Occupational exposure to antineoplastic drugs: what about hospital sanitation personnel?

OBJECTIVE: Occupational exposure to antineoplastic drugs (ANPs) occurs mainly through dermal contact. Our study was set up to assess the potential exposure of hospital sanitation (HS) personnel, for whom almost no data are available, through contamination of surfaces they regularly touch. METHODS: In the oncology departments of two hospitals around Montreal, surface wipe samples of 120-2000 cm2 were taken at 10 sites cleaned by the HS personnel and five other sites frequently touched by nursing and pharmacy personnel. A few hand wipe samples were collected to explore skin contamination. Wipes were analyzed by ultra-performance liquid chromatography tandem-mass spectrometry for 10 ANPs. RESULTS: Overall, 60.9% of 212 surface samples presented at least one ANP above the limits of detection (LOD). Cyclophosphamide and gemcitabine were most often detected (52% and 31% of samples respectively), followed by 5-fluorouracil and irinotecan (15% each). Highest concentrations of five ANPs were found in outpatient clinics on toilet floors (5-fluorouracil, 49 ng/cm2; irinotecan, 3.6 ng/cm2), a perfusion pump (cyclophosphamide, 19.6 ng/cm2) and on a cytotoxic waste bin cover (gemcitabine, 4.97 ng/cm2). Floors in patient rooms had highest levels of cytarabine (0.12 ng/cm2) and methotrexate (6.38 ng/cm2). Hand wipes were positive for two of 12 samples taken on HS personnel, seven of 18 samples on nurses, and two of 14 samples on pharmacy personnel. CONCLUSIONS: A notable proportion of surfaces showed measurable levels of ANPs, with highest concentrations found on surfaces cleaned by HS personnel, who would benefit from appropriate preventive training. As potential sources of worker exposure, several hospital surfaces need to be regularly monitored to evaluate environmental contamination and efficacy of cleaning.

Quality control of cytostatic drug preparations-comparison of workflow and performance of Raman/UV and high-performance liquid chromatography coupled with diode array detection (HPLC-DAD).

The drugs used for treatment during chemotherapy are manufactured individually for each patient in specialised pharmacies. Thorough quality control to confirm the identity of the delivered active pharmaceutical ingredient and the final concentration of the prepared application solution is not standardized yet except for optical or gravimetric testing. However, solution stability problems, counterfeit drugs, and erroneous or deliberate underdosage may occur and negatively influence the quality of the product and could cause severe health risks for the patient. To take a step towards analytical quality control, an on-site analytical instrument using Raman and UV absorption spectroscopy was employed and the results were compared to high-performance liquid chromatography coupled to diode array detection. Within the scope of the technology evaluation, the uncertainty of measurement was determined for the analysis of the five frequently used cytostatic drugs 5-fluorouracil, cyclophosphamide, gemcitabine, irinotecan and paclitaxel. The Raman/UV technique (2.0-3.2% uncertainty of measurement; level of confidence: 95%) achieves a combined uncertainty of measurement comparable to HPLC-DAD (1.7-3.2% uncertainty of measurement; level of confidence: 95%) for the substances 5-fluorouracil, cyclophosphamide and gemcitabine. However, the uncertainty of measurement for the substances irinotecan and paclitaxel is three times higher when the Raman/UV technique is used. This is due to the fact that the Raman/UV technique analyses the undiluted sample; therefore, the sample has a higher viscosity and tendency to foam. Out of 136 patient-specific preparations analysed within this study, 96% had a deviation of less than 10% from the target content.

Ultrahigh-Throughput and Chromatography-Free Bioanalysis of Polar Analytes with Acoustic Ejection Mass Spectrometry.

