Fiber Laser-Generated Silver-109 Nanoparticles for Laser Desorption/Ionization Mass Spectrometry of Illicit Drugs

Cannabinoids and opioids are the most prominently used drugs in the world, with fentanyl being the main cause of drug overdose-related deaths. Monitoring drug use in groups as well as in individuals is an important forensic concern. Analytical methods, such as mass spectrometry (MS), have been found most useful for the identification of drug abuse on a small and large scale. Pulsed fiber laser 2D galvoscanner laser-generated nanomaterial (PFL 2D GS LGN) was obtained from monoisotopic silver-109. Nanomaterial was used for laser desorption/ionization mass spectrometry of selected illicit drug standards with standard high-resolution reflectron-based time-of-flight MALDI apparatus. Δ9-THC, 11-OH-THC, 11-COOH-THC, fentanyl, codeine, 6-monoacetylmorphine (6-MAM), heroin, tramadol, and methadone were chosen as test compounds. Illicit drugs were tested in a concentration range from 100 μg/mL to 10 pg/mL, equating to 50 μg to 50 fg per measurement spot. For all analyzed compounds, identification and quantification by silver-109-assisted laser desorption/ionization (LDI) MS was possible, with uncommon [M + 109Ag3]+ and [M - H]+ ions present for certain structures. The results of the quantitative analysis of drugs using silver-109 PFL 2D GS LGN for LDI MS are presented. Laser-generated NPs are proven to be useful for the analysis of selected drugs, with exceptionally good results for fentanyl monitoring in a broad range of concentrations.

Uncontrolled Post-Industrial Landfill-Source of Metals, Potential Toxic Compounds, Dust, and Pathogens in Environment-A Case Study

The aim of this case study was the evaluation of the selected metals' concentration, potential toxic compound identification, cytotoxicity analysis, estimation of the airborne dust concentration, biodiversity, and number of microorganisms in the environment (leachate, soil, air) of the biggest uncontrolled post-industrial landfills in Poland. Based on the results obtained, preliminary solutions for the future management of post-industrial objects that have become an uncontrolled landfill were indicated. In the air, the PM1 fraction dominated, constituting 78.1-98.2% of the particulate matter. Bacterial counts were in the ranges of 9.33 × 101-3.21 × 103 CFU m-3 (air), 1.87 × 105-2.30 × 106 CFU mL-1 (leachates), and 8.33 × 104-2.69 × 106 CFU g-1 (soil). In the air, the predominant bacteria were Cellulosimicrobium and Stenotrophomonas. The predominant fungi were Mycosphaerella, Cladosporium, and Chalastospora. The main bacteria in the leachates and soils were Acinetobacter, Mortierella, Proteiniclasticum, Caloramator, and Shewanella. The main fungi in the leachates and soils were Lindtneria. Elevated concentrations of Pb, Zn, and Hg were detected. The soil showed the most pronounced cytotoxic potential, with rates of 36.55%, 63.08%, and 100% for the A-549, Caco-2, and A-549 cell lines. Nine compounds were identified which may be responsible for this cytotoxic effect, including 2,4,8-trimethylquinoline, benzo(f)quinoline, and 1-(m-tolyl)isoquinoline. The microbiome included bacteria and fungi potentially metabolizing toxic compounds and pathogenic species.

Untargeted metabolomics of bladder tissue using liquid chromatography and quadrupole time-of-flight mass spectrometry for cancer biomarker detection

Bladder cancer (BC) ranks among the most common cancers globally, with an increasing occurrence, particularly in developed nations. Utilizing tissue metabolomics presents a promising strategy for identifying potential biomarkers for cancer detection. In this study, we utilized ultra-high-performance liquid chromatography coupled with ultra-high-resolution mass spectrometry (UHPLC-UHRMS), incorporating both C18-silica and HILIC columns, to comprehensively analyze both polar and non-polar metabolite profiles in tissue samples from 99 patients with bladder cancer. By utilizing an untargeted approach with external validation, we identified twenty-five tissue metabolites that hold promise as potential indicators of BC. Furthermore, twenty-five characteristic tissue metabolites that exhibit discriminatory potential across bladder cancer tumor grades, as well as thirty-nine metabolites that display correlations with tumor stages were presented. Receiver operating characteristics analysis demonstrated high predictive power for all types of metabolomics data, with area under the curve (AUC) values exceeding 0.966. Notably, this study represents the first report in which human bladder normal tissues adjacent to cancerous tissues were analyzed using UHPLC-UHRMS. These findings suggest that the metabolite markers identified in this investigation could serve as valuable tools for the detection and monitoring of bladder cancer stages and grades.

Metabolomic profiling of human bladder tissue extracts

INTRODUCTION

Bladder cancer is a common malignancy affecting the urinary tract and effective biomarkers and for which monitoring therapeutic interventions have yet to be identified.

OBJECTIVES

Major aim of this work was to perform metabolomic profiling of human bladder cancer and adjacent normal tissue and to evaluate cancer biomarkers.

