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.

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.

Engineering liposomal nanoparticles of cholesterol-tethered amphiphilic Pt(iv) prodrugs with prolonged circulation time in blood.

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.

A New Sensitive Method for Quantitative Determination of Cisplatin in Biological Samples by Kinetic Spectrophotometry.

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 (3sb/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.

Clinical and Genome-Wide Analysis of Serum Platinum Levels after Cisplatin-Based Chemotherapy.

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/m2 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 ORhigh/low = 1.46; P = 0.04), as well as a higher likelihood of developing tinnitus (age-adjusted ORhigh/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.

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.

Pharmacokinetics of cisplatin during open and minimally-invasive secondary cytoreductive surgery plus HIPEC in women with platinum-sensitive recurrent ovarian cancer: a prospective study.

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 Cmax 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 Cmax in peritoneal tissue was higher in patients treated with MI-SCS compared to O-SCS (Cmax=8.262 µg/mL vs. Cmax=4.057 µg/mL). Furthermore, median cisplatin plasma Cmax was higher in patients treated with MI-SCS compared to O-SCS (Cmax=0.511 vs. Cmax=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 Cmax 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.

The reduction of cis-platinum(iv) complexes by ascorbate and in whole human blood models using 1H NMR and XANES spectroscopy.

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.

Therapeutic drug monitoring and dose adaptation of cisplatin in a newborn with hepatoblastoma: a case report.

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 (AUC0-∞) for each administration. Toxicity and clinical response were monitored. RESULTS: The first cisplatin dose (1.6 mg/kg) resulted in an AUC0-∞ 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.

Improving the safety of metal-based drugs by tuning their metabolism with chemoprotective agents.

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 platinum­sulfur 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.

Zwitterionic hydrophilic interaction liquid chromatography-tandem mass spectrometry with HybridSPE-precipitation for the determination of intact cisplatin in human plasma.

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.

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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Development and validation of a LC-MS/MS assay for quantification of cisplatin in rat plasma and urine.

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-C18 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.

Associations between long-term serum platinum and neurotoxicity and ototoxicity, endocrine gonadal function, and cardiovascular disease in testicular cancer survivors.

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.

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.

Determination of Liposomal Cisplatin by High-Performance Liquid Chromatography and Its Application in Pharmacokinetic Studies.

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.

Preliminary data of the antipancreatic tumor efficacy and toxicity of long-circulating and pH-sensitive liposomes containing cisplatin.

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-ßAla-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-ßAla-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.

A pharmacokinetic analysis of cisplatin and 5-fluorouracil in a patient with esophageal cancer on peritoneal dialysis.

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.

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.