Liquid chromatographic methods for the therapeutic drug monitoring of methotrexate as clinical decision support for personalized medicine: A brief review

A new kind of polystyrene/polyethyleneimine nanofibres coordinated with palladium for fast and efficient extraction of methotrexate and its polyglutamate metabolites in different matrices

Methotrexate (MTX) is a drug that has long been used in high doses as an anti-cancer drug and lately in low doses as a treatment for autoimmune diseases. It is necessary to be determined in various matrices because the drug has a narrow therapeutic range and a high persistence in the environment. Since MTX and its polyglutamate metabolites (MTXPGs) have strong polarity and the potential to be converted during sample processing, rapid and efficient extraction of these targets has provided technical challenges for development of analytical methods for them. A new Pd(ii)/polyethyleneimine (PEI)/polystyrene (PS) nanofibre was prepared and characterized by X-ray diffraction, FTIR spectroscopy, thermal analysis, scanning electron microscopy and transmission electron microscopy, etc. The nanofibre was applied as a sorbent to extract MTX and MTXPGs in whole blood and MTX in urine and water. The extracted analytes were then desorbed by a water solution containing 10% methanol and 20% ammonium hydroxide (v/v) and eventually quantified by high performance liquid chromatography. The peak area of the target substances in the extraction solution and its concentration were linear in the range of 20.0 (∼37.8 to 1000 ng/mL); intraday and interday RSD were 4.6-6.4% and 5.7-14.6%, respectively. The detection limit of this method was 6.0-11.3 ng/mL. The results showed that the method can be used for the determination of MTX and MTXPGs in human whole blood and MTX in urine/water samples.

Sers-based methodology for nanomolar methotrexate concentration detection for clinics

The paper proposes a new rapid and reliable method for the detection of methotrexate (MTX) in human blood serum using truncated triangular silver nanoparticles (AgNP) deposited on quartz glass. The article describes the application of the SERS method and the synthesized surfaces for the detection of pure MTX, MTX molecules and its metabolites in patient serum. Using this approach, it was possible to detect methotrexate in controls up to 10-9 M concentration and in human plasma samples at clinical concentration up to 10-6 M. The developed methodology can be a fast and cheap alternative to traditional methods in clinics, such as high-performance liquid chromatography (HPLC).

The interest of therapeutic and pharmacological drug monitoring of methotrexate: A systematic review

Methotrexate (MTX) is largely prescribed for cancers, particularly hematological malignancies. To reduce its toxicity, therapeutic drug monitoring (TDM) is highly recommended. This review aimed to assess knowledge on methotrexate monitoring and compare strategies for managing its toxicities. We searched several databases for articles that met the selection criteria. All articles were screened and data on analytical methods, results, and toxicities were extracted. Thirty articles were included in this review, consisting mainly of single-center studies. MTX monitoring studies have been conducted in various countries. Patient demographics covered children and adults, with one study focusing on elderly patients. MTX doses varied primarily between high-dose regimens. Sample collection times were varied. Various techniques were used to quantify MTX levels. This review highlights the diversity of study designs, patient populations, dosing regimens, and analytical techniques, emphasizing the need for standardized protocols and further research to optimize MTX treatment, ensuring both efficacy and safety.

Implantable photoelectrochemical-therapeutic methotrexate monitoring system with dual-atomic docking strategy

The need for precise modulation of blood concentrations of pharmaceutical molecule, especially for high-risk drugs like Methotrexate (MTX), is underscored by the significant impact of individual variations on treatment efficacy. Achieving selective recognition of pharmaceutical molecules within the complex biological environment is a substantial challenge. To tackle this, we propose a synergistic atomic-molecular docking strategy that utilizes a hybrid-dual single-atom Fe1-Zn1 on a TiO2 photoelectrode to selectively bind to the carboxyl and aminopyrimidine groups of MTX respectively. By integrating this Fe1-Zn1-TiO2 photoelectrode with a microcomputer system, an implantable photoelectrochemical-therapeutic drug monitoring (PEC-TDM) system is developed for real-time, continuous in vivo MTX monitoring. This system facilitates personalized therapeutic decision-making and intelligent drug delivery for individualized cancer therapy, potentially revolutionizing oncological care and enhancing patient outcomes.