METHODS

This study utilized nuclear magnetic resonance (NMR) and high-resolution nanoparticle-based laser desorption/ionization mass spectrometry (LDI-MS) methods to investigate polar metabolite profiles in tissue samples from 99 bladder cancer patients.

RESULTS

Through NMR spectroscopy, six tissue metabolites were identified and quantified as potential indicators of bladder cancer, while LDI-MS allowed detection of 34 compounds which distinguished cancer tissue samples from adjacent normal tissue. Thirteen characteristic tissue metabolites were also found to differentiate bladder cancer tumor grades and thirteen metabolites were correlated with tumor stages. Receiver-operating characteristics analysis showed high predictive power for all three types of metabolomics data, with area under the curve (AUC) values greater than 0.853.

CONCLUSION

To date, this is the first study in which bladder human normal tissues adjacent to cancerous tissues are analyzed using both NMR and MS method. These findings suggest that the metabolite markers identified in this study may be useful for the detection and monitoring of bladder cancer stages and grades.

Infrared pulsed fiber laser-produced gold and silver-109 nanoparticles for laser desorption/ionization mass spectrometry of steroid hormones

RATIONALE

Hormones are compounds that perform many important functions in the human body, but above all their task is to maintain homeostasis by adapting them to the constantly changing environmental conditions. Even minor hormonal disorders have a negative effect on the body, leading to physical or mental changes. Therefore, monitoring these changes and precise quantification of hormones are essential for the early diagnosis of diseases related to hormonal disorders.

METHODS

Application of monoisotopic silver-109 and gold nanoparticles obtained by PFL (pulsed fiber laser) 2D GS (galvo-scanner) LGN (laser-generated nanomaterial) for high-resolution laser desorption/ionization mass spectrometry (LDI-MS) and mass spectrometry imaging (MSI) of steroid hormones is presented. Four steroid hormones, estrone, prednisolone, corticosterone and progesterone, were used as test compounds for quantitative analysis with matrix-assisted LDI time-of-flight MS apparatus. Moreover, comparison of manual measurements and semiautomatic MSI with both types of nanoparticles was performed. Methods were also tested on spiked human blood serum for quantification of steroid hormones and for estimation of the matrix effect.

RESULTS

Hormones were directly tested in 1 000 000-fold concentration change conditions ranging from 1 mg/mL to 1 ng/mL which equates to 300 ng to 300 fg of hormone per measurement spot. For almost all tested hormones MSI allowed one to obtain equal or lower limit of detection value than manual LDI-MS. The best results judged by lowest limit of detection values are found for silver-109 nanoparticles.

CONCLUSION

The results of the quantitative analysis of steroid hormones using silver-109 and gold nanoparticles prepared with PFL 2D GS LGN for LDI-MS and semiautomatic LDI-MSI are presented. It has been proven that nanoparticles obtained by laser synthesis can be successfully used for the analysis of steroid hormones in a wide range of concentrations.

Biological and chemical contamination of illegal, uncontrolled refuse storage areas in Poland

This study focused on assessing the microbiological and chemical contamination of air, soil and leachate in uncontrolled refuse storage areas in central Poland. The research included an analysis of the number of microorganisms (culture method), endotoxin concentration (gas chromatography-mass spectrometry), heavy metals level (atomic absorption spectrometry), elemental characteristics (elemental analyser), cytotoxicity assessment against A-549 (human lung) and Caco-2 (human colon adenocarcinoma) cell lines (PrestoBlue™ test) and toxic compound identification (ultra-high-performance liquid chromatography-quadrupole time-of-flight ultrahigh-resolution mass spectrometry). Microbial contamination differed depending on the dump and the group of tested microorganisms. The number of bacteria was: 4.3 × 10² - 1.8 × 10³ CFU m^-3 (air); 1.1 × 10³ - 1.2 × 10⁶ CFU mL^-1 (leachate); 1.0 × 10⁶ - 3.9 × 10⁶ CFU g^-1 (soil). Respectively, for air and soil the number of fungi was: 2.2 × 10² - 4.6 × 10² CFU m^-3; 1.8 × 10² - 3.9 × 10³ CFU g^-1. Metal levels (Fe, Mn, Pb, Zn, Al, Hg, Cd, Cu, Cr) were higher than in the control sample; however, the average concentrations did not exceed the permissible standards. The cytotoxicity of soil and leachate samples depended on the dump, sample and cell line tested. The leachates were more cytotoxic than soil extracts. Compounds belonging to pesticides, surfactants and biocides, chemicals and/or polymer degradation products, medicinal drugs and insect repellents were found. The detection of potential pathogens in the air, soil and leachate, the presence of toxic compounds and the confirmation of the cytotoxic effect of leachate and soil on human cell lines justify the need for further research on the risks posed by illegal dumps. These studies should aim at developing a unified assessment method and a method to minimise the risk of contaminants spreading in the environment, including harmful biological agents.

