FTIR spectroscopy of whole cells for the monitoring of yeast apoptosis mediated by p53 over-expression and its suppression by Nigella sativa extracts

Decoding myasthenia gravis: advanced diagnosis with infrared spectroscopy and machine learning

Myasthenia Gravis (MG) is a rare neurological disease. Although there are intensive efforts, the underlying mechanism of MG still has not been fully elucidated, and early diagnosis is still a question mark. Diagnostic paraclinical tests are also time-consuming, burden patients financially, and sometimes all test results can be negative. Therefore, rapid, cost-effective novel methods are essential for the early accurate diagnosis of MG. Here, we aimed to determine MG-induced spectral biomarkers from blood serum using infrared spectroscopy. Furthermore, infrared spectroscopy coupled with multivariate analysis methods e.g., principal component analysis (PCA), support vector machine (SVM), discriminant analysis and Neural Network Classifier were used for rapid MG diagnosis. The detailed spectral characterization studies revealed significant increases in lipid peroxidation; saturated lipid, protein, and DNA concentrations; protein phosphorylation; PO2-asym + sym /protein and PO2-sym/lipid ratios; as well as structural changes in protein with a significant decrease in lipid dynamics. All these spectral parameters can be used as biomarkers for MG diagnosis and also in MG therapy. Furthermore, MG was diagnosed with 100% accuracy, sensitivity and specificity values by infrared spectroscopy coupled with multivariate analysis methods. In conclusion, FTIR spectroscopy coupled with machine learning technology is advancing towards clinical translation as a rapid, low-cost, sensitive novel approach for MG diagnosis.

Label-Free Monitoring of Coculture System Dynamics: Probing Probiotic and Cancer Cell Interactions via Infrared Spectroscopic Imaging

Evaluating the dynamic interaction of microorganisms and mammalian cells is challenging due to the lack of suitable platforms for examining interspecies interactions in biologically relevant coculture conditions. In this work, we demonstrate the interaction between probiotic bacteria (Lactococcus lactis and Escherichia coli) and A498 human cancer cells in vitro, utilizing a hydrogel-based platform in a label-free manner by infrared spectroscopy. The L. lactis strain recapitulated in the compartment system secretes polypeptide molecules such as nisin, which has been reported to trigger cell apoptosis. We propose a mid-infrared (IR) spectroscopic imaging approach to monitor the variation of biological components utilizing kidney cells (A498) as a model system cocultured with bacteria. We characterized the biochemical composition (i.e., nucleic acids, protein secondary structures, and lipid conformations) label-free using an unbiased measurement. Several IR spectral features, including unsaturated fatty acids, β-turns in protein, and nucleic acids, were utilized to predict cellular response. These features were then applied to establish a quantitative relationship through a multivariate regression model to predict cellular dynamics in the coculture system to assess the effect of nisin on A498 kidney cancer cells cocultured with bacteria. Overall, our study sheds light on the potential of using IR spectroscopic imaging as a label-free tool to monitor complex microbe-host cell interactions in biological systems. This integration will enable mechanistic studies of interspecies interactions with insights into their underlying physiological processes.

Bio-synthesis and characterization of silver nanoparticles from Trichoderma species against cassava root rot disease

Cassava root rot disease caused by the fungal pathogens Fusarium solani and Lasiodiplodia theobromae produces severe damages on cassava production. This research was conducted to produce and assess silver nanoparticles (AgNPs) synthesized by Trichoderma harzianum for reducing root rot disease. The results revealed that using the supernatants of T. harzianum on a silver nitrate solution changed it to reddish color at 48 h, indicating the formation of AgNPs. Further characterization was identified using dynamic light scattering (DLS) and scanning electron microscope (SEM). DLS supported that the Z-average size is at 39.79 nm and the mean zeta potential is at - 36.5 mV. SEM revealed the formation of monodispersed spherical shape with a diameter between 60-75 nm. The antibacterial action of AgNPs as an antifungal agent was demonstrated by an observed decrease in the size of the fungal colonies using an increasing concentration of AgNPs until the complete inhibition growth of L. theobromae and F. solani at > 58 µg mL-1 and at ≥ 50 µg mL-1, respectively. At in vitro conditions, the applied AgNPs caused a decrease in the percentage of healthy aerial hyphae of L. theobromae (32.5%) and of F. solani (70.0%) compared to control (100%). The SR-FTIR spectra showed the highest peaks in the first region (3000-2800 cm-1) associated with lipids and fatty acids located at 2962, 2927, and 2854 cm-1 in the AgNPs treated samples. The second region (1700-1450 cm-1) consisting of proteins and peptides revealed the highest peaks at 1658, 1641, and 1548 cm-1 in the AgNPs treated samples. The third region (1300-900 cm-1), which involves nucleic acid, phospholipids, polysaccharides, and carbohydrates, revealed the highest peaks at 1155, 1079, and 1027 cm-1 in the readings from the untreated samples. Finally, the observed root rot severity on cassava roots treated with AgNPs (1.75 ± 0.50) was significantly lower than the control samples (5.00 ± 0.00).

FTIR microspectroscopic study of gastric cancer AGS cells apoptosis induced by As2O3

As2O3 has shown significant anti-gastric cancer effects, but the mechanism is still unclear. Thus, biomacromolecular changes induced by As2O3 were investigated by using human gastric cancer AGS cells as the model. Flow cytometry results confirmed that As2O3 induced AGS cells apoptosis. Fourier transform infrared (FTIR) microspectroscopy detected biomacromolecular changes during As2O3-induced AGS cells apoptosis sensitively: IR spectra showed significant changes in the lipids content and the proteins and DNA structure. Peak-area ratios indicated obvious changes in the lipids and DNA content and the proteins structure, while also showing a relatively good linear relationship between A1733/A969 and the apoptosis rate. PCA exhibited significant alteration in nucleic acids while curve fitting further revealed the changes in nucleic acids and proteins. On the whole, our study explored As2O3-induced gastric cancer cells apoptosis in depth on the basis of analyzing biomacromolecular changes, in addition, it also suggested FTIR microspectroscopy to be possibly useful in the research of apoptosis.

Exploring salivary exosomes as early predictors of oral cancer in susceptible tobacco consumers: noninvasive diagnostic and prognostic applications

BACKGROUND

Salivary exosome analysis provides a noninvasive and comprehensive approach with potential applications in oral cancer diagnosis and prognosis. The early detection of oral cancer has remained a critical concern in enhancing the quality of life, especially for individuals who consume tobacco and are at greater risk of developing the disease. The current study investigates the potential of salivary exosomes in screening smokers for early signs and transformations of oral cancer.

