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This work aimed to simplify and improve the process of binding monoclonal antibodies (mAbs) covalently to filter paper for use in dried blood spot sampling, enabling instant capture of protein biomarkers for targeted protein determination. Incorporating the necessary immunocapture sample preparation step in the initial sampling stage saves time and reduces the workload. The biomarker human chorionic gonadotropin (hCG) was used as the model analyte. The antibody‐based paper samplers were prepared by functionalizing paper discs (6 mm) through a simple reaction using divinyl sulfone (DVS). After DVS activation, the paper discs were incubated with E27 hCG mAbs, followed by 0.05% tween/phosphate buffer saline to block the surface. After sample application and drying, the discs only needed to be washed before tryptic digestion and finally analysed on a nanoliquid chromatography–tandem mass spectrometry system. The finished DVS‐mAbs samplers could selectively capture hCG (100 ng/mL) from human serum, with a recovery of 50%. Sample clean‐up reduced the number of identified proteins from 132 to 82 before and after wash, respectively, with a 70% reduction in serum albumin signal while still retaining hCG on the sampler during the washing protocol. An evaluation of the samplers revealed excellent linearity (R2 = 0.9995) for hCG in serum with relative standard deviations below 15%. This work has presented the first ever reported paper samplers immobilized with antibodies utilizing DVS chemistry, showing promise in the future of paper‐based sampling. [ABSTRACT FROM AUTHOR]

Valproic acid (VPA) is mainly used in the clinic to treat epilepsy, for which the therapeutic window is narrow to avoid causing adverse reactions such as hepatotoxicity and teratogenicity. Therefore, timely therapeutic drug monitoring is needed. A hapten containing a benzene ring and an amino group was designed and used to screen a monoclonal antibody (mAb) 3G10 with high specificity and sensitivity. The IC50 value of mAb 3G10 was ascertained as 68.13 ng mL−1 through an indirect competitive enzyme-linked immunosorbent assay. A colloidal gold-based immunochromatographic strip (CG-ICS) for the detection of free VPA in human serum was developed with gold-labeled mAb 3G10. Qualitative analysis of human serum samples can be conducted through visual observation. The visual limit of detection (vLOD) was 2 μg mL−1, and the cut-off value was 100 μg mL−1. A standard curve for quantitative detection was generated using a portable scanner, with a calculated LOD (cLOD) value of 0.144 μg mL−1 and a linear range of 0.565–48.385 μg mL−1. Comparing the results of CG-ICS for actual positive samples with those of a direct chemiluminescence kit, there was a good correlation between the two methods. Therefore, our CG-ICS can be applied to the rapid clinical monitoring of free VPA. [ABSTRACT FROM AUTHOR]

Routine childhood vaccinations are key for the protection of children from a variety of serious and potentially fatal diseases. Current pediatric vaccine schedules mainly cover active vaccines. Active vaccination in infants is a highly effective approach against several infectious diseases; however, thus far, for some important viral pathogens, including respiratory syncytial virus (RSV), vaccine development and license by healthcare authorities have not been accomplished. Nirsevimab is a human-derived, highly potent monoclonal antibody (mAb) with an extended half-life for RSV prophylaxis in all infants. In this manuscript, we consider the potential implications for the introduction of an anti-viral mAb, such as nirsevimab, into the routine pediatric vaccine schedule, as well as considerations for coadministration. Specifically, we present evidence on the general mechanism of action of anti-viral mAbs and experience with palivizumab, the only approved mAb for the prevention of RSV infection in preterm infants, infants with chronic lung disease of prematurity and certain infants with hemodynamically significant heart disease. Palivizumab has been used for over two decades in infants who also receive routine vaccinations without any alerts concerning the safety and efficacy of coadministration. Immunization guidelines (Advisory Committee on Immunization Practices, Joint Committee on Vaccination and Immunization, National Advisory Committee on Immunization, Centers for Disease Control and Prevention, American Academy of Pediatrics, The Association of the Scientific Medical Societies in Germany) support coadministration of palivizumab with routine pediatric vaccines, noting that immunobiologics, such as palivizumab, do not interfere with the immune response to licensed live or inactivated active vaccines. Based on the mechanism of action of the new generation of anti-viral mAbs, such as nirsevimab, which is highly specific targeting viral antigenic sites, it is unlikely that it could interfere with the immune response to other vaccines. Taken together, we anticipate that nirsevimab could be concomitantly administered to infants with routine pediatric vaccines during the same clinic visit.

