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Cancer remains one of the leading causes for death worldwide. Palliative chemotherapy is vital for certain cancer patients, highlighting the critical need for treatment monitoring tools to prevent drug accumulation and mitigate the risk of high toxicity. Therefore, our aim was to evaluate the potential of screen-printed electrodes for the development of sensitive and accurate biosensors for the detection/quantification of antineoplastic drugs. To this purpose, we developed a cisplatin sensor. By functionalizing the gold electrode with human serum albumin and by collecting the electrochemical signal obtained in a H 2 O 2 solution, through voltammetry measurements, we were able to correlate the current measured at 430 mV with the concentration of cisplatin present in human serum samples, with a correlation coefficient of R 2 = 0.99. Also, a bleomycin biosensor was developed and proven functional, but further optimization steps were employed in order to improve the accuracy. The developed biosensors have a detection range of 0.0006-43.2 mg/mL for cisplatin and 0.23-7.56 μg/mL for bleomycin in the serum samples. Our preliminary results show that these biosensors can facilitate the real-time monitoring of cisplatin and bleomycin serum levels, allowing healthcare professionals to tailor treatment strategies based on individual patient responses.

Quantification of the unbound portion of platinum (Pt) in human plasma is important for assessing the pharmacokinetics of the chemotherapeutic drug cisplatin. In this study, we sought to compare the recovery of unbound Pt using Nanosep® filters to 1) traditional filters (Centrifree®, Centrisart®, Amicon®) or trichloroacetic acid (TCA) protein precipitation, and 2) unbound, bound, and total Pt concentrations in clinical specimens. For the tested filters, the impact of 1) molecular weight cut-offs, 2) centrifugation force, and 3) total Pt concentration on Pt binding in human plasma was evaluated. Pt was quantified using inductively coupled-plasma mass spectrometry. In human plasma spiked with 0.9 μg/mL Pt, the percent of unbound Pt increased at higher centrifugation speeds. By comparison, the percent of unbound Pt was highest (42.1%) following TCA protein precipitation. When total Pt was ≤0.9 μg/mL, unbound Pt (∼20-30%) was consistent across filters. Conversely, when plasma was spiked with Pt exceeding 0.9 μg/mL, the percent of unbound Pt increased from 36.5 to 48% using ultrafiltration, compared to 63.4% to 79% with TCA precipitation. In patients receiving cisplatin-containing chemotherapy, the fraction of unbound Pt at concentrations exceeding 0.9 μg/mL ranged between 35 and 90%. Moreover, the unbound fraction of Pt in plasma correlated with the concentration of unbound (R 2  = 0.738) and total Pt (R 2  = 0.335). In summary, this study demonstrates that 1) the percent of unbound Pt is influenced by total and unbound Pt levels in vitro and in clinical specimens, and 2) ultrafiltration with Nanosep® filters is a feasible method for quantifying unbound Pt concentrations in human plasma., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. The following are the supplementary data related to this article. Supplementary data to this article can be found online at https://doi.org/10.1016/j.vascn.2024.107535., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

This study describes a kinetic spectrophotometric method for accurate, sensitive and rapid determination of cisplatin in biofluids. The developed method is based on the inhibitory effect of cisplatin on the oxidization of Janus Green by bromate in acidic media. The change in absorbance as the criteria of the oxidation reaction was followed spectrophotometrically. To obtain the highest rate of sensitivity, efficient reaction parameters were optimized. Under optimum experimental conditions, a calibration graph was obtained linearly over the range 10.0 - 5750.0 μg L -1 and the limit of detection (3s b /m) was 4.2 μg L -1 of cisplatin. The interfering effect of diverse species was investigated. The developed method was used for the quantification of cisplatin in bio fluids of patients treated with cisplatin, spiked bio fluids and pharmaceutical samples and yielded satisfactory results.

Cisplatin is a platinum-based chemotherapeutic agent widely used in the treatment of various solid tumors. However, a major challenge in the use of cisplatin and in the development of cisplatin derivatives, namely Pt(iv) prodrugs, is their premature reduction in the bloodstream before reaching cancer cells. To circumvent this problem, we designed liposomal nanoparticles coupled with a cholesterol-tethered amphiphilic Pt(iv) prodrug. The addition of cholesterol served to stabilize the formation of the liposome, while selectively incorporating cholesterol as the axial ligand also allowed the Pt(iv) prodrug to readily migrate into the liposomal bilayer. Notably, upon embedding into the nanoparticles, the Pt(iv) prodrug showed marked resistance against premature reduction in human plasma in vitro. Pharmacokinetic analysis in a mouse model also showed that the nanoparticles significantly extend the half-life of the Pt(iv) prodrug to 180 min, which represents a >6-fold increase compared to cisplatin. Importantly, such lipid modification did not compromise the genotoxicity of cisplatin, as the Pt(iv) prodrug induced DNA damage and apoptosis in ovarian cancer cell lines efficiently. Taken together, our strategy provides a novel insight as to how to stabilize a platinum-based compound to increase the circulation time in vivo, which is expected to enhance the efficacy of drug treatment.

Purpose: Serum platinum is measurable for years after completion of cisplatin-based chemotherapy (CBC). We report the largest investigation of serum platinum levels to date of 1,010 testicular cancer survivors (TCS) assessed 1-35 years after CBC and evaluate genetic contributions to these levels., Experimental Design: Eligible TCS given 300 or 400 (±15) mg/m 2 cisplatin underwent extensive audiometric testing, clinical examination, completed questionnaires, and had crude serum platinum levels measured. Associations between serum platinum and various risk factors and toxicities were assessed after fitting a biexponential model adjusted for follow-up time and cumulative cisplatin dose. A genome-wide association study (GWAS) was performed using the serum platinum residuals of the dose and time-adjusted model., Results: Serum platinum levels exceeded the reference range for approximately 31 years, with a strong inverse relationship with creatinine clearance at follow-up (age-adjusted P = 2.13 × 10 -3 ). We observed a significant, positive association between residual platinum values and luteinizing hormone (age-adjusted P = 6.58 × 10 -3 ). Patients with high residual platinum levels experienced greater Raynaud phenomenon than those with medium or low levels (age-adjusted OR high/low = 1.46; P = 0.04), as well as a higher likelihood of developing tinnitus (age-adjusted OR high/low = 1.68, P = 0.07). GWAS identified one single-nucleotide polymorphism (SNP) meeting genome-wide significance, rs1377817 ( P = 4.6 × 10 -8 , a SNP intronic to MYH14 )., Conclusions: This study indicates that residual platinum values are correlated with several cisplatin-related toxicities. One genetic variant is associated with these levels., (©2019 American Association for Cancer Research.)

Objective: Evidences from animal models seem to suggest that minimally invasive surgery may enhance cisplatin diffusion when the drug is administered in the context of post-operative hyperthermic intraperitoneal chemotherapy (HIPEC). The present study evaluates the cisplatin pharmacokinetic profile in a prospective series of women with platinum sensitive recurrent epithelial ovarian cancer treated with open secondary cytoreductive surgery (O-SCS) or minimally-invasive secondary cytoreductive surgery (MI-SCS)., Methods: Cisplatin levels were assessed at 0, 20, 40, 60, and 120 minutes in: 1) blood samples, 2) peritoneal perfusate, and 3) peritoneal biopsies at the end of HIPEC. Median C max has been used to identify women with high and low drug levels. Progression-free survival (PFS) was calculated as the time elapsed between SCS+HIPEC and secondary recurrence or last follow-up visit., Results: Nine (45.0%) women received MI-SCS, and 11 (55.0%) O-SCS. At 60 minutes, median cisplatin C max in peritoneal tissue was higher in patients treated with MI-SCS compared to O-SCS (C max =8.262 μg/mL vs. C max =4.057 μg/mL). Furthermore, median cisplatin plasma C max was higher in patients treated with MI-SCS compared to O-SCS (C max =0.511 vs. C max =0.254 μg/mL; p-value=0.012) at 120 minutes. With a median follow-up time of 24 months, women with higher cisplatin peritoneal C max showed a longer PFS compared to women with low cisplatin peritoneal levels (2-years PFS=70% vs. 35%; p-value=0.054)., Conclusions: We demonstrate for the first time that minimally invasive route enhances cisplatin peritoneal tissue uptake during HIPEC, further evaluations are needed to confirm the correlation between peritoneal cisplatin levels after HIPEC and survival., Trial Registration: ClinicalTrials.gov Identifier: NCT01539785., Competing Interests: No potential conflict of interest relevant to this article was reported., (Copyright © 2019. Asian Society of Gynecologic Oncology, Korean Society of Gynecologic Oncology.)

