Antigen-antibody Reaction Research Articles

One-Step Synthesis of Carboxylated Polyethylene Glycol-Modified Polystyrene Microspheres and Their Application in the Luminescent Oxygen Channel Immunoassay.

As one of the key diagnostic methods for detecting biomarkers and antigen-antibody interactions, the luminescent oxygen channel immunoassay (LOCI) has been widely applied in bioanalysis and other fields. In the context of LOCI, the performance of the prepared donor polystyrene (PS) microspheres significantly impacts the detection signal values. In this study, an attempt was made to synthesize PS microspheres via one-step polymerization of styrene with an amphiphilic monomer (PEOOH), followed by swelling the silicon phthalocyanine photosensitizer into the PS microspheres, resulting in the functionalization of the PS microspheres with polyethylene glycol segments. The chemical stability and water solubility of polyethylene glycol (PEG) make it a versatile surface modification material while also inhibiting nonspecific protein adsorption. Results indicated that with increasing PEOOH content, the nonspecific protein adsorption of the resulting PS microspheres reduced, with the adsorption ability for BSA decreasing from 26.8 to 1.3 mg/g, approximately decreasing by 95.2%. Furthermore, the results demonstrated that PS microspheres prepared with 6% PEOOH exhibited a maximum signal-to-noise ratio (S/N) (approximately 28.7), nearly 14 times higher than PS microspheres without PEOOH (approximately 2.1). The analytical performance of the system for detecting staphylococcal enterotoxin B (SEB) revealed a detection limit of 0.1 ng/mL and a linear concentration range of 0.1 to 50 ng/mL for the donor PS microspheres (6% PEOOH). The synthesized donor PS microspheres exhibit a uniform particle size and stable signals, making them effective LOCI microcarriers. These properties facilitate a deeper understanding of molecular interactions and signal transduction mechanisms within biological systems.

High-affinity VNARs targeting human hemoglobin: Screening, stability and binding analysis.

Hemoglobin, composed of α- and β-chains, is essential for oxygen transport and is key in diagnosing and treating gastrointestinal and blood disorders. It also aids in detecting blood contamination and estimating transfusion volumes. Immunological methods, based on antigen-antibody interactions, are distinguished by their high sensitivity and accuracy. Consequently, it is necessary to develop hemoglobin-specific antibodies characterized by high specificity and affinity to enhance detection accuracy. The variable domain of the new antigen receptor (VNAR) from sharks, the smallest antigen-binding unit, is ideal for disease diagnosis and treatment due to its small size, stability, and high affinity. In this study, Chiloscyllium plagiosum was immunized with human hemoglobin protein. Nine VNAR immune libraries with sizes ranging from 1 × 108 to 1.82 × 109 colony-forming units (CFU) were constructed and biopanned using phage display, resulting in three hemoglobin-specific VNAR sequences (5-10C, 7-11 A, T-12-4D). These sequences were inserted into pTT5-TEV-Fc vectors and transfected into HEK 293F cells. The resulting VNAR-Fc fusion proteins were purified from the cell culture supernatants. Binding activity, cross-reactivity, physicochemical stability, and epitope competition were evaluated using non-competitive enzyme-linked immunosorbent assay (ELISA) and biolayer interferometry (BLI). T-12-4D-Fc exhibited the highest affinity with a KD value of 7.59 nM and superior physicochemical stability. It maintained over 80 % binding activity at 90 °C, over 51 % in extreme pH conditions (pH 2 and 12), and above 65 % in urea concentrations up to 8 mol/L. Its binding activity remained largely unaffected after 6 h of incubation in human plasma-like medium (HPLM). The binding epitope competition results showed that 5-10C-Fc and T-12-4D-Fc targeted the same hemoglobin epitope. Molecular dynamics simulations revealed hydrogen bonds as the primary interaction force between VNARs and hemoglobin. Furthermore, a double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) method was established for the detection of human hemoglobin, utilizing T-12-4D-Fc as the coating antibody. This technique demonstrated high accuracy, reproducibility and specificity when applied to human whole blood samples. Hence, the identified VNARs, particularly T-12-4D, demonstrated good stability, specificity, and high affinity, filling the gap of hemoglobin-targeting shark-derived single-domain antibodies and offering a foundation for diagnosing and monitoring hemoglobin-related diseases.

Establishment of a Rapid and Convenient Fluoroimmunoassay Platform Using Antibodies Against PDL1 and HER2.