SARS-CoV-2 has mutated many times since the onset of the COVID-19 pandemic, and the omicron is currently the most dominant variant. Determining the specific strain of the virus is beneficial in providing proper care and containment of the disease. We have previously reported a novel method of counting the number of particle immunoagglutination on a paper microfluidic chip using a smartphone-based fluorescence microscope. A single-copy-level detection was demonstrated from clinical saline gargle samples. In this work, we further evaluated two different SARS-CoV-2 monoclonal antibodies to spike vs. nucleocapsid antigens for detecting omicron vs. delta and spike vs. nucleocapsid proteins. The SARS-CoV-2 monoclonal antibody to nucleocapsid proteins could distinguish omicron from delta variants and nucleocapsid from spike proteins. However, such distinction could not be found with the monoclonal antibody to spike proteins, despite the numerous mutations found in spike proteins among variants. This result may suggest a clue to the role of nucleocapsid proteins in recognizing different variants. [ABSTRACT FROM AUTHOR]

During the past decades autoimmune diseases have been usually treated with immunosuppressive drugs mostly active on T-Cell mediated responses. Only in recent years, with our extended knowledge of the pathogenic mechanisms of autoreactive disorders and the tremendous development of new therapeutic monoclonal antibodies, anti-B-Cell therapies have emerged as a new option for treating autoimmune diseases. The rationale for this changeover from T-Cell to B-Cell targeted therapies resides in the recently accumulated evidence of the role of B-Cells in the pathogenesis of autoimmune diseases and in the generation of tissue damage. Targeting memory and effector BCells may then disrupt the production of pathogenic antibodies, counteract the role of B-Cells in sustaining antigen presentation to T-Cells and block the synthesis of B-Cell activation cytokines. The anti-CD20 monoclonal antibody Rituximab was first introduced more than 20 years ago for the treatment of CD20+ chronic B-lymphoproliferative disorders, and was then successfully experimented in the treatment of an ever-increasing spectrum of autoimmune diseases. Newer anti-CD20 monoclonal antibodies have been introduced more recently, which vary in their biological effects. The need for laboratory indicators that may help the rational usage and follow-up of anti-CD20 treatments has now emerged, due to the high variability of individual response, to the markedly different outcomes in the various diseases and to the controversial role of pathogenic autoantibodies as indicators of disease activity. Flow cytometric (FCM) analyses to identify and enumerate the B-cell functional subsets in the peripheral blood have been developed in recent years. They can be used to assess the degree and the persistence of memory B-Cell depletion, the quality and the timing of B-Cell reconstitution, along with the highly sensitive FCM counting technique needed for the detection of extremely low cell levels. The long-term aim of this innovative approach is to provide clinicians with a tool for a safer and more rational usage of anti-CD20 agents.

In order to achieve a highly sensitive detection of procymidone in vegetables, three paper-based biosensors based on a core biological immune scaffold (CBIS) were developed, which were time-resolved fluorescence immunochromatography strips with Europium (III) oxide (Eu-TRFICS). Goat anti-mouse IgG and europium oxide time-resolved fluorescent microspheres formed secondary fluorescent probes. CBIS was formed by secondary fluorescent probes and procymidone monoclonal antibody (PCM-Ab). The first type of Eu-TRFICS (Eu-TRFICS-(1)) fixed secondary fluorescent probes on a conjugate pad, and PCM-Ab was mixed with a sample solution. The second type of Eu-TRFICS (Eu-TRFICS-(2)) fixed CBIS on the conjugate pad. The third type of Eu-TRFICS (Eu-TRFICS-(3)) was directly mixed CBIS with the sample solution. They solved the problems of steric hindrance of antibody labeling, insufficient exposure of antigen recognition region and easy loss of activity in traditional methods. They realized multi-dimensional labeling and directional coupling. They replaced the loss of antibody activity. And the three types of Eu-TRFICS were compared, among which Eu-TRFICS-(1) was the best detection choice. Antibody usage was reduced by 25% and sensitivity was increased by 3 times. Its detection range was 1–800 ng/mL, the limit of detection (LOD) was 0.12 ng/mL with the visible LOD (vLOD) of 5 ng/mL. [Display omitted] • Time-resolved fluorescent microspheres were applied to CBIS. • The monoclonal antibody usage was reduced by 25% prepared by the CBIS. • The CBIS connect multiple microspheres to one antibody molecule. • The linear range of Eu-TRFICS-(1) used to detect procymidone is 1–800 ng/mL. • Three kinds of Eu-TRFICS used to detect procymidone are constructed and compared. [ABSTRACT FROM AUTHOR]

tert-Butylhydroquinone (TBHQ) residues in foods pose a threat to human health. Therefore, it is necessary to develop a rapid method for TBHQ detection. In this study, a sensitive monoclonal antibody 5C3 (IgG2a subclass) against TBHQ was produced. It possessed a half maximal inhibitory concentration of 7.43 ng mL−1. A gold nanoparticle-based immunochromatographic assay (ICA) was established for the rapid and sensitive screening of TBHQ in soybean oil. Qualitative analysis results were obtained within 10 min and observed with the naked eye. The visual limit of detection (LOD) was 50 ng g−1 and the cut-off value was 1000 ng g−1. A hand-held strip reader was used for quantitative analysis, in which the calculated LOD was defined as 18.68 ng g−1. The average recoveries of TBHQ ranged from 89.55% ± 2.70% to 100.66% ± 3.02% for soybean oil, with a coefficient of variation of 2.89%–7.05%. Therefore, our developed ICA is a useful tool for the rapid and on-site detection of TBHQ in real food samples. [ABSTRACT FROM AUTHOR]

