Specific determination of intact cisplatin and monohydrated cisplatin in human plasma and culture medium ultrafiltrates using HPLC on-line with inductively coupled plasma mass spectrometry

Analysis of free cisplatin in microdialysates and plasma ultrafiltrate by liquid chromatography-tandem mass spectrometry

Cisplatin is a potent cytotoxic agent used in the treatment of various malignancies and exerts its antitumor effect through malignant cell DNA damage and apoptosis induction. Evaluation of systemic delivery of cisplatin is important in optimization of cisplatin treatment. However, accurate quantification of systemic cisplatin is challenging due to its various forms in circulation. This study aimed to develop a sensitive (LOQ < 0.1 µg/mL) and precise Ultra Performance Liquid Chromatography (UPLC) - Tandem Mass Spectrometry (MS/MS) method for quantifying free cisplatin in microdialysates and plasma. Furthermore the aim was to compare free cisplatin concentrations measured in standard plasma samples with those obtained from intravenous microdialysis catheters in a porcine model. The method developed utilizes dichloro(ethylenediamine)platinum(II) as an internal standard that co-elutes with cisplatin, ensuring precise correction for ion suppression/enhancement effects. The method was validated, demonstrating linearity up to 100 µg/mL and good intermediate precision (CV% < 6 %) in the range of 1.0-100 µg/mL, with an LOQ of 0.03 µg/mL. The pharmacokinetic parameters (AUC0-last, Cmax, T1/2, and Tmax) showed no significant differences between the two sampling methods. This validated LC-MS/MS method provides a reliable tool for quantifying systemic free cisplatin concentrations, facilitating future systemic and local pharmacokinetic evaluations for optimization of cisplatin-based cancer treatments.

Using HPLC for the determination of platinum drugs in biological matrixes after derivatization with diethyldithiocarbamate

Challenges and pitfalls in the application of diethyldithiocarbamate derivatization for LC analysis of cisplatin and oxaliplatin, as well as the suitability of this method for different biological matrices with implications for use in routine practice have been identified. The LC of platinum drugs presents a significant challenge. They are polar compounds with poor retention on reverse phase packings. Cisplatin also exhibits poor absorption in UV and ionization in mass spectrometry. Therefore, we developed and optimized a derivatization approach for the LC analysis of total platinum in plasma, plasma ultrafiltrate, peritoneal fluid, and urine. Derivatization in urine proved to be difficult due to the complexity of the matrix, and extended testing was required. Our results highlight the important issues affecting the efficiency, reliability, and suitability of platinum drug derivatization. Although precolumn derivatization is less selective than its postcolumn counterpart, the application of precolumn derivatization is a simple, rapid, and universal approach for the determination of platinum drugs by HPLC. One of its major advantages is that it allows a more affordable analysis using UV detection without the need for additional high-end instrumentation such as a MS detector.

Facets of ICP-MS and their potential in the medical sciences-Part 1: fundamentals, stand-alone and hyphenated techniques

Since its inception in the early 80s, inductively coupled plasma-mass spectrometry has developed to the method of choice for the analysis of elements in complex biological systems. High sensitivity paired with isotopic selectivity and a vast dynamic range endorsed ICP-MS for the inquiry of metals in the context of biomedical questions. In a stand-alone configuration, it has optimal qualities for the biomonitoring of major, trace and toxicologically relevant elements and may further be employed for the characterisation of disrupted metabolic pathways in the context of diverse pathologies. The on-line coupling to laser ablation (LA) and chromatography expanded the scope and application range of ICP-MS and set benchmarks for accurate and quantitative speciation analysis and element bioimaging. Furthermore, isotopic analysis provided new avenues to reveal an altered metabolism, for the application of tracers and for calibration approaches. In the last two decades, the scope of ICP-MS was further expanded and inspired by the introduction of new instrumentation and methodologies including novel and improved hardware as well as immunochemical methods. These additions caused a paradigm shift for the biomedical application of ICP-MS and its impact in the medical sciences and enabled the analysis of individual cells, their microenvironment, nanomaterials considered for medical applications, analysis of biomolecules and the design of novel bioassays. These new facets are gradually recognised in the medical communities and several clinical trials are underway. Altogether, ICP-MS emerged as an extremely versatile technique with a vast potential to provide novel insights and complementary perspectives and to push the limits in the medical disciplines. This review will introduce the different facets of ICP-MS and will be divided into two parts. The first part will cover instrumental basics, technological advances, and fundamental considerations as well as traditional and current applications of ICP-MS and its hyphenated techniques in the context of biomonitoring, bioimaging and elemental speciation. The second part will build on this fundament and describe more recent directions with an emphasis on nanomedicine, immunochemistry, mass cytometry and novel bioassays.

