Raman Imaging-A Valuable Tool for Tracking Fatty Acid Metabolism-Normal and Cancer Human Colon Single-Cell Study.

Altered metabolism of lipids is a key factor in many diseases including cancer. Therefore, investigations into the impact of unsaturated and saturated fatty acids (FAs) on human body homeostasis are crucial for understanding the development of lifestyle diseases. In this paper, we focus on the impact of palmitic (PA), linoleic (LA), and eicosapentaenoic (EPA) acids on human colon normal (CCD-18 Co) and cancer (Caco-2) single cells using Raman imaging and spectroscopy. The label-free nature of Raman imaging allowed us to evaluate FAs dynamics without modifying endogenous cellular metabolism. Thanks to the ability of Raman imaging to visualize single-cell substructures, we have analyzed the changes in chemical composition of endoplasmic reticulum (ER), mitochondria, lipid droplets (LDs), and nucleus upon FA supplementation. Analysis of Raman band intensity ratios typical for lipids, proteins, and nucleic acids (I1656/I1444, I1444/I1256, I1444/I750, I1304/I1256) proved that, using Raman mapping, we can observe the metabolic pathways of FAs in ER, which is responsible for the uptake of exogenous FAs, de novo synthesis, elongation, and desaturation of FAs, in mitochondria responsible for energy production via FA oxidation, in LDs specialized in cellular fat storage, and in the nucleus, where FAs are transported via fatty-acid-binding proteins, biomarkers of human colon cancerogenesis. Analysis for membranes showed that the uptake of FAs effectively changed the chemical composition of this organelle, and the strongest effect was noticed for LA. The spectroscopy studies have been completed using XTT tests, which showed that the addition of LA or EPA for Caco-2 cells decreases their viability with a stronger effect observed for LA and the opposite effect observed for PA. For normal cells, CCD-18 Co supplementation using LA or EPA stimulated cells for growing, while PA had the opposite impact.

Raman-AFM-fluorescence-guided impact of linoleic and eicosapentaenoic acids on subcellular structure and chemical composition of normal and cancer human colon cells.

The regular overconsumption of high-energy food (rich in lipids and sugars) results in elevated nutrient absorption in intestine and consequently excessive accumulation of lipids in many organs e.g.: liver, adipose tissue, muscles. In the long term this can lead to obesity and obesity-associated diseases e.g. type 2 diabetes, non-alcoholic fatty liver disease, cardiovascular disease, inflammatory bowel disease (IBD). In the presented paper based on RI data we have proved that Raman maps can be used successfully for subcellular structures visualization and analysis of fatty acids impact on morphology and chemical composition of human colon single cells - normal and cancer. Based on Raman data we have investigated the changes related to endoplasmic reticulum, mitochondria, lipid droplets and nucleus. Analysis of ratios calculated based on Raman bands typical for proteins (1256, 1656 cm-1), lipids (1304, 1444 cm-1) and nucleic acids (750 cm-1) has confirmed for endoplasmic reticulum the increased activity of this organelle in lipoproteins synthesis upon FAs supplementation; for LDs the changes of desaturation of accumulated lipids with the highest unsaturation level for CaCo-2 cells upon EPA supplementation; for mitochondria the stronger effect of FAs supplementation was observed for CaCo-2 cells confirming the increased activity of this organelle responsible for energy production necessary for tumor development; the weakest impact of FAs supplementation was observed for nucleus for both types of cells and both types of acids. Fluorescence imaging was used for the investigations of changes in LDs/ER morphology. Our measurements have shown the increased area of LDs/ER for CaCo-2 cancer cells, and the strongest effect was noticed for CaCo-2 cells upon EPA supplementation. The increased participation of lipid structures for all types of cells upon FAs supplementation has been confirmed also by AFM studies. The lowest YM values have been observed for CaCo-2 cells including samples treated with FAs.

The Composite Material of (PEDOT-Polystyrene Sulfonate)/Chitosan-AuNPS-Glutaraldehyde/as the Base to a Sensor with Laccase for the Determination of Polyphenols.