Bioanalysis of polar analytes using liquid chromatography-tandem mass spectrometry (LC-MS/MS) remains a significant challenge because of their poor chromatographic retention on the commonly used reversed-phase LC columns and the resulting severe ionization suppression from coeluting matrix components. Here we present a novel approach to perform ultrahigh-throughput and chromatography-free bioanalysis of polar compounds using a prototype acoustic ejection mass spectrometer (AEMS) platform. Previously developed for direct analysis of solid or liquid samples by MS, the open port interface (OPI) has recently been modified and coupled to an acoustic nanoliter dispenser to enable high-speed direct MS analysis from 384-well plates with a reported speed as fast as 0.5 s/sample. Ionization suppression was reduced due to the >1000 fold dilution of the original sample by the carrier solvent in the AE-OPI-MS operation. Taking full advantage of the chromatography-free and suppression-reducing features of this prototype instrument, we successfully demonstrated the ultrahigh-throughput bioanalysis of metformin, a small polar substrate commonly used in high-throughput in vitro transporter inhibition assays in the early ADME profiling space in drug discovery. The AEMS platform achieved a speed of 2.2 s/sample using only 10 nL of sample volume. Similar bioanalytical and biological results from actual assay samples were obtained by AEMS when compared to those obtained by the fastest LC-MS/MS method previously reported, along with a 15-fold speed advantage and ∼500-fold less sample consumption to enable future assay miniaturization. The general applicability of this novel approach to bioanalysis of several classes of polar analytes including ethambutol, isoniazid, ephedrine, and gemcitabine in biological matrices was further demonstrated.

Protonation-Suppression-Free LC-MS/MS Analysis for Profiling of DNA Cytosine Modifications in Adult Mice.

DNA cytosine modifications are important epigenetic marks. To elucidate their roles by a large scale of comparative studies, it is important to quantify the abundance of DNA cytosine modifications accurately. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is a golden option. The performance of LC-MS/MS is heavily dependent on the ionization or protonation of target analytes. Initially, we found that two factors, DNA hydrolysate buffer and residual coeluted nucleosides, might greatly suppress the protonation of 5-(hydroxymethyl)-2'-deoxycytidine (5hmdC). Surprisingly, ammonium bicarbonate can eliminate the suppression caused by both factors. Mechanistically, ammonium bicarbonate increases the protonation capacity in the gas phase and facilitates proton transfer to the target nucleosides. Benefiting from these findings, we developed a suppression-free, sensitive, and robust ultrahigh-performance LC-MS/MS assay for massive detection of three DNA cytosine modifications, including 5-methyl-2'-deoxycytidine (5mdC), 5hmdC, and 5-formyl-2'-deoxycytidine (5fdC). In 30 consecutive analyses, the relative standard deviation (RSD) of the 5hmdC and 5fdC peak areas is 2.0% and 3.2%, respectively. In this case, no stable isotope-labeled standard is required for internal calibration. We further performed a comprehensive profiling of DNA cytosine modifications in 26 tissues of age-different C57BL/6N mice. Interestingly, we found that only liver 5hmdC abundance increases with the increasing age of adult mice, suggesting that liver 5hmdC might be a potential indicator of age in adulthood.

Development and validation of a liquid chromatography tandem mass spectrometry quantification method for 14 cytotoxic drugs in environmental samples.

RATIONALE: Cytotoxic drug preparation in hospital pharmacies is associated with chronic occupational exposure leading to a risk of adverse effects. The objective was to develop and validate a quantification method for the following cytotoxic drugs in environmental wipe samples: cyclophosphamide, ifosfamide, cytarabine, dacarbazine, docetaxel, paclitaxel, doxorubicin, epirubicin, etoposide, 5-fluorouracil, gemcitabine, irinotecan, methotrexate and pemetrexed. METHODS: The quantification method was developed using liquid chromatography coupled to tandem mass spectrometry and a wiping technique using viscose swabs. Linearity, accuracy, precision, limit of quantification, specificity and stability were assessed, from swab desorbed solution, to validate the analytical method, with respect to ICH guidelines. Environmental samples were collected by wiping five work surfaces of 225 cm2 with viscose swabs, during three days. RESULTS: The quantification method was linear over the calibration range with a lower limit of quantification ranging from 0.5 to 5.0 ng mL-1 depending on the cytotoxic drug. The intra-day and inter-day relative biases were below 1.5% and 13.5%, respectively. This method was successfully applied to surface-wipe sampling and environmental contaminations ranged from 0.7 to 1840.0 ng cm-2 for the most contaminated areas. CONCLUSIONS: This quantification method for 14 cytotoxic drugs was successfully applied to environmental contamination monitoring and could therefore be a useful tool for monitoring and toxicological studies.

A fully validated simple new method for environmental monitoring by surface sampling for cytotoxics.

