Needle-in-needle electrochemical sensor for in-vivo monitoring of anticancer drug etoposide.

Therapeutic drug monitoring (TDM) serves as a potent tool for adjusting drug concentration within a reasonable range. However, continuous monitoring of anticancer drugs in-vivo presents a significant challenge. Herein, we propose a needle-in-needle electrochemical sensor based on an acupuncture needle electrode, capable of monitoring the anticancer drug etoposide in the peritoneal cavity of living rats. The acupuncture needle was modified with Au nanoparticles and etoposide-templated molecularly imprinted polymer (MIP), resulting in high sensitivity and selectivity in the electrochemical detection of etoposide. The modified acupuncture needle (0.16 mm diameter) was anchored inside a syringe needle (1.40 mm diameter), allowing the outer syringe needle to protect the modified materials of the inner acupuncture needle during skin piercing. Due to the unique needle-in-needle design, high stability was obtained during in-vivo etoposide monitoring. Connecting to a smartphone-controlled portable electrochemical workstation, the needle-in-needle sensor offers great convenience in point-of-care TDM. Moreover, the electrode materials on the acupuncture needle were carefully characterized and optimized. Under the optimized conditions, low detection limits and wide linear range were achieved. This work provides new insights into acupuncture needle electrochemical sensors and further expands the feasibility for real-time and in-vivo detection.

Micro/nanofluidic device for tamsulosin therapeutic drug monitoring in patients with benign prostatic hyperplasia at point of care.

Discovering the balance between toxicity and efficacy for many drugs requires therapeutic drug monitoring (TDM) of their concentrations in the blood. Here, a hot-embossed microfluidic device with a new design integrated to a nanofracture is presented for purification of blood samples from numerous proteins and cells, allowing to the separation of small molecules from blood matrix. The device was used to separate and quantitatively detect tamsulosin drug after derivatization with fluorescamine reagent, allowing converting it from a neutral molecule into a charged fluorescent complex under the experimental conditions, and thus its separation by electrophoresis. The device is portable and easy operated, and the presented method showed good linearity (R2 = 0.9948) over a concentration range of 0.1-1 µg/mL. The relative standard deviation (RSD%) was below 10% (n = 3), indicating good precisions, and the limit of detection (LOD) and limit of quantitation (LOQ) values were estimated to be 0.1 and 0.55 µg/mL, respectively. Whole blood samples from 10 patients with benign prostatic hyperplasia (BPH) were analyzed, showing good percentage recoveries of tamsulosin in whole blood. This point-of-care (POC), low-cost method could increase the convenience of patients and doctors, make therapies safer, and make TDM available in different regions and places.

Evaluation of Busulfan as a Third-Party Immunoassay on a Clinical Chemistry Analyzer.

BACKGROUND: Busulfan is widely used in conditioning regimens to prepare patients for hematopoietic stem cell transplantation. Therapeutic drug monitoring (TDM) is critical due to large inter- and intra-individual variability in busulfan pharmacokinetics, and the risk of adverse consequences of toxicity including hepatic veno-occlusive disease. Busulfan is most commonly measured by liquid chromatography-mass spectrometry (LC-MS/MS), which is not as widely available in clinical laboratories as automated routine clinical chemistry analyzers. The objective was to perform analytical verification of a busulfan immunoassay on the Abbott Alinity c platform. METHODS: The MyCare Oncology busulfan immunoassay was configured as a third-party reagent on the Abbott Alinity c. Imprecision, linearity, sample carryover, and onboard stability of reagent studies were evaluated. The performance of the busulfan immunoassay using the Abbott Alinity c was compared to the Beckman Coulter AU480 using sodium heparinized plasma, as well as to LC-MS/MS using lithium heparinized plasma. RESULTS: The imprecision goal of 8% was met, and linearity within the analytical measurement range of 240 to 1700 ng/mL was verified. Sample carryover was negligible, and the reagents were stable onboard for at least 84 days. The busulfan immunoassay correlated well with LC-MS/MS (slope = 0.949, y-intercept = -7.8 ng/mL, r2 = 0.9935) and the Beckman Coulter AU480 (slope = 1.090, y-intercept = -34.5 ng/mL, r2 = 0.9988). CONCLUSIONS: This study demonstrated successful analytical verification of a busulfan third-party immunoassay on the Abbott Alinity c platform. The ability to perform TDM of busulfan on a routine clinical chemistry analyzer will positively impact turnaround times to improve patient outcomes.