Untargeted urinary metabolomics for bladder cancer biomarker screening with ultrahigh-resolution mass spectrometry

Bladder cancer (BC) is a common urological malignancy with a high probability of death and recurrence. Cystoscopy is used as a routine examination for diagnosis and following patient monitoring for recurrence. Repeated costly and intrusive treatments may discourage patients from having frequent follow-up screenings. Hence, exploring novel non-invasive ways to help identify recurrent and/or primary BC is critical. In this work, 200 human urine samples were profiled using ultra-high-performance liquid chromatography and ultra-high-resolution mass spectrometry (UHPLC-UHRMS) to uncover molecular markers differentiating BC from non-cancer controls (NCs). Univariate and multivariate statistical analyses with external validation identified metabolites that distinguish BC patients from NCs disease. More detailed divisions for the stage, grade, age, and gender are also discussed. Findings indicate that monitoring urine metabolites may provide a non-invasive and more straightforward diagnostic method for identifying BC and treating recurrent diseases.

Targeted and untargeted urinary metabolic profiling of bladder cancer

Bladder cancer (BC) is frequent cancer affecting the urinary tract and is one of the most prevalent malignancies worldwide. No biomarkers that can be used for effective monitoring of therapeutic interventions for this cancer have been identified to date. This study investigated polar metabolite profiles in urine samples from 100 BC patients and 100 normal controls (NCs) using nuclear magnetic resonance (NMR) and two methods of high-resolution nanoparticle-based laser desorption/ionization mass spectrometry (LDI-MS). Five urine metabolites were identified and quantified using NMR spectroscopy to be potential indicators of bladder cancer. Twenty-five LDI-MS-detected compounds, predominantly peptides and lipids, distinguished urine samples from BC and NCs individuals. Level changes of three characteristic urine metabolites enabled BC tumor grades to be distinguished, and ten metabolites were reported to correlate with tumor stages. Receiver-Operating Characteristics analysis showed high predictive power for all three types of metabolomics data, with the area under the curve (AUC) values greater than 0.87. These findings suggest that metabolite markers identified in this study may be useful for the non-invasive detection and monitoring of bladder cancer stages and grades.

Monoisotopic silver nanoparticles-based mass spectrometry imaging of human bladder cancer tissue: Biomarker discovery

PURPOSE

Bladder cancer (BC) is the 10th most common form of cancer worldwide and the 2nd most common cancer of the urinary tract after prostate cancer, taking into account both incidence and prevalence.

MATERIALS/METHODS

Tissues from patients with BC and also tissue extracts were analyzed by laser desorption/ionization mass spectrometry imaging (LDI-MSI) with monoisotopic silver-109 nanoparticles-enhanced target (¹⁰⁹AgNPET).

RESULTS

Univariate and multivariate statistical analyses revealed 10 metabolites that differentiated between tumor and normal tissues from six patients with diagnosed BC. Selected metabolites are discussed in detail in relation to their mass spectrometry (MS) imaging results. The pathway analysis enabled us to link these compounds with 17 metabolic pathways.

CONCLUSIONS

According to receiver operating characteristic (ROC) analysis of biomarkers, 10 known metabolites were identified as the new potential biomarkers with areas under the curve (AUC) higher than >0.99. In both univariate and multivariate analysis, it was predicted that these compounds could serve as useful discriminators of cancerous versus normal tissue in patients diagnosed with BC.

Infrared pulsed fiber laser-produced silver-109 nanoparticles for laser desorption/ionization mass spectrometry of 3-hydroxycarboxylic acids

RATIONALE

3-Hydroxycarboxylic acids are one of the major components of bacterial lipopolysaccharides (LPS), also known as endotoxins. Endotoxins pose a serious health risk and can seriously damage the internal organs of humans and animals. 3-Hydroxycarboxylic acids can be used as environmental markers to determine endotoxin levels. At the time of preparation of this manuscript no studies on laser mass spectrometry (MS) and analysis with silver nanoparticles (NP) for 3-hydroxycarboxylic acids have been published in literature.

METHODS

Six acids, 3-hydroxyoctanoic (3-OH-C8:0), 3-hydroxydecanoic (3-OH-C10:0), 3-hydroxydodecanoic (3-OH-C12:0), 3-hydroxytetradecanoic (3-OH-C14:0), 3-hydroxyhexadecanoic (3-OH-C16:0), and 3-hydroxyoctadecanoic (3-OH-C18:0) acids, were used as test compounds on the target containing silver-109 NPs for quantification using matrix-assisted laser desorption/ionization (MALDI)-type mass spectrometer. Methods were also tested on spiked human blood serum samples to quantify 3-hydroxycarboxylic acids and verify the influence of the biological matrix on the measurement.

RESULTS

Analyzed acids were directly tested in 1 000 000-fold concentration change conditions ranging from 1 mg/mL to 1 ng/mL. The semi-automatic MSI (MS imaging) method allowed us to obtain two to five times lower limit of detection (LOD) and lower limit of quantitation (LLOQ) values than common LDI (Bruker Daltonics, Bremen, Germany) method for analyzed acids. For almost all results of 3-hydroxycarboxylic acids, the trendline fit was better for the semi-automatic MSI method than the manual LDI method.