A wipe sampling procedure followed by a simple ultra-performance liquid chromatography - tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for simultaneous quantification of six cytotoxic drugs: 5-fluorouracil (5FU), doxorubicin (DOXO), epirubicin (EPI), ifosfamide (IF), cyclophosphamide (CP) and gemcitabine (GEM), as surrogate markers for occupational exposure. After a solid-phase extraction of wiping filter on 10 × 10 cm surface, the separation was performed within 6.5 min, using a gradient mobile phase and the analytes were detected by mass spectrometry in the multiple reaction ion monitoring mode. The method was validated according to the recommendations of the US Food and Drug Administration. The method was linear (r2 > 0.9912) between 2.5 and 200 ng per wiping sample (25 to 2000 pg/cm2) for 5FU, doxorubicin and epirubicin and between 0.2 and 40 ng per wiping sample (2 to 400 pg/cm2) for cyclophosphamide, ifosfamide and gemcitabine. The lower limits of quantification were 2.5 ng (25 pg/ cm2) for 5FU, doxorubicin and epirubicin, and 0.2 ng (2 pg/cm2) for CP, IF and GEM. Within-day and between-day imprecisions were <14.0, 10.6, 11.1, 8.7, 11.2 and 10.9% for 5-fluorouracil, doxorubicin, epirubicin, ifosfamide cyclophosphamide and gemcitabine, respectively. The inaccuracies did not exceed 2.7, 10.9, 1.1, 4.5, 1.6 and 2.9% for the studied molecules, respectively. This new sensitive validated method for surface contamination studies of cytotoxics was successfully applied on different localizations in hospital. This approach is particularly suitable to assess occupational exposure risk to cytotoxic drugs.

A DNA aptamer for binding and inhibition of DNA methyltransferase 1.

DNA methyltransferases (DNMTs) are enzymes responsible for establishing and maintaining DNA methylation in cells. DNMT inhibition is actively pursued in cancer treatment, dominantly through the formation of irreversible covalent complexes between small molecular compounds and DNMTs that suffers from low efficacy and high cytotoxicity, as well as no selectivity towards different DNMTs. Herein, we discover aptamers against the maintenance DNA methyltransferase, DNMT1, by coupling Asymmetrical Flow Field-Flow Fractionation (AF4) with Systematic Evolution of Ligands by EXponential enrichment (SELEX). One of the identified aptamers, Apt. #9, contains a stem-loop structure, and can displace the hemi-methylated DNA duplex, the native substrate of DNMT1, off the protein on sub-micromolar scale, leading for effective enzymatic inhibition. Apt. #9 shows no inhibition nor binding activity towards two de novo DNMTs, DNMT3A and DNMT3B. Intriguingly, it can enter cancer cells with over-expression of DNMT1, colocalize with DNMT1 inside the nuclei, and inhibit the activity of DNMT1 in cells. This study opens the possibility of exploring the aptameric DNMT inhibitors being a new cancer therapeutic approach, by modulating DNMT activity selectively through reversible interaction. The aptamers could also be valuable tools for study of the functions of DNMTs and the related epigenetic mechanisms.

Immunohistochemical evaluation of nuclear 5-hydroxymethylcytosine (5-hmC) accurately distinguishes malignant pleural mesothelioma from benign mesothelial proliferations.

Accurate distinction of benign mesothelial proliferations from malignant mesothelioma remains a diagnostic challenge. Sequential use of BAP1 immunohistochemistry and CDKN2A fluorescence in situ hybridization is specific for diagnosis of mesothelioma, but fluorescence in situ hybridization is both costly and time-consuming. Early data indicate that mesothelioma shows extensive loss of nuclear 5-hydroxymethylcytosine (5-hmC). We studied 49 cases of mesothelioma (17 epithelioid mesothelioma, 22 biphasic mesothelioma, and 10 sarcomatoid mesothelioma) and 23 benign mesothelial proliferations using a 5-hmC single immunohistochemical stain, CAM5.2/5-hmC double immunohistochemical stain, and BAP1 immunohistochemistry. Estimations of extent of 5-hmC loss were made using the 5-hmC single stain and CAM5.2/5-hmC double stain, and extent of nuclear 5-hmC loss was definitively quantitated in at least 1000 cells per case. Mean nuclear 5-hmC loss in mesothelioma (84%) was significantly greater than in benign mesothelial proliferations (4%) (p < 0.0001). Using 5-hmC loss in > 50% of tumor nuclei to define the diagnosis of mesothelioma, 5-hmC immunohistochemistry showed sensitivity of 92% and specificity of 100%. An immunopanel including 5-hmC and BAP1 immunohistochemistry achieved sensitivity of 98% and specificity of 100%. Extensive nuclear 5-hmC loss is sensitive and specific for mesothelioma in the differential diagnosis with benign mesothelial proliferations. In challenging mesothelial lesions, immunohistochemical studies showing either extensive 5-hmC loss or BAP1 loss indicate a diagnosis of mesothelioma, precluding the need for CDKN2A fluorescence in situ hybridization in a considerable number of cases.

