Quantitative phase analysis and molecular structure of human gallstones using synchrotron radiation X-ray diffraction and FTIR spectroscopy.

Human gallstones are the most common disorder in the biliary system, affecting up to 20 % of the adult population. The formation of gallstones is primarily due to the supersaturating of cholesterol in bile. In order to comprehend gallstone disease in detail, it is necessary to have accurate information about phase identification and molecular structure. Different types of gallstone samples were collected from the Middle East area after surgical operations including; cholesterol, pigment, and mixed gallstones. To estimate the basic information about the stone formation and the pathophysiology of cholelithiasis as well as to classify the collected human gallstones, attenuated total reflection Fourier transform Infrared spectrometry (ATR-FTIR) was used to analyze the different gallstone structures in the wavenumber range from 400 to 4000 cm-1. Calcium bilirubinate was specified by the bands at 1662 cm-1, 1626 cm-1, and 1572 cm-1, while cholesterol rings were designated by the bands at 1464, 1438, 1055, and 1022 cm-1. It can be assumed that all samples consist of mixed gallstones based on the doublets at 1375 cm-1 and 1365 cm-1. The levels of calcium bilirubin and various minerals varied among the analyzed samples, indicating the heterogeneity in their composition and suggesting potential implications for gallstone formation. Based on the quantitative phase analysis using synchrotron radiation X-ray diffraction (SR-XRD), two phases of anhydrous cholesterol as a major content and one phase of monohydrate cholesterols as trace content represent the main components of most of the gallstones. Additional phases of calcium carbonate in the form of calcite, vaterite, aragonite, and bilirubinate were also quantified. According to the outcomes of the FTIR and the SR-XRD measurements, there exists a statistical correlation between the different types of chemical constituents of the gallstones.

Performance Evaluation of Focal Plane Array (FPA)-FTIR and Synchrotron Radiation (SR)-FTIR Microspectroscopy to Classify Rice Components.

The development of biochemical analysis techniques to study heterogeneous biological samples is increasing. These techniques include synchrotron radiation Fourier transform infrared (SR-FTIR) microspectroscopy. This method has been applied to analyze biological tissue with multivariate statistical analysis to classify the components revealed by the spectral data. This study aims to compare the efficiencies of SR-FTIR microspectroscopy and focal plane array (FPA)-FTIR microspectroscopy when classifying rice tissue components. Spectral data were acquired for mapping the same sample areas from both techniques. Principal component analysis and cluster imaging were used to investigate the biochemical variations of the tissue types. The classification was based on the functional groups of pectin, protein, and polysaccharide. Four layers from SR-FTIR microspectroscopy including pericarp, aleurone layer, sub-aleurone layer, and endosperm were classified using cluster imaging, while FPA-FTIR microspectroscopy could classify only three layers of pericarp, aleurone layer, and endosperm. Moreover, SR-FTIR microspectroscopy increased the image contrast of the biochemical distribution in rice tissue more efficiently than FPA-FTIR microspectroscopy. We have demonstrated the capability of the high-resolution synchrotron technique and its ability to clarify small structures in rice tissue. The use of this technique might increase in future studies of tissue characterization.

Partial least squares regression and fourier transform infrared (FTIR) microspectroscopy for prediction of resistance in hepatocellular carcinoma HepG2 cells.

We evaluated the feasibility of FTIR microspectroscopy combined with partial least squares regression (PLS-R) for determination of resistance in HepG2 cells. Cell viability testing was performed using neutral red assay for the concentration of cisplatin resulting in 50% antiproliferation (IC50). The resistance index (RI) is the ratio of the IC50 in resistant HepG2 cells vs. parental HepG2 cells. Principal component and unsupervised hierarchical cluster analyses were applied and a differentiation of samples of cells (parental, 1.8RI, 2.3RI, 3.0RI, and 3.5RI) was demonstrated (3000-2800cm-1 in the lipid and 1700-1500cm-1 in the protein regions. The FTIR spectra were preprocessed with several treatments to test the algorithm. PLS-R models were built using the 1170 spectra of the HepG2 cells. Cross-validation was used to evaluate prediction of the RI value using this model. PLS-R models-preprocessed with the second derivative FTIR spectra-yielded the best model (R2=0.99, RMSEE=0.095 and RPD=7.98). Most RI values were predicted with high accuracy (91-100%) such that the linear correlation between the actual and predicted RI values was nearly perfect (slope~1). FTIR microspectroscopy combined with chemometric analysis using PLS-R offers quick, accurate, and reliable quantitative analysis of HepG2 cell resistance.

FTIR microspectroscopy defines early drug resistant human hepatocellular carcinoma (HepG2) cells.