A retrospective analysis to estimate trough concentrations of teicoplanin in patients with suspected or documented Gram-positive infections

Abstract Teicoplanin is a glycopeptide antibiotic commonly used to treat Gram-positive bacterial infections in the clinic. The aim of this study was to provide a therapeutic reference for the clinical application and dosage regimen adjustment of teicoplanin by identifying factors associated with its plasma trough concentration (Ctrough). A retrospective study was performed on patients with suspected or documented Gram-positive infections who were hospitalized from November 2017 to January 2020 and treated with teicoplanin while undergoing routine therapeutic drug monitoring (TDM). A total of 112 Ctrough trough measurements were obtained from 72 patients were included in this study. SPSS software was used for correlation analysis and receiver operator characteristic curve (ROC) analysis. The Ctrough for teicoplanin showed statistically significant relationships (P<0.05) with PLT, Scr, CLcr, eGFR, BUN and Cys-C. ROC curve analysis revealed that CLcr and eGFR were more sensitive and specific for Ctrough compared to the other factors. These findings should be considered in the clinical application of teicoplanin and for its dosage adjustment.

Preliminary results using a kit to measure tamoxifen and metabolites concentrations in capillary blood samples from women with breast cancer.

The aim of the study was to compare 3 blood sampling methods, including capillary blood sampling, for determining Tamoxifen (TAM), Z-endoxifen (END), and 4-hydroxytamoxifen (4HT) concentrations. High performance liquid chromatography-mass spectrometry was used to quantify concentrations of TAM, END, and 4HT in plasma, venous blood, and capillary blood samples of 16 participants on TAM therapy for breast cancer. The rhelise kit was used for capillary sampling. Calibration curves using 13C-labeled analogs of TAM, END, and 4HT as internal standards were used for quantifications. A capillary sampling kit was used successfully for all participants. Mean TAM concentrations did not differ significantly in the 3 types of samples. Mean END and 4HT concentrations did differ significantly between capillary and venous blood samples, possibly related to photodegradation in the internal standards prior to use or degradation products with chromatographic retention times similar to the metabolites. TAM, END, and 4HT concentrations were relatively stable when stored for 14 days at 8 °C and 20 °C. Therapeutic drug monitoring of TAM using an innovative kit and capillary blood sampling is feasible. Preliminary data from this study will aid in developing a multicenter, randomized clinical trial of personalized TAM dose monitoring and adjustments, with the goal of enhancing the quality-of-life and outcomes of patients with breast cancer.Clinical Trial Identification: EudraCT No 2017-000641-44.

Therapeutic drug monitoring of gabapentin: the applicability in patients with neuropathic pain

Abstract Gabapentin is an antiepileptic drug prescribed for several neuropathic pain conditions. This study aimed to evaluate gabapentin (GAB) trough plasma concentration range and the applicability of therapeutic drug monitoring in patients with neuropathic pain. Fifty-three patients with neuropathic pain, aged 20 to 75, received gabapentin as treatment for at least 7 days. Gabapentin plasma concentration was sampled before GAB administration and quantified by liquid chromatography with a UV detector. GAB trough plasma concentration ranged between 0.40 and 11.94 µg/mL in patients with chronic neuropathic pain. No differences were observed in terms of GAB plasma concentrations between responsive and non-responsive patients. Our data suggest that the reference ranges suggested in the literature for patients with epilepsy should not be used for patients with neuropathic pain. Therapeutic drug monitoring of GAB was shown to be an important tool to assess treatment adherence.

Management of Iron Overload in Beta-Thalassemia Patients: Clinical Practice Update Based on Case Series.