A novel chemiluminescence resonance energy transfer (CRET) system was developed and combined with a structure-switching aptamer for the highly sensitive detection of platinum. Platinum was chosen as a model analyte to demonstrate the generality of the new CRET system. This aptameric platform consisted of a streptavidin labeled aptamer against platinum and a streptavidin-coated magnetic bead for the selective separation of platinum-bound aptamer. The platinum-aptamer probe contained several guanine (G) bases bound to the 3,4,5-trimethoxyphenyl-glyoxal (TMPG) donor group at the 5' end, a fluorescent acceptor (6-carboxy-2',4,7,7'-tetrachlorofluorescein, TET) at the 3' end, and a streptavidin aptamer sequence in which several base pairs were replaced by the G-G mismatch to induce the platinum-oligonucleotide coordination. The chemiluminescence (CL) generated by TMPG/G bases is transferred to the acceptor (TET). In the presence of platinum, the platinum-aptamer probe was folded such that the G bases at the 5' end and TET at the 3' were in close proximity. The complex was separated using streptavidin-coated magnetic beads by the addition of TMPG to form the TMPG/G bases complex. The ultraweak CL from the TMPG/G bases was strongly enhanced by TET. This novel CRET-based method can be easily performed with high limit of detection (50 ng·mL -1 ) and selectivity over other metal ions. This technique provides a novel method for simple, fast, and convenient point-of-care diagnostics for monitoring proteins and metal ions. Graphical abstract Schematic presentation of chemiluminescence resonance energy transfer (CRET) detection of platinum(II) by Pt-base pair coordination to the aptamer. TMPG: 3,4,5-trimethoxyphenyl-glyoxal, fluorophore TET: 6-carboxy-2',4,7,7'-tetrachlorofluorescein.

The efficacy of platinum(iv) prodrugs depends on their relative resistance to reduction in the extra- and intra-cellular environments. In the study reported here we investigated the influence of the nature of the axial and equatorial ligands on the pathway of reduction of the platinum(iv) complexes by the endogenous reductant, ascorbate, and their relative resistance to reduction in human blood serum and in a whole human blood model. The pathway of reduction of platinum(iv) complexes in the presence of excess ascorbate was found to be dependent on the nature of their axial and equatorial ligands in that complexes with chloride in the equatorial sites lost either both axial ligands or combinations of axial and equatorial ligands while those with oxalate occupying the equatorial sites lost both axial ligands only. Using XANES spectroscopy, complexes with axial hydroxide ligands were found to be highly resistant to reduction in blood serum and were only slowly and incompletely reduced in whole blood. The dihydroxide complex with an oxalate ligand occupying the equatorial leaving group sites was more resistant to reduction, both in serum and in whole blood, than the complex with chloride ligands in these sites. cis, trans-[PtCl2(OAc)2(en)] and trans-[Pt(OAc)2(ox)(en)] were observed to be reduced rapidly and almost completely in whole blood but the latter was substantially resistant to reduction in human blood serum, and consequently demonstrates many of the features of an optimal platinum(iv) anticancer agent.

Purpose: Chemotherapy dosing in neonates represents a major clinical challenge because of a lack of clinical pharmacology information in this patient population. In this study, we investigate the use of cisplatin dose adaptation based on therapeutic drug monitoring in a 2-week-old neonate with localized hepatoblastoma., Methods: Cisplatin concentrations were determined in plasma and ultrafiltrate samples collected on each of six cycles of a monotherapy regimen, beginning with a dose of 1.6 mg/kg at 16 days of age. Pharmacokinetic data were analyzed to generate clearance (CL) and area under the curve (AUC 0-∞ ) for each administration. Toxicity and clinical response were monitored., Results: The first cisplatin dose (1.6 mg/kg) resulted in an AUC 0-∞ of 535 µg/mL · min, was well tolerated and associated with a good response. This AUC was, therefore, considered as an appropriate target for this patient. Increases in cisplatin CL were observed across consecutive treatment cycles, and, therefore, dose was gradually increased to finally reach 2.5 mg/kg on the sixth cycle. Treatment was well tolerated over the six courses and resulted in a good response, with the patient remaining in remission at 15 months. Cisplatin CL was significantly correlated to age (p = 0.013) and weight (p = 0.013)., Conclusions: Our study provides useful data on the pharmacokinetics of cisplatin monotherapy in neonates treated within the first few weeks of life. These data provide a reference point to support clinicians in determining appropriate dosing regimens for neonates and support the implementation of therapeutic drug monitoring in such challenging patients.

Metal-based drugs remain a tiny minority of all drugs that are on the market. The success story of the quintessential metal-based drug cisplatin (CP), which is intravenously administered to 70% of all cancer patients, however, demonstrates the inherent potential of metal-based drugs. A distinct disadvantage of CP is the dose-limiting severe toxic-side effects that it exerts in patients. To better understand the biomolecular basis for its toxicity, we employed a metallomics method to observe all platinum metabolites that are formed in blood plasma. These investigations revealed that a highly toxic CP-derived hydrolysis product - the highly toxic monoaqua hydrolysis complex (MHC) - is formed within 5min. More importantly, the application of this research tool has unraveled the mechanisms by which the chemoprotective agents sodium thiosulfate, d-methionine, N-acetyl-cysteine and l-glutathione modulate the metabolism of CP in plasma, namely by rapidly reacting with the MHC to form platinum‑sulfur complexes. Since CP remained in plasma for a considerable time, the possibility of 'tuning' its metabolism with chemoprotective agents in a desirable way has emerged. These observations are highly relevant because these chemoprotective agents were previously shown to significantly reduce the toxicity of CP in animal models, often without appreciably affecting its anticancer efficiency. Collectively, these results suggest that the toxicity of other metal-based drugs may be overcome if their metabolism in the bloodstream is adequately tuned with a suitable chemoprotective agent. This principle strategy has considerable potential in terms of harnessing the full potential of bringing more metal-based drugs to the market., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Cisplatin is a first-line chemotherapeutic for the treatment of a wide variety of cancers since its discovery in the 1960s. Although various techniques have been reported for the measurement of total platinum in biological matrices, such as inductively coupled plasma-mass spectrometry and derivatization procedures, a specific, sensitive and robust assay for the quantification of intact cisplatin is still lacking. Therefore, we present a rapid, selective, sensitive, and reliable UHPLC-MS/MS based method for the determination of intact cisplatin in human plasma in support of a Phase II clinical trial. The optimal chromatographic behavior of cisplatin was achieved on a Syncronis HILIC column (50 × 2.1mm, 1.7µm, zwitterionic stationary phase). The retention behavior of cisplatin on this zwitterion-based stationary phase was well described by an adsorptive interaction model. A simple sample preparation based on protein precipitation combined with the removal of phospholipids by HybridSPE-precipitation was developed. The method was proven to be free of a relative matrix effect. The assay was validated within a range of 20 - 10,000ng/mL using 100μL of plasma sample. The intra and inter-day precisions were all less than 7.6%, and none of the bias was greater than 13.1%, thus corroborating that the developed method is precise and accurate. As a proof of concept, the assay has been successfully applied to plasma samples obtained from different patients who were enrolled in the Phase II trial and were treated with cisplatin., (Copyright © 2017 Elsevier B.V. All rights reserved.)

The main aim of this study is to assess the safety and antitumor efficacy of a palladium(II) (Pd)-saccharinate complex with terpyridine. To characterize the Pd(II) complex in vitro, its cytotoxicity was evaluated using a water-soluble tetrazolium salt cell viability assay and the mechanism of cell death was assessed by DNA fragmentation/condensation and live cell imaging analyses. The antitumor efficacy and safety of the Pd(II) complex in-vivo were examined by analyzing reduction in tumor size, changes in body and organ weight, histopathological analysis of liver, kidney, and tumor sections, and biochemical analysis of serum in C57BL/6 mice. Our results showed that the Pd(II) complex was more cytotoxic to cancer cells than noncancer cell lines and caused cell death through apoptotic pathways. The treatment of the Pd(II) complex in tumor-bearing mice effectively reduced the tumor size at half the dose used for cisplatin. The Pd(II) complex appeared to exert less liver damage than the cisplatin-based complex on changes in the hepatic enzymes levels in the serum. Hence, the complex appears to be a potential chemotherapeutic drug with high antitumor efficacy and fewer hepatotoxic complications, providing an avenue for further studies.