The described research aimed to develop the properties of the conductive composite /poly(3,4-ethylenedioxy-thiophene-poly(4-lithium styrenesulfonic acid)/chitosan-AuNPs-glutaraldehyde/ (/PEDOT-PSSLi/chit-AuNPs-GA/) and to develop an electrochemical enzyme sensor based on this composite material and glassy carbon electrodes (GCEs). The composite was created via electrochemical production of an /EDOT-PSSLi/ layer on a glassy carbon electrode (GCE). This layer was covered with a glutaraldehyde cross-linked chitosan and doped with AuNPs. The influence of AuNPs on the increase in the electrical conductivity of the chitosan layers and on facilitating the oxidation of polyphenols in these layers was demonstrated. The enzymatic sensor was obtained via immobilization of the laccase on the surface of the composite, with glutaraldehyde as the linker. The investigation of the surface morphology of the GCE/PEDOT-PSSLi/chit-AuNPs-GA/Laccase sensor was carried out using SEM and AFM microscopy. Using EDS and Raman spectroscopy, AuNPs were detected in the chitosan layer and in the laccase on the surface of the sensor. Polyphenols were determined using differential pulse voltammetry. The biosensor exhibited catalytic activity toward the oxidation of polyphenols. It has been shown that laccase is regenerated through direct electron transfer between the sensor and the enzyme. The results of the DPV tests showed that the developed sensor can be used for the determination of polyphenols. The peak current was linearly proportional to the concentrations of catechol in the range of 2-90 µM, with a limit of detection (LOD) of 1.7 µM; to those of caffeic acid in the range of 2-90 µM, LOD = 1.9 µM; and to those of gallic acid in the range 2-18 µM, LOD = 1.7 µM. Finally, the research conducted in order to determine gallic acid in a natural sample, for which white wine was used, was described.

Biochemistry and Nanomechanical Properties of Human Colon Cells upon Simvastatin, Lovastatin, and Mevastatin Supplementations: Raman Imaging and AFM Studies.

One of the most important areas of medical science is oncology, which is responsible for both the diagnostics and treatment of cancer diseases. Over the years, there has been an intensive development of cancer diagnostics and treatment. This paper shows the comparison of normal (CCD-18Co) and cancerous (CaCo-2) cell lines of the human gastrointestinal tract on the basis of nanomechanical and biochemical properties to obtain information on cancer biomarkers useful in oncological diagnostics. The research techniques used were Raman spectroscopy and imaging and atomic force microscopy (AFM). In addition, the studies also included the effect of the statin compounds─mevastatin, lovastatin, and simvastatin─and their influence on biochemical and nanomechanical changes of cell properties using Raman imaging and AFM techniques. The cytotoxicity of statins was determined using XTT tests.

The Effect of ß-Carotene, Tocopherols and Ascorbic Acid as Anti-Oxidant Molecules on Human and Animal In Vitro/In Vivo Studies: A Review of Research Design and Analytical Techniques Used.

Prolonged elevated oxidative stress (OS) possesses negative effect on cell structure and functioning, and is associated with the development of numerous disorders. Naturally occurred anti-oxidant compounds reduce the oxidative stress in living organisms. In this review, antioxidant properties of ß-carotene, tocopherols and ascorbic acid are presented based on in vitro, in vivo and populational studies. Firstly, environmental factors contributing to the OS occurrence and intracellular sources of Reactive Oxygen Species (ROS) generation, as well as ROS-mediated cellular structure degradation, are introduced. Secondly, enzymatic and non-enzymatic mechanism of anti-oxidant defence against OS development, is presented. Furthermore, ROS-preventing mechanisms and effectiveness of ß-carotene, tocopherols and ascorbic acid as anti-oxidants are summarized, based on studies where different ROS-generating (oxidizing) agents are used. Oxidative stress biomarkers, as indicators on OS level and prevention by anti-oxidant supplementation, are presented with a focus on the methods (spectrophotometric, fluorometric, chromatographic, immuno-enzymatic) of their detection. Finally, the application of Raman spectroscopy and imaging as a tool for monitoring the effect of anti-oxidant (ß-carotene, ascorbic acid) on cell structure and metabolism, is proposed. Literature data gathered suggest that ß-carotene, tocopherols and ascorbic acid possess potential to mitigate oxidative stress in various biological systems. Moreover, Raman spectroscopy and imaging can be a valuable technique to study the effect of oxidative stress and anti-oxidant molecules in cell studies.