CONCLUSION

For the first time, the use of laser MS for the quantification of 3-hydroxycarboxylic acids has been demonstrated, and it has been proven that it can be used in the quantitative analysis of such compounds over a wide range of concentrations. In addition, a comparison of two methods-manual LDI-MS and semi-automatic MSI-is presented.

Untargeted ultra-high-resolution mass spectrometry metabolomic profiling of blood serum in bladder cancer

Bladder cancer (BC) is a common urological cancer of high mortality and recurrence rates. Currently, cystoscopy is performed as standard examination for the diagnosis and subsequent monitoring for recurrence of the patients. Frequent expensive and invasive procedures may deterrent patients from regular follow-up screening, therefore it is important to look for new non-invasive methods to aid in the detection of recurrent and/or primary BC. In this study, ultra-high-performance liquid chromatography coupled with ultra-high-resolution mass spectrometry was employed for non-targeted metabolomic profiling of 200 human serum samples to identify biochemical signatures that differentiate BC from non-cancer controls (NCs). Univariate and multivariate statistical analyses with external validation revealed twenty-seven metabolites that differentiate between BC patients from NCs. Abundances of these metabolites displayed statistically significant differences in two independent training and validation sets. Twenty-three serum metabolites were also found to be distinguishing between low- and high-grade of BC patients and controls. Thirty-seven serum metabolites were found to differentiate between different stages of BC. The results suggest that measurement of serum metabolites may provide more facile and less invasive diagnostic methodology for detection of bladder cancer and recurrent disease management.

Laser Ablation Synthesis in Solution and Nebulization of Silver-109 Nanoparticles for Mass Spectrometry and Mass Spectrometry Imaging

Preparation of monoisotopic silver-109 nanoparticles (¹⁰⁹AgNPs) by pulsed fiber laser (PFL) ablation synthesis in solution (LASiS) with the use of a 2D galvoscanner (2D GS) is described. The procedure of covering of custom-made stainless-steel MALDI targets containing studied objects via nebulization is also presented. Examples of application of the new method (PFL-2D GS LASiS and nebulization) in mass spectrometry (MS) analyses and MS imaging (MSI) are shown. These include tests with a nonionic nucleoside and saccharide, ionic amino acids, and also a low-molecular-weight polymer. Fingerprint MS imaging is shown as an example of a fast and simple MSI procedure.

Infrared pulsed fiber laser-produced silver-109-nanoparticles for laser desorption/ionization mass spectrometry of amino acids

Application of monoisotopic cationic 109 Ag nanoparticles (109 AgNPs) obtained by pulsed fiber laser (PFL) 2D galvo-scanner (GS) laser generated nanomaterial (LGN) for both high resolution laser desorption/ionization mass spectrometry and mass spectrometry imaging of amino acids is presented. Four amino acids, alanine, isoleucine, lysine, and phenylalanine were used as test compounds for quantification with matrix-assisted laser desorption/ionization mas (MALDI)-type mass spectrometer. Comparison of commonly made manual measurements with semiautomatic mass spectrometry imaging (MSI) was performed providing very interesting findings. Amino acids were directly tested in 1 000 000-fold concentration change conditions ranging from 1 mg/ml to 1 ng/ml, which equates to 500 ng to 500 fg of amino acid per measurement spot. Methods were also tested on samples of human blood plasma for quantification of endogenous amino acids.

Serum and urine analysis with gold nanoparticle-assisted laser desorption/ionization mass spectrometry for renal cell carcinoma metabolic biomarkers discovery

PURPOSE

Renal cell carcinoma (RCC) is a very aggressive and often fatal heterogeneous disease that is usually asymptomatic until late in the disease. There is an urgent need for RCC specific biomarkers that may be exploited clinically for diagnostic and prognostic purposes.

MATERIALS/METHODS

Serum and urine samples were collected from patients with diagnosed kidney cancer and assessed with gold nanoparticle enhanced target (AuNPET) surface assisted-laser desorption/ionization mass spectrometry (SALDI MS) based metabolomics and statistical analysis.

RESULTS

A database search allowed providing assignment of signals for the most promising features with a satisfactory value of the area under the curve and accuracy. Four potential biomarkers were found in urine and serum samples to distinguish clear cell renal cell carcinoma (ccRCC) from controls, 4 for the ccRCC with and without metastases, and 6 metabolites to distinguish low and high stages or grades.

CONCLUSIONS

This pilot study suggests that serum and urine metabolomics based on AuNPET-LDI MS may be useful in distinguishing types, grades and stages of human RCC.

Metabolomic and elemental profiling of human tissue in kidney cancer

INTRODUCTION

Kidney cancer is one of the most frequently diagnosed and the most lethal urinary cancer. Despite advances in treatment, no specific biomarker is currently in use to guide therapeutic interventions.

OBJECTIVES

Major aim of this work was to perform metabolomic and elemental profiling of human kidney cancer and normal tissue and to evaluate cancer biomarkers.