In order to facilitate monitoring of cannabidiol (CBD), we devised a gold immunochromatographic sensor based on a specific monoclonal antibody (mAb). To prepare the antigen, a novel hapten with CBD moiety and a linear carbon chain was employed. By utilizing hybridoma technology, a specific mAb was screened and identified that exhibited a 50% maximal inhibitory concentration against CBD ranging from 28.97 to 443.97 ng/mL. Extensive optimization led to the establishment of visual limits of detection for CBD, achieving a remarkable sensitivity of 8 μg/mL in the assay buffer. To showcase the accuracy and stability, an analysis of CBD-spiked wine, sparkling water, and sports drink was conducted. The recovery rates observed were as follows: 88.4–109.2% for wine, 89.9–107.8% for sparkling water, and 83.2–95.5% for sports drink. Furthermore, the coefficient of variation remained impressively low, less than 4.38% for wine, less than 2.07% for sparkling water, and less than 6.34% for sports drink. Importantly, the developed sensor exhibited no cross-reaction with tetrahydrocannabinol (THC). In conclusion, the proposed paper sensor, employing gold nanoparticles, offers a user-friendly and efficient approach for the precise, rapid, and dependable determination of CBD in products. [ABSTRACT FROM AUTHOR]

Veterinary drug residues in food-producing animals pose a threat to human health and public safety, and accurate measurement of these drug residues is necessary. However, detecting nitrofuran metabolite residues is challenging because of their low molecular weight and the long derivatisation time required for their indirect detection. Current antibodies produced against these metabolites have limited accuracy and sensitivity owing to the traditional and ineffective hapten design based on the reaction of 3-amino-5-morpholinomethyl-2-oxazolidone (AMOZ) with nitrobenzaldehyde. In this study, a new antigen strategy was adopted using an original-structure-based hapten design combined with a new carrier protein with immunosynergistic effects to produce a monoclonal antibody that could recognise the metabolite of furaltadone (AMOZ) directly without derivatisation with excellent analytical performance. Finally, a gold-based paper lateral flow immunoassay for AMOZ without derivatisation was established with a visual limit of detection of 5 ng/mL, IC 50 of 0.97 ng/mL and linear range (IC 20 ∼IC 80) of 0.45–2.07 ng/mL. The method was sensitive and accurate, and detection was completed within 10 min. This new antigen design strategy provides a theoretical basis and reference for antibody production of other ultrasmall molecules. [Display omitted] • An antigen strategy of AMOZ was proposed by hapten design and new carrier proteins. • The excellent antibody directly recognizes AMOZ without derivatization. • Effect of EP distribution and spatial structure to antibody production was studied. • This method could be used as a rapid screening method for AMOZ analysis on site. [ABSTRACT FROM AUTHOR]

The diagnosis of dengue infection is still a critical factor determining success in the clinical management and treatment of patients. Here, the development of microfluidic paper-based analytical devices (μPADs) utilizing a sandwich immunoassay on wax patterned paper functionalized with anti-dengue NS1 monoclonal antibodies for point-of-care detection of dengue NS1 (DEN-NS1-PAD) is reported. Various assay conditions, including the length of the channel and diluent, were optimized, and the response detected by the naked eye and digitized images within 20–30 min. The DEN-NS1-PAD was successfully tested in the field for detecting dengue NS1 in buffer, cell culture media, and human serum. The limit of detection (LoD) of the DEN-NS1-PAD obtained with the naked eye, scanner, and a smartphone camera was 200, 46.7, and 74.8 ng mL−1, respectively. The repeatability, reproducibility, and stability of the DEN-NS1-PAD were also evaluated. High true specificity and sensitivity in the serum of pediatric patients were observed. These evaluation results confirm that the DEN-NS1-PAD can potentially be used in point-of-care dengue diagnostics, which can significantly impact on the spreading of mosquito-borne diseases, which are likely to become more prevalent with the effects of global warming. [ABSTRACT FROM AUTHOR]

We report for the first time a highly sensitive and rapid quantitative method for the detection of Salmonella Typhimurium (S. Typhimurium) using a conductive immunosensor on a paper-based device (PAD). S. Typhimurium monoclonal antibodies (MA) were first immobilized on a paper-based device and then captured by S. Typhimurium. After an immunoreaction on the device, the polyclonal antibody-colloidal gold conjugate (PA-AuNPs) was dropped to bind with S. Typhimurium. After a complete sandwich reaction, a dark red color appeared on the paper-based device, which can be observed by the naked eye for a rapid screening test. The electrical conductivity of PA-AuNPs between the screen-printed electrodes on the paper-based device was also measured for an accurate quantitative analysis. The electrical conductivity correlated well with the concentration of S. Typhimurium, which was controlled by the amount of S. Typhimurium attached to the polyclonal antibody-colloidal gold conjugate. The device showed a linear correlation for the concentration of the S. Typhimurium in the range of 10–108 CFU mL−1 in a logarithmic plot, with an R2 value of 0.9882 and a limit of detection (LOD) as low as 10 CFU mL−1. This simple, highly sensitive, and rapid method for the S. Typhimurium detection was successfully performed within 30 min, and it can be developed into small portable measuring devices in order to facilitate preliminary screening tests. [ABSTRACT FROM AUTHOR]