Raman Spectroscopy and Imaging Studies of Human Digestive Tract Cells and Tissues-Impact of Vitamin C and E Supplementation.

Cancers of digestive tract such as colorectal cancer (CRC) and gastric cancer (GC) are the most commonly detected types of cancer worldwide and their origin can be associated with oxidative stress conditions. Commonly known and followed antioxidants, such as vitamin C and E, are widely considered as potential anti-cancer agents. Raman spectra have great potential in the biochemical characterization of matter based on the fact that each molecule has its own unique vibrational properties. Raman spectroscopy allows to precisely characterize components (proteins, lipids, nucleic acids). The paper presents the application of the Raman spectroscopy technique for the analysis of tissue samples and cells of the human colon and stomach. The main goal of this study is to show the differences between healthy and cancerous tissues from the human digestive tract and human normal and cancer colon and gastric cell lines. The paper presents the spectroscopic characterization of normal colon cells, CCD-18 Co, in physiological and oxidative conditions and effect of oxidative injury of normal colon cells upon supplementation with vitamin C at various concentrations based on Raman spectra. The obtained results were related to the Raman spectra recorded for human colon cancer cells-CaCo-2. In addition, the effect of the antioxidant in the form of vitamin E on gastric cancer cells, HTB-135, is presented and compared with normal gastric cells-CRL-7869. All measured gastric samples were biochemically and structurally characterized by means of Raman spectroscopy and imaging. Statistically assisted analysis has shown that normal, ROS injured and cancerous human gastrointestinal cells can be distinguished based on their unique vibrational properties. ANOVA tests, PCA (Principal Component Analysis) and PLSDA (Partial Least Squares Discriminant Analysis) have confirmed the main role of nucleic acids, proteins and lipids in differentiation of human colon and stomach normal and cancer tissues and cells. The conducted research based on Raman spectra proved that antioxidants in the form of vitamin C and E exhibit anti-cancer properties. In consequence, conducted studies proved that label-free Raman spectroscopy may play an important role in clinical diagnostic differentiation of human normal and cancerous gastrointestinal tissues and may be a source of intraoperative information supporting histopathological analysis.

Vitamin C-Protective Role in Oxidative Stress Conditions Induced in Human Normal Colon Cells by Label-Free Raman Spectroscopy and Imaging.

Colorectal cancer is the second most frequently diagnosed cancer worldwide. Conventional diagnostics methods of colorectal cancer can detect it at an advanced stage. Spectroscopic methods, including Raman spectroscopy and imaging, are becoming more and more popular in medical applications, and allow fast, precise, and unambiguous differentiation of healthy and cancerous samples. The most important advantage of Raman spectroscopy is the ability to identify biomarkers that help in the differentiation of healthy and cancerous cells based on biochemistry of sample and spectra typical for lipids, proteins, and DNA. The aim of the study was to evaluate the biochemical and structural features of human colon cell lines based on Raman spectroscopy and imaging: normal cells CCD-18 Co, normal cells CCD-18 Co under oxidative stress conditions, and normal cells CCD-18 Co at first treated by using tert-Butyl hydroperoxide and then supplemented by vitamin C in high concentration to show the protective role of vitamin C in micromolar concentrations against ROS (Reactive Oxygen Species). Raman data obtained for normal cells injured by ROS were compared with spectra typical for cancerous cells. Statistically assisted analysis has shown that normal ROS-injured and cancerous human colon cells can be distinguished based on their unique vibrational properties. The research carried out proves that label-free Raman spectroscopy may play an important role in clinical diagnostics differentiation of normal and cancerous colon cells and may be a source of intraoperative information supporting histopathological analysis.