Objective: To examine germline single nucleotide polymorphisms (SNPs) as markers of response to gemcitabine platinum (GP) combination chemotherapy in urothelial carcinoma (UC)., Methods: Saliva or blood was prospectively collected from 216 patients treated with GP for UC of the bladder between 1991 and 2011. Based on reported associations with gemcitabine and cisplatin response or putative mechanisms of gemcitabine or cisplatin/carboplatin activity, we selected SNPs of interest and were able to genotype 59 SNPs (using the SequenomMass ARRAYiPLEX platform) in 261 patients randomly split 2/3 into a training set (n = 174) and 1/3 into a test set (n = 87). Logistic regression was used to test the association between response to GP and SNPs., Results: The median age at diagnosis was 64 years (range: 28 - 85) for the discovery set and 67 years (range: 30 - 84) for the validation set. Males composed 76% and 69%, and white non-Hispanics composed 88% and 91% of the training and test validation sets, respectively. Three SNPs on GALNTL4 (rs7937567, rs12278731, and rs9988868) and one intergenic SNP (rs1321391) were significantly associated with response to GP in the training set and were used to build a SNP score. However, when assessed in the test set, the SNP score was not significantly associated with response., Conclusion: Multiple SNPs selected from previous studies failed to predict response to GP in this cohort. Larger studies capable of accounting for population-based allele frequency heterogeneity may be required for replication of genetic alterations important to pharmacogenomics.
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Till date, no analytical method published to detect Cisplatin has been validated according to the U.S. Food and Drug Administration (FDA) guidance using liquid chromatography mass spectrometry (LC-MS/MS). We report, a validated LC-MS/MS method for quantitative determination of cisplatin in rat plasma and urine according to FDA guidlines. Cisplatin is a platinum containing compound used for the treatment of different types of cancers. Quantitative determination of cisplatin has been carried out using atomic absorption spectroscopy, high pressure liquid chromatography with phosphorescence, ultra-violet detection, or with inductively coupled plasma mass spectrometry. Few LC-MS/MS methods have been reported for the analysis of cisplatin either for direct quantification or indirect by derivatizing with organic compounds but none of the reported methods have validated the method. The developed and validated assay presented here is a highly sensitive LC-MS/MS method developed and validated for the quantitative determination of cisplatin following derivatization with diethyldithiocarbamate (DDTC) in order to detect platinum (Pt) of cisplatin, suitable for pharmacokinetic studies in rats and to further use it to study human toxicology. Chromatographic separation was achieved using a Poroshell 120 EC-C 18 column (3×50mm, 2.7μm) with a binary gradient mobile phase. Quantification was performed on a triple quadruple with electrospray ionization and detection was performed using multiple reaction monitoring. The method has a limit of detection of 1ng/mL, and the quantifiable range was 3-3000ng/mL in rat plasma and urine. The method was accurate and precise with an accuracy and precision for intra-day and inter-day of ±20% for lower limit of quantitation and of ±15% for low, mid and high quality control samples. This method was successfully applied to study the pharmacokinetic profile of cisplatin in rat plasma and urine given a range of doses from 0.5 to 3.5mg/kg., (Published by Elsevier B.V.)

Objective: To evaluate the associations between long-term serum levels of platinum (se-Pt) and neurotoxicity and ototoxicity (NTX), endocrine gonadal function (endocrine-GF), and cardiovascular disease (CVD) in testicular cancer survivors., Material and Methods: A total of 292 cisplatin-treated testicular cancer survivors (1980-1994) participated in a national follow-up study (2007-2008). Se-Pt was quantified by inductively coupled plasma mass spectrometry, and categorized in quartiles. Symptoms of NTX were assessed with scale for chemotherapy-induced neurotoxicity (SCIN), with each symptom in 4 categories and total SCIN score categorized in quartiles. Endocrine-GF was categorized according to cutoff values for the 25, 50, and 75 percentiles of luteinizing hormone (LH) and testosterone within each decadal age group established from a control group. CVD was defined as ischemic heart disease, stroke, or artery occlusion. Associations between se-Pt levels and NTX, endocrine-GF, or risk for CVD, were analyzed with ordinal logistic regression and Cox regression, respectively., Results: Median follow-up was 19 years (range: 13-28). In ordinal regression analyses, increasing quartiles of se-Pt were significantly associated with increasing quartiles of SCIN (P for trend = 0.05), increased tinnitus (P<0.001), and increased hearing impairment (P = 0.04). The association remained significant for tinnitus when adjusting for cisplatin dose. Increasing LH quartiles was associated with increasing se-Pt quartiles (P = 0.04). No association between se-Pt in quartiles and CVD was established., Conclusion: Median 19 years after treatment, increasing quartiles of se-Pt are associated with increasing SCIN score, tinnitus, hearing impairment, and increasing LH levels. However, these associations remained significant only for tinnitus and LH when adjusting for administered cisplatin dose., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Liposomes have been employed as carriers for antineoplastic drugs to improve delivery. We describe an HPLC-UV method for determining cisplatin levels in liposomal and biological samples, which represents an attractive alternative to the widely used flame atomic absorption spectroscopy. Liposomal cisplatin was extracted from liposomes, plasma and tissue samples by using acetonitrile and separated on a Symmetry C18 column. The mobile phase was a mixture of water, methanol and acetonitrile, and detection was performed at 254 nm. The method was linear in the range of 0.5-10 µg/mL. Using this method, cisplatin concentration was measured in plasma, kidney, liver and tumor at different times post-administration of liposomal cisplatin. This method is proved suitable for measuring the levels of cisplatin encapsulated in a liposomal system, in plasma or tissue samples of experimental animals, after intravenous administration of liposomal cisplatin. Owing to the small plasma volume employed, a complete pharmacokinetic study can be done with a single animal., (© The Author 2016. Published by Oxford University Press.)

Purpose: Pancreatic cancer is the fourth most common cause of cancer-related death in the USA. This is mainly because of the chemoresistance of this type of tumor; thus, the development of novel therapeutic modalities is needed., Methods: Long-circulating and pH-sensitive liposomes containing cisplatin (SpHL-CDDP) were administered systemically into pancreatic tumor-bearing mice for a period of 14 days. The antitumor efficacy and toxicity of this new treatment method on the basis of cisplatin-loaded liposomes was compared with the classical free-CDDP method. Tc-HYNIC-βAla-bombesin(7-14) tumor uptake and histopathologic findings were used to monitor and compare the two treatment modalities., Results: The antitumor activity of SpHL-CDDP treatment was shown by (a) decrease in tumor volume, (b) development of tumor necrotic areas, and (c) decrease in Tc-HYNIC-βAla-bombesin(7-14) tumor uptake. Toxicity was evaluated by the development of inflammation and necrotic areas in the kidneys, liver, spleen, and intestine: toxic effects were greater with free-CDDP than SpHL-CDDP., Conclusion: SpHL-CDDP showed significant antitumor activity in pancreatic cancer-bearing mice, with lower toxicity in comparison with free-CDDP.

Background: Very little is known about the pharmacokinetics of chemotherapeutic agents in patients also being treated with continuous ambulatory peritoneal dialysis. We sought to evaluate the pharmacokinetics of cisplatin and 5-fluorouracil in plasma and peritoneal dialysate in a patient being treated for esophageal adenocarcinoma., Methods: A single patient with esophageal adenocarcinoma and on peritoneal dialysis for end-stage renal disease was treated with cisplatin 25 mg/m(2) on day 1 of weeks 1 and 5 and continuous infusional 5-fluorouracil 1000 mg/m(2)/day on days 1-4 of weeks 1 and 5 along with daily radiation therapy. Intense plasma and dialysate sampling was performed during the week 5 administration, followed by quantitation of platinum by atomic absorption spectrophotometry and 5-fluorouracil by LC-MS/MS., Results: Following systemic administration, clearance of ultrafilterable (active) platinum over the first 6 h was 20.8 L/h, which is lower than previously reported clearance levels of ultrafilterable platinum. Total platinum AUC was 131 μg h/mL, also higher than an AUC previously reported for total platinum in patients with normal renal function. Platinum-related material was detected in the peritoneal cavity, but this is likely inactive. 5-Fluorouracil penetrated the intraperitoneal cavity, but the contribution of peritoneal dialysis to drug clearance was negligible at 0.072 %., Conclusions: Administration of intravenous cisplatin and 5-fluorouracil chemotherapy to a patient treated with continuous ambulatory peritoneal dialysis is feasible, but clearance in dialysate is nominal, thus suggesting that dose reduction is indicated for cisplatin. Systemic drug administration results in limited intraperitoneal penetration of 5-fluorouracil and inactive platinum species., Competing Interests: The authors declare that they have no conflict of interest.

Introduction Peritoneal surface malignancies have long been regarded as incurable, however, they can be treated with cytoreductive surgery in addition to hyperthermic intraperitoneal chemotherapy. This approach is associated with an increase in morbidity and mortality, unless hyperhydration is provided in a timely manner. Methods Cisplatin (CDDP) is the most widely used chemotherapeutic agent. Plasma levels of cisplatin (CDDP), a widely used chemotherapeutic agent, were measured before, during, and after the procedure. This was done in order to identify the window of highest risk as a function of drug concentrations, assuming a dose-dependent effect. Results Plasma levels of CDDP peak during perfusion. The concentration remains high until the 4th post-operative day and returns to pre-operative levels by the 7th post-operative day. Conclusions Our findings suggest that ensuring hyperhydration as well as infusing albumin and fresh frozen plasma may be of particular value for at least the first 4 days after the procedure.