METHODS

Morphological characterization of salivary exosomes among three study groups (non-smokers as control, smokers as high-risk tobacco consumers, and Oral cancer) (n = 120) was carried out through dynamic light scattering, and nanoparticle tracking analysis. For molecular characterization, EXOCET and Fourier transform infrared spectroscopy methods were utilized. The expression of the exosomal surface protein CD63 was evaluated using Western blotting.

RESULTS

Salivary exosomes exhibit noticeable differences in size between control group and tobacco consumers. The differentiation extended beyond exosome size and included variations in concentration and bio-molecular composition, as determined by FTIR screening. Tobacco consumers and oral cancer groups showed significantly larger and more concentrated exosomes compared to the healthy group.

CONCLUSION

Our study provides strong evidence that the properties of salivary exosomes can serve as reliable noninvasive biomarkers for distinguishing tobacco consumers from non-smokers and oral cancer patients. Our results underscore the potential of exosome-based diagnostics in early oral cancer detection for high-risk individuals. The larger size and higher concentration of exosomes in tobacco consumers indicate early changes in cell secretions associated with the transformation from healthy to abnormal cells.

Nanoscale insight into biochemical changes in cervical cancer cells exposed to adaptogenic drug

This paper describes for the first time the application of atomic force microscopy-based infrared spectroscopy (AFM-IR) to evaluate cellular response to adaptogen, based on an in vitro model of cervical cancer. HeLa cervical cells were exposed to different concentrations of withaferin A, a very promising anti-cancer adaptogenic substance. AFM-IR approach was used to image single cells post-adaptogen treatment and to track subtle biochemical changes in cells at the nanoscale level. Partial least squares (PLS) regression was applied to build predictive models that allowed for the identification of spectral markers of adaptogen-induced alterations Spectroscopic studies were enriched with fluorescence staining to determine whether the adaptogen affects cell morphology. The results showed that with the increase in the concentration of adaptogen, changes in the cell nucleus and the actin cytoskeleton become more and more significant. It has been demonstrated that the AFM-IR technique can successfully study the cellular response to the anti-cancer agent at the single-cell level with nanoscale spatial resolution. On the basis of the promising findings presented in this paper, it is possible to conclude that withaferin A has great potential in inhibiting the proliferation of cervical cancer cells in a dose-dependent manner. It has been found that both the increase in the concentration of withaferin A and the increase in incubation time with the adaptogen resulted in a decrease in the intensity of the bands assigned to nucleic acids. This may be due to DNA condensation, internuclear cleavage, or degradation during apoptosis. The findings also suggest changes in the secondary structure of proteins that may be a consequence of disruption of the actin cytoskeleton, progressive apoptosis, or significant biochemical changes. Furthermore, noticeable changes were also observed in the bands originating from lipids vibrations, and an increased share of the band near 2920 cm^-1, considered an important marker of apoptosis, was noted. The metabolism of carbohydrates in cells also changes under the influence of the adaptogen. AFM-IR provides nanoscale insight into the structural and morphological properties of cells after drug treatment and is an indisputable milestone in the development of new anti-cancer approaches.

Prospects of a hot spring-originated novel cyanobacterium, Scytonema ambikapurensis, for wastewater treatment and exopolysaccharide-enriched biomass production

The present work performs the polyphasic characterization of a novel cyanobacterial species Scytonema ambikapurensis isolated from an Indian hot spring and evaluates its wastewater bioremediation potential. While the physicochemical analyses of the wastewater indicated high load of nutrients and metals, the wastewater bioremediation experiment performed using the test cyanobacterium denoted the removal of 70 and 86% phosphate, 49 and 66% sulfate, 96 and 98% nitrate, 91 and 92% nitrite, 95 and 96% ammonia, 66 and 72% chloride, 79 and 81% zinc, 68 and 80% nickel, 81 and 90% calcium, and 80 and 90% potassium from the autoclaved and un-autoclaved wastewater, respectively, after 20 days of culturing. The kinetics study of zinc and nickel removal from wastewater revealed that the cyanobacterium employed sequential biosorption (by following pseudo-second-order kinetics model) and bioaccumulation methods to remove these two metals. The quality of the autoclaved and un-autoclaved wastewater was further improved by the cyanobacterium through reduction of hardness by 74 and 81%, respectively. In wastewater, the cyanobacterium not only enhanced its biomass, chlorophyll and carbohydrate contents, but also produced small amount of released and high capsular exopolysaccharide (EPS). The FTIR and TGA analyses of capsular EPS unraveled that it was a negatively charged sulfated biomolecule having thermostability up to 240 °C, which suggested its possible use as excellent emulsifying, viscosifying, and biosorption agent. The credibility of this EPS as biosorption agent was ascertained by evaluating its metal chelating ability. Finally, the experimental data denoting the ability of S. ambikapurensis to bioremediate wastewater and simultaneously produce EPS was statistically validated by PCA1-pollutant removal model and the PCA2-cellular constituent model, respectively. Briefly, the study discloses that the cyanobacterium has huge biotechnological and industrial importance as it bioremediates wastewater and simultaneously produces thermostable exopolysaccharide.

Spectroscopic evidence of the radioresistance of Chroococcidiopsis biosignatures: A combined Raman, FT-IR and THz-TDs spectroscopy study

In the last decades, Mars has been widely studied with on-site missions and observations, showing a planet that could have hosted life in the past. For this reason, the recent and future space missions on the red planet will search for traces of past and, possibly, present life. As a basis for these missions, Space Agencies, such as the European Space Agency, have conducted many experiments on living organisms, studying their behavior in extraterrestrial conditions, learning to recognize their biosignatures with techniques remotely controllable such as Raman spectroscopy. Among these organisms, the radioresistant cyanobacterium Chroococcidiopsis was irradiated during the STARLIFE campaign with strong radiative insults. In this article we have investigated this cyanobacterium using Raman spectroscopy and extended the characterization of its biosignatures and its response to the radiative stress to the mid- Infrared and Terahertz spectral region using the Fourier Transform InfraRed (FT-IR) and Terahertz Time Domain spectroscopy (THz- TDs), which demonstrates the compatibility and suitability of these techniques for future space missions.