Berberine (BBR) is a highly effective animal feed additive, but it also has adverse side effects on animals and causes potential food safety issues. Here, based on the preparation of a BBR monoclonal antibody, we developed a rapid, simple and sensitive lateral flow immunoassay (LFIA) using gold nanoparticle (GNP)- and fluorescent microsphere (FM)-labelled BBR antibodies for quantitative detection of BBR in feed samples. Under a hand-held optical scanner, the limits of detection of the GNP-LFIA and FM-LFIA were found to be 4.40 μg kg−1 and 2.00 μg kg−1, respectively, in feed samples. The spiked feed samples had acceptable recovery rates using the LFIAs, and the results were further confirmed by liquid chromatography/mass spectrometry. The actual feed sample test results by GNP-LFIA and FM-LFIA also showed good consistency. These two LFIAs provide a good option for fast screening of BBR on-site in feed samples. [ABSTRACT FROM AUTHOR]

In this study, we describe the design and successful synthesis of a new hapten, which we used to prepare an anti-zilpaterol mouse monoclonal antibody (mAb) with an IC50 of 0.31 ng mL−1 and a limit of detection (LOD) of 0.02 ng mL−1. A colloidal gold immunochromatographic test strip was further developed and optimized using the antibody, and cross-reactivity experiments were carried out to prove its good specificity. Semi-quantitative and quantitative detections of zilpaterol were evaluated in swine urine and pork samples using the test strips. For semi-quantitative detection in swine urine and pork samples, the visual limit of detection values were 0.5 μg kg−1 and 0.5 μg kg−1, and the cut-off values were 5 μg kg−1 and 5 μg kg−1, respectively. For quantitative detection, the calculated limit of detection values were 0.08 μg kg−1 and 0.12 μg kg−1, and the remaining values were 10 μg kg−1 and 10 μg kg−1. The developed gold nanoparticle-based immunochromatographic assay is highly suitable for on-site detection and rapid preliminary screening of zilpaterol in swine urine and pork samples. [ABSTRACT FROM AUTHOR]

Abstract Norfloxacin (NOR) in milk may influence mammalian cell replication and bring about a decrease in the efficiency for treating infection in humans. However, current techniques for detecting NOR usually require expensive instruments and trained personnel. In this work, we have developed a low-cost and simple method via paper-based fluorescent immunoassay for highly sensitive and selective detection of NOR in milk at picogram level. The NOR monoclonal antibody labeled with quantum dots is used as a detection probe to recognize the corresponding NOR, which can quantitatively detect NOR on paper-based devices. The detection limits in aqueous solution and milk are 1 pg/mL and 10 pg/mL, respectively. The developed paper-based method provides a cheap, sensitive, eco-friendly, and rapid approach for quantitative detection of trace NOR in milk, which may find wide applications in food safety inspection. Noteworthy, the method is especially suitable for applications at resource-limited and on-site settings. Graphical abstract fx1 Highlights • Paper-based fluorescent immunoassay using quantum dots-labeled antibody as probe. • Highly sensitive and selective detection of norfloxacin (NOR) in milk on paper. • The fluorescent intensity changes linearly with logarithm of NOR concentration. • The detection limits in solution and milk are 1 pg/mL and 10 pg/mL, respectively. • The paper-based method shows excellent selectivity for detection of NOR. [ABSTRACT FROM AUTHOR]

The current approaches of diagnostic platforms for detecting SARS-CoV-2 infections mostly relied on adapting the existing technology. In this work, a simple and low-cost electrochemical sensing platform for detecting SAR-CoV-2 antigen was established. The proposed sensor combined the innovative disposable paper-based immunosensor and cost-effective plant-based anti-SARS-CoV-2 monoclonal antibody CR3022, expressed in Nicotiana benthamiana. The cellulose nanocrystal was modified on screen-printed graphene electrode to provide the abundant COOH functional groups on electrode surface, leading to the high ability for antibody immobilization. The quantification of the presence receptor binding domain (RBD) spike protein of SARS-CoV-2 was performed using differential pulse voltammetry by monitoring the changing current of [Fe(CN) 6 ]3-/4- redox solution. The current change of [Fe(CN) 6 ]3-/4- before and after the presence of target RBD could be clearly distinguished, providing a linear relationship with RBD concentration in the range from 0.1 pg/mL to 500 ng/mL with the minimum limit of detection of 2.0 fg/mL. The proposed platform was successfully applied to detect RBD in nasopharyngeal swab samples with satisfactory results. Furthermore, the paper-based immunosensor was extended to quantify the RBD level in spiked saliva samples, demonstrating the broadly applicability of this system. This electrochemical paper-based immunosensor has the potential to be employed as a point-of-care testing for COVID-19 diagnosis. [Display omitted] • The electrochemical paper-based device integrated with a label-free immunoassay was developed for detecting SARS-CoV-2. • A novel plant-based mAb CR3022 offers a remarkable simplicity and cost-effectiveness in terms of Ab production. • CNC containing the abundant COOH functional groups has the potential to be used as the immobilizing material. • The proposed immunosensor was successfully applied to detect SARS-CoV-2 from nasopharyngeal swabs and saliva samples. [ABSTRACT FROM AUTHOR]