Thalassemia syndromes are characterized by the inability to produce normal hemoglobin. Ineffective erythropoiesis and red cell transfusions are sources of excess iron that the human organism is unable to remove. Iron that is not saturated by transferrin is a toxic agent that, in transfusion-dependent patients, leads to death from iron-induced cardiomyopathy in the second decade of life. The availability of effective iron chelators, advances in the understanding of the mechanism of iron toxicity and overloading, and the availability of noninvasive methods to monitor iron loading and unloading in the liver, heart, and pancreas have all significantly increased the survival of patients with thalassemia. Prolonged exposure to iron toxicity is involved in the development of endocrinopathy, osteoporosis, cirrhosis, renal failure, and malignant transformation. Now that survival has been dramatically improved, the challenge of iron chelation therapy is to prevent complications. The time has come to consider that the primary goal of chelation therapy is to avoid 24-h exposure to toxic iron and maintain body iron levels within the normal range, avoiding possible chelation-related damage. It is very important to minimize irreversible organ damage to prevent malignant transformation before complications set in and make patients ineligible for current and future curative therapies. In this clinical case-based review, we highlight particular aspects of the management of iron overload in patients with beta-thalassemia syndromes, focusing on our own experience in treating such patients. We review the pathophysiology of iron overload and the different ways to assess, quantify, and monitor it. We also discuss chelation strategies that can be used with currently available chelators, balancing the need to keep non-transferrin-bound iron levels to a minimum (zero) 24 h a day, 7 days a week and the risk of over-chelation.

Saliva versus Plasma Therapeutic Drug Monitoring of Gentamicin in Jordanian Preterm Infants. Development of a Physiologically-Based Pharmacokinetic (PBPK) Model and Validation of Class II Drugs of Salivary Excretion Classification System.

Gentamicin has proven to be a very successful treatment for bacterial infection, but it also can cause adverse effects, especially ototoxicity, which is irreversible. Therapeutic drug monitoring (TDM) in saliva is a more convenient non-invasive alternative compared to plasma. A physiologically-based pharmacokinetic (PBPK) model of gentamicin was built and validated using previously-published plasma and saliva data. The validated model was then used to predict experimentally-observed plasma and saliva gentamicin TDM data in Jordanian pediatric preterm infant patients measured using sensitive LCMS/MS method. A correlation was established between plasma and saliva exposures. The developed PBPK model predicted previously reported gentamicin levels in plasma, saliva and those observed in the current study. A good correlation was found between plasma and saliva exposures. The PBPK model predicted that gentamicin in saliva is 5-7 times that in plasma, which is in agreement with observed results. Saliva can be used as an alternative for TDM of gentamicin in preterm infant patients. Exposure to gentamicin in plasma and saliva can reliably be predicted using the developed PBPK model in patients.

Tortuosity-powered microfluidic device for assessment of thrombosis and antithrombotic therapy in whole blood.

Accurate assessment of blood thrombosis and antithrombotic therapy is essential for the management of patients in a variety of clinical conditions, including surgery and on extracorporeal life support. However, current monitoring devices do not measure the effects of hemodynamic forces that contribute significantly to coagulation, platelet function and fibrin formation. This limits the extent to which current assays can predict clotting status in patients. Here, we demonstrate that a biomimetic microfluidic device consisting stenosed and tortuous arteriolar vessels would analyze blood clotting under flow, while requiring a small blood volume. When the device is connected to an inline pressure sensor a clotting time analysis is applied, allowing for the accurate measurement of coagulation, platelets and fibrin content. Furthermore, this device detects a prolonged clotting time in clinical blood samples drawn from pediatric patients on extracorporeal membrane oxygenation receiving anticoagulant therapy. Thus, this tortuosity activated microfluidic device could lead to a more quantitative and rapid assessment of clotting disorders and their treatment.

Towards point of care systems for the therapeutic drug monitoring of imatinib.

Therapeutic drug monitoring is used in the clinical setting in the optimisation of dosages to overcome inter-patient pharmacokinetic variability, increasing efficacy whilst reducing toxicity. Imatinib is a tyrosine kinase inhibitor, displaying large variations in plasma concentrations that impact therapeutic success. As a result, imatinib has been the focus in the development of innovative techniques, aimed at its quantification in plasma. Liquid chromatography coupled with tandem mass spectrometry is currently the gold standard; however, cost and availability of the equipment limit its wider application in clinical settings. Recent advances in the field have shown Raman spectroscopy and electrochemistry to be key techniques for the development of promising analytical tools. This article reviews the latest advances towards less costly, more portable solutions that can be used at the point of care. Graphical abstract.