Background: Second-line therapy has limited activity in patients with recurrent or persistent uterine cervical cancer that has progressed after chemoradiation and palliative chemotherapy. The purpose of this study was to evaluate the efficacy of negative-balance isolated pelvic perfusion (NIPP) in patients with pretreated recurrent/persistent uterine cervical cancer., Methods: Between April 2004 and May 2013, a total of 26 patients with recurrent or persistent uterine cervical cancer previously treated with platinum-based systemic chemotherapy and/or chemoradiotherapy received NIPP therapy at our institution, consisting of a 30-min isolated pelvic perfusion with cisplatin and fluorouracil, followed by isolated pelvic dialysis. Primary endpoints were response rate (RR) and progression-free survival (PFS), while secondary endpoints were overall survival (OS) and safety. Platinum pharmacokinetics were also evaluated., Results: The RR was 57.7 % (complete response, five patients; partial response, ten patients). The median PFS and OS after NIPP therapy were 11.0 (95 % confidence interval [CI] 6.6-15.4) and 25.1 (95 % CI 17.1-33.1) months, respectively. PFS was significantly better in patients without intestinal involvement (p = 0.016) or dissemination (p < 0.001). Survival rates at 1, 2, and 3 years after initial NIPP therapy were 65.2, 50.4, and 13.4 %, respectively. The plasma pelvic-to-systemic exposure ratios were 15.4 and 15.8, based on the maximum concentration and the concentration-time curve, respectively. Most adverse events were mild (grade 1-2) (Common Terminology Criteria for Adverse Events, version 3.0). Severe neutropenia (grade 3 or higher) occurred in only 7.7 % of patients., Conclusions: NIPP appears to be an effective and feasible method for patients with pretreated recurrent or persistent cervical cancer.

Background: Cisplatin (CDDP) is a highly effective chemotherapeutic agent used for therapy of many tumors and has been limited by its toxicity. Zengmian Yiliu granule (ZMYL), a compound preparation of traditional Chinese medicines, has been used in clinic as a complementary and alternative medicine for attenuating CDDP-induced toxicities and enhancing the tumor therapeutic effect of CDDP. The aim of the present study is to investigate hepaprotective effect of ZMYL against CDDP-induced hepatotoxicity. Further, the pharmacokinetic characteristics of CDDP in SKOV-3-bearing nude mice were observed., Methods: The ICR mice were dosed orally with ZMYL for 7 days and then CDDP was injected intraperitoneally at a dose of 45 mg/kg body weight. The serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were measured to evaluate the liver function. The total glutathione (T-GSH), reduced glutathione (GSH) and glutathione S-transferase (GST) levels were determined to evaluate the oxidant damage in liver homogenates. Tissue pathological change in liver was conducted by light microscopy analysis. The pharmacokinetic and tissue distribution of free and total platinum (Pt) after dosing of CDDP alone and combination with ZMYL were determined in SKOV-3-bearing nude mice by ICP-MS., Results: Oral administration of ZMYL prior to the CDDP treatment could prevent the CDDP-induced in lifting of ALT and AST, reduction of T-GSH, R-GSH and GST, and some histopathological alterations in ICR mice. Some differences in pharmacokinetic parameters between the two groups have been observed in higher CL and decreased MRT of free platinum (Pt) in plasma and total Pt in spleen in CDDP co-administration with ZMYL group. It indicated CDDP was cleared more quickly from blood and spleen, and could reduce the accumulation and toxic possibility of CDDP in combination with ZMYL., Conclusions: ZMYL could be used as a beneficial supplement, which could attenuate CDDP-induced hepatotoxicity during CDDP chemotherapy and did not disturb the pharmacokinetics fate of CDDP significantly.

Platinum-based polymeric nano-drugs, especially cisplatin-loaded polymeric nanoparticles (CDDP-NPs), have been extensively exploited for the treatment of solid tumors. However, it is still unclear what role the processing procedure and the properties of the polymeric carrier materials may play in influencing the plasma pharmacokinetics, biodistribution and in vivo efficacy of CDDP-NPs. In this study, a series of poly(l-glutamic acid)-g-methoxy poly(ethylene glycol) (PLG-g-mPEG) copolymers were synthesized for the preparation of CDDP-loaded PLG-g-mPEG (CDDP/PLG-g-mPEG) nanoparticles. All of the parameters, including PLG molecular weight, mPEG/PLG weight ratio, mPEG chain length, ultrafiltration purification and cisplatin loading content, were found to have a significant influence on the plasma pharmacokinetics of the CDDP/PLG-g-mPEG nanoparticles. The blood circulation time of the nanoparticles was prolonged with increases in PLG molecular weight, mPEG/PLG weight ratio, mPEG chain length and CDDP loading content. The use of ultrafiltration purification could prolong the blood circulation time of the nanoparticles as well. Experiments to measure the pharmacokinetics and biodistribution demonstrated that the selected CDDP/PLG-g-mPEG nanoparticles, NP10, had a long blood circulation time and could achieve selective and significant accumulation in Lewis lung carcinoma (LLC) tumors. The platinum plasma concentrations in the LLC tumor-bearing mice receiving NP10 remained up to 46-fold higher than that of mice receiving equivalent doses of free CDDP. In addition, the plasma area under the concentration time curve (AUC) of NP10 was 31-fold higher than that of free CDDP in 48h. The platinum concentration ratio of NP10 to free CDDP in tumors reached as high as 9.4. The tumor AUC ratio of NP10 to CDDP was 6. Using a mouse C26 tumor model, here we demonstrate that NP10 improves the safety and tolerance in vivo when compared to CDDP and effectively inhibits the growth of C26 tumors. Furthermore, increasing the dosage of NP10 by 2 or 3-fold of free CCDP improved its anticancer efficacy to comparable or higher levels. These results indicate that CDDP/PLG-g-mPEG nanoparticles have greater potential for the treatment of solid tumors in clinical application., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Purpose: Metallothioneins (MTs) have been disclosed as a useful diagnostic factor for tumour progression and drug resistance in a variety of malignancies. Increased levels of MT in blood serum have been found in patients with several types of cancer, but there is no available information on serum MT levels in patients with testicular germ cell tumour (TGCT). The aim of the study was to determine MT levels in serum of patients with TGCT and to evaluate the portion of platinum (Pt) that binds to MT after cisplatin administration since MTs could be involved in drug resistance., Methods: Concentration of total MT was determined in serum of 25 men with newly diagnosed TGCT by differential pulse voltammetry. The fractionation of serum was carried out by size exclusion high-performance liquid chromatography (SE-HPLC), while concentration of Pt in collected fractions was determined by inductively coupled plasma mass spectrometry., Results: Concentration of serum MT was significantly higher in TGCT patients than in healthy volunteers. The results of SE-HPLC analysis showed that only a small amount of Pt was bound to proteins in the area of MT elution., Conclusions: Significant increase in MT levels in individuals with TGCT indicates certain health problem and, in combination with other commonly used diagnostic tools, could improve early diagnosis.

A shotgun approach including peptide-based OFFGEL-isoelectric focusing (IEF) fractionation has been developed with the aim of improving the identification of platinum-binding proteins in biological samples. The method is based on a filter-aided sample preparation (FASP) tryptic digestion under denaturing and reducing conditions of cisplatin-, oxaliplatin-, and carboplatin-protein complexes, followed by OFFGEL-IEF separation of the peptides. Any risk of platinum loss is minimized throughout the procedure due to the removal of the reagents used after each stage of the FASP method and the absence of thiol-based reagents in the focusing buffer employed in the IEF separation. The platinum-peptide complexes stability after the FASP digestion and the IEF separation was confirmed by size exclusion chromatography-inductively coupled plasma-mass spectrometry (SEC-ICP-MS). The suitability of peptide-based OFFGEL-IEF fractionation for reducing the sample complexity for further nano-liquid chromatography-electrospray ionization-tandem mass spectrometry (nLC-ESI-MS/MS) analysis has been demonstrated, allowing the detection of platinum-containing peptides, with significantly lower abundance and ionization efficiency than unmodified peptides. nLC-MS/MS analysis of selected OFFGEL-IEF fractions from tryptic digests with different complexity degrees: standard human serum albumin (HSA), a mixture of five proteins (albumin, transferrin, carbonic anhydrase, myoglobin, and cytochrome-c) and human blood serum allowed the identification of several platinum-peptides from cisplatin-HSA. Cisplatin-binding sites in HSA were elucidated from the MS/MS spectra and assessed considering the protein three-dimensional structure. Most of the potential superficial binding sites available on HSA were identified for all the samples, including a biologically relevant cisplatin-cross-link of two protein domains, demonstrating the capabilities of the methodology.

Context: Cisplatin is a highly effective chemotherapeutic agent against many tumors; however, it has potent adverse effects. Zengmian Yiliu granule (ZMYL), a traditional Chinese medicine (TCM) compound, has been clinically used against platinum (Pt)-induced toxicity and to enhance the efficacy of cisplatin., Objective: The study was conducted to investigate the likelihood of potential pharmacokinetics drug-herbs interaction (DHI) between cisplatin and ZMYL., Materials and Methods: An improved ICP-MS method combined with ultrafiltration and microwave-assisted digestion was performed to determine the total and free Pt concentrations in rat plasma after intraperitoneal administration of cisplatin (9 mg/kg) or a combined administration with ZMYL (1 g/kg) by gavage., Results: ZMYL produced a potential DHI on the pharmacokinetic parameters of cisplatin, calculated from the total Pt concentration. The clearance rate decreased from 110.52 to 66.12 mLh(-1 )kg(-1), the mean residence time extended from 63.1 to 164.54 h, the area under the plasma concentration-time curve increased from 86.58 to 152.93 µg h mL(-1), the elimination half-life extended from 48.38 to 126.4 h, and the elimination rate constant decreased from 0.017 to 0.006 h, in the ZMYL combination group (p < 0.05). In terms of free Pt concentration, the apparent volume of distribution and clearance rate was statistically different (p < 0.05). The Pt plasma protein binding ratios in the early dose stages were significantly boosted by the co-administration of ZMYL (p < 0.01)., Discussion and Conclusion: ZMYL is a potential complementary and alternative medicine for cisplatin chemotherapy. The therapeutic benefits of ZMYL-cisplatin chemotherapy derived from pharmacokinetic interaction needs further investigation.

