Advances in the synthesis and application of silver nanoparticles for laser mass spectrometry: A mini-review.

Silver nanoparticles are used in laser mass spectrometry to replace organic matrices. Thanks to their unique properties, they enable effective desorption/ionization of samples of various polarities and ionization abilities. This review presents new methods for the synthesis of monoisotopic silver nanoparticles and the use of targets coated with these nanoparticles for qualitative and quantitative analyses of various small-molecule compounds. Additionally, the results of progress in the application of AgNPs for metabolomics analyses were presented.

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.

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.

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.

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.

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.

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.

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.

Metabolomic and elemental profiling of blood serum in bladder cancer.

Bladder cancer (BC) is one of the most frequently diagnosed types of urinary cancer. Despite advances in treatment methods, no specific biomarkers are currently in use. Targeted and untargeted profiling of metabolites and elements of human blood serum from 100 BC patients and the same number of normal controls (NCs), with external validation, was attempted using three analytical methods, i.e., nuclear magnetic resonance, gold and silver-109 nanoparticle-based laser desorption/ionization mass spectrometry (LDI-MS), and inductively coupled plasma optical emission spectrometry (ICP-OES). All results were subjected to multivariate statistical analysis. Four potential serum biomarkers of BC, namely, isobutyrate, pyroglutamate, choline, and acetate, were quantified with proton nuclear magnetic resonance, which had excellent predictive ability as judged by the area under the curve (AUC) value of 0.999. Two elements, Li and Fe, were also found to distinguish between cancer and control samples, as judged from ICP-OES data and AUC of 0.807 (in validation set). Twenty-five putatively identified compounds, mostly related to glycans and lipids, differentiated BC from NCs, as detected using LDI-MS. Five serum metabolites were found to discriminate between tumor grades and nine metabolites between tumor stages. The results from three different analytical platforms demonstrate that the identified distinct serum metabolites and metal elements have potential to be used for noninvasive detection, staging, and grading of BC.