Revision of Commonly Accepted Warburg Mechanism of Cancer Development: Redox-Sensitive Mitochondrial Cytochromes in Breast and Brain Cancers by Raman Imaging.

We used Raman imaging to monitor changes in the redox state of the mitochondrial cytochromes in ex vivo human brain and breast tissues, surgically resected specimens of human tissues and in vitro human brain cells of normal astrocytes (NHA), astrocytoma (CRL-1718), glioblastoma (U87-MG) and medulloblastoma (Daoy), and human breast cells of normal cells (MCF 10A), slightly malignant cells (MCF7) and highly aggressive cells (MDA-MB-231) by means of Raman microspectroscopy at 532 nm. We visualized localization of cytochromes by Raman imaging in the major organelles in cancer cells. We demonstrated that the "redox state Raman marker" of the ferric low-spin heme in cytochrome c at 1584 cm-1 can serve as a sensitive indicator of cancer aggressiveness. We compared concentration of reduced cytochrome c and the grade of cancer aggressiveness in cancer tissues and single cells and specific organelles in cells: nucleous, mitochondrium, lipid droplets, cytoplasm and membrane. We found that the concentration of reduced cytochrome c becomes abnormally high in human brain tumors and breast cancers in human tissues. Our results reveal the universality of Raman vibrational characteristics of mitochondrial cytochromes in metabolic regulation in cancers that arise from epithelial breast cells and brain glial cells.

Redox Imbalance and Biochemical Changes in Cancer by Probing Redox-Sensitive Mitochondrial Cytochromes in Label-Free Visible Resonance Raman Imaging.

To monitor redox state changes and biological mechanisms occurring in mitochondrial cytochromes in cancers improving methods are required. We used Raman spectroscopy and Raman imaging to monitor changes in the redox state of the mitochondrial cytochromes in ex vivo human brain and breast tissues at 532 nm, 633 nm, 785 nm. We identified the oncogenic processes that characterize human infiltrating ductal carcinoma (IDC) and human brain tumors: gliomas; astrocytoma and medulloblastoma based on the quantification of cytochrome redox status by exploiting the resonance-enhancement effect of Raman scattering. We visualized localization of cytochromes by Raman imaging in the breast and brain tissues and analyzed cytochrome c vibrations at 750, 1126, 1337 and 1584 cm-1 as a function of malignancy grade. We found that the concentration of reduced cytochrome c becomes abnormally high in human brain tumors and breast cancers and correlates with the grade of cancer. We showed that Raman imaging provides additional insight into the biology of astrocytomas and breast ductal invasive cancer, which can be used for noninvasive grading, differential diagnosis.

Zinc Phthalocyanine Photochemistry by Raman Imaging, Fluorescence Spectroscopy and Femtosecond Spectroscopy in Normal and Cancerous Human Colon Tissues and Single Cells.

Photodynamic therapy is a clinically approved alternative method for cancer treatment in which a combination of nontoxic drugs known as photosensitizers and oxygen is used. Despite intensive investigations and encouraging results, zinc phthalocyanines (ZnPcs) have not yet been approved as photosensitizers for clinical use. Label-free Raman imaging of nonfixed and unstained normal and cancerous colon human tissues and normal human CCD18-Co and cancerous CaCo-2 cell lines, without and after adding ZnPcS4 photosensitizer, was analyzed. The biochemical composition of normal and cancerous colon tissues and colon cells without and after adding ZnPcS4 at the subcellular level was determined. Analyzing the fluorescence/Raman signals of ZnPcS4, we found that in normal human colon tissue samples, in contrast to cancerous ones, there is a lower affinity to ZnPcS4 phthalocyanine. Moreover, a higher concentration in cancerous tissue was concomitant with a blue shift of the maximum peak position specific for the photosensitizer from 691-695 nm to 689 nm. Simultaneously for both types of samples, the signal was observed in the monomer region, confirming the excellent properties of ZnPcS4 for photo therapy (PDT). For colon cell experiments with a lower concentration of ZnPcS4 photosensitizer, c = 1 × 10-6 M, the phthalocyanine was localized in mitochondria/lipid structures; for a higher concentration, c = 9 × 10-6 M, localization inside the nucleus was predominant. Based on time-resolved experiments, we found that ZnPcS4 in the presence of biological interfaces features longer excited-state lifetime photosensitizers compared to the aqueous solution and bare ZnPcS4 film on CaF2 substrate, which is beneficial for application in PDT.