Simultaneous Determination of Methotrexate and 7-Hydroxy-Methotrexate by UHPLC-MS3 Assay Coupled With Multiple Stage Fragmentation to Enhance Sensitivity

A selective ultra-high performance liquid chromatography tandem mass spectrometry cubed (UHPLC/MS3) assay for simultaneous determination of methotrexate (MTX) and 7-hydroxy-methotrexate (7-OH-MTX) in human plasma was developed and validated. After protein precipitation with methanol, chromatographic separation of MTX, MTX-d3, and 7-OH-MTX was performed on a Waters AcQuity UPLC-BEH column (2.1 × 50 mm I.D., 1.7 µm) with gradient elution. MRM3 transition was used for the detection of MTX (m/z 455.2→308.0→175.1) and 7-OH-MTX (m/z 471.3→191.0→148.1). The linear range of UHPLC/MS3 assay for the determination of MTX and 7-OH-MTX was 0.5-300 ng/mL (R2 ≥ 0.99) and 5-1500 ng/mL (R2 ≥ 0.99), respectively. The enhanced selectivity and sensitivity are the novelties of the developed UHPLC/MS3 assay. The analytical method was successfully applied to simultaneous determination of MTX and its major metabolite 7-OH-MTX in real human plasma samples.

Selective and reliable fluorometric quantitation of anti-cancer drug in real plasma samples using nitrogen-doped carbon dots after MMIPs solid phase microextraction: Monitoring methotrexate plasma level

A novel selective and reliable ratiometric fluorescence probe has been successfully synthesized for precise, sensitive, and simple quantitation of methotrexate (MTX). Hydrothermal method was employed to fabricate nitrogen-doped carbon dots using Annona squamosa seeds (AS-CDs) as a starting material, and their characteristics were confirmed using transmission electron microscopy (TEM), UV-Vis spectroscopy, fluorescence spectroscopy, X-ray diffractometry (XRD), and Fourier Transform Infrared Spectroscopy (FTIR). The ratiometric fluorometric assay, which is based on measuring the ratio of emissions (F355/F430), has a wide detection range of 5-2000 ng /mL and a limit of detection (LOD, S/N = 3) of 1.5 ng /mL. The developed sensing method was successfully applied to the quantification of MTX in rabbit plasma samples and parenteral formulations, achieving satisfactory recoveries %. Magnetic molecularly imprinted solid-phase microextraction was used for selective extraction of MTX from plasma samples. The pharmacokinetic parameters were successfully determined in real rabbit plasma samples after intravenous administration of MTX. The as-designed probe does not only improve the sensitivity, but also enhances the precision and accuracy of the proposed method. Overall, this study presents a promising approach for the detection of MTX in genuine samples with acceptable degree of selectivity and sensitivity.

Pharmacokinetics of Anti-rheumatic Drugs Methotrexate and Tofacitinib with its Metabolite M9 in Rats by UPLC-MS/MS

BACKGROUND

Tofacitinib is an oral JAK inhibitor for the treatment of rheumatoid arthritis (RA). The clinical efficacy and safety of an administered tofacitinib, either monotherapy or in combination with conventional synthetic disease-modifying anti-rheumatic drugs, mainly methotrexate (MTX), have been evaluated. The high plasma concentration with delayed medicine clearance may affect the liver and/or kidney functions. In this study, an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC- MS/MS) method for the quantitative analysis of methotrexate, tofacitinib, and metabolite M9 in plasma of Sprague Dawley (SD) rats was developed, and its effectiveness was validated as well.

METHODS

Methotrexate, tofacitinib, M9 and fedratinib (internal standard, IS) were separated by gradient elution. The chromatography was performed on an Acquity BEH C18 (2.1 mm × 50 mm, 1.7 μm) column with the mobile phases of acetonitrile and 0.1% formic acid aqueous solution with different proportions at the flow rate of 0.30 mL/min. In the positive ionization mode, the analyzes were detected using a Xevo TQ-S triple quadrupole tandem mass spectrometer, with the following mass transition pairs: m/z 313.12 → 148.97 for tofacitinib, m/z 329.10 → 165.00 for M9 and m/z 455.12 → 308.05 for methotrexate.