Self-Supported Biopolymeric Films Based on Onion Bulb (Allium cepa L.): Gamma-Radiation Effects in Sterilizing Doses

Sterilization is a fundamental step to eliminate microorganisms prior to the application of products, especially in the food and medical industries. γ-irradiation is one of the most recommended and effective methods used for sterilization, but its effect on the properties and performance of bio-based polymers is negligible. This work is aimed at evaluating the influence of γ-radiation at doses of 5, 10, 15, 25, 30, and 40 kGy on the morphology, properties, and performance of bioplastic produced from onion bulb (Allium cepa L.), using two hydrothermal synthesis procedures. These procedures differ in whether the product is washed or not after bioplastic synthesis, and are referred to as the unwashed hydrothermally treated pulp (HTP) and washed hydrothermally treated pulp (W-HTP). The morphological analysis indicated that the film surfaces became progressively rougher and more irregular for doses above 25 kGy, which increases their hydrophobicity, especially for the W-HTP samples. In addition, the FTIR and XRD results indicated that irradiation changed the structural and chemical groups of the samples. There was an increase in the crystallinity index and a predominance of the interaction of radiation with the hydroxyl groups-more susceptible to the oxidative effect-besides the cleavage of chemical bonds depending on the γ-radiation dose. The presence of soluble carbohydrates influenced the mechanical behavior of the samples, in which HTP is more ductile than W-HTP, but γ-radiation did not cause a change in mechanical properties proportionally to the dose. For W-HTP, films there was no mutagenicity or cytotoxicity-even after γ-irradiation at higher doses. In conclusion, the properties of onion-based films varied significantly with the γ-radiation dose. The films were also affected differently by radiation, depending on their chemical composition and the change induced by washing, which influences their use in food packaging or biomedical devices.

Adaptogenic activity of withaferin A on human cervical carcinoma cells using high-definition vibrational spectroscopic imaging

Despite invaluable advances in cervical cancer therapy, treatment regimens for recurrent or persistent cancers and low-toxicity alternative treatment options are scarce. In recent years, substances classified as adaptogens have been identified as promising drug sources for preventing and treating cancer-based diseases on their ability to attack multiple molecular targets. This paper establishes the effectiveness of inhibition of the neoplastic process by a withaferin A (WFA), an adaptogenic substance, based on an in vitro model of cervical cancer. This study explores for the first time the potential of high-definition vibrational spectroscopy methods, i.e. Fourier-transform infrared (FT-IR) and Raman spectroscopic (RS) imaging at the single-cell level to evaluate the efficacy of the adaptogenic drug. HeLa cervical cancer cells were incubated with various concentrations of WFA at different incubation times. The multimodal spectroscopic approach combined with partial least squares (PLS) regression allowed the identification of molecular changes (e.g., lipids, protein secondary structures, or nucleic acids) induced by WFA at the cellular level. The results clearly illustrate the enormous potential of WFA in inhibiting the proliferation of cervical cancer cells. WFA inhibited the growth of the studied cancer cell line in a dose-dependent manner. Such studies provide comprehensive information on the sensitivity of cells to adaptogenic drugs. This is a fundamental step towards determining the rate and nature of adaptogen-induced changes in cancer cells.

Green Synthesis of Characterized Silver Nanoparticle Using Cullen tomentosum and Assessment of Its Antibacterial Activity

Plants serve as an important source of medicine and provide suitable candidate compounds to produce eco-friendly therapeutic agents. They also represent a source of bio-reducer and stabilizer for the development of nanoparticles for downstream applications. This study focused on the green synthesis of silver nanoparticle (CTAgNP) using Cullen tomentosum (Thunb.) J.W. Grimes acetone extract and the evaluation of the antibacterial activity of the plant extract and biogenic nanoparticles against two Gram-positive bacteria strains, namely Bacillus cereus and Staphylococcus aureus. In addition, the phytochemical profile of C. tomentosum was established using liquid chromatography-mass spectrometry (LC-MS). The antibacterial effect of the extract and CTAgNP was moderate based on the minimum inhibitory concentration (MIC) values obtained. The MIC values of 2.6 mg/mL and 3.1 mg/mL were recorded for C. tomentosum extract against B. cereus and S. aureus, respectively. On the other hand, the CTAgNP had MIC values of 1.5 mg/mL and 2.6 mg/mL against B. cereus and S. aureus, respectively. The nanoparticle exhibited surface charge of -37 ± 7.67 mV and average hydro-dynamic size of 145 nm. X-ray diffraction illustrates that metallic nanoparticles were formed and had a face-centered cubic structure. Microscopic and spectroscopic techniques revealed that the CTAgNP was covered by a protective shell layer constituted of organic compounds originating from the plant extract. The acetone extract of C. tomentosum could be useful to the bio-pharma industries in the large-scale manufacture of nanoparticle-based medications to fight against microbes that constitute a threat to the survival of humanity.

Fourier Transform Infrared Spectroscopy (FT-IR) of Pseudomonas aeruginosa post photodynamic therapy with Curcumin in vitro

Alternative therapies against pathogens are under intense investigation because of their increasing resistance to antibiotics. Photodynamic therapy (PDT) is one such alternative that has shown promising results. However, for the widespread use of PDT, it is essential to decipher underlying mechanisms, so as to improve PDT's therapeutic applications. Because of this, we have studied biochemical changes in pathogen Pseudomonas aeruginosa, a medically important bacteria that has developed antibiotic resistance, after PDT with curcumin photosensitizer. Results show a drastic decrease in α-helix protein and increased disordered and β-sheet secondary structure proteins in P. Aeruginosa post-PDT compared to control. Interestingly, these biochemical changes differ from PDT of pathogens Leishmania braziliensis and Leishmania major with photosensitizer methylene blue. This observation underlines the need for extensive studies on PDT of different pathogens to understand mechanisms of action and develop better PDT strategies.

Classification and Prediction by Pigment Content in Lettuce (Lactuca sativa L.) Varieties Using Machine Learning and ATR-FTIR Spectroscopy

Green or purple lettuce varieties produce many secondary metabolites, such as chlorophylls, carotenoids, anthocyanins, flavonoids, and phenolic compounds, which is an emergent search in the field of biomolecule research. The main objective of this study was to use multivariate and machine learning algorithms on Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR)-based spectra to classify, predict, and categorize chemometric attributes. The cluster heatmap showed the highest efficiency in grouping similar lettuce varieties based on pigment profiles. The relationship among pigments was more significant than the absolute contents. Other results allow classification based on ATR-FTIR fingerprints of inflections associated with structural and chemical components present in lettuce, obtaining high accuracy and precision (>97%) by using principal component analysis and discriminant analysis (PCA-LDA)-associated linear LDA and SVM machine learning algorithms. In addition, PLSR models were capable of predicting Chla, Chlb, Chla+b, Car, AnC, Flv, and Phe contents, with R2P and RPDP values considered very good (0.81−0.88) for Car, Anc, and Flv and excellent (0.91−0.93) for Phe. According to the RPDP metric, the models were considered excellent (>2.10) for all variables estimated. Thus, this research shows the potential of machine learning solutions for ATR-FTIR spectroscopy analysis to classify, estimate, and characterize the biomolecules associated with secondary metabolites in lettuce.