Monitoring Antiplatelet Aggregation In Vivo and In Vitro by Microtiter Plate Method.

BACKGROUND: The current light transmission aggregation method is a recognized conventional method for platelet function evaluation, but it is time-consuming and poor in parallelism and cannot simultaneously monitor multiple inducers at multiple levels. The microtiter plate method has been established because of the high-throughput characteristic, but it needs more practical applications. OBJECTIVES: To evaluate the microtiter plate method by using aspirin and clopidogrel in vivo and in vitro. METHODS: In vitro, the platelet aggregations inhibited by aspirin (0.3, 1, 3, 10, 30, 90 µM) and clopidogrel (1, 3, 10, 30, 100, 300 µM) were evaluated with the presence of arachidonic acid (AA) and adenosine diphosphate (ADP) agonists. Using the combination index (CI), the effect of the combination of aspirin and clopidogrel on platelet aggregation was evaluated. In vivo, New Zealand rabbits (n = 18) were randomly divided into 3 groups, aspirin group (5 mg/kg, intragastrical gavage [i.g.]), clopidogrel group (14 mg/kg at the first day, followed by 4 mg/kg, i.g.), and the combination of these two drugs, administered (i.g.) continuously for 7 days. Then, the blood was collected to measure platelet aggregation. RESULTS: Different concentrations of AA (12.5, 25, 50, 100 µM) and ADP (1.25, 2.5, 5, 10 µM) could promote platelet aggregation in concentration-dependent manner, and the most stable induction concentrations of AA and ADP were 50 and 5 µM. In vitro, with the above optimized detection system, aspirin and clopidogrel alone or in combination had concentration-dependent antiplatelet aggregation. The combination of aspirin and clopidogrel also showed synergistic inhibition effect within the concentration range studied. In vivo, aspirin and clopidogrel alone or in combination inhibited platelet aggregation induced by multiple concentrations of AA and ADP agonists, and the combined inhibition was more significant during the administration than aspirin or clopidogrel alone. CONCLUSIONS: The improved microtiter plate method combining the use of multiple levels of multiple agonists avoids the variation of the effective inducer concentrations due to individual different response of platelets to agonists. It may be a potential approach in the detection of platelet aggregation.

The utility of a statewide prescription drug-monitoring database vs the Current Opioid Misuse Measure for identifying drug-aberrant behaviors in emergency department patients already on opioids.

BACKGROUND: The most recent guidelines on prescribing opioids from the United States Centers for Disease Control recommend that clinicians not prescribe opioids as first-line therapy for chronic non-cancer pain. If an opioid prescription is considered for a patient already on opioids, prescribers are encouraged to check the statewide prescription drug monitoring database (PDMP). Some additional guidelines recommend screening tools such as the Current Opioid Misuse Measure (COMM) which may also help identify drug-aberrant behaviors. OBJECTIVE: To compare the PDMP and the Current Opioid Misuse Measure (COMM), a commonly-recommended screening tool for patients on opioids, in detecting drug-aberrant behaviors in patients already taking opioids at the time of ED presentation. METHODS: Patients on opioids were enrolled prospectively in a mixed urban-suburban ED seeing approximately 65,000 patients per year. The sensitivity, specificity, likelihood ratios, and diagnostic odds ratios of the PDMP and COMM were compared against objective criteria of drug-aberrant behaviors as documented in the electronic medical record (EMR) and medical examiner databases. RESULTS: Compared to the COMM, the PDMP had similar sensitivity (36% vs 45%) and similar specificity (79% vs 55%), but better positive predictive value, better negative predictive value, and better diagnostic odds ratio. The combination of the PDMP and the COMM did not improve the detection of drug-aberrant behaviors. CONCLUSIONS: The PDMP alone is a more useful as a screening instrument than either the COMM or the combination of the PDMP plus COMM in patients already taking opioids at time of ED presentation. However, the PDMP misses a majority of patients with documented drug-aberrant behaviors in the EMR, and should not be used in isolation to justify whether a particular opioid prescription is appropriate.