RESULTS

The obtained results manifested good calibration linearity over the ranges of tofacitinib at 0.1-100 ng/mL, M9 at 0.05-100 ng/mL, and methotrexate at 0.05-100 ng/mL. The lower limit of quantifications (LLOQs) of methotrexate, tofacitinib and M9 were 0.05 ng/mL, 0.1 ng/mL and 0.05 ng/mL, respectively. Intra-day and inter-day accuracy values were confirmed with a range of -6.3% to 12.7%, while intra-day and inter-- day precision values were ≤14.4%. Additionally, recoveries were greater than 86.5% for each compound without significant matrix effects.

CONCLUSION

The currently established analytical method exhibited great potential for the evaluation of plasma concentrations of methotrexate, tofacitinib and M9 simultaneously, greatly reducing the detection time, which would serve as a supplementary role in formulating dose decisions to achieve personalized treatment, identify drugs that cause adverse reactions and finally, to assess drug-drug interactions on clinical studies.

An isotope dilution-liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS)-based candidate reference measurement procedure (RMP) for the quantification of methotrexate in human serum and plasma

OBJECTIVES

To develop an isotope dilution-liquid chromatography-tandem mass spectrometry-(ID-LC-MS/MS)-based candidate reference measurement procedure (RMP) for quantification of methotrexate in human serum and plasma.

METHODS

Quantitative nuclear magnetic resonance (qNMR) was used to determine absolute methotrexate content in the standard. Separation was achieved on a biphenyl reversed-phase analytical column with mobile phases based on water and acetonitrile, both containing 0.1% formic acid. Sample preparation included protein precipitation in combination with high sample dilution, and method validation according to current guidelines. The following were assessed: selectivity (using analyte-spiked samples, and relevant structural-related compounds and interferences); specificity and matrix effects (via post-column infusion and comparison of human matrix vs. neat samples); precision and accuracy (in a five-day validation analysis). RMP results were compared between two independent laboratories. Measurement uncertainty was evaluated according to current guidelines.

RESULTS

The RMP separated methotrexate from potentially interfering compounds and enabled measurement over a calibration range of 7.200-5,700 ng/mL (0.01584-12.54 μmol/L), with no evidence of matrix effects. All pre-defined acceptance criteria were met; intermediate precision was ≤4.3% and repeatability 1.5-2.1% for all analyte concentrations. Bias was -3.0 to 2.1% for samples within the measuring range and 0.8-4.5% for diluted samples, independent of the sample matrix. RMP results equivalence was demonstrated between two independent laboratories (Pearson correlation coefficient 0.997). Expanded measurement uncertainty of target value-assigned samples was ≤3.4%.

CONCLUSIONS

This ID-LC-MS/MS-based approach provides a candidate RMP for methotrexate quantification. Traceability of methotrexate standard and the LC-MS/MS platform were assured by qNMR assessment and extensive method validation.

Terbium-triggered aggregation-induced emission of bimetallic nanoclusters for anticancer drugs sensing via the inner filter effect

The development of accurate and sensitive detection methods of anticancer drugs is of significant importance because they play vital roles in biological systems. In recent years, bimetallic nanoclusters (BMNCs) incorporating the advantages of two metals have gained more and more attention, and can be widely applied in sensing applications. In this work, for the first time, we designed a sensing platform based on terbium ion (Tb³⁺) triggered aggregation-induced emission (AIE) of BMNCs. Tb³⁺ hybrid glutathione (GS) protected Ag/Cu nanoclusters (Tb³⁺@GS-AgCuNCs) were facilely fabricated according to the complexation reaction between Tb³⁺ and the carboxyl group of GS. Due to the inner filter effect (IFE), the fluorescence of Tb³⁺@GS-AgCuNCs decreased significantly in the presence of anticancer drugs with 6-thioguanine and methotrexate as representatives. In addition, the sensing platform was applied to monitor 6-thioguanine and methotrexate in real serum samples, indicating that it has great potential in anticancer drugs related applications.