Characterization and identification of cancer cell, chemotherapy, resistance is important for both routine cancer therapy and trouble-shooting the medication treatment regimen. Present techniques for characterizing cancer cell resistance require multiple methods and steps, which are time-consuming and expensive. We present a protocol for simple sample handling, rapid detection, and spectral characterization of early resistant hepatocellular carcinoma (HepG2) cells, using Fourier transform infrared microspectroscopy (FTIR). Studies on alteration of the biochemical properties in a resistant HepG2 cell were evaluated-viz., increase efflux proteins (MRP-1 and P-gp) activity, total GSH content, anti-apoptotic (Bcl2) expression, and reduction of pro-apoptotic (Bax) proteins. Principle component analysis (PCA) was used to discriminate resistant HepG2 cells from parental HepG2 cells. Three important FTIR spectral regions were evaluated for reproducibility and discrimination ability-viz., lipid (3,000-2,800 cm(-1)), protein (1,700-1,500 cm(-1)) and carbohydrate and nucleic acid (1,300-900 cm(-1)). These 3 spectral regions can be used as spectroscopic biomarkers for differentiation of early or low resistance. This work presents a novel concept for high-throughput, FTIR spectroscopic discrimination of early resistance; thus enabling identification and characterization of cancer cell resistance.

Diagnosis of liver cancer from blood sera using FTIR microspectroscopy: a preliminary study.

FTIR microspectroscopy was applied for studying macromolecular changes in human serum samples from patients with healthy livers, and those diagnosed with liver cirrhosis or hepatocellular carcinoma (HCC). Our study demonstrated that the serum samples from HCC and cirrhotic patients could readily be discriminated from those from healthy controls based on macromolecular differences related to their lipid and protein structure. Spectral changes appeared to indicate that the secondary structure of protein from HCC sample groups contained a more distinctive ß -sheet structure and a lower lipid content compared to samples from the healthy and cirrhosis group. This was correlated with measurements of large decreases in albumin levels in serum from diseased patients. We argue that this technique shows potential as a simple, rapid, inexpensive, and non-subjective methodology for the screening patients suspected of liver disease.

Application of FTIR microspectroscopy for characterization of biomolecular changes in human melanoma cells treated by sesamol and kojic acid.

BACKGROUND: Hyperpigmentation is aesthetic undesirable. Sesamol and the standard antimelanogenic agent (kojic acid) were shown to hinder melanogenesis by blocking tyrosinase and reducing melanin content. OBJECTIVE: The FTIR microspectroscopy was used in an attempt to find a novel method to define biological alternation in a melanogenesis inhibition of sesamol and kojic acid. METHODS: Tyrosinase inhibition and melanin content of sesamol and kojic acid were evaluated. The FTIR microspectroscopy was adopted to define the vibrational characteristic involved with the melanogenesis in the untreated SK-MEL2 cells vs. the sesamol- and kojic-treated SK-MEL2 cells. RESULTS: Sesamol and kojic acid inhibited mushroom tyrosinase at IC50 of 0.33 µg/ml and 6.1±0.4 µg/ml, respectively. Moreover, 30 µg/ml sesamol inhibited 23.55±8.25% cellular tyrosinase activity in human SK-MEL2 cells, while 600 µg/ml kojic acid inhibited 33.9±1.4% cellular tyrosinase activity in the same cells. In the SK-MEL2-treated with two inhibitors, the FTIR spectra assigned to the lipid and nucleic acid bands were significantly depleted with the secondary protein structure shifted to a more ß-pleated secondary protein one. CONCLUSION: Both sesamol and kojic acid display a similar pattern of antimelanogenesis activity albeit to a different degree. The mechanism of their whitening effect may be via the alteration of (a) the enzyme conformation disallowing the ordinary enzyme-substrate interaction and maybe (b) the integrity of the lipid-containing melanosome. Our results support the alternative use of FTIR microspectroscopy as a simple and reagent-free method for characterization of biomolecular changes in human melanoma cells.

Discrimination of functional hepatocytes derived from mesenchymal stem cells using FTIR microspectroscopy.

Functional hepatocytes differentiated in vitro from mesenchymal stem cells (MSCs) need to be fully characterized before they could be applied as a therapy to treat liver disease. Here, we employed Fourier Transform Infrared (FTIR) microspectroscopy to investigate the characteristics of hepatocyte-like cells derived from rat bone marrow mesenchymal stem cells (rBM-MSCs) by detecting changes in macromolecular composition occurring during the hepatogenesis process. Partial Least Squares Discriminant Analysis (PLS-DA) enabled us to discriminate undifferentiated rBM-MSCs, and early, mid-stage and late stage rBM-MSCs derived hepatocytes by their characteristic FTIR "spectroscopic signatures". The predominant spectroscopic changes responsible for this discrimination were changes in FTIR absorbance bands at: 3012 cm(-1) (cis C[double bond, length as m-dash]C stretch from unsaturated lipids), 2952 cm(-1) (ν(as)CH(3) from lipids), 2854 cm(-1) (ν(s)CH(2) from lipids) and 1722 cm(-1) (C[double bond, length as m-dash]O stretching from lipids), which were associated with triglyceride and unsaturated fatty acid accumulation in the hepatocyte-like cells occurring during differentiation. Based on these findings, rBM-MSCs derived hepatocytes are characterized by high lipid content which facilitates a means of identifying hepatocytes from their stem cells progenitors by using FTIR microspectroscopy. Other complex changes in spectral bands assigned to proteins and nucleic acids were observed during hepatocyte differentiation indicating that mRNA translation was taking place producing proteins related to the formation of the new hepatocyte-like phenotype, which was corroborated by immunohistochemistry. The results show FTIR microspectroscopy combined with bioinformatic modeling constitutes a powerful new phenotypic-based methodology for monitoring and characterization of the process of stem cell differentiation leading to the formation of hepatocytes, providing complementary information to existing methodologies such as immunohistochemistry and gene analysis, but having advantages of being reagent-free and non-destructive of the sample.