Analytical methods for the quantification of cisplatin, carboplatin, and oxaliplatin in various matrices over the last two decades

Background:

Platinum derivatives including cisplatin and its later generations carboplatin, and oxaliplatin remain the most largely used drugs in the therapy of malignant diseases. They exert notable anticancer activity towards numerous types of solid tumors such as gastric, colorectal, bladder, ovary, and several others. The chemotherapeutic activity of these compounds, however, is associated with many unwanted side effects and drug resistance problems limiting their application and effectiveness. Proper dosage is still an inherent problem, as these drugs are usually prescribed in small doses.

Objective:

Several analytical methods have been reported for the accurate quantification of cisplatin, carboplatin, and oxaliplatin and their metabolites either alone or in combination with other chemotherapeutic drugs, in different matrices such as pharmaceutical formulations, biological fluids, cancer cells, and environmental samples. The main goal of this review is to systematically study the analytical methods already used for the analysis of cisplatin, carboplatin, and oxaliplatin in various matrices during the last two decades.

Results and Conclusion:

In the literature, reviews showed that numerous analytical methods such as electroanalytical, UV-visible spectrophotometry, chromatographic, fluorescence, atomic absorption spectrophotometry, and other spectroscopic methods combined with mass spectrometry were used for the determination of these compounds in various matrices.

Serum-binding properties of isosteric ruthenium and osmium anticancer agents elucidated by SEC-ICP-MS

ABSTRACT

Size-exclusion chromatography-inductively coupled plasma-mass spectrometry (SEC-ICP-MS) was used to study the serum-binding preferences of two metallodrugs with anticancer activities in vivo, namely the organoruthenium compound plecstatin-1 and its isosteric osmium analog. The complexes were administered intraperitoneally into mice bearing a CT-26 tumor. Comparing the total metal content of mouse whole blood and serum underlined that the metallodrugs are mainly located in serum and not in the cellular fraction of the blood samples. In mouse serum, both compounds were not only found to bind extensively to the serum albumin/transferrin fraction but also to immunoglobulins. Free drug was not observed in any of the samples indicating rapid protein binding of the metallodrugs. These findings were validated by spiking human serum with the respective compounds ex vivo. An NCI-60 screen is reported for the osmium analog, which revealed a relative selectivity for cancer cell lines of the ovary and the central nervous system with respect to plecstatin-1. Finally, a COMPARE 170 analysis revealed disruption of DNA synthesis as a possible treatment effect of the osmium-based drug candidate.

GRAPHICAL ABSTRACT

Platinum(II)-Oligonucleotide Coordination Based Aptasensor for Simple and Selective Detection of Platinum Compounds

Wide use of platinum-based chemotherapeutic regimens for the treatment for carcinoma calls for a simple and selective detection of platinum compound in biological samples. On the basis of the platinum(II)-base pair coordination, a novel type of aptameric platform for platinum detection has been introduced. This chemiluminescence (CL) aptasensor consists of a designed streptavidin (SA) aptamer sequence in which several base pairs were replaced by G-G mismatches. Only in the presence of platinum, coordination occurs between the platinum and G-G base pairs as opposed to the hydrogen-bonded G-C base pairs, which leads to SA aptamer sequence activation, resulting in their binding to SA coated magnetic beads. These Pt-DNA coordination events were monitored by a simple and direct luminol-peroxide CL reaction through horseradish peroxidase (HRP) catalysis with a strong chemiluminescence emission. The validated ranges of quantification were 0.12-240 μM with a limit of detection of 60 nM and selectivity over other metal ions. This assay was also successfully used in urine sample determination. It will be a promising candidate for the detection of platinum in biomedical and environmental samples.