Purpose: Cisplatin induces nausea and emesis, even with antiemetic supportive care. To assess platinum exposure, which could activate nausea and emesis, we quantitated platinum in the brain and various organs, and hindbrain and spinal cord substance P, a key neuropeptide for the neuronal signaling of nausea and emesis., Methods: Musk shrews, a model species for nausea and emesis research, were dosed intraperitoneally with 20 mg/kg cisplatin and euthanized at up to 72 h after injection. Concentrations of platinum were quantitated in plasma ultrafiltrate, plasma, lung, kidney, combined forebrain and midbrain, hindbrain, and spinal cord by flameless atomic absorption spectrometry. Hindbrains and spinal cords were analyzed for substance P by immunohistochemistry after injection of 20 or 30 mg/kg., Results: Plasma ultrafilterable platinum concentrations decreased rapidly till 60 min after dosing and then more slowly by 24 h. The concentrations of total platinum in both the fore- and midbrain and the hindbrain were similar at all time points and were at least 20-fold lower than plasma total platinum concentrations. There were no significant changes in substance P immunoreactivity after cisplatin dosing. Histology revealed damage to the renal cortex by 72 h after injection of cisplatin., Conclusions: This is the first study to examine platinum concentrations in musk shrews after administration of cisplatin and delineate substance P immunohistochemical staining in the hindbrain and spinal cord of this species. The platinum concentrations detected in the brain could potentially contribute to the neurological side effects of cisplatin, such as nausea and emesis.

While cisplatin (CP) is still one of the world's bestselling anticancer drugs, its intravenous administration is inherently associated with severe, dose limiting toxic side-effects. Although the molecular basis of the latter are not well understood, biochemical transformations of CP in blood and the interaction of the generated platinum species with plasma proteins likely play a critical role since these processes will ultimately determine which platinum-species reach the intended tumor cells as well as non-target cells. Compared to healthy subjects, cancer patients often have decreased plasma human serum albumin (HSA) concentrations. Little, however, is known about how the plasma HSA concentration will affect the metabolism of CP. To gain insight, we obtained blood plasma from healthy adults (n = 20, 42 ± 4 g HSA per L) and pediatric cancer patients (n = 11, 26 ± 7 g HSA per L). After the incubation of plasma at 37 °C, a pharmacologically relevant dose of CP was added and the Pt-distribution therein was determined by size-exclusion chromatography coupled on-line to an inductively coupled plasma atomic emission spectrometer. At the 2 h time point, a 5.9% increase of toxic CP-derived hydrolysis products was detected in pediatric cancer patient plasma, while 9.8% less platinum was protein bound compared to plasma from healthy controls. These in vitro results suggest that the elevated concentration of highly reactive free CP-derived hydrolysis products in plasma may cause the toxic side-effects in cancer patients. More importantly, the deliberate increase of the plasma HSA concentration in cancer patients prior to CP treatment would represent a simple strategy to possibly alleviate the fraction of patients that suffer from drug induced toxic side-effects.

LY2603618 is an inhibitor of checkpoint kinase 1 (CHK1), an important regulator of the DNA damage checkpoints. Preclinical experiments analyzed NCI-H2122 and NCI-H441 NSCLC cell lines and in vitro/in vivo models treated with pemetrexed and LY2603618 to provide rationale for evaluating this combination in a clinical setting. Combination treatment of LY2603618 with pemetrexed arrested DNA synthesis following initiation of S-phase in cells. Experiments with tumor-bearing mice administered the combination of LY2603618 and pemetrexed demonstrated a significant increase of growth inhibition of NCI-H2122 (H2122) and NCI-H441 (H441) xenograft tumors. These data informed the clinical assessment of LY2603618 in a seamless phase I/II study, which administered pemetrexed (500 mg/m(2)) and cisplatin (75 mg/m(2)) and escalating doses of LY2603618: 130-275 mg. Patients were assessed for safety, toxicity, and pharmacokinetics. In phase I, 14 patients were enrolled, and the most frequently reported adverse events included fatigue, nausea, pyrexia, neutropenia, and vomiting. No DLTs were reported at the tested doses. The systemic exposure of LY2603618 increased in a dose-dependent manner. Pharmacokinetic parameters that correlate with the maximal pharmacodynamic effect in nonclinical xenograft models were achieved at doses ≥240 mg. The pharmacokinetics of LY2603618, pemetrexed, and cisplatin were not altered when used in combination. Two patients achieved a confirmed partial response (both non-small cell lung cancer), and 8 patients had stable disease. LY2603618 administered in combination with pemetrexed and cisplatin demonstrated an acceptable safety profile. The recommended phase II dose of LY2603618 was 275 mg.

SPI-077, cisplatin stealth liposome, is the best illustration of poor cisplatin release from liposomes and the subsequent negligible therapeutic activity. For this reason, optimizing drug release kinetics is desirable. In this report, cisplatin was encapsulated in liposomes composed of different phosphatidylcholines with various phase transition temperatures (Tm) (HSPC, DPPC, DMPC, soy phosphatidylcholine (SPC)), cholesterol and mPEG2000-DSPE. In vitro cytotoxicity studies indicated that lowering Tm of lipids increases cisplatin release; the highest cytotoxicity was observed in SPCs. Cisplatin plasma concentration was also sensitive to the transition temperature. The highest platinum concentration observed after treatment with HSPC and DPPC liposomes, whilst the lowest was observed with SPC. HSPC and DPPC containing liposomes showed the highest therapeutic efficacy and survival with DPPC exhibited better efficacy in mouse model of C26. It seems that DPPC with Tm (41.5°C) nearly, or close to body temperature maintains good drug retention in blood circulation. Upon extravasation through permeable tumor microvasculature, it gradually releases its payload in the tumor area better than HSPC, with a greater Tm of 55°C. Our data suggests, the choice of Tm for lipid mixture directed to a considerable extent the rate of cisplatin elimination from plasma and therapeutic effects., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Single drug-based cancer therapies are frequently associated with the development of drug resistance. To overcome this problem, combination therapy with two or more anticancer drugs is a promising strategy, but clinical studies are logistically challenging and costly. Intermediary in vitro studies, however, can provide critical insight to decide whether one should proceed to in vivo studies. To this end, cisplatin and the Ru-based anticancer drug NAMI-A were added to human plasma and the size distribution of Pt-containing and Ru-containing entities was determined over a 2 h period. The results revealed a dramatically different rate of plasma protein binding for each drug and/or their hydrolysis products. Both drugs bound to the same apparent plasma proteins, but crucially they did not adversely affect each other's metabolism. Therefore, combination therapy of patients with these metallodrugs should be further assessed in clinical studies in order to systematically develop an effective combination therapy protocol to prevent the resurgence of cancer.

Background: A phase I, dose-escalation study of AT-101 with cisplatin and etoposide was conducted to determine the maximum tolerated dose (MTD)/recommended phase 2 dose (RP2D), safety and pharmacokinetics in patients with advanced solid tumors, with an expanded cohort in patients with extensive-stage small cell lung cancer (ES-SCLC) to assess preliminary activity., Methods: In the dose escalation portion, increasing doses of AT-101 were administered orally BID on days 1-3 along with cisplatin on day 1 and etoposide on days 1-3 of a 21 day cycle. At the RP2D, an additional 7 patients with untreated ES-SCLC were enrolled., Results: Twenty patients were enrolled in the dose-escalation cohort, and 7 patients with ES-SCLC were enrolled in the expanded cohort. The MTD/RP2D was established at AT-101 40 mg BID days 1-3 with cisplatin 60 mg/m2 and etoposide 120 mg/m2 on day 1 of a 21 day cycle with pegfilgrastim support. Two DLTs of neutropenic fever were seen at dose level 1. After the addition of pegfilgrastim, no additional DLTs were observed. Grade 3/4 treatment-related toxicities included: diarrhea, increased AST, neutropenia, hypophosphatemia, hyponatremia, myocardial infarction and pulmonary embolism. No apparent PK interactions were observed between the agents. Preliminary activity was observed with PRs in patients with ES-SCLC, high-grade neuroendocrine tumor, esophageal cancer and NSCLC., Conclusions: AT-101 with cisplatin and etoposide is well tolerated with growth factor support. Anti-tumor activity was observed in a variety of cancers including ES-SCLC, supporting further investigation with BH-3 mimetics in combination with standard chemotherapy for ES-SCLC.