Development, validation, and clinical application of a high-performance liquid chromatography-tandem mass spectrometry assay for the quantification of total intracellular ß-decitabine nucleotides and genomic DNA incorporated ß-decitabine and 5-methyl-2'-deoxycytidine.

DNA hypermethylation is an epigenetic event that is commonly found in malignant cells and is used as a therapeutic target for ß-decitabine (ß-DEC) containing hypomethylating agents (eg Dacogen® and guadecitabine). ß-DEC requires cellular uptake and intracellular metabolic activation to ß-DEC triphosphate before it can get incorporated into the DNA. Once incorporated in the DNA, ß-DEC can exert its hypomethylating effect by trapping DNA methyltransferases (DNMTs), resulting in reduced 5-methyl-2'-deoxycytidine (5mdC) DNA content. ß-DEC DNA incorporation and its effect on DNA methylation, however, have not yet been investigated in patients treated with ß-DEC containing therapies. For this reason, we developed and validated a sensitive and selective LC-MS/MS method to determine total intracellular ß-DEC nucleotide (ß-DEC-XP) concentrations, as well as to quantify ß-DEC and 5mdC DNA incorporation relative to 2'-deoxycytidine (2dC) DNA content. The assay was successfully validated according to FDA and EMA guidelines in a linear range from 0.5 to 100 ng/mL (ß-DEC), 50 to 10,000 ng/mL (2dC), and 5 to 1,000 ng/mL (5mdC) in peripheral blood mononuclear cell (PBMC) lysate. An additional calibrator at a concentration of 0.1 ng/mL was added for ß-DEC to serve as a limit of detection (LOD). Clinical applicability of the method was demonstrated in patients treated with guadecitabine. Our data support the use of the validated LC-MS/MS method to further explore the intracellular pharmacokinetics in patients treated with ß-DEC containing hypomethylating agents.

Closed-system drug-transfer devices plus safe handling of hazardous drugs versus safe handling alone for reducing exposure to infusional hazardous drugs in healthcare staff.