METHODS

Metabolic and elemental profiling of tumor and adjacent normal human kidney tissue from 50 patients with kidney cancer was undertaken using three different analytical methods.

RESULTS

Five potential tissue biomarkers of kidney cancer were identified and quantified using with high-resolution nuclear magnetic resonance spectroscopy. The contents of selected chemical elements in tissues was analyzed using inductively coupled plasma optical emission spectrometry. Eleven mass spectral features differentiating between kidney cancer and normal tissues were detected using silver-109 nanoparticle enhanced steel target laser desorption/ionization mass spectrometry.

CONCLUSIONS

Our results, derived from the combination of ICP-OES, LDI MS and 1H NMR methods, suggest that tissue biomarkers identified herein appeared to have great potential for use in clinical prognosis and/or diagnosis of kidney cancer.

Nuclear magnetic resonance and surface-assisted laser desorption/ionization mass spectrometry-based metabolome profiling of urine samples from kidney cancer patients

Kidney cancer is one of the most frequently diagnosed cancers of the urinary tract in the world. Despite significant advances in kidney cancer treatment, no urine specific biomarker is currently used to guide therapeutic interventions. In an effort to address this knowledge gap, metabolic profiling of urine samples from 50 patients with kidney cancer and 50 healthy volunteers was undertaken using high-resolution proton nuclear magnetic resonance spectroscopy (¹H NMR) and silver-109 nanoparticle enhanced steel target laser desorption/ionization mass spectrometry (¹⁰⁹AgNPET LDI MS). Twelve potential urine biomarkers of kidney cancer were identified and quantified using one-dimensional (1D) ¹H NMR metabolomics. Seven mass spectral features which differed significantly in abundance (p < 0.05) between kidney cancer patients and healthy volunteers were also detected using ¹⁰⁹AgNPET-based laser desorption/ionization mass spectrometry (LDI MS). This work provides a framework to expand biomarker discovery that could be used as useful diagnostic or prognostic of kidney cancer progression.

Gold and silver nanoparticles-based laser desorption/ionization mass spectrometry method for detection and quantification of carboxylic acids

A comparison of ionization efficiency for gold and silver nanoparticles used as an active media of matrix-less laser desorption/ionization (LDI) mass spectrometry (MS) methods was made for carboxylic acids including fatty acids. The matrix-assisted laser desorption/ionization (MALDI)-type targets containing monoisotopic cationic ¹⁰⁹ Ag nanoparticles (¹⁰⁹ AgNPs) and Au nanoparticles (AuNPs) were used for rapid MS measurements of 10 carboxylic acids of different chemical properties. Carboxylic acids were directly quantified in experiments with 10 000-fold concentration change conditions ranging from 1 mg/ml to 100 ng/ml which equates to 1 μg to 100 pg of carboxylic acids per measurement spot.

Nuclear magnetic resonance and surface-assisted laser desorption/ionization mass spectrometry-based serum metabolomics of kidney cancer

Kidney cancer is one of the most frequently diagnosed and the most lethal urinary cancer. Despite all the efforts made, no serum-specific biomarker is currently used in the clinical management of patients with this tumor. In this study, comprehensive high-resolution proton nuclear magnetic resonance spectroscopy (1H NMR) and silver-109 nanoparticle-enhanced steel target laser desorption/ionization mass spectrometry (109AgNPET LDI MS) approaches were conducted, in conjunction with multivariate data analysis, to discriminate the global serum metabolic profiles of kidney cancer (n = 50) and healthy volunteers (n = 49). Eight potential biomarkers have been identified using 1H NMR metabolomics and nine mass spectral features which differed significantly (p < 0.05) between kidney cancer patients and healthy volunteers, as observed by LDI MS. A partial least squares discriminant analysis (OPLS-DA) model generated from metabolic profiles obtained by both analytical approaches could robustly discriminate normal from cancerous samples (Q2 > 0.7), area under the receiver operative characteristic curve (ROC) AUC > 0.96. Compared with healthy human serum, kidney cancer serum had higher levels of glucose and lower levels of choline, glycerol, glycine, lactate, leucine, myo-inositol, and 1-methylhistidine. Analysis of differences between these metabolite levels in patients with different types and grades of kidney cancer was undertaken. Our results, derived from the combination of LDI MS and 1H NMR methods, suggest that serum biomarkers identified herein appeared to have great potential for use in clinical prognosis and/or diagnosis of kidney cancer. Graphical abstract.