Animal studies have shown that the nephrotoxicity and ototoxicity of the anti-cancer drug cisplatin (CP) can be ameliorated by the co-administration with D-methionine. The molecular mechanisms of this activity, however, are not well understood. Since CP is intravenously administered, the underlying chemistry may involve the interaction of CP-derived Pt-species with D-methionine in the bloodstream. Our previous studies have shown that the chemoprotective agents N-acetyl-l-cysteine and sodium thiosulfate modulate the metabolism of CP in human plasma in vitro, albeit in a different manner. Using a metallomics approach, we show that the incubation of human plasma with D-methionine and CP (molar ratio of 20 : 1) leads to the formation of a Pt-D-methionine complex independent of the order of addition. These results were corroborated by analogous experiments that were carried out using PBS-buffer instead of plasma. In addition, CP and D-methionine were added simultaneously to PBS-buffer and samples were analyzed at certain time intervals by the same metallomics method and LC-ESI-MS over a ∼21 h time period. Whereas the intermediate [Pt(NH3)Cl(D-methionine)](+) species was detected between 1-4 h, only the terminal [Pt(D-methionine)2](+) complex was present 21 h later. Combined, these studies demonstrate that in plasma and at the 20 : 1 D-methionine : CP molar ratio, an early CP hydrolysis product reacts with D-methionine to form a 1 : 1 complex that is followed by the formation of a 2 : 1 compound at a later time point. The formation of these Pt-D-methionine species may therefore play an important role in the processes by which D-methionine protects mammalian organisms against CP-induced toxicities.

Rationally designed PIC nanoparticles as next-generation delivery system: we have developed a core-shell-corona PIC nanoparticle (⊕) NP/Pt@PPC-DA as a next-generation delivery system. (⊕) NP/Pt@PPC-DA exhibits prolonged circulation and enhanced drug accumulation in tumors. Subsequently, tumor pH leads to the release of (⊕) NP/Pt, which facilitates cellular uptake followed by rapid intracellular cisplatin release. Using this delivery strategy cisplatin-resistant tumor growth in a murine xenograft model has been successfully suppressed., (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

This study optimized the radiolabeling of cisplatin with technetium-99m (99mTc) and evaluated its biodistribution in an experimental model of lung carcinogenesis. The percentage labeling of cisplatin with 99mTc was assessed using an ascending chromatographic technique. For biodistribution studies, male rats were divided into 2 groups. The control group received normal saline intratracheally, whereas the treatment group received intratracheal administration of carcinogen 7,12-dimethylbenz(a)anthracene (DMBA) at a dose of 20 mg/kg body weight. The resulting radiopharmaceutical (99mTc-cisplatin) showed 98% labeling efficiency and was found to be stable for up to 6 hours both in both serum and saline under normal conditions. The blood clearance of the 99mTc-cisplatin followed a biphasic release pattern whereby a fast-release phase was observed at 35 seconds and a slow-release phase was observed after 30 minutes of drug administration. The biodistribution studies of control and treated animals revealed high uptake of 99mTc-cisplatin by the liver and slow excretion via the kidneys. However, a time-dependent increase in the lung-to-muscle specific uptake ratio was observed in DMBA-treated rats. The study concluded that 99mTc-cisplatin possesses selectivity toward cancerous lung tissue and can be explored further for its diagnostic potential in the detection of lung cancer and the evaluation of treatment response.

Conjoint liquid chromatography (CLC) on monolithic convective interaction media (CIM) disks coupled on-line to UV and inductively coupled plasma mass spectrometry (ICP-MS) detectors was used for the first time in speciation analysis of Pt in human serum spiked with Pt-based chemotherapeutics. CIM Protein G and CIM DEAE disks were assembled together in a single housing forming a CLC monolithic column. Such a set-up allows rapid two-dimensional separation by affinity and ion-exchange (IE) modes to be carried out in a single chromatographic run. By applying isocratic elution with Tris-HCl-NaHCO3 buffer (pH 7.4) in the first minute, followed by gradient elution with 1 mol L(-1) NH4Cl (pH 7.4) in the next 9 min, immunoglobulins (IgG) were retained by the Protein G disk enabling subsequent separation of unbound Pt from Pt bound to transferrin (Tf) and albumin (HSA) on the CIM DEAE disk. Further elution with acetic acid (AcOH) in the next 3 min allowed separation of Pt associated with IgG. Separated Pt species were quantified by post-column isotope dilution-ICP-MS. Pt recovery on the CLC column was close to 100%. In comparison to commonly applied procedures that involve separation of protein peaks by size-exclusion chromatography (SEC) followed by IE separation of metal-based chemotherapeutic fractions bound to serum proteins, the CLC method developed is much faster and simpler. Its sensitivity (LOQs adequate for quantification of all separated Pt species, lower than 2.4 ng Pt mL(-1)), good selectivity and method repeatability (RSD±3%) enabled investigation of the kinetics of interaction of Pt-based chemotherapeutics with serum proteins and the distribution of Pt species in spiked human serum. Pt species present in spiked serum were bound preferentially to HSA. The proportion of Pt associated with IgG and Tf was lower than 13%. Cisplatin and especially oxaliplatin react rapidly with serum proteins, while carboplatin much less. The method developed may be reliably applied in preclinical and clinical studies of the kinetics of the interaction and distribution of different metallodrugs with proteins in blood serum., (Copyright © 2013 Elsevier B.V. All rights reserved.)

In this work, stability and the pH-sensitivity of pH-sensitive stealth liposomes containing cisplatin exposed to plasma medium and their subsequent responses to pH modifications were evaluated. A method to determine platin in mouse plasma by electrothermal atomic absorption spectroscopy (ET AAS) was developed and validated. At first, a comparative study of sample preparation treatments with basic, acidic, and acidic added with Triton X-100 as a modifier was done. The best treatment was obtained with HCl 3% (v/v). The ET AAS method with acid treatment presented linearity at a range of 10-160 ng Pt/mL. The limits of detection (LOD) was 3.1 ng/mL Pt for acid treatment, while the limit quantification (LOQ) was 10 ng/mL Pt. The acid treatment presented good repeatability (VC<15.0%) and recovery close to 100%. This treatment was chosen for subsequent studies due to its best value of repeatability, recovery, LOD and lowest cost. pH-sensitive stealth liposomes, containing cisplatin, demonstrated low stability and poor response to pH variation after plasma incubation. These findings suggest that further studies are needed to improve liposome formulation i.e., to reduce its size., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Background: 5-fluorouracil (5-FU) and cisplatin (CDDP) are used to enhance radiotherapy (RT) effect for head and neck (HN) cancers. However, the effect of local RT on systemic chemotherapeutics remains unclear. Here, we evaluated the influence of HN irradiation on the pharmacokinetics (PK) of 5-FU and CDDP in rats as experimental model., Methods: The radiation dose distributions of HN cancer patients were determined for the low dose areas, which are generously deposited around the target volume. Two Gy and 0.5 Gy RT were selected. Single-fraction radiation was delivered to the HN of Sprague-Dawley rats. 5-FU at 100 mg/kg or CDDP at 5 mg/kg was intravenously infused 24 hours after radiation., Results: Radiation at 2 Gy reduced the area under the plasma concentration vs. time curve (AUC) of 5-FU and CDDP by 16% and 29% compared to non-irradiated controls, respectively. This was accompanied by incremental total plasma clearance values. Intriguingly, low dose radiation at 0.5 Gy resulted in a similar pharmacokinetic profile, with a 17% and 33% reduction in the AUC of 5-FU and CDDP, respectively. The changes in AUC of bile, which increases with RT, were opposite to AUC of plasma for both drugs., Conclusions: The local HN RT could modulate systemic PK of 5-FU and CDDP in rats. This unexpected RT-PK phenomena may provide a reference for adjustment of drug administration and is worthy of further investigation., Trial Registration: ClinicalTrials.gov ID NCT01755585 and NCT01609114.

Platinum agents continue to be the main chemotherapeutic agents used in the first-line and second-line treatments of cancer patients. It is important to fully understand the biological profile of these compounds in order to optimize the dose given to each patient. In a joint project with the Australian Nuclear Science and Technology Organisation and the Nuclear Medicine Department at Steve Biko Academic Hospital, South African Nuclear Energy Corporation synthesized and supplied (195m) Pt-cisplatinum (commonly referred to as cisplatin) for a clinical pilot study on healthy volunteers. Enriched (194) PtCl2 was prepared by digestion of enriched (194) Pt metal (>95%) followed by thermal decomposition over a 3 h period. The (194) PtCl2 was then placed in a quartz ampoule, was irradiated in SAFARI-1 up to 200 h, then decay cooled for a minimum of 34 h prior to synthesis of final product. (195m) Pt(NH3 )2 I2 , formed with the addition of KI and NH4 OH, was converted to the diaqua species [(195m) Pt(NH3 )2 (H2 O)2 ](2+) by reaction with AgNO3 . The conversion to (195m) Pt-cisplatinum was completed by the addition of concentrated HCl. The final product yield was 51.7% ± 5.2% (n = 5). The chemical and radionuclidic purity in each case was >95%. The use of a high flux reactor position affords a higher specific activity product (15.9 ± 2.5 MBq/mg at end of synthesis) than previously found (5 MBq/mg). Volunteers received between 108 and 126 MBq of radioactivity, which is equivalent to 6.8-10.0 mg of carrier cisplatinum. Such high specific activities afforded a significant reduction (~50%) in the chemical dose of a carrier cisplatinum, which represents less than 10% of a typical chemotherapeutic dose given to patients. A good manufacturing practice GMP compliant product was produced and was administered to 10 healthy volunteers as part of an ethically approved Phase 0 clinical trial. The majority of the injected activity 27.5% ± 5.8% was excreted in the urine within 5 h post injection (p.i.). Only 8.5% ± 3.1% of cisplatinum remained in blood pools at 5 h, which gradually cleared over the 6-day monitoring period p.i. At the end of the study (6 days p.i.), a total of 37.4% ± 5.3% of the product had cleared from the blood into urine, and approximately 63% remained in the body. The significantly lower concentration of carrier cisplatinum used for imaging resulted in a well-tolerated product., (Copyright © 2013 John Wiley & Sons, Ltd.)