Effect of Antibiotic Amphotericin B Combinations with Selected 1,3,4-Thiadiazole Derivatives on RPTECs in an In Vitro Model

4-(5-methyl-1,3,4-thiadiazole-2-yl) benzene-1,3-diol (C1) and 4-[5-(naphthalen-1-ylmethyl)-1,3,4-thiadiazol-2-yl] benzene1,3-diol (NTBD) are representative derivatives of the thiadiazole group, with a high antimycotic potential and minimal toxicity against normal human fibroblast cells. The present study has proved its ability to synergize with the antifungal activity of AmB. The aim of this work was to evaluate the cytotoxic effects of C1 or NTBD, alone or in combination with AmB, on human renal proximal tubule epithelial cells (RPTECs) in vitro. Cell viability was assessed with the MTT assay. Flow cytometry and spectrofluorimetric techniques were used to assess the type of cell death and production of reactive oxygen species (ROS), respectively. The ELISA assay was performed to measure the caspase-2, -3, and -9 activity. ATR-FTIR spectroscopy was used to evaluate biomolecular changes in RPTECs induced by the tested formulas. The combinations of C1/NTBD and AmB did not exert a strong inhibitory effect on the viability/growth of kidney cells, as evidenced by the negligible changes in the apoptotic/necrotic rate and caspase activity, compared to the control cells. Both NTBD and C1 displayed stronger anti-oxidant activity when combined with AmB. The relatively low nephrotoxicity of the thiadiazole derivative combinations and the protective activity against AmB-induced oxidative stress may indicate their potential use in the therapy of fungal infections.

Extracellular vesicles derived from microgreens of Raphanus sativus L. var. caudatus Alef contain bioactive macromolecules and inhibit HCT116 cells proliferation

Extracellular vesicles (EVs) are phospholipid bilayer vesicles released from cells, containing natural cargos. Microgreens of Raphanus sativus L. var. caudatus Alef were used in this study as the source of EVs. EVs were isolated by differential centrifugation. The physical properties were determined by dynamic light scattering (DLS) and electron microscopy. The biological and chemical composition were studied by Fourier-transform infrared (FTIR) microspectroscopy and high-performance liquid chromatography analysis, respectively. EVs had a median size of 227.17 and 234.90 ± 23.30 nm determined by electron microscopy and DLS, respectively with a polydispersity index of 0.293 ± 0.019. Electron microscopy indicated the intact morphology and confirmed the size. The FTIR spectra revealed that EVs are composed of proteins as the most abundant macromolecules. Using a curve-fitting analysis, β-pleated sheets were the predominant secondary structure. Notably, the micromolecular biomarkers were not detected. EVs exerted anti-cancer activity on HCT116 colon cancer over Vero normal cells with an IC₅₀ of 448.98 µg/ml and a selectivity index of > 2.23. To conclude, EVs could be successfully prepared with a simple and effective isolation method to contain nano-sized macromolecules possessing anti-cancer activity.

A Simple Assay for the Detection of Late-Stage Apoptosis Features in Saccharomyces cerevisiae

Unicellular eukaryotic organisms such as yeast and protozoa serve as useful models for studying the impact of chemicals on cell physiology, cellular growth, and genome duplication. The yeast Saccharomyces cerevisiae has been widely used to assess apoptosis induced by chemicals due to its genetic tractability, ease of evaluation, and readily available impact assessment tools. Apoptosis in S. cerevisiae is characterized by many features, including increased cell death, loss of membrane integrity, release of caspases, chromatin condensation, and nuclear fragmentation, which are similar to the ones observed in mammalian cells. Current methods of apoptosis assessment typically require specialized equipment and reagents, which limits wide adoption. Here, we describe a rapid, inexpensive, and easy-to-perform assay in yeast for the analysis of late-stage apoptotic features in cells treated with a chemical. We describe a protocol for assessing loss of cell survival and changes in the nucleus. We demonstrate the approach by using acetic acid and hydrogen peroxide as test chemicals. This assay for the study of late-stage apoptotic features in S. cerevisiae can be performed reliably and rapidly by any laboratory with basic equipment and may be extended for studying apoptosis in similar single-cell organisms after treatment with toxicological agents. © 2022 Wiley Periodicals LLC. Basic Protocol 1: Culture of Saccharomyces cerevisiae, treatment with acetic acid or hydrogen peroxide, and semi-quantitative growth assay Basic Protocol 2: DAPI staining and fluorescence microscopy for the assessment of change in nucleus-to-cytoplasm ratio and nuclear integrity.

Vermiculite as a potential functional additive for water treatment bioreactors inhibiting toxic action of heavy metal cations upsetting the microbial balance

A new adsorbent that combines mineral vermiculite with the yeast Saccharomyces cerevisiae, was used for Cd²⁺ removal. The influence of vermiculite presence on the toxic effects of Cd²⁺ to Saccharomyces cerevisiae yeast was evaluated as a function of the microorganisms' respiratory activity (CO₂ production). The Cd²⁺ toxicity increased with prolonged exposure time reaching the LC₅₀ value of 857 and 489 mg L^-1 after 30 and 120 min, respectively. The yeast managed to bioaccumulate 25.0 ± 0.6 mg g^-1 of Cd²⁺ at the initial Cd²⁺ concentration of 741.9 mg L^-1; the maximum Cd²⁺ adsorption capacity of vermiculite reached 25 ± 5 mg g^-1. The addition of the mineral decreased the cations toxic effect; the LC₂₀ value in vermiculite absence attained approximately 200 mg L^-1 after 30 min and decreased to 80 mg L^-1 after 2 h, while in the bio-mineral system it was at the level of 435 ± 50 mg L^-1 without a significant change in time. The mineral provided a superior living environment for the yeast by removing part of the cations, releasing essential microelements and providing a protective, clay hutch-like habitat for the cells.

Hydroxycinnamic acid derivatives effect on hypercholesterolemia, comparison with ezetimibe: Permeability assays and FTIR spectroscopy on Caco-2 cell line

High blood cholesterol levels may increase the risk of developing atherosclerosis. Since intestinal cholesterol absorption plays a major role in maintaining total body cholesterol homeostasis, the aim of the present study was to compare the effect of ezetimibe and three hydroxycinnamic acid derivatives (rosmarinic acid, chlorogenic acid and m-coumaric acid) that are present in several medicinal plants on cholesterol absorption in the intestinal Caco-2 ​cells. In addition to the permeability assays, studies on alteration of the biochemical properties of Caco-2 ​cells under the effect of ezetimibe and hydroxycinnamic acid derivatives was evaluated using FTIR accompanied with multivariate analysis by PCA. The cholesterol permeability assays showed that these compounds could decrease cholesterol permeability with a percentage ranging from 76.98 to 96.6% with the highest inhibition for ezetimibe. whereas the FTIR studies didn't show similar changes between ezetimibe and the three hydroxycinnamic acid derivatives in protein and nucleic acids region, suggesting that these compounds have hypocholesterolemic effect. Nevertheless, each compound originated a different change on Caco-2 treated cells suggesting a different mode of action.