BACKGROUND: Occupational exposure to hazardous drugs can decrease fertility and result in miscarriages, stillbirths, and cancers in healthcare staff. Several recommended practices aim to reduce this exposure, including protective clothing, gloves, and biological safety cabinets ('safe handling'). There is significant uncertainty as to whether using closed-system drug-transfer devices (CSTD) in addition to safe handling decreases the contamination and risk of staff exposure to infusional hazardous drugs compared to safe handling alone. OBJECTIVES: To assess the effects of closed-system drug-transfer of infusional hazardous drugs plus safe handling versus safe handling alone for reducing staff exposure to infusional hazardous drugs and risk of staff contamination. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, OSH-UPDATE, CINAHL, Science Citation Index Expanded, economic evaluation databases, the World Health Organization International Clinical Trials Registry Platform, and ClinicalTrials.gov to October 2017. SELECTION CRITERIA: We included comparative studies of any study design (irrespective of language, blinding, or publication status) that compared CSTD plus safe handling versus safe handling alone for infusional hazardous drugs. DATA COLLECTION AND ANALYSIS: Two review authors independently identified trials and extracted data. We calculated the risk ratio (RR) and mean difference (MD) with 95% confidence intervals (CI) using both fixed-effect and random-effects models. We assessed risk of bias according to the risk of bias in non-randomised studies of interventions (ROBINS-I) tool, used an intracluster correlation coefficient of 0.10, and we assessed the quality of the evidence using GRADE. MAIN RESULTS: We included 23 observational cluster studies (358 hospitals) in this review. We did not find any randomised controlled trials or formal economic evaluations. In 21 studies, the people who used the intervention (CSTD plus safe handling) and control (safe handling alone) were pharmacists or pharmacy technicians; in the other two studies, the people who used the intervention and control were nurses, pharmacists, or pharmacy technicians. The CSTD used in the studies were PhaSeal (13 studies), Tevadaptor (1 study), SpikeSwan (1 study), PhaSeal and Tevadaptor (1 study), varied (5 studies), and not stated (2 studies). The studies' descriptions of the control groups were varied. Twenty-one studies provide data on one or more outcomes for this systematic review. All the studies are at serious risk of bias. The quality of evidence is very low for all the outcomes.There is no evidence of differences in the proportion of people with positive urine tests for exposure between the CSTD and control groups for cyclophosphamide alone (RR 0.83, 95% CI 0.46 to 1.52; I² = 12%; 2 studies; 2 hospitals; 20 participants; CSTD: 76.1% versus control: 91.7%); cyclophosphamide or ifosfamide (RR 0.09, 95% CI 0.00 to 2.79; 1 study; 1 hospital; 14 participants; CSTD: 6.4% versus control: 71.4%); and cyclophosphamide, ifosfamide, or gemcitabine (RR not estimable; 1 study; 1 hospital; 36 participants; 0% in both groups).There is no evidence of a difference in the proportion of surface samples contaminated in the pharmacy areas or patient-care areas for any of the drugs except 5-fluorouracil, which was lower in the CSTD group than in the control (RR 0.65, 95% CI 0.43 to 0.97; 3 studies, 106 hospitals, 1008 samples; CSTD: 9% versus control: 13.9%).The amount of cyclophosphamide was lower in pharmacy areas in the CSTD group than in the control group (MD -49.34 pg/cm², 95% CI -84.11 to -14.56, I² = 0%, 7 studies; 282 hospitals, 1793 surface samples). Additionally, one interrupted time-series study (3 hospitals; 342 samples) demonstrated a change in the slope between pre-CSTD and CSTD (3.9439 pg/cm², 95% CI 1.2303 to 6.6576; P = 0.010), but not between CSTD and post-CSTD withdrawal (-1.9331 pg/cm², 95% CI -5.1260 to 1.2598; P = 0.20). There is no evidence of difference in the amount of the other drugs between CSTD and control groups in the pharmacy areas or patient-care areas.None of the studies report on atmospheric contamination, blood tests, or other measures of exposure to infusional hazardous drugs such as urine mutagenicity, chromosomal aberrations, sister chromatid exchanges, or micronuclei induction.None of the studies report short-term health benefits such as reduction in skin rashes, medium-term reproductive health benefits such as fertility and parity, or long-term health benefits related to the development of any type of cancer or adverse events.Five studies (six hospitals) report the potential cost savings through the use of CSTD. The studies used different methods of calculating the costs, and the results were not reported in a format that could be pooled via meta-analysis. There is significant variability between the studies in terms of whether CSTD resulted in cost savings (the point estimates of the average potential cost savings ranged from (2017) USD -642,656 to (2017) USD 221,818). AUTHORS' CONCLUSIONS: There is currently no evidence to support or refute the routine use of closed-system drug transfer devices in addition to safe handling of infusional hazardous drugs, as there is no evidence of differences in exposure or financial benefits between CSTD plus safe handling versus safe handling alone (very low-quality evidence). None of the studies report health benefits.Well-designed multicentre randomised controlled trials may be feasible depending upon the proportion of people with exposure. The next best study design is interrupted time-series. This design is likely to provide a better estimate than uncontrolled before-after studies or cross-sectional studies. Future studies may involve other alternate ways of reducing exposure in addition to safe handling as one intervention group in a multi-arm parallel design or factorial design trial. Future studies should have designs that decrease the risk of bias and enable measurement of direct health benefits in addition to exposure. Studies using exposure should be tested for a relevant selection of hazardous drugs used in the hospital to provide an estimate of the exposure and health benefits of using CSTD. Steps should be undertaken to ensure that there are no other differences between CSTD and control groups, so that one can obtain a reasonable estimate of the health benefits of using CSTD.

Quantification and tracking of genetically engineered dendritic cells for studying immunotherapy.

PURPOSE: Genetically encoded reporters can assist in visualizing biological processes in live organisms and have been proposed for longitudinal and noninvasive tracking of therapeutic cells in deep tissue. Cells can be labeled in situ or ex vivo and followed in live subjects over time. Nevertheless, a major challenge for reporter systems is to identify the cell population that actually expresses an active reporter. METHODS: We have used a nucleoside analog, pyrrolo-2'-deoxycytidine, as an imaging probe for the putative reporter gene, Drosophila melanogaster 2'-deoxynucleoside kinase. Bioengineered cells were imaged in vivo in animal models of brain tumor and immunotherapy using chemical exchange saturation transfer MRI. The number of transduced cells was quantified by flow cytometry based on the optical properties of the probe. RESULTS: We performed a comparative analysis of six different cell lines and demonstrate utility in a mouse model of immunotherapy. The proposed technology can be used to quantify the number of labeled cells in a given region, and moreover is sensitive enough to detect less than 10,000 cells. CONCLUSION: This unique technology that enables efficient selection of labeled cells followed by in vivo monitoring with both optical and MRI. Magn Reson Med 79:1010-1019, 2018. © 2017 International Society for Magnetic Resonance in Medicine.