Decreased P-glycoprotein is associated with the inhibitory effects of static magnetic fields and cisplatin on K562 cells

In this study, we explored the mechanism of the killing effects of a moderate-intensity static magnetic field (SMF) and cisplatin (DDP) on K562 cells. We analyzed the metabolic activity of cells, the extracellular DDP content, and P-glycoprotein (P-gp) expression after K562 cells were exposed continuously to a uniform 8.8 mT SMF for 8 h, with or without DDP. We found that SMF combined with DDP (10 µg/ml) significantly inhibited the metabolic activity of K562 cells (P < 0.05), while neither DDP nor SMF alone affected the metabolic activity of these cells. In the SMF + DDP group, extracellular DDP content was significantly reduced (P < 0.05). DDP also induced the expression of P-gp (P < 0.05). By contrast, in the SMF + DDP group, P-gp expression decreased compared with the DDP group (P < 0.05). Taken together, our results showed that 8.8 mT SMF enhanced the killing potency of DDP on K562 cells by decreasing the expression of P-gp.

Exosome release and low pH belong to a framework of resistance of human melanoma cells to cisplatin

Intrinsic resistance to cytotoxic drugs has been a main issue in cancer therapy for decades. Microenvironmental acidity is a simple while highly efficient mechanism of chemoresistance, exploited through impairment of drug delivery. The latter is achieved by extracellular protonation and/or sequestration into acidic vesicles. This study investigates the importance of extracellular acidosis and nanovesicle (exosome) release in the resistance of human tumour cell to cisplatin (CisPt); in parallel to proton pump inhibitors (PPI) ability of interfering with these tumour cell features. The results showed that CisPt uptake by human tumour cells was markedly impaired by low pH conditions. Moreover, exosomes purified from supernatants of these cell cultures contained various amounts of CisPt, which correlated to the pH conditions of the culture medium. HPLC-Q-ICP-MS analysis revealed that exosome purified from tumour cell culture supernatants contained CisPt in its native form. PPI pre-treatment increased cellular uptake of CisPt, as compared to untreated cells, in an acidic-depend manner. Furthermore, it induced a clear inhibition of exosome release by tumour cells. Human tumours obtained from xenografts pretreated with PPI contained more CisPt as compared to tumours from xenografts treated with CisPt alone. Further analysis showed that in vivo PPI treatment induced a clear reduction in the plasmatic levels of tumour-derived exosomes which also contained lower level of CisPt. Altogether, these findings point to the identification of a double mechanism that human malignant melanoma use in resisting to a dreadful cellular poison such as cisplatin. This framework of resistance includes both low pH-dependent extracellular sequestration and an exosome-mediated elimination. Both mechanisms are markedly impaired by proton pump inhibition, leading to an increased CisPt-dependent cytotoxicity.

Anticancer metallodrug research analytically painting the "omics" picture--current developments and future trends

Anticancer metallodrug development has for a long time been characterised by the similarity of new drug candidates to cisplatin and DNA as the primary target. Recent advances in bioanalytical techniques with high sensitivity and selectivity have revealed that metal-based drugs can undergo a wide range of biomolecular interactions beyond DNA and have generated interest in proteins as possible targets for metallodrugs. In fact, implementation of metallomics approaches that are able to reveal the fate of the compounds in biological systems can help to move drug development towards more targeted and rational design of novel metallodrugs. Additionally, proteomic screening and gene expression analysis can provide insight into physiological response to drug treatment and identify the reasons for drug resistance. Herein, we review selected applications which led to a better understanding of the mode of action of clinically established metal-based anticancer agents and novel metallodrug candidates.