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Hydroxycinnamic acid derivatives and ezetimibe permeated the intestinal barrier.

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Hydroxycinnamic acid derivatives decreased cholesterol permeability.

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Hydroxycinnamic acid derivatives could affect the cell components.

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PCA of FTIR spectra showed differences on protein and nucleic acid regions.

The Inhibitory Activity of Citral against Malassezia furfur

The lipophilic yeast Malassezia furfur, is a member of the cutaneous commensal microbiota and is associated with several chronic diseases such as dandruff, pityriasis versicolor, folliculitis, and seborrheic dermatitis, that are often difficult to treat with current therapies. The development of alternatively effective antifungal therapies is therefore of paramount importance. In this study, we investigated the treatment effect of citral on M. furfur. The minimal inhibitory concentration of citral for M. furfur was 200 μg/mL, and the minimal fungicidal concentration was 300 μg/mL. Citral significantly increased the proportion of yeast cells to mycelial forms 2.6-fold. Phosphatidylserine externalization, DNA fragmentation, and metacaspase activation supported a citral-induced apoptosis in M. furfur. Moreover, citral at sub-minimum inhibitory concentrations reduced the invasion of M. furfur in HaCaT keratinocytes. Finally, we demonstrated that citral inhibited IL-6 and TLR-2 expression and enhanced HBD-2 and TSLP expression in M. furfur-infected HaCaT keratinocytes. These results showed that citral has antifungal activity at high concentrations and can decrease the infection of M. furfur by modulating the keratinocyte immune responses at low concentrations. Our results suggest that citral is a potential candidate for topical therapeutic application for M. furfur-associated human skin diseases.

Whole and Purified Aqueous Extracts of Nigella sativa L. Seeds Attenuate Apoptosis and the Overproduction of Reactive Oxygen Species Triggered by p53 Over-Expression in the Yeast Saccharomyces cerevisiae

Plants are an important source of pharmacologically active compounds. In the present work, we characterize the impact of black cumin (Nigella sativa L.) aqueous extracts on a yeast model of p53-dependent apoptosis. To this end, the Saccharomyces cerevisiae recombinant strain over-expressing p53 was used. The over-expression of p53 triggers the expression of apoptotic markers: the externalization of phosphatidylserine, mitochondrial defect associated with cytochrome-c release and the induction of DNA strand breaks. These different effects were attenuated by Nigella sativa L. aqueous extracts, whereas these extracts have no effect on the level of p53 expression. Thus, we focus on the anti-apoptotic molecules present in the aqueous extract of Nigella sativa L. These extracts were purified and characterized by complementary chromatographic methods. Specific fluorescent probes were used to determine the effect of the extracts on yeast apoptosis. Yeast cells over-expressing p53 decrease in relative size and have lower mitochondrial content. The decrease in cell size was proportional to the decrease in mitochondrial content and of mitochondrial membrane potential (ΔΨm). These effects were prevented by the purified aqueous fraction obtained by fractionation with different columns, named C4 fraction. Yeast cell death was also characterized by reactive oxygen species (ROS) overproduction. In the presence of the C4 fraction, ROS overproduction was strongly reduced. We also noted that the C4 fraction promotes the cell growth of control yeast cells, which do not express p53, supporting the fact that this purified extract acts on cellular mediators activating cell proliferation independently of p53. Altogether, our data obtained on yeast cells over-expressing p53 demonstrate that anti-apoptotic molecules targeting p53-induced apoptosis associated with mitochondrial dysfunction and ROS overproduction are present in the aqueous extracts of Nigella seeds and in the purified aqueous C4 fraction.

High Pressure Thermal Sterilization and ε-Polylysine Synergistically Inactivate Bacillus subtilis Spores by Damaging the Inner Membrane

ABSTRACT

This study was conducted to determine the sterilization effect of a combination of high pressure thermal sterilization (HPTS) and ε-polylysine (ε-PL) on Bacillus subtilis spores. The spores were treated with HPTS (550 MPa at 25, 65, and 75°C) and ε-PL at 0.1 and 0.3%. HPTS and ε-PL synergistically decreased the number of surviving spores and increased the release of the intracellular components in the spore suspension, with the maximal effects from treatment with 550 MPa at 75°C plus 0.3% ε-PL. Maximum fluidity and permeability of the cell inner membrane were observed with 550 MPa at 75°C plus 0.3% ε-PL. Changes in membrane lipids were detected from 3,000 to 2,800 cm-1 by Fourier transform infrared spectroscopy. The results provide new insights into the mechanism by which HPTS and ε-PL synergistically sterilize B. subtilis spores.

HIGHLIGHTS

CoronaVac (Sinovac) COVID-19 vaccine-induced molecular changes in healthy human serum by infrared spectroscopy coupled with chemometrics

From the beginning of the COVID-19 coronavirus pandemic in December of 2019, the disease has infected millions of people worldwide and caused hundreds of thousands of deaths. Since then, several vaccines have been developed. One of those vaccines is inactivated CoronaVac-Sinovac COVID-19 vaccine. In this proof of concept study, we first aimed to determine CoronaVac-induced biomolecular changes in healthy human serum using infrared spectroscopy. Our second aim was to see whether the vaccinated group can be separated or not from the non-vaccinated group by applying chemometric techniques to spectral data. The results revealed that the vaccine administration induced significant changes in some functional groups belonging to lipids, proteins and nucleic acids. In addition, the non-vaccinated and vaccinated groups were successfully separated from each other by principal component analysis (PCA) and linear discriminant analysis (LDA). This proof-of-concept study will encourage future studies on CoronaVac as well as other vaccines and will lead to make a comparison between different vaccines to establish a better understanding of the vaccination outcomes on serum biomolecules.