Monitoring Surface Contamination by Antineoplastic Drugs in Italian Hospitals: Performance-Based Hygienic Guidance Values (HGVs) Project.

Antineoplastic drugs (ADs) will continue to represent a potential risk for personnel involved in the handling of these compounds and great concerns have been raised by the presence of ADs in many surveyed workplaces. Eight hospitals were investigated by means of wipe sampling for surface residue determination. Each wipe sample was tested for five ADs considered suitable exposure markers. Cyclophosphamide (CP), gemcitabine (GEM), 5-fluorouracil (5-FU), platinum-containing drugs (Pt), and epi-doxorubicin (EPI) contamination levels were measured in 85 per cent of the studied pharmacies and 93 per cent of outpatient care units (OpCUs). This study showed that 83 out of 349 samples were positive in Pharmacies, this proportion being statistically significant (χ2 = 42.9, p < 0.001). The positive samples provided evidence of at least one substance with levels greater than the limit of detection (LOD). The two most frequently detected substances were Pt (42%) and CP (30%). These accounted for 72 per cent of the whole dataset, followed by 5-FU and GEM. Based on the 90th percentile of wipe sampling data distribution, we suggest hygienic guidance values (HGVs) of 3.6, 1.0, 0.9, and 0.5 ng cm-2 for CP, 5-FU, GEM and Pt, respectively, as the best target levels of the surface contamination load in Italian pharmacies. The approach of proposing guidance values at the 90th percentile of results obtained from workplaces with good hygiene practice was found to be a simple and practical way of controlling occupational exposure. HGVs were challenged in this study as technical threshold limits to benchmark AD residual surface contamination at workplaces.

HPLC method development, validation, and impurity characterization of a potent antitumor nucleoside, T-dCyd (NSC 764276).

An HPLC method for the assay of an anticancer nucleoside, 4'-thio-2'-deoxycytidine (T-dCyd, NSC 764276), has been developed and validated. The stress testing of T-dCyd was carried out in accordance with ICH guidelines Q1A (R2) under acidic, alkaline, oxidative, thermolytic, and photolytic conditions. The separation of T-dCyd from its impurities and degradation products was achieved in 40min on a Luna® Phenyl-Hexyl column (150mm×4.6mm i.d., 3µm) with a gradient elution using ammonium phosphate buffer (pH 3.85) and methanol as the mobile phase. The gradient starts from 2% and ends at 80% of methanol. Detection is by UV at 282nm. LC-QTOF/MS was used to obtain mass data for characterization of impurities and degradation products. The proposed HPLC assay method was validated for specificity, linearity (concentration range 0.25-0.75mg/mL, r≥0.9998), accuracy (recovery 98.1-102.0%), precision (RSD≤1.5%), and sensitivity (LOD 0.1µg/mL). The developed method was suitable for the quality control and stability monitoring of the T-dCyd drug substance.

Irreversible electroporation enhances delivery of gemcitabine to pancreatic adenocarcinoma.

INTRODUCTION: Irreversible electroporation (IRE) utilizes short, high-voltage pulses to irreversibly permeabilize the cell membrane, resulting in apoptotic cell death. In addition to the irreversible zone, IRE creates a reversible zone that could be utilized for enhanced drug delivery. The hypothesis of this study is that a zone of reversible electroporation exists and allows for increased chemotherapy delivery. METHODS: Ten immunocompromised mice with orthotopic human pancreatic adenocarcinoma tumors (Panc1) were treated with either IRE between two doses of gemcitabine (15 mg/kg) (ECT) (N = 5) or gemcitabine alone (N = 5). Gemcitabine levels in the serum, liver, and pancreas were analyzed with liquid chromatography/mass spectrometry (LC/MS). RESULTS: Concentration of gemcitabine within reversibly electroporated pancreatic tissue was higher in mice receiving ECT compared to those receiving gemcitabine alone (13,567 ng/ml vs.4,126 ng/ml; P = 0.0009). Pancreatic gemcitabine levels were 5.52 and 5.96 times higher than liver and serum levels, respectively, in the ECT group compared to 2.85 and 2.53 times higher (P = 0.117, P = 0.058), respectively, in mice receiving gemcitabine alone. CONCLUSION: IRE can potentially reduce local recurrence by allowing increased drug delivery to the tissue in the reversible electroporation zone. This holds significant potential in augmenting efficacy of gemcitabine in treatment of locally advanced and borderline resectable pancreatic adenocarcinoma. J. Surg. Oncol. 2016;114:181-186. © 2016 Wiley Periodicals, Inc.