Background: Self-expandable metallic stents (SEMSs) are effective in the palliation of malignant airway obstruction. Tumor ingrowth, however, frequently occurs because of a shortage of effective local therapy. Additionally, SEMSs are frequently associated with problems of fracture, migration, and difficult removals. Our goal was to develop a novel bioabsorbable stent with cisplatin elution to circumvent such problems., Methods: Biodegradable stents made of polycaprolactone were fabricated by a laboratory-made, microinjection molding machine. In vitro mechanical strength of the stents was compared with the strength of Ultraflex SEMSs. Polylactide-polyglycolide copolymer and cisplatin were coated onto the surfaces of the stents. Elution method and high-performance liquid chromatography (HPLC) analysis were used to examine the in vitro cisplatin release characteristics. In vivo, the stents were surgically implanted into the cervical trachea of 15 New Zealand white rabbits. Bronchoscopic examination was performed weekly (1 to approximately 5 weeks) before killing. Cisplatin concentrations in trachea, lung, and blood were analyzed by HPLC. Histologic examination was also performed., Results: The biodegradable stent exhibited mechanical strength comparable to the strength of Ultraflex SEMSs and provided a steady release of cisplatin for >4 weeks in vitro. The in vivo study showed sustained cisplatin levels in rabbit trachea for >5 weeks with a minimum drug level in blood. Histologic examination showed an intact ciliated epithelium and marked leukocyte infiltration in the submucosa of the stented area., Conclusions: Our study demonstrated that the biodegradable stents provided physical properties comparable to the properties of SEMSs and a sustained release of cisplatin for >5 weeks, which showed great potential in the treatment of malignant airway obstruction.

An in vitro method for simultaneous assessment of platinum release and liposome stability of liposomal formulations in human plasma is demonstrated. The development and assessment of the method was performed on a PEGylated liposomal formulation containing cisplatin. Complete separation of free cisplatin, encapsulated cisplatin and cisplatin bound to plasma components was achieved by capillary electrophoresis (CE) separation and simultaneous monitoring of phosphorous (phospholipid) and platinum (cisplatin) by inductively coupled plasma mass spectrometry (ICP-MS). The method allows assessment of the encapsulation efficiency of the formulation, the physical stability of liposomes as well as cisplatin leakage in human plasma. The method was applied for studying the disintegration of liposomes and the interactions of leaked cisplatin with plasma components. Triggered release of the drug into plasma by sonication was also demonstrated. Analysis of liposomal formulations with alternative phospholipid compositions containing oxaliplatin showed similar results. Thus, the present in vitro method is suitable for mimicking the in vivo drug release profile in human plasma after administration of liposomal platinum formulations to patients. This approach may be of use in early drug development as well as in quality control., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Cis-Platin (CP) is a remarkably effective Pt-based anticancer drug, but it also exhibits severe toxic side-effects, including nephrotoxicity and ototoxicity. Previous studies conducted with mammalian model organisms have clearly demonstrated that the intravenous administration of N-acetyl-L-cysteine (NAC) or sodium thiosulfate (STS) along with CP can significantly reduce these toxic side effects. A molecular understanding of the biochemical events that unfold in the bloodstream when these 'ameliorating agents' and CP are co-administered, therefore, constitutes an important first step in devising novel strategies to ultimately improve the quality of life of patients undergoing treatment with CP. We have employed size exclusion chromatography (SEC) coupled on-line to an inductively coupled plasma atomic emission spectrometer (ICP-AES) to visualize how NAC affects the metabolism of CP in human plasma (obtained from healthy male volunteers) in vitro. Clinically relevant doses of CP and NAC were added to plasma at various NAC : CP molar ratios and the Pt-distribution was determined after 10 and 50 min. The results revealed that a putative Pt-NAC complex was formed in plasma with NAC : CP molar ratios ≥ 50 : 1 and that plasma protein binding of CP-derived Pt-species was marginally affected by NAC. In addition, the anti-tumor active CP remained in plasma for more than 50 min. Furthermore, NAC (but not CP) adversely affected the integrity of Fe and Zn plasma metalloproteins in a dose and a time dependent manner. Based on these in vitro data, NAC appears to be a less ideal ameliorating agent to mitigate CP toxicity compared to STS.

A capillary electrophoresis inductively coupled plasma mass spectrometry method for separation of free cisplatin from liposome-encapsulated cisplatin and protein-bound cisplatin was developed. A liposomal formulation of cisplatin based on PEGylated liposomes was used as model drug formulation. The effect of human plasma matrix on the analysis of liposome-encapsulated cisplatin and intact cisplatin was studied. The presence of 1 % of dextran and 4 mM of sodium dodecyl sulfate in HEPES buffer was demonstrated to be effective in improving the separation of liposomes and cisplatin bound to proteins in plasma. A detection limit of 41 ng/mL of platinum and a precision of 2.1 % (for 10 μg/mL of cisplatin standard) were obtained. Simultaneous measurements of phosphorous and platinum allows the simultaneous monitoring of the liposomes, liposome-encapsulated cisplatin, free cisplatin and cisplatin bound to plasma constituents in plasma samples. It was demonstrated that this approach is suitable for studies of the stability of liposome formulations as leakage of active drug from the liposomes and subsequent binding to biomolecules in plasma can be monitored. This methodology has not been reported before and will improve characterization of liposomal drugs during drug development and in studies on kinetics.

This study focuses on the identification of the products that are formed upon binding of therapeutically relevant platinum complexes to proteins like β-lactoglobulin A (LGA), human serum albumin (HSA), or human hemoglobin (HB). The respective proteins were incubated with the platinum-based anticancer drugs cisplatin, carboplatin, and oxaliplatin. LGA was selected as the model protein in addition to the two most abundant blood proteins HSA and HB. In case of the model protein, the effect of free thiol groups on the affinity of cisplatin, carboplatin, and oxaliplatin was investigated by means of liquid chromatography electrospray ionization time-of-flight mass spectrometry (LC/ESI-ToF-MS). The reduced form of LGA, which contains four free thiol groups more than the native LGA, shows a much higher affinity to the platinum-based drugs. By means of liquid chromatography coupled to inductively coupled plasma mass spectrometry, the reaction behavior of the platinum-based drugs towards HSA and HB was investigated under different conditions considering the chloride concentration (4 or 100 mM) and the incubation time (24 and 48 h). In case of carboplatin, less than 6 % protein-bound platinum was detected. However, both cisplatin and oxaliplatin display a high affinity to the proteins investigated. Further information was obtained by means of LC/ESI-ToF-MS. In case of oxaliplatin, the complex [Pt(DACH)](2+) (DACH=C(6)N(2)H(14)) was identified interacting with HSA and HB. For cisplatin, different results were observed for the two proteins. The complex [Pt(NH(3))(2)Cl](+) interacted predominantly with HSA and [Pt(NH(3))(2)](2+) with HB.

Objective: To determine the effects of intratumoral injection of a hyaluronan-cisplatin nanoconjugate on local and systemic platinum concentrations and systemic toxicosis., Animals: 5 dogs with spontaneous soft tissue sarcomas (STSs)., Procedures: For each dog, approximately 1.5 mL of hyaluronan nanocarrier conjugated with 20 mg of cisplatin was injected into an external STS. Blood samples were collected immediately before (0 hours) and at 0.5, 1, 2, 3, 4, 24, and 96 hours after hyaluronan-cisplatin injection for pharmacokinetic analyses. Urine samples were obtained at 0 and at 96 hours after hyaluronan-cisplatin injection for urinalysis. Each treated STS and its sentinel lymph nodes were surgically removed 96 hours after the hyaluronan-cisplatin injection. Inductively coupled plasma mass spectrometry was used to measure platinum concentrations in blood samples, tumors, and lymph nodes., Results: No tissue reactions were detected 96 hours after hyaluronan-cisplatin injection. Mean ± SD area under the curve, peak concentration, and terminal half-life for unbound (plasma) and total (serum) platinum were 774.6 ± 221.1 ng•h/mL and 3,562.1 ± 2,031.1 ng•h/mL, 56.5 ± 20.9 ng/mL and 81.6 ± 40.4 ng/mL, and 33.6 ± 16.1 hours and 51.2 ± 29.1 hours, respectively. Platinum concentrations ranged from 3,325 to 8,229 ng/g in STSs and 130 to 6,066 ng/g in STS-associated lymph nodes., Conclusions and Clinical Relevance: Intratumoral injection of the hyaluronan-cisplatin nanoconjugate was well tolerated in treated dogs. Following intratumoral hyaluronan-cisplatin injection, platinum concentration was 1,000-fold and 100-fold greater within treated tumors and tumor-draining lymphatics, respectively, compared with that in plasma.