Localization of Metabolites of Human Kidney Tissue with Infrared Laser-Based Selected Reaction Monitoring Mass Spectrometry Imaging and Silver-109 Nanoparticle-Based Surface Assisted Laser Desorption/Ionization Mass Spectrometry Imaging

Infrared (IR) laser ablation-remote-electrospray ionization (LARESI) platform coupled to a tandem mass spectrometer (MS/MS) operated in selected reaction monitoring (SRM) or multiple reaction monitoring (MRM) modes was developed and employed for imaging of target metabolites in human kidney cancer tissue. SRM or MRM modes were employed to avoid artifacts that are present in full scan MS mode. Four tissue samples containing both cancerous and noncancerous regions, obtained from three patients with renal cell carcinoma (RCC), were imaged. Sixteen endogenous metabolites that were reported in the literature as varying in abundance between cancerous and noncancerous areas in various human tissues were selected for analysis. Target metabolites comprised ten amino acids, four nucleosides and nucleobases, lactate, and vitamin E. For comparison purposes, images of the same metabolites were obtained with ultraviolet (UV) desorption/ionization mass spectrometry imaging (UV-LDI-MSI) using monoisotopic silver-109 nanoparticle-enhanced target (¹⁰⁹AgNPET) in full-scan MS mode. The acquired MS images revealed differences in abundances of selected metabolites between cancerous and noncancerous regions of the kidney tissue. Importantly, the two imaging methods offered similar results. This study demonstrates the applicability of the novel ambient LARESI SRM/MRM MSI method to both investigating and discovering cancer biomarkers in human tissue.

Mass spectrometry imaging of low molecular weight metabolites in strawberry fruit (Fragaria x ananassa Duch.) cv. Primoris with 109Ag nanoparticle enhanced target

Strawberry (Fragaria x ananassa Duch., Rosaceae) is the subject of many research studies due to its numerous features such as unique taste, aroma and health qualities. The distribution of low molecular weight metabolites belonging to aldehydes, ketones, alcohols, esters, organic acids, phenolics, amino acids and sugars classes within strawberry fruit cross-section was studied using mass spectrometry imaging (MSI) method with ¹⁰⁹Ag nanoparticle enhanced target (¹⁰⁹AgNPET). Correlation of distribution of over thirty compounds found in cross-section of strawberry with their biological function is also included.

Metabolomic study of human tissue and urine in clear cell renal carcinoma by LC-HRMS and PLS-DA

Renal cell carcinoma (RCC) is the most prevalent and lethal malignancy of the kidney. Despite all the efforts made, no tissue biomarker is currently used in the clinical management of patients with kidney cancer. A search for possible biomarkers in urine for clear cell renal cell carcinoma (ccRCC) has been conducted. Non-targeted metabolomic analyses were performed on paired samples of surgically removed renal cancer and normal tissue, as well as on urine samples. Extracts were analyzed by liquid chromatography/high-resolution mass spectrometry (LC-HRMS). Hydroxybutyrylcarnitine, decanoylcarnitine, propanoylcarnitine, carnitine, dodecanoylcarnitine, and norepinephrine sulfate were found in much higher concentrations in both cancer tissues (compared with the paired normal tissue) and in urine of cancer patients (compared with control urine). In contrast, riboflavin and acetylaspartylglutamate (NAAG) were present at significantly higher concentrations both in normal kidney tissue as well as in urine samples of healthy persons. This preliminary study resulted in the identification of several compounds that may be considered potential clear cell renal carcinoma biomarkers. Graphical abstract PLS-DA plot based on LC-MS data for normal and cancer human tissue samples. The aim of this work was the identification of up- and downregulated compounds that could potentially serve as renal cancer biomarkers.

Silver-109-based laser desorption/ionization mass spectrometry method for detection and quantification of amino acids

A new methodology applicable for both high-resolution laser desorption/ionization mass spectrometry and mass spectrometry imaging of amino acids is presented. The matrix-assisted laser desorption ionization-type target containing monoisotopic cationic ¹⁰⁹ Ag nanoparticles (¹⁰⁹ AgNPs) was used for rapid mass spectrometry measurements of 11 amino acids of different chemical properties. Amino acids were directly tested in 100,000-fold concentration change conditions ranging from 100 μg/mL to 1 ng/mL which equates to 50 ng to 500 fg of amino acid per measurement spot. Limit of detection values obtained suggest that presented method/target system is among the fastest and most sensitive ones in laser mass spectrometry. Mass spectrometry imaging of spots of human blood plasma spiked with amino acids showed their surface distribution allowing optimization of quantitative measurements.

N(4)-[B-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan)methyl]-2'-deoxycytidine as a potential boron delivery agent with respect to glioblastoma

Glioblastoma multiforme (GBM) is a central nervous system tumor of grade IV, according to the WHO classification, extremely resistant to all currently used forms of therapy, including resection, radiotherapy, chemotherapy or combined therapy. Therefore, more effective treatment strategies of this tumor are needed, with boron neutron capture therapy (BNCT) being a potential solution, provided a proper cancer cells-targeted 10B delivery agent is found. In search of such an agent, toxicity and capacity to target DNA of a boronated derivative of 2'-deoxycytidine, N(4)-[B-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan)methyl]-2'-deoxycytidine (1), was tested against human tumor vs. normal cells. The present in vitro results revealed 1 to show low toxicity for human U-118 MG glioma cells (in the mM range) and even by 3-4 - fold lower against normal human fibroblasts. In accord, induction of apoptosis dependent on caspase-3 and caspase-7 was detected at high (>20mM) concentration of 1. Although demonstrated to be susceptible to phosphorylation by human deoxycytidine kinase and to undergo incorporation in cellular DNA, the boron analogue did not disturb cell proliferation when applied at non-toxic concentrations and showed low toxicity to a model metazoan organism, Caenorhabditis elegans. Thus, N(4)-[B-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan)methyl]-2'-deoxycytidine appears a promising candidate for a 10B delivery agent to be used in BNCT, with C. elegans indicated as a good model for in vivo studies.