Infrared microspectroscopy studies on the protective effect of curcumin coated gold nanoparticles against H2O2-induced oxidative stress in human neuroblastoma SK-N-SH cells

The contribution of oxidative stress in several chronic and degenerative diseases suggests that antioxidant therapy can be a promising therapeutic strategy. However, in the case of many antioxidants, their biodistribution and bioactivity are restricted due to low water solubility. Curcumin is a powerful free radical scavenger that upon conjugation to gold nanoparticles results in the formation of stable gold nanoparticles that act as highly water-soluble carriers for the curcumin molecules. In the present study, the effect of curcumin-coated gold nanoparticles (Cur-GNPs) on the H₂O₂-treated human neuroblastoma (SK-N-SH) cell line was evaluated by using Fourier transform infrared (FTIR) microspectroscopy. Biochemical changes in cells resulting from exposure to reactive oxygen species (ROS) and antioxidant treatment on cells were investigated. Analyzing changes in PO₂^- bands and amide bands in the fingerprint region and also changes in the ratio of CH_2(asym) to CH_3(asym) bands in the lipid region revealed that post-treatment with Cur-GNPs could effectively decrease the damage on DNA caused by H₂O₂ treatment, whereas pre-treatment of cells with Cur-GNPs was found to be more effective at preventing lipid peroxidation than post-treatment. Further analysis of the CH_2(asym) to CH_3(asym) ratio provided information on not only the lipid peroxidation level in cells, but also the interaction of nanoparticles with the plasma membrane, as confirmed by lactate dehydrogenase assay.

Molecular-level changes induced by hydroxycinnamic acid derivatives in HepG2 cell line: Comparison with pravastatin

Hydroxycinnamic acid derivatives are an important class of polyphenols found in fruits, vegetables, and medicinal plants and widely consumed in human diet. In the present work, alterations of HepG2 cells biochemical profile under the effect of four hydroxycinnamic acid derivatives (caffeic acid, m-coumaric acid, chlorogenic acid and rosmarinic acid) relatively to the effect of pravastatin, a drug often prescribed to inhibit HMG-CoA reductase enzyme, the regulator enzyme in the cholesterol biosynthesis pathway, were reported. The application of FTIR spectroscopy in combination with multivariate analysis by PCA showed a similarity between pravastatin and the four hydroxycinnamic acid derivatives in metabolite profile modification expressed by various changes in proteins region, the phosphate region which mainly corresponds to nucleic acids as well as in lipids regions. FTIR structural analysis in the amide I region, using resolution enhancement methods, such as second derivative and amide I deconvolution method, revealed significant decrease in α-helix/random coil and intermolecular β-sheet decreased while intramolecular β-sheet in treated cells showed an increase. It was also noticed that the intracellular cholesterol as well as esterified ingredients such as cholesterol esters in the cell membrane decreased. Moreover, principal component analysis (PCA) of the spectral data showed that the compounds and pravastatin were well separated from untreated cells showing a different mode of action on HepG2 treated cells for each compound.

A new Ti-based IMAC nanohybrid with high hydrophilicity and enhanced absorption capacity for the selective enrichment of phosphopeptides

Ti-based immobilized metal affinity chromatography (IMAC) nanomaterial has shown high potential in phosphoproteome mass-spectrometric (MS) analysis. However, the limited surface area and poor solubility will greatly restrict its use in phosphoproteome research. To overcome these two key drawbacks, a novel Ti-based IMAC nanomaterial was prepared by Ti-bonded β-cyclodextrin (β-CD) anchored on the surface of carbon nanotubes (CNTs) (denoted as COOH-CNTs-CD-Ti) and successfully applied as a biofunctional adsorbent for selectively enriching trace phosphopeptides. In the selective enrichment process, CNTs provided greater surface area for the absorption of phosphopeptides, while β-CD also offered a greater opportunity for the interaction between phosphopeptides and Ti⁴⁺. COOH-CNTs-CD-Ti with the aforementioned properities exhibited higher selectivity for phosphopeptides from the standard protein digests, the tryptic digests of nonfat milk and human serum, showing a great selective enrichment capability towards complex biological samples.

Pulsed Electric Field (PEF) Enhances Iron Uptake by the Yeast Saccharomyces cerevisiae

The aim of the study was to investigate the influence of a pulsed electric field (PEF) on the level of iron ion accumulation in Saccharomyces cerevisiae cells and to select PEF conditions optimal for the highest uptake of this element. Iron ions were accumulated most efficiently when their source was iron (III) nitrate. When the following conditions of PEF treatment were used: voltage 1500 V, pulse width 10 μs, treatment time 20 min, and a number of pulses 1200, accumulation of iron ions in the cells from a 20 h-culture reached a maximum value of 48.01 mg/g dry mass. Application of the optimal PEF conditions thus increased iron accumulation in cells by 157% as compared to the sample enriched with iron without PEF. The second derivative of the FTIR spectra of iron-loaded and -unloaded yeast cells allowed us to determine the functional groups which may be involved in metal ion binding. The exposure of cells to PEF treatment only slightly influenced the biomass and cell viability. However, iron-enriched yeast (both with or without PEF) showed lower fermentative activity than a control sample. Thus obtained yeast biomass containing a high amount of incorporated iron may serve as an alternative to pharmacological supplementation in the state of iron deficiency.

Graphene Oxide-Induced Protein Conformational Change in Nasopharyngeal Carcinoma Cells: A Joint Research on Cytotoxicity and Photon Therapy

The objectives of this work aim to investigate the interaction and cytotoxicity between nanometric graphene oxide (GO) and nasopharyngeal carcinoma cells (NPC-BM1), and possible application in photon therapy. GO nanosheets were obtained in the size range of 100-200 nm, with a negative surface charge. This nanometric GO exhibited a limited (<10%) cytotoxicity effect and no significant dimensional change on NPC-BM1 cells in the tested GO concentration range (0.1-10 µg·mL-1). However, the secondary protein structure was modified in the GO-treated NPC-BM1 cells, as determined through synchrotron radiation-based Fourier transform infrared microspectroscopy (SR-FTIRM) mapping. To further study the cellular response of GO-treated NPC-BM1 cancer cells at low GO concentration (0.1 µg·mL-1), photon radiation was applied with increasing doses, ranging from 2 to 8 Gy. The low radiation energy (<5 Gy) did not cause significant cell mortality (5-7%). Increasing the radiation energy to 6-8 Gy accelerated cell apoptosis rate, especially in the GO-treated NPC-BM1 cells (27%). This necrosis may be due to GO-induced conformational changes in protein and DNA/RNA, resulting in cell vulnerability under photon radiation. The findings of the present work demonstrate the potential biological applicability of nanometric GO in different areas, such as targeted drug delivery, cellular imaging, and radiotherapy, etc.

Inhibitory Effect of Eugenol and trans-Anethole Alone and in Combination with Antifungal Medicines on Candida albicans Clinical Isolates

One of the most common pathogens among yeasts is Candida albicans, which presents a serious health threat. The study aimed to check the antifungal properties of trans-anethole and eugenol with selected antifungal medicines (AMs) against C. albicans clinical isolates. The checkerboard method was used to tests of interactions between these compounds. Achieved results indicated that eugenol showed synergistic and additive activities with miconazole and econazole against investigated clinical isolates, respectively. Moreover, the combination - trans-anethole - miconazole also showed an additive effect against two clinical isolate. We tried to relate the results to changes in C. albicans cell sheaths under the influence of essential oils compounds (EOCs) performing the Fourier transform infrared spectra analysis to confirm the presence of particular chemical moieties in C. albicans cells. Nevertheless, no strong relationships was observed between synergistic and additive actions of used EOC-AMs combinations and chemical moieties in C. albicans cells.