Análise da notificação de eventos adversos através da pesquisa de cultura de segurança do paciente / Adverse event notification analysis through patient safety culture research / Análisis de la notificación de eventos adversos a través de la investigación de cultura de seguridad del paciente

Objetivo: a avaliação da cultura de segurança do paciente permite aos hospitais identificar e gerir prospectivamente questões relevantes de segurança em suas rotinas de trabalho. Método: estudo quantitativo, transversal e descritivo, ocorrida no ano de 2017 na Unidade de Terapia Intensiva Adulta em um hospital privado, localizado em Niterói/RJ. A população foram os profissionais médicos e equipe de enfermagem, utilizando análise estatística por meio de programa R, com a interface Rcmdr. Resultados: baseados nas respostas às perguntas sobre notificação de eventos aplicada com a Pesquisa de Cultura de Segurança do Paciente a 97 profissionais, com uma taxa de resposta de 85,6%, correspondendo a 83 profissionais. Menos de 45% dos participantes da pesquisa sempre notificam um erro, engano ou falha, que afete ou não o paciente, 59,0% não fizeram nenhuma notificação nos últimos 12 meses antecedentes à pesquisa e não houve diferença significativa na quantidade de notificação que destacasse uma categoria profissional, graduados ou não. Discussão: houve maior adesão à notificação de eventos pelos com maior tempo de hospital e com maior tempo naquela terapia intensiva. Não se encontrou correlação do número de notificações relatadas com o tempo de profissão e com a carga horária de trabalho. Conclusão: no que tange à conscientização de incrementar a adesão à notificação de eventos, a análise realizada contribuiu para a melhoria da segurança do paciente

Objective: ealuating the patient's safety culture allows hospitals to identify and manage relevant safety issues prospectively in their work routines. Method: a quantitative, transversal and descriptive study, carried out in 2017 at the Adult Intensive Care Unit in a private hospital, located in Niterói / RJ. The population were medical professionals and nursing staff, using statistical analysis through program R, with the Rcmdr interface. Results: based on responses to questions about event notification applied with the Patient Safety Culture Survey to 97 professionals, with a response rate of 85.6%, corresponding to 83 professionals. Less than 45% of respondents report an error, deception, or failure, affecting the patient, 59.0% did not report in the last 12 months prior to the survey, and there was no significant difference in the amount of notification that stood out a professional category, graduates or not. Discussion: there was greater adherence to the notification of events by those with longer hospital time and with more time in that intensive therapy. There was no correlation between the number of reports reported with the time of profession and the workload. Conclusion: with regard to the awareness of increasing adherence to event notification, the analysis performed contributed to the improvement of patient safety

Objetivo: la evaluación de la cultura de seguridad del paciente permite a los hospitales identificar y gestionar prospectivamente cuestiones relevantes de seguridad en sus rutinas de trabajo. Método: estudio cuantitativo, transversal y descriptivo, ocurrido en el año 2017 en la Unidad de Terapia Intensiva Adulta en un hospital privado, ubicado en Niterói / RJ. La población fueron los profesionales médicos y equipo de enfermería, utilizando análisis estadístico por medio del programa R, con la interfaz Rcmdr. Resultados: basados en las respuestas a las preguntas sobre notificación de eventos aplicada con la Encuesta de Cultura de Seguridad del Paciente a 97 profesionales, con una tasa de respuesta del 85,6%, correspondiendo a 83 profesionales. En la mayoría de los casos, la mayoría de las personas que sufren de la enfermedad de Alzheimer, una categoría profesional, graduados o no. Discusión: hubo mayor adhesión a la notificación de eventos por los con mayor tiempo de hospital y con mayor tiempo en aquella terapia intensiva. No se encontró correlación del número de notificaciones relatadas con el tiempo de profesión y con la carga horaria de trabajo. Conclusión: en lo que concierne a la concientización de incrementar la adhesión a la notificación de eventos, el análisis realizado contribuyó a la mejora de la seguridad del paciente

LEGENDplex™: Bead-assisted multiplex cytokine profiling by flow cytometry.