Visualizing spatial distribution of small molecules in the rhubarb stalk (Rheum rhabarbarum) by surface-transfer mass spectrometry imaging

Laser desorption/ionization mass spectrometry imaging (LDI-MSI) with gold nanoparticle-enhanced target (AuNPET) was used for visualization of small molecules in the rhubarb stalk (Rheum rhabarbarum L.). Analysis was focused on spatial distribution of biologically active compounds which are found in rhubarb species. Detected compounds belong to a very wide range of chemical compound classes such as anthraquinone derivatives and their glucosides, stilbenes, anthocyanins, flavonoids, polyphenols, organic acids, chromenes, chromanones, chromone glycosides and vitamins. The analysis of the spatial distribution of these compounds in rhubarb stalk with the nanoparticle-rich surface of AuNPET target plate has been made without additional matrix and with minimal sample preparation steps.

Biological activity of N(4)-boronated derivatives of 2'-deoxycytidine, potential agents for boron-neutron capture therapy

Boron-neutron capture therapy (BNCT) is a binary anticancer therapy that requires boron compound for nuclear reaction during which high energy alpha particles and lithium nuclei are formed. Unnatural, boron-containing nucleoside with hydrophobic pinacol moiety was investigated as a potential BNCT boron delivery agent. Biological properties of this compound are presented for the first time and prove that boron nucleoside has low cytotoxicity and that observed apoptotic effects suggest alteration of important functions of cancer cells. Mass spectrometry analysis of DNA from cancer cells proved that boron nucleoside is inserted into nucleic acids as a functional nucleotide derivative. NMR studies present very high degree of similarity of natural dG-dC base pair with dG-boron nucleoside system.

Properties of phosphorylated thymidylate synthase

Thymidylate synthase (TS) may undergo phosphorylation endogenously in mammalian cells, and as a recombinant protein expressed in bacterial cells, as indicated by the reaction of purified enzyme protein with Pro-Q® Diamond Phosphoprotein Gel Stain (PGS). With recombinant human, mouse, rat, Trichinella spiralis and Caenorhabditis elegans TSs, expressed in Escherichia coli, the phosphorylated, compared to non-phosphorylated recombinant enzyme forms, showed a decrease in Vmax(app), bound their cognate mRNA (only rat enzyme studied), and repressed translation of their own and several heterologous mRNAs (human, rat and mouse enzymes studied). However, attempts to determine the modification site(s), whether endogenously expressed in mammalian cells, or recombinant proteins, did not lead to unequivocal results. Comparative ESI-MS/analysis of IEF fractions of TS preparations from parental and FdUrd-resistant mouse leukemia L1210 cells, differing in sensitivity to inactivation by FdUMP, demonstrated phosphorylation of Ser(10) and Ser(16) in the resistant enzyme only, although PGS staining pointed to the modification of both L1210 TS proteins. The TS proteins phosphorylated in bacterial cells were shown by (31)P NMR to be modified only on histidine residues, like potassium phosphoramidate (KPA)-phosphorylated TS proteins. NanoLC-MS/MS, enabling the use of CID and ETD peptide fragmentation methods, identified several phosphohistidine residues, but certain phosphoserine and phosphothreonine residues were also implicated. Molecular dynamics studies, based on the mouse TS crystal structure, allowed one to assess potential of several phosphorylated histidine residues to affect catalytic activity, the effect being phosphorylation site dependent.

Gold nanoparticle-enhanced target (AuNPET) as universal solution for laser desorption/ionization mass spectrometry analysis and imaging of low molecular weight compounds

Preparation is described of a durable surface of cationic gold nanoparticles (AuNPs), covering commercial and custom-made MALDI targets, along with characterization of the nanoparticle surface properties and examples of the use in MS analyses and MS imaging (IMS) of low molecular weight (LMW) organic compounds. Tested compounds include nucleosides, saccharides, amino acids, glycosides, and nucleic bases for MS measurements, as well as over one hundred endogenous compounds in imaging experiment. The nanoparticles covering target plate were enriched in sodium in order to promote sodium-adduct formation. The new surface allows fast analysis, high sensitivity of detection and high mass determination accuracy. Example of application of new Au nanoparticle-enhanced target for fast and simple MS imaging of a fingerprint is also presented.

Silver nanostructures in laser desorption/ionization mass spectrometry and mass spectrometry imaging

Silver nanoparticles have been successfully applied as a matrix replacement for the laser desorption/ionization time-of-flight mass spectrometry (LDI-ToF-MS).