Microflow injection chemiluminescence system with spiral microchannel for the determination of cisplatin in human serum

A new microflow injection chemiluminescence (μFI-CL) system was described for the determination of cisplatin in human serum. By using the microchip with double spiral channel configuration, the sensitivity was greatly enhanced due to more efficient mixing of the analyte and reagent solutions. Experimental results revealed that common ions in human serum, such as Mn(2+), Co(2+), Fe(3+), Cu(2+), Zn(2+), Ni(2+), Na(+), K(+), Ca(2+), Cl(-), NO(3)(-), Ac(-), CO(3)(2-), PO(4)(3-), SO(4)(2-) did not cause interference with the detection of Pt(II) by using 1,10-phenanthroline as the masking agent. Under the optimized conditions, a linear calibration curve (R(2)=0.998) over the range 2.0 × 10(-8) to 2.0 × 10(-6) mol L(-1) was obtained with the detection limit of 1.24 × 10(-9) mol L(-1). The relative standard deviation was found to be 3.46% (n=12) for 2.0 × 10(-7) mol L(-1). The sample consumption was only 2 μL with the sample throughput of 72 h(-1). It had been used for trace platinum determination in cisplatin injection and human serum samples after the dosage of cisplatin. The recovery varied from 97.6 to 103.9%. The results proved that the proposed μFI-CL system had the advantages of high sensitivity and precision, low sample and reagents consumption, and high analytical throughput.

Comparative protein binding, stability and degradation of satraplatin, JM118 and cisplatin in human plasma in vitro

1. Satraplatin is an investigational orally administered platinum-based antitumour drug. The present study compared the plasma protein binding, stability and degradation of satraplatin with that of its active metabolite JM118 and cisplatin. 2. The platinum complexes were incubated in human plasma for up to 2 h at 37 degrees C and quantified in plasma fractions by inductively coupled plasma-mass spectrometry on- or off-line to high-performance liquid chromatography. 3. All three platinum drugs became irreversibly bound to plasma proteins and showed negligible reversible protein binding. They were also unstable in plasma and generated one or more platinum-containing degradation products during their incubation. However, the three platinum complexes differed in the kinetics of their instability and protein binding, as well as in the number of degradation products formed during their incubation. 4. In conclusion, the plasma protein binding, instability and degradation of satraplatin and its active metabolite JM118 are qualitatively similar to that of cisplatin and other clinically approved platinum-based drugs. Quantitative differences in their irreversible protein binding and degradation were related to their respective physiochemical properties and bioactivation mechanisms.

The application of inductively coupled plasma mass spectrometry in clinical pharmacological oncology research

Metal-based anticancer agents are frequently used in the treatment of a wide variety of cancer types. The monitoring of these anticancer agents in biological samples is important to understand their pharmacokinetics, pharmacodynamics, and metabolism. In addition, determination of metals originating from anticancer agents is relevant to assess occupational exposure of health care personnel working with these drugs. The high sensitivity of inductively coupled plasma mass spectrometry (ICP-MS) has resulted in an increased popularity of this technique for the analysis of metal-based anticancer drugs. In addition to the quantitative analysis of the metal of interest in a sample, ICP-MS can be used as an ultrasensitive metal selective detector in combination with speciation techniques such as liquid chromatography. In the current review we provide a systematic survey of publications describing the analysis of platinum- and ruthenium-containing anticancer agents using ICP-MS, focused on the determination of total metal concentrations and on the speciation of metal compounds in biological fluids, DNA- and protein-adducts, and environmental samples. We conclude that ICP-MS is a powerful tool for the quantitative analysis of metal-based anticancer agents from multiple sample sources.

Analytical methodologies for the determination of cisplatin

cis-Diamminedichloroplatinum(II) (cisplatin) is a important chemotherapeutic drug for cancer treatment since 1978. Unfortunately, because of the severe side-effects like nephrotoxicity, ototoxicity, etc., they are administered in small doses at low concentration establishing the maximum limit dosage to 100 mg/m(2) (21 days). A variety of analytical methods have been proposed for the determination of cisplatin in biological fluids and tissues that permit the accurate determination at or below the part per billion level in the native sample. The purpose of the current review is to provide a systematic survey of the latest analytical techniques for the determination of cisplatin in biological samples.