A look into the use of Raman spectroscopy for brain and breast cancer diagnostics: linear and non-linear optics in cancer research as a gateway to tumor cell identity.

Introduction: Currently, intensely developing of linear and non-linear optical methods for cancer detection provides a valuable tool to improve sensitivity and specificity. One of the main reasons for insufficient progress in cancer diagnostics is related to the fact that most cancer types are not only heterogeneous in their genetic composition but also reside in varying microenvironments and interact with different cell types. Until now, no technology has been fully proven for effective detecting of invasive cancer, which infiltrating the extracellular matrix.Areas covered: This review investigates the current status of Raman spectroscopy and Raman imaging for brain and breast cancer diagnostics. Moreover, the review provides a comprehensive overview of the applicability of atomic force microscopy (AFM), linear and non-linear optics in cancer research as a gateway to tumor cell identity.Expert commentary: A combination of linear and non-linear optics, particularly Raman-driven methods, has many additional advantages to identify alterations in cancer cells that are crucial for their proliferation and that distinguish them from normal cells.

Aberrant Protein Phosphorylation in Cancer by Using Raman Biomarkers.

(1) Background: Novel methods are required for analysing post-translational modifications of protein phosphorylation by visualizing biochemical landscapes of proteins in human normal and cancerous tissues and cells. (2) Methods: A label-free Raman method is presented for detecting spectral changes that arise in proteins due to phosphorylation in the tissue of human breasts, small intestines, and brain tumours, as well as in the normal human astrocytes and primary glioblastoma U-87 MG cell lines. Raman spectroscopy and Raman imaging are effective tools for monitoring and analysing the vibrations of functional groups involved in aberrant phosphorylation in cancer without any phosphorecognition of tag molecules. (3) Results: Our results based on 35 fresh human cancer and normal tissues prove that the aberrant tyrosine phosphorylation monitored by the unique spectral signatures of Raman vibrations is a universal characteristic in the metabolic regulation in different types of cancers. Overexpressed tyrosine phosphorylation in the human breast, small intestine and brain tissues and in the human primary glioblastoma U-87 MG cell line was monitored by using Raman biomarkers. (4) We showed that the bands at 1586 cm-1 and 829 cm-1, corresponding to phosphorylated tyrosine, play a pivotal role as a Raman biomarker of the phosphorylation status in aggressive cancers. We found that the best Raman biomarker of phosphorylation is the 1586/829 ratio showing the statistical significance at p Values of ≤ 0.05. (5) Conclusions: Raman spectroscopy and imaging have the potential to be used as screening functional assays to detect phosphorylated target proteins and will help researchers to understand the role of phosphorylation in cellular processes and cancer progression. The abnormal and excessive high level of tyrosine phosphorylation in cancer samples compared with normal samples was found in the cancerous human tissue of breasts, small intestines and brain tumours, as well as in the mitochondria and lipid droplets of the glioblastoma U-87 MG cell line. Detailed insights are presented into the intracellular oncogenic metabolic pathways mediated by phosphorylated tyrosine.

Hyperglycemia Changes Expression of Key Adipogenesis Markers (C/EBPα and PPARᵞ)and Morphology of Differentiating Human Visceral Adipocytes.