Disentangling the Impact of Sulfur Limitation on Exopolysaccharide and Functionality of Alr2882 by In Silico Approaches in Anabaena sp. PCC 7120

The wide applications, uniqueness, and high quality of cyanobacterial exopolysaccharides (EPSs) have attracted many biotechnologists. Despite it, the inducers and molecular determinants of EPS biosynthesis in cyanobacteria are lesser known. Although, studies revealed that environmental cues especially C/N ratio as the prime modulator, the factors like light, temperature, moisture, and nutrient availability, etc. have been overlooked. Due to this, the possibilities to modify cyanobacterial system for achieving higher quantity of EPS either by modifying growth medium or metabolic engineering are restricted to few optimisations. Therefore, the present work describes the impact of sulfate limitations on the EPS production and compositions in the cyanobacterium Anabaena sp. PCC 7120. Increased EPS production with enhanced expression of alr2882 was observed in lower sulfate supplementations; however, FTIR analysis depicted an altered composition of supramolecule. Furthermore, in silico analysis of Alr2882 depicted the presence of ExoD domain and three transmembrane regions, thereby indicating its membrane localisation and role in the EPS production. Additionally, the phylogeny and multiple sequence alignment showed vertical inheritance of exoD and conservation among cyanobacteria. The meta-threading template-based modelling and ab initio full atomic relaxation by LOMET and ModRefiner servers, respectively, also exhibited helical topology of Alr2882, with nine α-helices arranged antiparallel to the preceding one. Moreover, post-translational modifications predicted in Alr2882 indicated high order of molecular regulation underlining EPS production in Anabaena sp. PCC 7120. This study provides a foundation for understanding the EPS biosynthesis mechanism under sulfur limitation and the possible role of ExoD in cyanobacteria.

Study of the intracellular nanoparticle-based radiosensitization mechanisms in F98 glioma cells treated with charged particle therapy through synchrotron-based infrared microspectroscopy

The use of nanoparticles (NP) as dose enhancers in radiotherapy (RT) is a growing research field. Recently, the use of NP has been extended to charged particle therapy in order to improve the performance in radioresistant tumors. However, the biological mechanisms underlying the synergistic effects involved in NP-RT approaches are not clearly understood. Here, we used the capabilities of synchrotron-based Fourier Transform Infrared Microspectroscopy (SR-FTIRM) as a bio-analytical tool to elucidate the NP-induced cellular damage at the molecular level and at a single-cell scale. F98 glioma cells doped with AuNP and GdNP were irradiated using several types of medical ion beams (proton, helium, carbon and oxygen). Differences in cell composition were analyzed in the nucleic acids, protein and lipid spectral regions using multivariate methods (Principal Component Analysis, PCA). Several NP-induced cellular modifications were detected, such as conformational changes in secondary protein structures, intensity variations in the lipid CHx stretching bands, as well as complex DNA rearrangements following charged particle therapy irradiations. These spectral features seem to be correlated with the already shown enhancement both in the DNA damage response and in the reactive oxygen species (ROS) production by the NP, which causes cell damage in the form of protein, lipid, and/or DNA oxidations. Vibrational features were NP-dependent due to the NP heterogeneous radiosensitization capability. Our results provided new insights into the molecular changes in response to NP-based RT treatments using ion beams, and highlighted the relevance of SR-FTIRM as a useful and precise technique for assessing cell response to innovative radiotherapy approaches.

Embryo-derived teratoma in vitro biological system reveals antitumor and embryotoxic activity of valproate

Antiepileptic/teratogen valproate (VPA) is a histone deacetylase inhibitor/epigenetic drug proposed for the antitumor therapy where it is generally crucial to target poorly or undifferentiated cells to prevent a recurrence. Transplanted rodent gastrulating embryos‐proper (primitive streak and three germ layers) are the source of teratoma/teratocarcinoma tumors. Human primitive‐streak remnants develop sacrococcygeal teratomas that may recur even when benign (well differentiated). To screen for unknown VPA impact on teratoma‐type tumors, we used original 2‐week embryo‐derived teratoma in vitro biological system completed by a spent media metabolome analysis. Gastrulating 9.5‐day‐old rat embryos‐proper were cultivated in Eagle's minimal essential medium (MEM) with 50% rat serum (controls) or with the addition of 2 mmVPA. Spent media metabolomes were analyzed by FTIR. Compared to controls, VPA acetylated histones; significantly diminished overall teratoma growth, impaired survival, increased the apoptotic index, and decreased proliferation index and incidence of differentiated tissues (e.g., neural tissue). Control teratomas continued to grow and differentiate for 14 days in isotransplants in vivo, but in vitro VPA‐treated teratomas resorbed. Principal component analysis of FTIR results showed that spent media metabolomes formed well‐separated clusters reflecting the treatment and day of cultivation. In metabolomes of VPA‐treated teratomas, we found elevation of previously described histone acetylation biomarkers [amide I α‐helix and A(CH₃)/A(CH₂)]) with apoptotic biomarkers within the amide I region for β‐sheets, and unordered and CH₂ vibrations of lipids. VPA may be proposed for therapy of the undifferentiated component of teratoma tumors and this biological system completed by metabolome analysis, for a faster dual screening of antitumor/embryotoxic agents.

Metabolomic Alterations Do Not Induce Metabolic Burden in the Industrial Yeast M2n[pBKD2-Pccbgl1]-C1 Engineered by Multiple δ-Integration of a Fungal β-Glucosidase Gene

In the lignocellulosic yeast development, metabolic burden relates to redirection of resources from regular cellular activities toward the needs created by recombinant protein production. As a result, growth parameters may be greatly affected. Noteworthy, Saccharomyces cerevisiae M2n[pBKD2-Pccbgl1]-C1, previously developed by multiple δ-integration of the β-glucosidase BGL3, did not show any detectable metabolic burden. This work aims to test the hypothesis that the metabolic burden and the metabolomic perturbation induced by the δ-integration of a yeast strain, could differ significantly. The engineered strain was evaluated in terms of metabolic performances and metabolomic alterations in different conditions typical of the bioethanol industry. Results indicate that the multiple δ-integration did not affect the ability of the engineered strain to grow on different carbon sources and to tolerate increasing concentrations of ethanol and inhibitory compounds. Conversely, metabolomic profiles were significantly altered both under growing and stressing conditions, indicating a large extent of metabolic reshuffling involved in the maintenance of the metabolic homeostasis. Considering that four copies of BGL3 gene have been integrated without affecting any parental genes or promoter sequences, deeper studies are needed to unveil the mechanisms implied in these metabolomic changes, thus supporting the optimization of protein production in engineered strains.