Electrochemical DNA biosensor based on poly(2,6-pyridinedicarboxylic acid) modified glassy carbon electrode for the determination of anticancer drug gemcitabine.

In this study, a simple methodology was used to develop a new electrochemical DNA biosensor based on poly(2,6-pyridinedicarboxylic acid) (P(PDCA)) modified glassy carbon electrode (GCE). This modified electrode was used to monitor for the electrochemical interaction between the dsDNA and gemcitabine (GEM) for the first time. A decrease in oxidation signals of guanine after the interaction of the dsDNA with the GEM was used as an indicator for the selective determination of the GEM via differential pulse voltammetry (DPV). The guanine oxidation peak currents were linearly proportional to the concentrations of the GEM in the range of 1-30mgL(‒1). Limit of detection (LOD) and limit of quantification (LOQ) were found to be 0.276mgL(‒1) and 0.922mgL(‒1), respectively. The reproducibility, repeatability, and applicability of the analysis to pharmaceutical dosage forms and human serum samples were also examined. In addition to DPV method, UV-vis and viscosity measurements were utilized to propose the interaction mechanism between the GEM and the dsDNA. The novel DNA biosensor could serve for sensitive, accurate and rapid determination of the GEM.

High-Sensitivity and High-Efficiency Detection of DNA Hydroxymethylation in Genomic DNA by Multiplexing Electrochemical Biosensing.

DNA hydroxymethylation (5-hmC) is a kind of new epigenetic modification, which plays key roles in DNA demethylation, genomic reprogramming, and the gene expression in mammals. For further exploring the functions of 5-hmC, it is necessary to develop sensitive and selective methods for detecting 5-hmC. Herein, we developed a novel multiplexing electrochemical (MEC) biosensor for 5-hmC detection based on the glycosylation modification of 5-hmC and enzymatic signal amplification. The 5-hmC was first glycosylated by T4 ß-glucosyltransferase and then oxidated by sodium periodate. The resulting glucosyl-modified 5-hmC (5-ghmC) was incubated with ARP-biotin and was bound to avidin-HRP. The 5-hmC can be detected at the subnanogram level. Finally, we performed 5-hmC detection for mouse tissue samples and cancer cell lines. The limit of detection of the MEC biosensor is 20 times lower than that of commercial kits based on optical meaurement. Also, the biosensor presented high detection specificity because the chemical reaction for 5-hmC modification can not happen at any other unhydroxymethylated nucleic acid bases. Importantly, benefited by its multiplexing capacity, the developed MEC biosensor showed excellent high efficiency, which was time-saving and cost less.

Decrease of TET2 expression and increase of 5-hmC levels in myeloid sarcomas.

BACKGROUND: Myeloid sarcoma is a tumor mass that consists of myeloblasts or immature myeloid cells at an extramedullary site. Pathological diagnosis is very difficult based on morphology if systemic signs of disease are absent. The subtype of myeloid sarcoma is also minimally identifiable in the histological picture. FINDINGS: We investigated 18 paraffin-embedded myeloid sarcoma samples, and our immunohistochemical data confirmed the relevance of some key markers for the diagnosis and subclassification of myeloid sarcoma. CD34 was found as a marker in 67% of the myeloid sarcoma cases, and CD34 was positive in all immature types of myeloid sarcoma. CD68 was found in 83% of the myeloid sarcoma cases, but CD68 was most identified in the differentiated type of myeloid sarcoma. Myeloperoxidase (MPO) was positive in all myeloid sarcomas. Notably, the reactivity of MPO in the blastic subtype was much lower in myeloid sarcomas. CD117 reactivity was found in 67% of myeloid sarcomas. Ten-eleven translocation 2 (TET2) protein exhibited significant negative reactivity in 88% of the cases, and 5-methylcytosine (5-hmC) was significantly positive in the nucleus in 100% of the cases. CONCLUSIONS: Our findings indicated that an immunohistochemical panel that included MPO, CD68 and CD34 could be used for the detection of blastic, differentiated and immature types of myeloid sarcoma. Changes in novel epigenetic regulators, including the loss of TET2 and gain of 5-hmC, as characteristics of myeloid malignancies may be useful novel markers of myeloid sarcoma.