Antioxidant nutrients can increase high-dose Methotrexate efficacy in 4T1 breast tumor Model: An experimental study on Vitamin E Succinate and Methyl-selenic acid

BACKGROUND

We aimed to evaluate the anti-cancer and immune system enhancing properties of Vitamin E succinate (VES) and methylselenic acid (MSA) administration on 4T1 breast tumor model under high-dose methotrexate (HDMTX) therapy and folinic acid (FA) rescue.

METHODS

Thirty six 4T1 mammary carcinoma bearing mice were randomly divided into six groups: control (untreated; n = 6), treatment-1 (T1 group; HDMTX; n = 6), T2 (T1 + FA; n = 6), T3 (T2 + MSA; n = 6), T4 (T2 + VES; n = 6) and T5 (T3 + VES; n = 6). On day 21 of the study, all surviving mice were sacrificed and primary tumors and peripheral tissues were examined for histological and gene expression assays. The expression of GATA Binding Protein-3 (GATA3), forkhead box-P3 (FOXP3), T-bet and Retinoic acid receptor-related orphan receptor γt (RORγt) were evaluated in tumors and spleens. Also, vascular endothelial growth factor-A (VEGF-A) and UL16-Binding Protein 1 (ULBP-1) expression were evaluated in tumors.

RESULTS

The control, T4 and T5 groups were able to complete the entire 21-day study period. Also, significant tumor shrinkage was occurred in T4 group (P < 0.05). Suppression of splenic FOXP3 and GATA3 were observed in the mice receiving T4 and T5 regimens. Also, induction of tumoral FOXP3 and GATA3 were achieved in the T4 and T5 groups, respectively (P < 0.05). No metastasis occurred in T4 receiving group; while, lung and liver metastasis were observed in T5 group.

CONCLUSION

In this study, high and fixed dose of MTX was used. Further studies are needed to optimize MTX dose along with FA, VES and MSA.

Dried plasma spot-based liquid chromatography-tandem mass spectrometry for the quantification of methotrexate in human plasma and its application in therapeutic drug monitoring

Methotrexate, a folic acid antitumor drug, is widely used to treat childhood acute lymphoblastic leukemia. Therapeutic drug monitoring is crucial for adjusting the dosage of methotrexate according to its plasma concentration and reducing adverse effects. Micro-sampling strategies, like dried plasma spot, is an attractive but underutilized method that has the desired features of easy collection, storage, and transport, and overcomes known hematocrit issues in dried blood spot analysis. This study describes a dried plasma spot-based liquid chromatography-tandem mass spectrometry method for quantification of methotrexate. The assay showed good linearity over 30-2000 ng/mL (R² ≥ 0.995) as well as excellent precision (0.6-9.3%) and accuracy (89.2-108.3%). Methotrexate was extracted from dried plasma spot and wet plasma samples with recoveries greater than 92.1%, and no significant matrix effect was observed. A comparison of dried plasma spot and wet plasma concentrations was assessed in 27 patients treated with methotrexate and Passing-Bablok regression coefficients showed that no significant difference between the two methods. Bland-Altman plots showed similar agreement between the methods, indicating that the proposed dried plasma spot sampling method is an effective way to monitor the concentration of methotrexate in human plasma. This article is protected by copyright. All rights reserved.

Design of a methotrexate-controlled chemical dimerization system and its use in bio-electronic devices

Natural evolution produced polypeptides that selectively recognize chemical entities and their polymers, ranging from ions to proteins and nucleic acids. Such selective interactions serve as entry points to biological signaling and metabolic pathways. The ability to engineer artificial versions of such entry points is a key goal of synthetic biology, bioengineering and bioelectronics. We set out to map the optimal strategy for developing artificial small molecule:protein complexes that function as chemically induced dimerization (CID) systems. Using several starting points, we evolved CID systems controlled by a therapeutic drug methotrexate. Biophysical and structural analysis of methotrexate-controlled CID system reveals the critical role played by drug-induced conformational change in ligand-controlled protein complex assembly. We demonstrate utility of the developed CID by constructing electrochemical biosensors of methotrexate that enable quantification of methotrexate in human serum. Furthermore, using the methotrexate and functionally related biosensor of rapamycin we developed a multiplexed bioelectronic system that can perform repeated measurements of multiple analytes. The presented results open the door for construction of genetically encoded signaling systems for use in bioelectronics and diagnostics, as well as metabolic and signaling network engineering.