Disturbances in adipose tissue significantly contribute to the development of metabolic disorders, which are connected with hyperglycemia (HG) and underlain by epigenetics-based mechanisms. Therefore, we aimed to evaluate the effect of hyperglycemia on proliferating, differentiating and maturating human visceral pre/adipocytes (HPA-v). Three stages of cell culture were conducted under constant or variable glycemic conditions. Adipogenesis progress was assessed using BODIPY 505/515 staining. Lipid content typical for normal and hyperglycemic conditions of adipocytes was analyzed using Raman spectroscopy and imaging. Expression of adipogenic markers, PPARγ and C/EBPα, was determined at the mRNA and protein levels. We also examined expression of miRNAs proven to target PPARγ (miR-34a-5p) and C/EBPα (miR-137-3p), employing TaqMan Low-Density Arrays (TLDA) cards. Hyperglycemia altered morphology of differentiating HPA-v in relation to normoglycemia by accelerating the formation of lipid droplets and making their numbers and volume increase. Raman results confirmed that the qualitative and quantitative lipid composition under normal and hyperglycemic conditions were different, and that the number of lipid droplets increased in (HG)-treated cells. Expression profiles of both examined genes markedly changed either during adipogenesis under physiological and hyperglycemic conditions, orat particular stages of adipogenesis upon chronic and/or variable glycemia. Expression levels of PPARγ seemed to correspond to some expression changes of miR-34a-5p. miR-137-3p, whose expression was rather stable throughout the culture, did not seem to affect C/EBPα. Our observations revealed that chronic and intermittent hyperglycemia change the morphology of visceral pre/adipocytes during adipogenesis. Moreover, hyperglycemia may utilize miR-34a-5p to induce some expression changes in PPARγ.

Analysis of Human Colon by Raman Spectroscopy and Imaging-Elucidation of Biochemical Changes in Carcinogenesis.

Noninvasive Raman imaging of non-fixed and unstained human colon tissues based on vibrational properties of noncancerous and cancerous samples can effectively enable the differentiation between noncancerous and tumor tissues. This work aimed to evaluate the biochemical characteristics of colon cancer and the clinical merits of multivariate Raman image and spectroscopy analysis. Tissue samples were collected during routine surgery. The non-fixed, fresh samples were used to prepare micrometer sections from the tumor mass and the tissue from the safety margins outside of the tumor mass. Adjacent sections were used for typical histological analysis. We have found that the chemical composition identified by Raman spectroscopy of the cancerous and the noncancerous colon samples is sufficiently different to distinguish pathologically changed tissue from noncancerous tissue. We present a detailed analysis of Raman spectra for the human noncancerous and cancerous colon tissue. The multivariate analysis of the intensities of lipids/proteins/carotenoids Raman peaks shows that these classes of compounds can statistically divide analyzed samples into noncancerous and pathological groups, reaffirming that Raman imaging is a powerful technique for the histochemical analysis of human tissues. Raman biomarkers based on ratios for lipids/proteins/carotenoids content were found to be the most useful biomarkers in spectroscopic diagnostics.

Advances in Raman imaging combined with AFM and fluorescence microscopy are beneficial for oncology and cancer research.

Aim: The aim of this paper is to provide images of the universal cancer Raman biomarkers based on lipidomic, proteomic, glycomic profiles and nanomechanical properties. Materials & methods: Biochemical mapping and nanomechanical properties (topography, stiffness and adhesion) of human breast and brain for normal and cancer tissues and cell culture line U87 MG of glioblastoma were obtained using Raman imaging combined with atomic force microscopy (AFM) and fluorescence microscopy. Results & conclusion: Detailed analysis of breast ductal carcinoma in situ, and astrocytoma brain tissues as well as cells of glioblastoma U87 MG showed that Raman scattering generates images as accurately as histology hematoxylin and eosin stain used in clinical practice with additional advantage of biochemical information. Combination of AFM maps and Raman images allows to correlate mechanical properties with biochemical composition of cells.

Effect of PHRs and PCPs on Microalgal Growth, Metabolism and Microalgae-Based Bioremediation Processes: A Review.