Background: Susceptibility to cisplatin (CDDP) nephrotoxicity is known to vary between individuals, but the basis of this variation has not been fully elucidated. In the kidney, CDDP is taken up into the renal proximal tubular cells mainly via SLC22A2 organic cation transporter 2 (OCT2) and secreted into lumen via other transporters including SLC47A1 multidrug and toxin extrusion 1 (MATE1). Here, we explore the effect of single-nucleotide polymorphisms (SNPs) at 808G>T in OCT2 and at rs2289669 G>A in MATE1 on CDDP-induced adverse events., Methods: Fifty-three patients who had been treated with CDDP were enrolled. The plasma concentration of CDDP was measured on days 4 and 7 after treatment. The grade of hematology and nephrotoxicity was evaluated by Common Terminology Criteria for Adverse Events., Results: In the first treatment cycle, serum creatinine (SCr) levels in the patients with OCT2 808GG and 808GT were increased by 1.43- and 1.19-fold, respectively. In the total treatment cycles, 12 patients (27 %) with 808GG experienced over grade 2 SCr elevation, whereas those with 808GT did not show any apparent nephrotoxicity. The hematological toxicity and plasma concentrations of CDDP showed no difference between patients in both groups. The rs2289669 G>A SNP in MATE1 was not associated with adverse effects and disposition of CDDP., Conclusion: The 808G>T SNP in OCT2 ameliorated CDDP-induced nephrotoxicity without alteration of disposition, whereas the rs2289669 G>A SNP in MATE1 had no effect on CDDP toxicity.

The anticancer drug cis-platin (CP) is widely used to treat patients, but it is also associated with significant side effects, including nephrotoxicity. Given that this metallodrug is intravenously (iv) administered, its biotransformations in the bloodstream are likely to be involved in mediating these side-effects. Previous studies have revealed that the iv administration of patients/mammalian model organisms with sodium thiosulfate (STS) can ameliorate the side effects of CP, but the underlying molecular basis remains elusive. We have studied the effect of STS on the metabolism of CP in human plasma in vitro by determining the platinum (Pt) distribution using size exclusion chromatography (SEC) coupled on-line to an inductively coupled plasma atomic emission spectrometer (ICP-AES). The addition of STS to plasma 10 min before CP was added accelerated the hydrolysis of CP and resulted in the formation of a Pt-STS complex. Conversely, when plasma was incubated with CP for up to 3 h and STS was added thereafter the analysis of the obtained mixture revealed that the formation of the same Pt-STS complex which in turn greatly diminished the plasma protein binding of CP-derived hydrolysis products. Thus, the observed amelioration of the side effects of CP by STS can be rationalized in terms of the rapid formation of a biologically inactive Pt-STS complex in the bloodstream. This is the first mechanism that can explain the amelioration of the side effects of CP by STS. Based on the fact that cis-platin remained in plasma for a considerable amount of time, the optimization of the administration sequence, the molar ratio and the time delay between the administration of both drugs emerges as a viable strategy to achieve a careful balance between ameliorating the side effects while leaving the antitumour activity intact. Our results demonstrate that in vitro studies can be useful to develop feasible strategies to mitigate the side-effects of Pt-based anticancer drugs in patients.

Purpose: To investigate the pharmacokinetics and efficacy of chemoembolization with a cisplatin-loaded superabsorbent polymer (SAP) suspension in a rabbit model with transplanted liver VX2 tumors., Materials and Methods: VX2 tumors were implanted into the left lobe of the liver in eight rabbits. Embolization of the proper hepatic artery was performed with cisplatin-loaded or unloaded SAP. In the cisplatin-loaded SAP group (n = 4), 5 mg of SAP (106-150 μm) loading 2.35 mg of cisplatin and 0.5 mL of ionic contrast material (ioxaglic acid 320 mgI/mL) was injected into the proper hepatic artery. In the control group (hepatic arterial infusion [HAI] + SAP; n = 4), 5 mg of SAP loading 0.5 mL of ioxaglic acid alone was injected after a bolus infusion of an equivalent amount of cisplatin. Sequential change of the plasma platinum concentration within the first 24 hours was measured. Blood sampling and histopathologic examination were performed at 1-week follow-up. Magnetic resonance (MR) images were used to calculate the growth rate of the VX2 tumor., Results: All animals underwent successful embolization. Both total and free plasma platinum mean concentrations within the first 24 hours remained lower in the cisplatin-loaded SAP group, although without statistical significance (P > .05). The mean tumor growth rate was significantly lower in the cisplatin-loaded SAP group than the control group (20% vs 116%; P = .049). Histopathologic examination revealed coagulative necrosis to nontumorous liver parenchyma in two rabbits in the cisplatin-loaded SAP group, although no deaths occurred., Conclusions: These results suggested that chemoembolization with cisplatin-loaded SAP was a safe and tolerable treatment and was more effective in suppressing the tumor growth., (Copyright © 2012 SIR. Published by Elsevier Inc. All rights reserved.)

Purpose: Preclinical studies demonstrate synergistic anti-tumor activity with the combination of everolimus and cisplatin. We conducted a phase I study to establish the recommended phase II of oral everolimus to be given with low-dose weekly intravenous cisplatin., Methods: Part A used a standard 3 + 3 dose escalation scheme. There were 4 planned dose levels of everolimus: 2.5, 5, 7.5, and 10 mg/day. Subjects received oral everolimus during days 1-21 and cisplatin 20 mg/m(2) intravenously (fixed dose) on days 1, 8, and 15 of a 28-day cycle. Pharmacokinetic (PK) blood samples were collected on day 1 and day 8 of cycle 1 in Part A. After the phase II recommended dose was established (Part A), 6 additional subjects were enrolled in an expansion cohort (Part B). Response was assessed by RECIST q 2 cycles for all subjects., Results: Thirty patients were enrolled (18 male, 12 female) and 29 were treated. Median age was 61 years (31-79) and the median number of prior cytotoxic chemotherapy regimens was 2 (0-3). Eighty-three percent of subjects had received prior RT. DLTs occurred at dose level 1 (sudden death of unclear cause in a patient with melanoma metastatic to liver) and dose level 2 (bowel obstruction). No DLTs occurred at dose levels 3 and 4. The most common adverse events (≥grade 3) among 28 patients evaluable for toxicity were lymphopenia (36%), hyperglycemia (11%), fatigue (11%), and venous thrombosis (11%). PK analysis of everolimus demonstrated dose-proportional increases in C (max) (mean 91.9 ng/ml) and AUC(0-INF) (mean 680.5 h*ng/ml) at dose level 4. Three partial responses were seen (metastatic pulmonary carcinoid, n = 2; metastatic sinus carcinoma, n = 1). Prolonged stable disease ≥6 cycles occurred in subjects with pulmonary carcinoid, oropharyngeal squamous cell carcinoma, basal cell carcinoma, papillary thyroid carcinoma, and esthesioneuroblastoma (n = 1 each)., Conclusion: The phase II recommended dose is everolimus 10 mg/day (days 1-21) + cisplatin 20 mg/m(2) (days 1, 8, and 15) of a 28-day cycle. PK data demonstrate dose-proportional increases in exposure, as previously described for everolimus monotherapy. Anti-tumor activity was observed in several tumor types.

Cholesterol anchored derivatives of 5-Cholestene-3-beta-ol 3-hemisuccinate (CHO-HS) and 1-cholesteryl-4-ω-methoxy-polyethylene glycol succinate (CHO-PEG) have been synthesized via esterification and employed at various ratios with di-stearoylphosphatidylcholine (DSPC) in the preparation of anionic long-circulating nanoliposmes for cisplatin (CDDP) delivery. In the present study, CHO-HS and CHO-PEG were characterized by FTIR and (1)H NMR. The particle size and zeta potential of liposomes were determined by Dynamic lights scattering (DLS). The obtained liposomes have concentratedly distributed nanosizes around 100 nm and proper zeta potentials between -39.7 mV and -3.18 mV and good physical stability in test period of 28 days. Fine morphology of the liposomal vesicles can be observed via transmission electron microscopy (TEM). The CDDP encapsulating percentage of liposomes was 43-94% and loading efficiency was 7.5-29.3%, depending on the presence or absence of CHO-HS and CHO-PEG. In addition, the in vitro drug release behaviors, in vitro cytotoxicity against HeLa cells and 293T cells and in vivo CDDP distribution of CDDP loaded CHO-HS/CHO-PEG liposomes were evaluated. The results suggest that CHO-HS/CHO-PEG nanoliposomes represent a promising strategy for the CDDP delivery as an effective long-circulating drug carrier system which may reduce the acute renal toxicity., (Copyright © 2011 Elsevier Ltd. All rights reserved.)