The characterization of ancient silk provides significant historical information and contribute to the identification of the origin of the material. At present, there are many ways to characterize silk. However, on-site identification of ancient silk remains a crucial challenge. In this study, a paper chromatography system consisting of a colloidal gold immunochromatographic strip (GICS) and a time-resolved fluorescence immunochromatographic strip (TICS) is proposed to meet this challenge. On the basis of the original paper chromatography technique, a monoclonal antibody against silk fibroin (SF) was prepared and applied in this new paper chromatography system. Both the GICS and the TICS showed good sensitivity, specificity and reliability, with the limit of detection for silk fibroin being 30 μg/mL and 49.20 ng/mL, respectively. Moreover, there was no cross reaction with possible interferents. Furthermore, the GICS had acceptable thermal stability. The recovery of the TICS assay was in the range from 98.12% to 103%, and the variation coefficient was from 5.34% to 6.93%. This work significantly improves access to scientific information at archaeological sites, providing new scientific evidence for exploring the origin and transmission roadmap of ancient silk. [ABSTRACT FROM AUTHOR]

Valnemulin (VAL) and tiamulin (TIA) are pleuromutilin antibiotics used primarily for treating bacterial infections in swine or other food animals. Furthermore, VAL and TIA are also employed as feed additives to promote animal growth. However, the illegal use of VAL and TIA could cause a series of hazards to consumers. Here, VAL was designed to be conjugated with bovine serum protein to prepare immunogen. A highly sensitive monoclonal antibody that recognized both VAL and TIA has been successfully produced. Moreover, an immunochromatographic strip assay for rapidly screening VAL and TIA in porcine liver was established with visual detection limits (cutoff values) of 50 and 25 ng/g, respectively. The IC50 values calculated from the equation of the standard curve were 6.06 and 3.45 ng/g and the limits of detection were 0.96 and 0.29 ng/g for VAL and TIA. According to the recovery experiment results, the test strip exhibited acceptable accuracy and precision. Generally, the proposed strip provided a practical tool for the detection of VAL and TIA. Practical Application: We produced a highly sensitive monoclonal antibody and developed an immunoassay strip for simultaneously monitoring TIA and VAL. Additionally it was preliminarily confirmed that the rapid detection tool was suitable for screening TIA and VAL in porcine liver. [ABSTRACT FROM AUTHOR]

Highlight • A highly sensitive monoclonal antibody has been produced for first time. • The proposed assay has cutoff values of <20 μg/kg for Tol and 50 μg/kg for Tol sulfone when evaluated with the naked eye in 15 min. • Quantitative results were obtained with a strip scan reader, with limits of detection <2.60 μg/kg for Tol and its metabolites in real samples. • This immunoassay can be applied to the high throughput on-site determination of Tol and Tol sulfone in food and agricultural samples. Abstract In this study, a sensitive monoclonal antibody (mAb) against toltrazuril (Tol) was developed based on a novel hapten. The 50% inhibitory concentrations (IC 50) of toltrazuril and its metabolites ranged from 2.19 ng/mL to 4.21 ng/mL. Based on this mAb, a colorimetric paper-based sensor was developed for the rapid screening of Tol and its metabolites in samples. The proposed assay has cutoff values of <20 μg/kg for Tol and 50 μg/kg for Tol sulfone when evaluated with the naked eye, and the results could be obtained in 15 min. Quantitative results were obtained with a strip scan reader, with limits of detection <2.60 μg/kg for Tol and its metabolites in real samples. The sensitivity of both qualitative and quantitative detection meets the European Union requirements. Therefore, this strip assay provides a useful tool for the on-site detection and rapid initial screening of Tol and its derivatives in feed, egg, and chicken samples. [ABSTRACT FROM AUTHOR]

The genus ofListeriaconsists of heterologous species and its presence in the food chain is an indicator of poor hygiene. However, a portable and simple paper sensor for detection of listeria spp. with high accuracy was still unknown. In this study, we prepared a pair of monoclonal antibodies (mAbs) that specifically recognize the P60 protein on the cell surface ofListeriaspp. The selected pair was found to be sensitive to both the P60 protein and cell body of the genusListeria. On this basis, a rapid paper sensor was established for sensitiveListeriaspp. detection. The developed paper sensor broadly cross-reacted with the 12 tested strains ofListeriaand the sensitivity in PBS buffer was 103–104colony-forming units (CFU) judged by the gray values of the test line. No cross-reaction with any other gram-positive or gram-negative strains tested was observed. A study using milk samples showed that this paper sensor could detect samples contaminated with low levels of the testedListeriaspp. (1–9 CFU/mL) after 8 h of enrichment and further concentrate for approximately 10 times by centrifugation. The results were in accordance with those obtained using the polymerase chain reaction method. [ABSTRACT FROM AUTHOR]