In this review, the effect of pharmaceuticals (PHRs) and personal care products (PCPs) on microalgal growth and metabolism is reported. Concentrations of various PHRs and PCPs that cause inhibition and toxicity to growths of different microalgal strains are summarized and compared. The effect of PHRs and PCPs on microalgal metabolism (oxidative stress, enzyme activity, pigments, proteins, lipids, carbohydrates, toxins), as well as on the cellular morphology, is discussed. Literature data concerning the removal of PHRs and PCPs from wastewaters by living microalgal cultures, with the emphasis on microalgal growth, are gathered and discussed. The potential of simultaneously bioremediating PHRs/PCPs-containing wastewaters and cultivating microalgae for biomass production in a single process is considered. In the light of reviewed data, the feasibility of post-bioremediation microalgal biomass is discussed in terms of its contamination, biosafety and further usage for production of value-added biomolecules (pigments, lipids, proteins) and biomass as a whole.

Label-free diagnostics and cancer surgery Raman spectra guidance for the human colon at different excitation wavelengths.

Raman spectroscopy and imaging are highly structure-sensitive methods that allow the characterization of biological samples with minimal impact. In this paper, Raman spectra and imaging of noncancerous and cancerous human colon tissue samples were measured at different excitation wavelengths: 355, 532, and 785 nm. Intra-patient variability in the analyzed spectra showed colon sample heterogeneity for both noncancerous and cancerous human sample types. The lowest inter-patient variability of Raman spectra was observed for the fingerprint region of noncancerous samples for the 532 nm excitation laser line. The bands of principal biochemical constituents (proteins, lipids, nucleic acids) predominate in VIS and NIR-Raman spectra (excitation: 532, 785 nm), with the special role of the bands of intrinsic tissue chromophores-carotenoids for VIS excitation due to resonance enhancement. At 355 nm excitation, high autofluorescence of colon tissues were observed. Our studies proved high potential of Raman spectroscopy and Raman imaging in differentiation of noncancerous and cancerous human colon tissues and that the wavelengths 532 and 785 nm offer wide possibilities for the detection of human colon tissue pathology for ex vivo and in vivo measurements and prevail over 355 nm excitation.

New look inside human breast ducts with Raman imaging. Raman candidates as diagnostic markers for breast cancer prognosis: Mammaglobin, palmitic acid and sphingomyelin.

Looking inside the human body fascinated mankind for thousands of years. Current diagnostic and therapy methods are often limited by inadequate sensitivity, specificity and spatial resolution. Raman imaging may bring revolution in monitoring of disease and treatment. The main advantage of Raman imaging is that it gives spatial information about various chemical constituents in defined cellular organelles in contrast to conventional methods (liquid chromatography/mass spectrometry, NMR, HPLC) that rely on bulk or fractionated analyses of extracted components. We demonstrated how Raman imaging can drive the progress on breast cancer just unimaginable a few years ago. We looked inside human breast ducts answering fundamental questions about location and distribution of various biochemical components inside the lumen, epithelial cells of the duct and the stroma around the duct during cancer development. We have identified Raman candidates as diagnostic markers for breast cancer prognosis: carotenoids, mammaglobin, palmitic acid and sphingomyelin as key molecular targets in ductal breast cancer in situ, and propose the molecular mechanisms linking oncogenes with lipid programming.

Raman microspectroscopy of noncancerous and cancerous human breast tissues. Identification and phase transitions of linoleic and oleic acids by Raman low-temperature studies.

We present the results of Raman studies in the temperature range of 293-77 K on vibrational properties of linoleic and oleic acids and Raman microspectroscopy of human breast tissues at room temperature. Our results confirmed the significant role of unsaturated fatty acids in differentiation of noncancerous and cancerous breast tissues and the role of vibrational spectroscopy in phase transition identification. We have found that vibrational properties are very sensitive indicators to specify phases and phase transitions typical of unsaturated fatty acids at the molecular level. Using Raman spectroscopy we have identified high-temperature, middle-temperature and low-temperature phases of linoleic acid. Results obtained for linoleic acid were compared with parameters characteristic of α and γ phases of oleic acid - the parent compound of polyunsaturated fatty acids.