Quantification of the janus kinase 1 inhibitor upadacitinib in human plasma by LC-MS/MS

Upadacitinib is a selective janus-kinase-1 inhibitor effective in the treatment of autoimmune related diseases like rheumatoid arthritis or psoriatic arthritis. Here, we described a LC-MS/MS method for the quantification of upadacitinib in human plasma applicable for therapeutic drug monitoring. Pexidartinib was used as internal standard. Plasma samples were prepared by acidic protein precipitation and the analytes were separated on a C-18 reversed phase column. Detection took place by tandem mass spectroscopy after ionization in the positive mode and collision induced fragmentation at m/z 381 → 256, 213 for upadacitinib and m/z 418 → 258, 165 for pexidartinib. The calibration function was linear in the range of 0.15 - 150 ng/mL. Precisions and accuracies were better than 10% in intra- as well as inter-day evaluations. The method was applied in therapeutic drug monitoring of patients undergoing treatment for rheumatoid arthritis with the standard dose of 15 mg upadacitinib extended release formulation once daily. At steady state, we found trough levels of 4.13 (3.51 - 11.0) ng/mL, which is comparable to values found in healthy volunteers receiving the same dose (2.8 ± 1.2 ng/mL).

Methotrexate Polyglutamates Analysis by Chromatography Methods in Biological Matrices: A Review

Methotrexate (MTX) is used as an immunosuppressant and antineoplastic drug in clinical practice. MTX is a parent drug and converts to MTX polyglutamates (MTXPGs) to exhibit its biological activity. Clinical studies found that MTXPG levels were associated with MTX response and toxicities, especially at low doses. Due to huge variance of MTX response and toxicities between individuals, therapeutic drug monitoring is necessary for its use in individualized therapy. Various chromatography methods coupled with ultraviolet-visible detector, fluorescence detector and mass spectrometry have been reported for MTXPG analysis in various biological matrices. The aim of this paper is to review the chromatographic based methods for the measurement of total and/or individual MTXPGs. We searched Embase, Science Direct and PubMed databases using "methotrexate polyglutamate" and "chromatography" as search terms, and found 745 articles. Of those, 14 articles were extracted for this study. The key steps for method development (sample pretreatment, parameter optimization of liquid chromatography and mass spectrometry, selection of internal standard) and validation (lower limit of quantitation, accuracy, precision, recovery, matrix effect and stability) were analyzed and summarized, which might be helpful for researchers to develop their own methods.

Studies on the intracellular accumulation process of methotrexate and its correlation with the key protein using an LC-MS/MS method: a novel way to realize prospective individualized medication

High-dose methotrexate (HDMTX) combined with leucovorin (LV) is the first-line drug therapy for many kinds of malignant tumors. However, the specific treatment plans, such as dosage and duration of administration, are usually formulated according to the clinician's experience and therapeutic drug monitoring (TDM) of methotrexate in patients' plasma, which are responsible for strong individual differences of drug usage. A large number of studies have shown that methotrexate targets the inside of the cell. The key cytotoxic component is the methotrexate polyglutamates (MTXPGs) in the cell. The concentration of methotrexate in plasma does not reflect the efficacy and side effects well. Based on mass spectrometry technology, we developed and validated an accurate, sensitive, and stable method to quantify the intracellular MTX (MTXPG₁) and its metabolites MTXPG_2-7 simultaneously. The lower limit of quantification was 0.100 ng/ml, and the run time was only 3 min. Moreover, our team has already developed two LC-MS/MS-based methods to respectively quantify methotrexate in plasma samples and two key proteins (γ-glutamyl hydrolase [GGH] and folylpolyglutamate synthetase [FPGS]) in peripheral blood mononuclear cells (PBMC). Through these highly sensitive and accurate approaches, we have gained a deep understanding of the whole pharmacokinetic process of MTX and explored the key factors affecting the accumulation process of intracellular active components (MTXPGs). Based on this research, it is possible to find a more effective way to provide an accurate reference for clinical drug use than traditional therapeutic drug monitoring (TDM).