Herein, we report the first paper-based microfluidic device encompassing the filter paper to manage the flow and to load the reagents for a reagent-free competitive magnetic-bead-based immunosensor for cortisol analysis in sweat. The paper-based microfluidic pattern was made using wax printing and laser-cutter techniques, for the delivery of capillary-driven microfluidics. The presence of magnetic beads functionalized with monoclonal antibodies for the recognition of the cortisol in the reaction zone allows for the specific measurement of the target analyte. The competitive reaction between the target cortisol and the labeled cortisol with acetylcholinesterase enzyme gives a response inversely proportional to the target cortisol in the range of 10 and 140 ng/mL, by simply folding the pad loaded with the enzymatic substrate. The paper-based microfluidic device was successively combined with a Near-Field Communication wireless module to develop a flexible integrated wearable analytical tool for cortisol detection in sweat. The paper-based integrated device was successfully applied to determine the level of cortisol in sweat in one volunteer during cycling activities at two different times, demonstrating the reliability of this sustainable paper-based device. • Wearable electrochemical paper-based immunosensor for cortisol detection. • Sweat analysis by exploiting filter paper for capillary-driven flow and reagents loading. • Origami configuration for immunoassay without washing step and reagent addition. • Wireless and battery-free wearable device. [ABSTRACT FROM AUTHOR]

Chronic lymphocytic leukemia (CLL) mainly affects older people: the median age at diagnosis is>70 years. Elderly patients with CLL are heterogeneous with regard both to the biology of their disease and aging. Following the diagnosis of CLL in an elderly individual, careful risk assessment is essential when treatment options are evaluated. This includes not only clinical staging and evaluation of disease-specific prognostic biomarkers such as 17p deletion and TP53 mutation, but also of comorbidities, physical capacity, nutritional status, cognitive capacity, ability to perform activities of daily living and social support. Comorbidity scoring and geriatric assessment tools are helpful in achieving such multidimensional evaluation in a systematic manner. The introduction of new drugs including novel monoclonal antibodies and kinase inhibitors offers enhanced opportunities for the treatment of elderly patients with CLL. This position paper of a Task Force of the International Society of Geriatric Oncology (SIOG) reviews currently available evidence relevant to such patients. All types of elderly patient (i.e. chronological age>65-70 years) are considered, from robust (fit) to vulnerable (unfit) to the terminally ill. Among the topics covered are the following: (i) the relationship between chronological age, prognosis and survival, (ii) assessment of biological aging, (iii) biological age as a determinant of treatment feasibility and tolerance and (iv) tailoring of both first and further-line treatment to the circumstances of the individual patient. [ABSTRACT FROM AUTHOR]

The article discusses a study on the development of an immunoenzymatic method for total immunoglobulin E (IgE) quantification of dried blood on filter paper. It involves the use of ultramicroenzyme-linked immunosorbent assay (UMELISA) IgE kits for human serum. The study also identified the analytical characteristics considering precision, accuracy, tracking record and specificity of the monoclonal antibody of the assay. It compared the results obtained with the UMELISA IgE kit with a commercial kit from Boehringer Mannheim.

This perspective explores the feasibility of smart sampling with dried blood spots for the determination of proteins and peptides from human biomatrices using liquid chromatography coupled to mass spectrometry for clinical purposes. The focus is on innovative approaches to transform filter paper from a mere sample carrier to an active element in sample preparation, with the aim of reducing the need for extensive and intensive sample preparation in the conventional sense. Specifically, we discuss the use of modified cellulose to integrate sample preparation at an early stage of sample handling. The use of paper immobilized with either trypsin or monoclonal antibodies for protein digestion and affinity clean‐up is discussed as a potential benefit of starting sample preparation instantly at the moment of sampling to optimize time efficiency and enable faster analysis, diagnosis, and follow‐up of patients. [ABSTRACT FROM AUTHOR]

• An immunosensor was developed for the determination of amanitins. • Half-maximal inhibitory concentration was 0.48 ng/mL and the LOD was 0.095 ng/mL. • Good correlations of the results verified by immunosensor and LC–MS/MS. Amanitin (AMA) is responsible for human fatalities after ingestion of poisonous mushrooms, thus, a rapid and accurate detection method is urgently needed. Here, gold nanoparticle-based immunosensor with monoclonal antibody against AMA was constructed for rapid detection of alpha- and beta-amanitin (α- and β-AMA) in mushroom, serum and urine samples. Under optimized conditions, the visual limits of detection (vLOD) and calculated LOD for α-AMA and β-AMA in mushroom were 10 ng/g, 20 ng/g, and 0.1 ng/g, 0.2 ng/g, respectively. Analysis of wild mushroom samples was also performed using a strip scan reader in the 10 min range. Furthermore, in mushrooms containing amatoxins results were confirmed and compared with those determined by liquid chromatography tandem mass spectrometry. Thus, this immunosensor provided a useful monitoring tool for rapid detection and screening of mushroom samples and in serum and urine from subjects who accidentally consumed AMA-containing mushrooms. [ABSTRACT FROM AUTHOR]