Synthesis, reactivity and biological activity of N(4)-boronated derivatives of 2'-deoxycytidine

By seeking new stable boron-containing nucleoside derivatives, potential BNCT boron delivery agents, a novel synthetic approach was tested, aimed at a boron attachment via a single bond to an aliphatic carbon of sp(3) hybridization. The latter allowed successful modification of deoxycytidine in the reaction with 2-(iodomethyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane of the deoxynucleoside amino group. For new compounds, detailed NMR, LDI HRMS (Laser Desorption/Ionization High-Resolution Mass Spectrometry) analyses along with in vivo phosphorylation studies, toxicity assays and DFT modelling are presented.

Novel dipyrazolopyridine derivatives as deep blue emitters for polymer based organic light emitting diodes

Paper reports synthesis and spectroscopic properties of four newly synthesized dipyrazolo[3,4-b; 3',4'-e]pyridine (DPP) derivatives. The spectroscopic studies are supplemented by quantum-chemical calculations using DFT/TDDFT/PCM method at the B3LYP/6-31+G(d,p) level of theory. The optical absorption and fluorescence emission processes appear to be weakly dependent on attached side phenyl and/or methyl groups exhibiting in cyclohexane solution the first absorption band (00' transition) in the region of 386-401 nm and the fluorescence band (0'0 transition) in the range of 412-425 nm. The electroluminescence devices (OLEDs) with an active PVK layer doped by DPP dyes have been designed. All the devices exhibit deep blue electroluminescence with the emission maximum being rather weakly dependent on the type of the fluorescent dopant. The obtained results demonstrate that a series of newly synthesized DPP dyes may be considered as perspective blue fluorescent emitters for electroluminescent applications.

Influence of chromophore dipole moments in parameters of organic light emitting devices based on phenyl and methyl modified pyrazoloquinoline

Absorption, photo- and electroluminescence spectra of some trityl substituted 1H-pyrazolo[3,4-b]quinolines derivatives (methyl- and phenyl substituted) and fabrication of the single layered organic light emitting diodes are reported. The bulky trityl substituent was introduced to prevent aggregation and crystallization of the dopant in polymer matrix. Role of ground state dipole moments in the observed red Stokes shift, electroluminescent features and photocarrier transport is explored. The maximally achieved brightness about 50Cd/m(2) is observed in the spectral range extending from 443nm up to 462nm. The voltage threshold was varied from 7.8V up to 10V. The brightness-current dependences show an existence of at least two types of carrier injections.

Spectral emission properties of 4-aryloxy-3-methyl-1-phenyl-1H-pyrazolo[3,4-b]quinolines

Spectral emission properties of novel 4-aryloxy-1H-pyrazolo[3,4-b]quinolines were investigated. All of the compounds exhibit strong blue luminescence in the solution and in the solid state as well. Pyrazoloquinolines were used as dopants in PVK matrices in electroluminescent devices with ITO/PVK:PQ/Ca/Al light emitting diode configuration.

Photoluminescence of 1-phenyl,3-methyl pyrazoloquinoline derivatives

Paper presents the absorption and photoluminescence of 7-TFM, 6-F, 6-CN, 6-TBu and 6-COOEt derivatives of 1-phenyl-3-methyl-1H-Pyrazolo[3,4-b]quinoline (MPPQ). The measured spectra are compared with the results of the quantum chemical calculations performed by means of the semi-empirical methods (AM1 or PM3) that have been applied either to the equilibrium molecular conformations in vacuo (T=0K) or combined with the MD simulations (T=300 K). The photoluminescent spectra of MPPQ dyes are highly solvatochromic. The emission bands broaden and shift to the red with the increasing of solvent polarity, indicating thus a substantial dipole moment of the excited states. According to the quantum chemical analysis the reason for the strong solvatochromism of MPPQ dyes is related with intramolecular charge transfer (ICT) state. Due to the large dipole moment in the twisted geometry the ICT state is believed to become the lowest excited state in a strongly polar environment. This would explain a considerable solvatochromic shift in the highly polar solvents observed for all MPPQ dyes in the experiment. Such hypothesis is supported by the semi-empirical quantum chemical evaluations.

Significance of the 14C-urea breath test in the determination of the location infected by Helicobacter pylori in the alimentary canal

118 patients with chronic gastritis were the subject of the tests; they were divided into two groups on the basis of a bacteriological (culture) diagnosis of the infections by Helicobacter pylori: group I-patients with the infection present only in the stomach; group II-patients with the infection synchronically occurring in the mouth and the stomach. Both groups underwent the 14C-urea breath test to detect the Helicobacter pylori infection. In general, for the patients of group I the radioactivity of the samples of blown air showed a single maximum after ca 15-25 min. For patients of group II two maxima were obtained, the first after ca 5 min and the second after ca 15-25 min. Our investigations indicate that the 14C-urea breath test can not only be used to detect patients infected by Helicobacter pylori but also to establish the location (mouth, stomach) in the alimentary canal of the infection by that bacterium.