Calibrating from Within: Multipoint Internal Calibration of a Quantitative Mass Spectrometric Assay of Serum Methotrexate

BACKGROUND

Clinical LC-MS/MS assays traditionally require that samples be run in batches with calibration curves in each batch. This approach is inefficient and presents a barrier to random access analysis. We developed an alternative approach called multipoint internal calibration (MPIC) that eliminated the need for batch-mode analysis.

METHODS

The new approach used 4 variants of 13C-labeled methotrexate (0.026-10.3 µM) as an internal calibration curve within each sample. One site carried out a comprehensive validation, which included an evaluation of interferences and matrix effects, lower limit of quantification (LLOQ), and 20-day precision. Three sites evaluated assay precision and linearity. MPIC was also compared with traditional LC-MS/MS and an immunoassay.

RESULTS

Recovery of spiked analyte was 93%-102%. The LLOQ was validated to be 0.017 µM. Total variability, determined in a 20-day experiment, was 11.5%CV. In a 5-day variability study performed at each site, total imprecision was 3.4 to 16.8%CV. Linearity was validated throughout the calibrator range (r2 > 0.995, slopes = 0.996-1.01). In comparing 40 samples run in each laboratory, the median interlaboratory imprecision was 6.55%CV. MPIC quantification was comparable to both traditional LC-MS/MS and immunoassay (r2 = 0.96-0.98, slopes = 1.04-1.06). Bland-Altman analysis of all comparisons showed biases rarely exceeding 20% when MTX concentrations were >0.4 µM.

CONCLUSION

The MPIC method for serum methotrexate quantification was validated in a multisite proof-of-concept study and represents a big step toward random-access LC-MS/MS analysis, which could change the paradigm of mass spectrometry in the clinical laboratory.

Barriers and opportunities for the clinical implementation of therapeutic drug monitoring in oncology

There are few fields of medicine in which the individualisation of medicines is more important than in the area of oncology. Under-dosing can have significant ramifications due to the potential for therapeutic failure and cancer progression; by contrast, over-dosing may lead to severe treatment-limiting side effects, such as agranulocytosis and neutropenia. Both circumstances lead to poor patient prognosis and contribute to the high mortality rates still seen in oncology. The concept of dose individualisation tailors dosing for each individual patient to ensure optimal drug exposure and best clinical outcomes. While the value of this strategy is well recognised, it has seen little translation to clinical application. However, it is important to recognise that the clinical setting of oncology is unlike that for which therapeutic drug monitoring (TDM) is currently the cornerstone of therapy (e.g. antimicrobials). Whilst there is much to learn from these established TDM settings, the challenges presented in the treatment of cancer must be considered to ensure the implementation of TDM in clinical practice. Recent advancements in a range of scientific disciplines have the capacity to address the current system limitations and significantly enhance the use of anticancer medicines to improve patient health. This review examines opportunities presented by these innovative scientific methodologies, specifically sampling strategies, bioanalytics and dosing decision support, to enable optimal practice and facilitate the clinical implementation of TDM in oncology.

Mass spectrometry-based metabolomics in health and medical science: a systematic review

Metabolomics is the study of the investigation of small molecules derived from cellular and organism metabolism, which reflects the outcomes of the complex network of biochemical reactions in living systems. As the most recent member of the omics family, there has been notable progress in metabolomics in the last decade, mainly driven by the improvement in mass spectrometry (MS). MS-based metabolomic strategies in modern health and medical science studies provide innovative tools for novel diagnostic and prognostic approaches, as well as an augmented role in drug development, nutrition science, toxicology, and forensic science. In the present review, we not only introduce the application of MS-based metabolomics in the above fields, but also discuss the MS analysis technologies commonly used in metabolomics and the application of metabolomics in precision medicine, and further explore the challenges and perspectives of metabolomics in the field of health and medical science, which are expected to make a little contribution to the better development of metabolomics.

Mass Spectrometry for Research and Application in Therapeutic Drug Monitoring or Clinical and Forensic Toxicology

This article reviews current applications of various hyphenated low- and high-resolution mass spectrometry techniques in the field of therapeutic drug monitoring and clinical/forensic toxicology in both research and practice. They cover gas chromatography, liquid chromatography, matrix-assisted laser desorption ionization, or paper spray ionization coupled to quadrupole, ion trap, time-of-flight, or Orbitrap mass analyzers.