. This amount is used as a signpost of the degree of physisorption that altered during malignant transformation. The results of linear discriminant analysis (LDA) of oral cell lines indicated that the methylene (CH(2)) and methyl group (CH(3)) stretching vibrations in the range of 3,000-2,800 cm(-1) have the highest accuracy rate (89.6 %) to discriminate the healthy keratinocytes (NHOK) from cancer cells. The results of wax-physisorption-based FTIR imaging showed a stronger physisorption with beeswax in oral precancerous and cancer cells as compared with that of NHOK, which showed a strong capability with paraffin wax. The infrared kinetic study of oral cavity tissue showed a consistency in the wax physisorption of the cell lines. On the basis of our findings, these results show the potential use of wax-physisorption-based kinetic FTIR imaging for the early screening of oral cancer lesions and the chemical changes during oral carcinogenesis.

Profiling pluripotent stem cells and organelles using synchrotron radiation infrared microspectroscopy

FTIR micro-spectroscopy is a sensitive, non-destructive and label-free method offering diffraction-limited resolution with high signal-to-noise ratios when combined with a synchrotron radiation source. The vibrational signature of individual cells was used to validate an alternative strategy for reprogramming induced pluripotent stem cells generated from amniocytes. The iPSC lines PB09 and PB10, were reprogrammed from the same amniocyte cell line using respectively the Oct54, Sox2, Lin28, and Nanog and the Oct4 and Sox2 transcription factor cocktail. We show that cells reprogrammed by the two different sets of transfection factors have similar spectral signatures after reprogramming, except for a small subpopulation of cells in one of the cell lines. Mapping HeLa cells at subcellular resolution, we show that the Golgi apparatus, the cytoplasm and the nucleus have a specific spectral signature. The CH(3):CH(2) ratio is the highest in the nucleus and the lowest in the Golgi apparatus/endoplasmic reticulum, in agreement with the membrane composition of these organelles. This is confirmed by specific staining of the organelles with fluorescent dyes. Subcellular differentiation of cell compartments is also demonstrated in living cells.

Synchrotron Radiation Spectroscopic Techniques as Tools for the Medicinal Chemist: Microprobe X-Ray Fluorescence Imaging, X-Ray Absorption Spectroscopy, and Infrared Microspectroscopy

This review updates the recent advances and applications of three prominent synchrotron radiation techniques, microprobe X-ray fluorescence spectroscopy/imaging, X-ray absorption spectroscopy, and infrared microspectroscopy, and highlights how these tools are useful to the medicinal chemist. A brief description of the principles of the techniques is given with emphasis on the advantages of using synchrotron radiation-based instrumentation rather than instruments using typical laboratory radiation sources. This review focuses on several recent applications of these techniques to solve inorganic medicinal chemistry problems, focusing on studies of cellular uptake, distribution, and biotransformation of established and potential therapeutic agents. The importance of using these synchrotron-based techniques to assist the development of, or validate the chemistry behind, drug design is discussed.

IR spectroscopy reveals effect of non-cytotoxic doses of anti-tumour drug on cancer cells

Identifying early cellular events in response to a chemotherapy drug treatment, in particular at low doses that will destroy the highest possible number of cancer cells, is an important issue in patient management. In this study, we employed Fourier transform infrared spectroscopy as a potential tool to access such information. We used as model the non-small cell lung cancer cell line, Calu-1. They were exposed to cytostatic doses (0.1 to 100 nM for 24, 48 and 72 h) of gemcitabine, an anti-tumour drug, currently used in treatment of lung cancer patients. In these conditions, inhibition of cell proliferation ranges from weak (< or = 5%), to moderate (approximately 23%), to high (82-95%) without affecting cell viability. Following drug treatment as a function of doses and incubation times, the spectra of cell populations and of individual cells were acquired using a bench-top IR source and a synchrotron infrared microscope. It is demonstrated that spectral cell response to gemcitabine is detectable at sublethal doses and that effects observed on cell populations are similar to those from single cells. Using cluster analysis, spectra could be classified in two main groups: a first group that contains spectra of cells exhibiting a weak or moderate proliferation rate and a second group with spectra from cells presenting a high growth inhibition. These results are promising since they show that effects of subtoxic doses can also be monitored at the single-cell level with the clinical implications that this may have in terms of patient benefit and response to chemotherapy.