Background Monoclonal ( MoAb) reagents are routinely used and are usually very reliable for the serologic determination of ABO blood types. However, the fine specificity and cross-reactivity of these reagents are often unknown, particularly against synthetic antigens used in some diagnostic assays. If nonserologic assays or very sensitive techniques other than those specifically prescribed by the manufacturer are used, then there is a risk of incorrect interpretation of results. Study Design and Methods Forty-seven MoAbs and two polyclonal ABO reagents were tested against red blood cell ( RBC) kodecytes prepared with A trisaccharide, A Type 1, A Type 2, A Type 3, A Type 4, B trisaccharide, B Type 1, B Type 2, acquired B trisaccharide, and Lea trisaccharide function-spacer-lipid ( FSL) constructs. Natural RBCs were tested in parallel. In addition these FSL constructs were printed onto paper with a desktop inkjet printer and used in a novel immunoassay that identifies reactivity through the appearance of alphanumeric characters. Results Mapping of MoAbs with kodecytes and printed FSL constructs revealed a series of broad recognition patterns. All ABO MoAbs tested were reactive with the RBC dominant Type 2 ABO antigens. Unexpectedly some anti- A reagents were reactive against the B Type 1 antigen, while others were poorly reactive with trisaccharide antigens. Conclusions All ABO MoAbs detect the RBC dominant Type 2 ABO antigens; however, some reagents may show minor reactivity with inappropriate blood group antigens, which needs to be considered when using these reagents in alternative or highly sensitive analytic systems. [ABSTRACT FROM AUTHOR]

Mas-related G-protein-coupled receptor X2 (MRGPRX2) has recently been reported to be associated with anaphylaxis. Detection of MRGPRX2 levels in human peripheral blood might serve as a powerful tool for predicting the predisposition of patients to anaphylactic reactions. For rapid measurement of MRGPRX2, we established a paper-based double-antibody sandwich enzyme-linked immunosorbent assay (ELISA) using mouse monoclonal antibody and horseradish peroxidase (HRP)-labelled rabbit polyclonal antibody as capture antibody and detection antibody, respectively. We avoided chemical functionalization of the cellulose paper by introducing bovine serum albumin (BSA) to provide COOH and NH 2 groups for covalent immobilization of the capture antibody. Through amide condensation, a two-layer immobilization strategy was applied with BSA-BSA and BSA-capture antibody networks as the first and second layers, respectively. This strategy improved the quantity, activity and stability of the immobilized antibody. We then established a paper-based ELISA to detect MRGPRX2 in human peripheral blood. Our method is less laborious, easier to implement, and more cost-effective than conventional ELISA, while offering similar sensitivity, specificity, and accuracy. Therefore, it could serve as an innovative clinical point-of-care diagnostic tool, especially in areas that lack advanced clinical equipment. [Display omitted] • A rapid and sensitive paper-based ELISA method was established to detect MRGPRX2. • A two-layer capture antibody immobilization strategy was applied. • Improved capture antibody immobilization effect and enhanced stability were achieved. • The established method is less laborious, easier to implement, and more cost-effective than conventional ELISA. [ABSTRACT FROM AUTHOR]

Nowadays, the development of systems, devices, or methods that integrate several process steps into one multifunctional step for clinical, environmental, or industrial purposes constitutes a challenge for many ongoing research projects. Here, we present a new integrated paper based cadmium (Cd2+) immunosensing system in lateral flow format, which integrates the sample treatment process with the analyte detection process. The principle of Cd2+ detection is based on competitive reaction between the cadmium–ethylenediaminetetraacetic acid–bovine serum albumin–gold nanoparticles (Cd–EDTA–BSA–AuNP) conjugate deposited on the conjugation pad strip and the Cd–EDTA complex formed in the analysis sample for the same binding sites of the 2A81G5 monoclonal antibody (mAb), specific to Cd–EDTA but not Cd2+ free, which is immobilized onto the test line. This platform operates without any sample pretreatment step for Cd2+ detection thanks to an extra conjugation pad that ensures Cd2+ complexation with EDTA and interference masking through ovalbumin (OVA). The detection and quantification limits found for the device were 0.1 and 0.4 ppb, respectively, these being the lowest limits reported up to now for metal sensors based on paper. The accuracy of the device was evaluated by addition of known quantities of Cd2+ to different drinking water samples and subsequent Cd2+ content analysis. Sample recoveries ranged from 95 to 105% and the coefficient of variation for the intermediate precision assay was less than 10%. In addition, the results obtained here were compared with those obtained with the well-established inductively coupled plasma emission spectroscopy (ICPES) and the analysis of certificate standard samples. [ABSTRACT FROM AUTHOR]