Over the past two decades there have been tremendous advances in our understanding of tumor immunology, which have in turn led to new and exciting immunology-based therapeutics. However, further research is needed into the dynamics and regulation of the immune response in the tumor microenvironment in order to achieve the full potential of these agents in treating all cancer patients. Defining the role of cytokines, chemokines, and other soluble mediators will be essential to this endeavor. This chapter describes, in detail, the technical protocol and applicability of LEGENDplex™ bead-based multiplex assays in quantifying these critical signaling molecules.

Assessment of annexin A1 release during immunogenic cell death.

The protein annexin A1 (ANXA1) belongs to the danger-associated molecular patterns (DAMPs) that alert the innate immune system about tissue perturbations. In the context of immunogenic cell death (ICD), ANXA1 is released from the cytoplasm of dying cells and, once extracellular, acts on formyl peptide receptor 1 (FPR1) expressed on dendritic cells to favor long-term interactions between dying and dendritic cells. As a result, the accumulation of extracellular ANXA1 constitutes one of the hallmarks of ICD. In the past, the detection of ANXA1 was based on semiquantitative immunoblots. More recently, a commercial enzyme-linked immunosorbent assay (ELISA) has been developed to measure ANXA1 in an accurate fashion. Here, we detail the protocol to measure the concentration of ANXA1 in the supernatants of cancer cells treated with chemotherapy.

Estudio comparativo de equipos INR capilar "point of care" versus INR venoso, en pacientes en tratamiento con antagonistas de vitamina K / Comparison of point of care capillary international normalized ratio (INR) with INR measured in venous samples

Background: INR is used to monitor the treatment with vitamin K antagonists. A strategy to reduce waiting times for sampling is to measure INR in a capillary sample using a portable point of care (POC) type coagulometer. Aim: To evaluate the correlation of CoaguChek Pro II™, Xprecia™ and microINR™ with venous INR measured at the clinical laboratory and their ease of use. Materials and Methods: Patients provided capillary and venous blood samples for parallel tests comparing Xprecia™ Stride with CoaguChek Pro II™ and with venous INR, microINR™ with CoaguChek Pro IITM and with venous INR. The devices' ease of use was assessed surveying the sampling staff. Results: The three tested devices had good correlation coefficients with venous INR: CoaguChek Pro IITM 0.953 and 0.962; Xprecia™ of 0.912 and microINR™ of 0.932. The correlation coefficient of Xprecia™ with CoaguChek Pro IITM was 0.937 and microINR™ with CoaguChek Pro IITM was 0.976. Conclusions: CoaguChek Pro IITM, Xprecia™ and microINR™ results had a good correlation coefficient with INR measured at the laboratory. Our results indicate that, in the hands of trained users, POC-type coagulometers are reliable and acceptable for routine use in anticoagulant treatment control.

DNA-SWCNT Biosensors Allow Real-Time Monitoring of Therapeutic Responses in Pancreatic Ductal Adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is a highly desmoplastic cancer with limited treatment options. There is an urgent need for tools that monitor therapeutic responses in real time. Drugs such as gemcitabine and irinotecan elicit their therapeutic effect in cancer cells by producing hydrogen peroxide (H2O2). In this study, specific DNA-wrapped single-walled carbon nanotubes (SWCNT), which precisely monitor H2O2, were used to determine the therapeutic response of PDAC cells in vitro and tumors in vivo. Drug therapeutic efficacy was evaluated in vitro by monitoring H2O2 differences in situ using reversible alteration of Raman G-bands from the nanotubes. Implantation of the DNA-SWCNT probe inside the PDAC tumor resulted in approximately 50% reduction of Raman G-band intensity when treated with gemcitabine versus the pretreated tumor; the Raman G-band intensity reversed to its pretreatment level upon treatment withdrawal. In summary, using highly specific and sensitive DNA-SWCNT nanosensors, which can determine dynamic alteration of hydrogen peroxide in tumor, can evaluate the effectiveness of chemotherapeutics. SIGNIFICANCE: A novel biosensor is used to detect intratumoral hydrogen peroxide, allowing real-time monitoring of responses to chemotherapeutic drugs.