Effect of cigarette smoke extract on mitochondrial heme-metabolism: An in vitro model of oral cancer progression

Tobacco smoking is considered as one of the major risk factors for development of oral cancer. In vitro studies indicate that cigarette smoke initiates transformation of epithelial cells toward development of oral cancer through altering mitochondrial metabolic pathways. However the present in vitro models need to be improved to correlate these molecular changes with epithelial transformations. In present study, we investigated the association of mitochondrial metabolic events with oral cancer progression under cigarette smoke extract (CSE). In this regard, an in vitro model of oral keratinocyte cell line (MOE1A) was developed by exposing them with different concentrations of CSE. Alterations in cellular phenomena were confirmed by Fourier-transform infrared spectroscopy (FTIR) study, which indicated changes in important functional groups of CSE-induced oral cells. Enhanced reactive oxygen species (ROS) of exposed cells altered the mitochondrial metabolic activities in terms of increased mitochondrial mass and DNA content. Further, mitochondrial heme-metabolism was investigated and real-time PCR study showed altered expression of important genes like ALAS1, ABCB6, CPOX, FECH, HO-1. Both transcriptomic and proteomic studies showed up- and down-regulation of important biomarkers related to cellular cancer progression. Overall data suggest that CSE alters mitochondrial heme metabolic pathway and initiates cancer progression through modifying cellar biomarkers in oral epithelial cells.

Whole-Organism Analysis by Vibrational Spectroscopy

Vibrational spectroscopy has contributed to the understanding of biological materials for many years. As the technology has advanced, the technique has been brought to bear on the analysis of whole organisms. Here, we discuss advanced and recently developed infrared and Raman spectroscopic instrumentation to whole-organism analysis. We highlight many of the recent contributions made in this relatively new area of spectroscopy, particularly addressing organisms associated with disease with emphasis on diagnosis and treatment. The application of vibrational spectroscopic techniques to entire organisms is still in its infancy, but new developments in imaging and chemometric processing will likely expand in the field in the near future.

SUMOylation Evoked by Oxidative Stress Reduced Lens Epithelial Cell Antioxidant Functions by Increasing the Stability and Transcription of TP53INP1 in Age-Related Cataracts

Oxidative stress plays an important role in the pathogenesis of cataracts. Small ubiquitin-like modifier (SUMO) proteins have great effects on cell stress response. Previous studies have shown that TP53INP1 can arrest cell growth and induce apoptosis by modulating p53 transcriptional activity and that both TP53INP1 and p53 are substrates of SUMOylation. However, no previous research has studied the effect of SUMOylation on the oxidative stress response in cataracts. This is the first study to investigate the effect of SUMOylation of TP53INP1 in oxidative stress-induced lens epithelial cell injury and age-related cataract formation. We found that the oxidative stress-induced endogenous SUMOylation of TP53INP1 promoted human lens epithelial cell (holed) apoptosis and regulated hLEC antioxidant effects by increasing the stability and transcription of TP53INP1 in age-related cataracts. SUMO-1, SUMOylation, and TP53INP1 were upregulated in lens tissues affected by age-related cataracts. A SUMO-1-specific protease, SENP1, acted as an oxidative stress-sensitive target gene in hLECs. This study identified for the first time that TP53INP1 can be SUMOylated in vivo, that the SUMOylation of TP53INP1 is induced by oxidative stress, and that SUMOylation/deSUMOylation can affect the stability and transcription of TP53INP1 in hLECs.

FTIR and Raman Spectroscopy-Based Biochemical Profiling Reflects Genomic Diversity of Clinical Candida Isolates That May Be Useful for Diagnosis and Targeted Therapy of Candidiasis

Despite the fact that Candida albicans is documented to be the main cause of human candidiasis, non-C. albicans Candida (NCAC) species, such as Candida glabrata and Candida tropicalis, are also suggested to be implicated in the etiopathogenesis of opportunistic fungal infections. As biology, epidemiology, pathogenicity, and antifungal resistance of NCAC species may be affected as a result of genomic diversity and plasticity, rapid and unambiguous identification of Candida species in clinical samples is essential for proper diagnosis and therapy. In the present study, 25 clinical isolates of C. albicans, C. glabrata, and C. tropicalis species were characterized in terms of their karyotype patterns, DNA content, and biochemical features. Fourier transform infrared (FTIR) spectra- and Raman spectra-based molecular fingerprints corresponded to the diversity of chromosomal traits and DNA levels that provided correct species identification. Moreover, Raman spectroscopy was documented to be useful for the evaluation of ergosterol content that may be associated with azole resistance. Taken together, we found that vibrational spectroscopy-based biochemical profiling reflects the variability of chromosome patterns and DNA content of clinical Candida species isolates and may facilitate the diagnosis and targeted therapy of candidiasis.

Detection of mycoplasma in contaminated mammalian cell culture using FTIR microspectroscopy

Mycoplasma contamination represents a significant problem to the culture of mammalian cells used for research as it can cause disastrous effects on eukaryotic cells by altering cellular parameters leading to unreliable experimental results. Mycoplasma cells are very small bacteria therefore they cannot be detected by visual inspection using a visible light microscope and, thus, can remain unnoticed in the cell cultures for long periods. The detection techniques used nowadays to reveal mycoplasma contamination are time consuming and expensive with each having significant drawbacks. The ideal detection should be simple to perform with minimal preparation time, rapid, inexpensive, and sensitive. To our knowledge, for the first time, we employed Fourier transform infrared (FTIR) microspectroscopy to investigate whether we can differentiate between control cells and the same cells which have been infected with mycoplasmas during the culturing process. Chemometric methods such as HCA and PCA were used for the data analysis in order to detect spectral differences between control and intentionally infected cells, and spectral markers were revealed even at low contamination level. The preliminary results showed that FTIR has the potential to be used in the future as a reliable complementary detection technique for mycoplasma-infected cells. Graphical abstract FTIR microspectroscopy is able to differentiate between mycoplasma infected cells (LC for low contamination and HC for high contamination) and control non-infected cells (CN).

Miniature diamond-anvil cells for FTIR-microspectroscopy of small quantities of biosamples

A small amount of biosample is mounted on a diamond anvil cell and spectra registered using simple 15× infrared objective instead of being grown on a diamond and measured by FTIR-ATR.