Accurate, Direct, and High-Throughput Analyses of a Broad Spectrum of Endogenously Generated DNA Base Modifications with Isotope-Dilution Two-Dimensional Ultraperformance Liquid Chromatography with Tandem Mass Spectrometry: Possible Clinical Implication.

Our hereby presented methodology is suitable for reliable assessment of the most common unavoidable DNA modifications which arise as a product of fundamental metabolic processes. 8-Oxoguanine, one of the oxidatively modified DNA bases, is a typical biomarker of oxidative stress. A noncanonical base, uracil, may be also present in small quantities in DNA. A set of ten-eleven translocation (TET) proteins are involved in oxidation of 5-methylcytosine to 5-hydroxymethylcytosine which can be further oxidized to 5-formylcytosine and 5-carboxycytosine. 5-Hydroxymethyluracil may be formed in deamination reaction of 5-hydroxymethylcytosine or can be also generated by TET enzymes. All of the aforementioned modifications seem to play some regulatory roles. We applied isotope-dilution automated online two-dimensional ultraperformance liquid chromatography with tandem mass spectrometry (2D-UPLC-MS/MS) for direct measurement of the 5-methyl-2'-deoxycytidine, 5-(hydroxymethyl)-2'-deoxycytidine, 5-formyl-2'-deoxycytidine, 5-carboxy-2'-deoxycytidine, 5-(hydroxymethyl)-2'-deoxyuridine, 2'-deoxyuridine, and 8-oxo-2'-deoxyguanosine. Analyses of DNA extracted from matched human samples showed that the 5-(hydroxymethyl)-2'-deoxycytidine level was 5-fold lower in colorectal carcinoma tumor in comparison with the normal one from the tumor's margin; also 5-formyl-2'-deoxycytidine and 5-carboxy-2'-deoxycytidine were lower in colorectal carcinoma tissue (ca. 2.5- and 3.5-fold, respectively). No such differences was found for 2'-deoxyuridine and 5-(hydroxymethyl)-2'-deoxyuridine. The presented methodology is suitable for fast, accurate, and complex evaluation of an array of endogenously generated DNA deoxynucleosides modifications. This novel technique could be used for monitoring of cancer and other diseases related to oxidative stress, aberrant metabolism, and environmental exposure. Furthermore, the fully automated two-dimensional separation is extremely useful for analysis of material containing a considerable amount of coeluting interferents with mass-spectrometry-based methods.

Development and validation of a stability indicating isocratic HPLC method for gemcitabine with application to drug release from poly lactic-co-glycolic acid nanoparticles and enzymatic degradation studies.

OBJECTIVES: Previously reported HPLC methods for gemcitabine determination are time-consuming with complicated mobile phases and gradient elution. Thus, a sensitive and stability-indicating isocratic HPLC method, which provides simple, fast and precise measurements, was developed. This method was applied to study the digestive enzymatic degradation of gemcitabine, for the first time, and the protection afforded following incorporation into poly lactic-co-glycolic acid (PLGA) nanoparticles. METHODS: An analytical HPLC method was developed with an optimized combination of operating conditions. Forced degradation and application of the method to in-vitro drug release studies were conducted. Finally, gemcitabine-loaded nanoparticles were exposed to the digestive enzymes pepsin, trypsin and α-chymotrypsin, and the resulting degradation evaluated. KEY FINDINGS: The analytical method was linear between 1 and 100 µg/ml, with excellent accuracy of 99.91-101.77% and precision of 1.71 or lower, with a 0.014 µg/ml limit of detection (LOD) and a 0.043 µg/ml limit of quantification (LOQ). Following exposure of gemcitabine to stressors, the drug was relatively stable in strong acid (1 N HCl), base (1 N NaOH) and as an aqueous solution exposed to light over 7 days, with less than 10% degradation. However, gemcitabine was more susceptible to degradation at 70°C and oxidative conditions (3% v/v H2 O2 ) with greater than 10% degradation noted after 7 days. In-vitro drug release studies demonstrated a sustained drug release profile from PLGA nanoparticles, which also improved the resistance of gemcitabine to enzymatic degradation. CONCLUSION: These results demonstrate the utility and effectiveness of this simple isocratic HPLC method in evaluating the overall performance of a gemcitabine-loaded formulation.