FTIR microspectroscopy discriminates anticancer action on human leukemic cells by extracts of Pinus kesiya; Cratoxylum formosum ssp. pruniflorum and melphalan.

Apoptosis is the principal molecular goal of chemotherapeutics for effective anticancer action. We studied the effect of 50% ethanolic-water extracts of Pinus kesiya, Cratoxylum formosum ssp. pruniflorum and melphalan on cytotoxicity and apoptosis induction for human leukemic U937 cells, and explored the mode of action using FTIR microspectroscopy. The number of viable U937 cells in vitro was decreased in a concentration-dependent manner by all tested compounds, although potency differed between the U937 and Vero cells. Melphalan and the extract of C. formosum exhibited relatively lower IC(50) values (15.0 ± 1.0 and 82.7 ± 3.2 µg/mL respectively) and higher selectivity (selective index>3) than the extract of P. kesiya (299.0 ± 5.2 µg/mL; selective index<3) on the U937 cells. All three compounds significantly induced apoptosis through the late stage - seen by the indicative DNA ladder - with the most effective being melphalan, then the P. kesiya and C. formosum extracts. FTIR microspectroscopy revealed that all three compounds raised the intensity of the ß-pleated sheet - higher than that of the untreated U937 cells - corresponding to a shift in the α-helix band associated with an alteration in the secondary structure of the protein band, confirming induction of apoptosis via pro-apoptotic proteins. The differences in intensity of the FTIR bands associated with lipids, proteins and nucleic acids were responsible for discrimination of the anticancer mode of action of each of the three compounds. The FTIR data suggest that the two plant extracts possessed anticancer activity with a different mode of action than melphalan.

Formation of chitin-based nanomaterials using a chitin-binding peptide selected by phage-display.

Targeting polymers with peptides is an efficient strategy to functionalize biomaterials. Phage display technology is one of the most powerful techniques for selecting specific peptides for a wide variety of targets. A method to select a chitin-binding peptide from a 12-mer random peptide library was successfully performed against chitin immobilized in wells of microtiter plates. The synthetic chitin binding peptide (ChiBP) could bind to chitin beads and disrupt their structure. This selected peptide was successfully used to immobilize alkaline phosphatase on chitin. In addition, the peptide could induce colloidal chitin in water to form a chitin coat on the surface of plastic tubes. Scanning electron microscopy (SEM) revealed that the peptide could induce colloidal chitin and chitohexaose to form networks when the temperature was raised to 42°C.

Synergistic anticancer effect of the extracts from Polyalthia evecta caused apoptosis in human hepatoma (HepG2) cells.

OBJECTIVE: To evaluate the anticancer activity of the extract fraction of Polyalthia evecta (P. evecta) (Pierre) Finet & Gagnep and the synergistic anticancer effect of the extracts from P. evecta by using the ATR/FT-IR spectroscopy. METHODS: The 50% ethanol-water crude leaf extract of P. evecta (EW-L) was prepared and was further fractionated to isolate various fractions. The anticancer activity was investigated from cytotoxicity against HepG2 using a neutral red assay and apoptosis induction by evaluation of nuclei morphological changes after DAPI staining. Synergistic anticancer effects of the extracts from P. evecta were performed using the ATR/FT-IR spectroscopy. RESULTS: The result showed that the EW-L showed higher cytotoxicity and apoptosis induction in HepG2 cells than its fractionated extracts. The hexane extract exhibited higher cytotoxicity and apoptosis induction than the water extracts, but less than the EW-L. The combined water and hexane extracts apparently increased cytotoxicity and apoptosis induction. The %apoptotic cells induced by the extract mixture were increased about 2-fold compared to the single hexane extract. CONCLUSIONS: The polar extract fraction is necessary for the anticancer activity of the non-polar extract fraction. The ATR/FT-IR spectra illustrates the physical interaction among the constituents in the extract mixture and reveals the presence of polyphenolic constituents in the EW-L, which might play a role for the synergistic anticancer effect.