Development and validation of an assay for quantifying budesonide in dried blood spots collected from extremely low gestational age neonates.

Budesonide is a potential therapeutic option for the prevention of bronchopulmonary dysplasia in mechanically ventilated premature neonates. The dose and concentrations of budesonide that drive effective prophylaxis are unknown, due in part to the difficulty in obtaining serial blood samples from this fragile population. Of primary concern is the limited total blood volume available for collection for the purposes of a pharmacokinetic study. Dried blood spots (DBS), which require the collection of <200 µL whole blood to fill an entire card, are an attractive low-blood volume alternative to traditional venipuncture sampling. We describe a simple and sensitive method for determining budesonide concentrations in DBS using an ultra-high-performance liquid chromatography - tandem mass spectrometry assay. Budesonide was liberated from a single 6 mm punch using a basified methyl tert-butyl ether extraction procedure. The assay was determined to be accurate and precise in the dynamic range of 1 to 50 ng/mL. The validated assay was then successfully applied to DBS collected as part of a multi-center, dose-escalation study of budesonide administered in surfactant via intra-tracheal instillation to premature neonates between 23 and 28 weeks gestational age. These findings show that DBS are a useful technique for collecting pharmacokinetic samples in premature neonates and other pediatric populations.

Development of a low-cost electrochemical sensor based on babassu mesocarp (Orbignya phalerata) immobilized on a flexible gold electrode for applications in sensors for 5-fluorouracil chemotherapeutics.

There are increasing concerns regarding the risks arising from the contamination of manipulators of antineoplastic drugs promoted by occupational exposure or even in the dosage of drugs. The present work proposes the use of an electrochemical sensor based on a biopolymer extracted from the babassu coconut (Orbignya phalerata) for the determination of an antineoplastic 5-fluorouracil (5-FU) drug as an alternative for the monitoring of these drugs. In order to reduce the cost of this sensor, a flexible gold electrode (FEAu) is proposed. The surface modification of FEAu was performed with the deposition of a casting film of the biopolymer extracted from the babassu mesocarp (BM) and modified with phthalic anhydride (BMPA). The electrochemical activity of the modified electrode was characterized by cyclic voltammetry (CV), and its morphology was observed by atomic force microscopy (AFM). The FEAu/BMPA showed a high sensitivity (8.8 µA/µmol/L) and low limit of detection (0.34 µmol/L) for the 5-FU drug in an acid medium. Electrochemical sensors developed from the babassu mesocarp may be a viable alternative for the monitoring of the 5-FU antineoplastic in pharmaceutical formulations, because in addition to being sensitive to this drug, they are constructed of a natural polymer, renewable, and abundant in nature. Graphical abstract ᅟ.

Acceleration of nano-surface and molecular-orientation limited (nSMOL) proteolysis with acidified reduction pretreatment for quantification of Tocilizumab.

Antibody drugs are effective therapeutic agents and provide treatment for many types of diseases such as cancer and rheumatoid arthritis. Because many antibody drugs are developed and approved, quantification technologies of antibodies are required for drug development and individualized therapy. We recently reported a high reproducible and robust therapeutic drug monitoring method for antibody drugs. This method was developed to be applicable to all type of antibody drugs and to provide accurate quantification values. The method is named nano-surface and molecular-orientation limited (nSMOL) proteolysis. nSMOL limits the access of protease to immunoglobulin G molecules and aims to selectively proteolyze on Fab region of substrate. However, the bioanalysis of Tocilizumab using nSMOL has not been validated. We newly discovered that acidified reduction pretreatment of Tocilizumab promotes digestive efficiency by nSMOL proteolysis. Exposure of Tocilizumab to Tris(2-carboxyethyl)phosphine hydrochloride before nSMOL proteolysis significantly improved the recovery of peptides. Under this condition, the quantification range of Tocilizumab in human serum was from 0.781 to 200 µg/mL. The quantification values of quality control samples fulfilled all guideline criteria for bioanalytical validation. The signature peptide with the highest quantitative sensitivity was on H-chain VTMLR. From these results, it is expected that the pretreatment with TCEP will broaden the application of antibody drugs quantification by nSMOL proteolysis.