Background: A simple filter paper method was developed for, the transport and storage of monoclonal antibodies (Mabs) at room temperature or -20°C after spotting on filter paper, for subsequent sero-typing of outer membrane antigens of N.meningitidis by dot-blot ELISA. Methods: Monoclonal antibodies (Mabs) were spotted within a 0.5-1 cm diameter area of Whatman grade 903 paper, which were stored individually at room temperature or at -20°C. These MAbs were stored and analyzed after periods of one week, 4 weeks, 12 months, or 13 years in the case of frozen Mab aliquots, or after 4 weeks at -20°C or at room temperature (RT) in the case of Mabs dried on filter paper strips. Assays were performed in parallel using dot-blot ELISA. In addition to the MAbs specific for serotyping class 1, 2 or 3, we used a larger number of Mabs for polysaccharides, lipooligosaccharides (LOS), class 5 and cross-reactive antigens for native outer membrane of N.meningitidis. The Mabs dried on filter paper were eluted with phosphate-buffered saline (PBS) containing 0.2% gelatin. Results: Mabs of the isotypes IgG and IgM dried on filter papers were not affected by duration of storage. The detection by serotyping Mabs was generally consistent for dried filter paper MAb samples stored frozen for over 1 year at -20°C, and although decreased reactive antibody titers were found after storage, this did not interfere with the specificity of the Mabs used after 13 years as dry spots on filter paper. Conclusion: The use of filter paper is an inexpensive and convenient method for collecting, storing, and transporting Mab samples for serotyping studies. In addition, the samples occupy little space and can be readily transported without freezing. The efficiency of using immunoglobulin G (IgG) or M (IgM) eluted was found to be consistent with measurement of IgG or IgM titers in most corresponding, ascites Mabs stored frozen for over 1 year. The application of meningococcal typing methods and designations depend on the question being asked. [ABSTRACT FROM AUTHOR]

Abstract: This review identifies a timeline to nanomedicine anticancer drug approval using the business model of inventors, innovators and imitators. By evaluating the publication record of nanomedicine cancer therapeutics we identified a trend of very few publications prior to FDA approval. We first enumerated the publications related to cancer involving polymers, liposomes or monoclonal antibodies and determined the number of citations per publication as well as the number of published clinical trials among the publications. Combining these data with the development of specific nanomedicines, we are able to identify an invention phase consisting of seminal papers in basic science necessary for the development of a specific nanomedicine. The innovation phase includes the first report, the development and the clinical trials involving that nanomedicine. Finally, the imitation phase begins after approval when others ride the wave of success by using the same formulation for new drugs or using the same drug to validate other nanomedicines. We then focused our analysis on nanomedicines containing camptothecin derivatives, which are not yet approved including two polymers considered innovations and one liposomal formulation in the imitation phase. The conclusion that may be drawn from the analysis of the camptothecins is that approved drugs reformulated in polymeric and liposomal cancer nanomedicines have a more difficult time navigating through the approval process than the parent molecule. This is probably due to the fact that for most currently approved drugs, reformulating them in a nanocarrier provides a small increase in performance that large pharmaceutical companies do not consider being worth the time, effort and expense of development. It also appears that drug carriers have a more difficult path through the clinic than monoclonal antibodies. The added complexity of nanocarriers also deters their use to deliver new molecular entities. Thus, the new drug candidates that might be most improved by drug delivery in nanocarriers are not formulated in this fashion. [Copyright &y& Elsevier]

An anti-phenolphthalein monoclonal antibody (mAb) was prepared based on the N,N′-Carbonyldiimidazole (CDI) method through phenolphthalein conjugated with proteins. Indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) and colloidal gold-based immunochromatographic assay (ICA) methods were used to determine phenolphthalein in slimming products. A standard curve was established, and the IC 50 and limit of detection of ic-ELISA were 0.95 and 0.10 ng/mL with a linear detection range of 0.27–3.37 ng/mL. The developed ICA was used to detect phenolphthalein in tablets, capsules, and slimming tea samples with visual limit of detection values of 10 μg/kg, and cut-off values of 200 μg/kg. The results indicated that these two methods could be used to quickly detect phenolphthalein in slimming products. Colloidal gold-based ICA methods were developed to determine phenolphthalein in slimming products. The developed ICA strip was used to detect phenolphthalein in tablets, capsules, and slimming tea samples with visual limit of detection values of 10 μg/kg, and cut-off values of 200 μg/kg. [Display omitted] • A sensitive anti-phenolphthalein monoclonal antibody (mAb) was fabricated. • ic-ELISA and the ICA strip methods were developed to determine phenolphthalein. • The visual limit of detection and cut-off values of the ICA were 10 and 200 μg/kg. [ABSTRACT FROM AUTHOR]

Abstract: Biological agents are widely used in rheumatology, dermatology and inflammatory bowel disease. Evidence about their efficacy and safety has been strengthened for all those therapeutic indications over the last decade. Biosimilar agents are monoclonal antibodies similar to previously approved biologics. In the European Union, they have been approved for all the indications in the management of immune-mediated inflammatory diseases (IMIDs), although data only in rheumatoid arthritis and ankylosing spondylitis are currently available. Direct evidence on efficacy, safety, and immunogenicity of biosimilars is mandatory in psoriasis, psoriatic arthritis, and inflammatory bowel disease, as well as in children. Based on the current evidence in the literature, we present the joint official position of the Italian Societies of Rheumatology, Dermatology and Inflammatory Bowel Disease on the use of biosimilars in IMIDs. [Copyright &y& Elsevier]