Screen-Printed Electrodes-A Promising Tool for Antineoplastic Drug Detection (Cisplatin and Bleomycin) in Biological Samples.

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 H2O2 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 R2 = 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.

A chemiluminescence resonance energy transfer strategy and its application for detection of platinum ions and cisplatin.

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.

A palladium(II)-saccharinate complex of terpyridine exerts higher anticancer potency and less toxicity than cisplatin in a mouse allograft model.

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.

Evaluating the association of multiple single nucleotide polymorphisms with response to gemcitabine and platinum combination chemotherapy in urothelial carcinoma of the bladder
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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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Evaluation of cisplatin plasma levels in patients undergoing cytoreductive surgery and hyperthermic intraperitoneal chemotherapy.

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.

Feasibility and Safety of Negative-Balance Isolated Pelvic Perfusion in Patients with Pretreated Recurrent or Persistent Uterine Cervical Cancer.

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.

A shotgun approach for the identification of platinum-protein complexes.

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.

Hepatotoxicity and pharmacokinetics of cisplatin in combination therapy with a traditional Chinese medicine compound of Zengmian Yiliu granules in ICR mice and SKOV-3-bearing nude mice.

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.

Pharmacokinetics of cisplatin in the absence or presence of zengmian yiliu granules (a traditional Chinese medicine compound) in rats determined via ICP-MS: an investigation on drug-herb interactions.

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.

A phase I study of AT-101 with cisplatin and etoposide in patients with advanced solid tumors with an expanded cohort in extensive-stage small cell lung 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.

Preclinical analyses and phase I evaluation of LY2603618 administered in combination with pemetrexed and cisplatin in patients with advanced cancer.

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.

Simultaneous observation of the metabolism of cisplatin and NAMI-A in human plasma in vitro by SEC-ICP-AES.

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.

Determination of unbound platinum concentrations in human plasma using ultrafiltration and precipitation methods.

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 (R2 = 0.738) and total Pt (R2 = 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.

Head and neck irradiation modulates pharmacokinetics of 5-fluorouracil and cisplatin.

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.

Metallomics in drug development: characterization of a liposomal cisplatin drug formulation in human plasma by CE-ICP-MS.

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.

The interaction of platinum-based drugs with native biologically relevant proteins.

This study focuses on the identification of the products that are formed upon binding of therapeutically relevant platinum complexes to proteins like ß-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.

Production of high specific activity (195m) Pt-cisplatinum at South African Nuclear Energy Corporation for Phase 0 clinical trials in healthy individual subjects.

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.

Intraperitoneal clearance as a potential biomarker of cisplatin after intraperitoneal perioperative chemotherapy: a population pharmacokinetic study.

BACKGROUND: Intraperitoneal (IP) perioperative chemotherapy with cisplatin is an interesting option in ovarian cancer treatment. A combination of cisplatin with IP epinephrine (already shown to improve IP and decrease systemic platinum (Pt) exposure) was evaluated using a population pharmacokinetic analysis. METHODS: Data from 55 patients treated with cisplatin-based IP perioperative chemotherapy with (n=26) or without (n=29) epinephrine were analysed using NONMEM. RESULTS: Epinephrine halves clearance between peritoneum and serum (IPCL) and increases the Pt central volume of distribution, IP exposure and penetration in tissue. IPCL has a better predictive value than any other parameter with respect to renal toxicity. CONCLUSION: This confirms that IPCL could be useful in assessing renal toxicity. As IPCL is also linked to tissue penetration and IP exposure, it may be proposed as biomarker. In addition to a Bayesian estimation, we propose a single-sample calculation-way to assess it. Prospective studies are needed to validate IPCL as a biomarker in this context.

Pharmacologic advantages of negative-balance isolated pelvic perfusion: achievement of intensive exposure of the pelvis to platinum without systemic leakage.

PURPOSE: To study tissue platinum concentrations and the correlation between tissue and plasma platinum concentrations after negative-balance isolated pelvic perfusion (NIPP) in a porcine model. MATERIALS AND METHODS: All animal experiments were conducted according to the University Guidelines for Animal Care and Experimentation. Cisplatin (5 mg per kilogram of body weight) was administered into balloon catheter-isolated porcine pelvic circulations (n=7) and also systemically to a control group (n=7). Platinum concentrations in pelvic blood, systemic blood, urine, pelvic tissues (uterus, bladder, lymph nodes, and muscles), and kidneys were measured. Maximum platinum concentration (maximum serum drug concentration [C-max]) and area under the blood concentration-time curve (AUC) were compared between the two groups. RESULTS: With NIPP, pelvic C-max (58.4 mg/L) and AUC (1163.6 mg⋅min/L) were 44.9- and 56.2-fold higher than systemic C-max (1.3 mg/L) and AUC (20.7 mg⋅min/L), respectively, whereas the corresponding values in the control group were almost identical. Tissue platinum concentrations in pelvic organs were 2.8-5.6-fold higher than the control values. Platinum concentrations in kidney tissue were markedly lower with NIPP (1.0 mg/L) compared with the controls (8.1 mg/L). High platinum concentrations in pelvic tissues correlated well (P<.01) with high pelvic C-max and AUC. CONCLUSION: The pharmacologic advantages of NIPP were evident, with achievement of high platinum C-max, AUC, and high pelvic tissue concentrations without exposing systemic organs to platinum.

In vivo evaluation of cisplatin-loaded superabsorbent polymer microspheres for use in chemoembolization of VX2 liver tumors.

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.