The development of accurate and high-throughput tools for cancer biomarker detection is crucial for the diagnosis, monitoring, and treatment of diseases. In this study, we developed a simple and rapid fluorescence-linked immunosorbent assay (FLISA) using fluorescent dye-conjugated antibody fragments against programmed cell death ligand 1 (PDL1) and human epithelial growth factor receptor 2 (HER2). We optimized key steps in the FLISA process, including antigen immobilization, blocking, and antibody reaction, reading the assay time to 3 h-significantly faster compared to the 23 h duration of usual FLISA. The limit of detection for the rapid FLISA in detecting PDL1 was lower than that of FLISA, and the detection of HER2 was similar between the two methods, indicating that the rapid FLISA provides a fast and accurate approach for detecting PDL1 and HER2. This robust platform can be readily adapted for various fluoroimmunoassays targeting other antigens of interest.

A whole gamma imaging prototype for higher quantitative imaging of 89Zr-labeled antibodies in a tumor mouse model

Objective.Positron emission tomography (PET) has become an important clinical modality, but it is limited to imaging the annihilation radiation from positron-electron collisions. Recently, PET imaging with89Zr, which has a half-life of 3 d, has attracted much attention in immuno-PET to visualize immune cells and cancer cells by targeting specific antibodies on the cell surface. However,89Zr emits a single gamma ray at 909 keV four times more frequently than positrons, causing image quality (IQ) degradation in conventional PET. To overcome this drawback, use of such single gamma rays for imaging was previously proposed as whole gamma imaging (WGI). In WGI, a single gamma ray is detected by Compton imaging; by inserting a scatter detector ring inside the PET ring, WGI can realize both PET imaging and Compton imaging in one modality. A prototype for WGI was developed and Compton imaging of a mouse after intravenous administration of89Zr oxalate was demonstrated. However, the Compton imaging of the single gamma ray still presented a challenge due to its low IQ compared to PET.Approach.In this study, the scatter detector insert of the earlier WGI prototype was redesigned with the aim of improving Compton imaging performance. The new prototype produced WGI images by additive averaging of PET and Compton images after optimizing the ratio of each iteration in the image reconstruction. WGI IQ was then evaluated using the NEMA NU4 IQ phantom, and a tumor-burdened mouse was imaged with WGI up to 12 d after89Zr labeled antibody injection.Main results.Consequently, the Compton imaging performance was improved by lowering the angular resolution measure from 6.7 degrees to 6.4 degrees and the sensitivity from 0.11% to 0.18% compared to the previous prototype WGI. The phantom images with WGI showed a 15% reduction in noise and a 3% increase in contrast recovery under low-statistical conditions compared to images reconstructed by PET data alone.Significance. In-vivomouse imaging with the new prototype WGI was successfully performed. This successful imaging leads to the expectation that future whole-body WGI imaging will enable more sensitive and better quantitative89Zr antigen-antibody reaction imaging to be obtained.

Comparative Pharmacokinetic Analysis of Aflibercept and Brolucizumab in Human Aqueous Humor Using Nano-Surface and Molecular-Orientation Limited Proteolysis.

Aflibercept and brolucizumab, two anti-VEGF agents used as intravitreal injections in ophthalmology, differ significantly in molecular weight (aflibercept-115 kDa and brolucizumab-26 kDa). Using aqueous humor samples collected after drug administration, we measured and performed a comparative analysis of pharmacokinetics and half-lives of these drugs in the human eye. Since the quantification of monoclonal antibodies (mAbs) using antigen-antibody reactions, such as ELISA, is influenced by endogenous ligands or anti-drug antibodies, we employed nano-surface and molecular-orientation limited proteolysis (nSMOL), combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS), for accurate measurements. Aqueous humor samples were collected from 59 eyes of 59 patients treated with aflibercept and 52 eyes of 52 patients treated with brolucizumab. Samples were obtained with a median post-injection period of 30 (range, 2-49) days for aflibercept and 28 (range, 4-60) days for brolucizumab. A population pharmacokinetic (PPK) analysis revealed that the half-life of aflibercept in human aqueous humor was significantly shorter than that of brolucizumab, 2.88 days versus 9.00 days, respectively (p = 1.16 × 10-7). Using the same mass spectrometry conditions, we calculated the half-lives of the two drugs. These results may be useful for optimizing the efficacy of these drugs in clinical practice.

Simplex Immunodotblot for detecting dog meat contaminants in foodstuffs

This study is an initial effort to develop a prototype kit based on the simplex immunodot blot method to detect dog meat contamination in food products. The simplex immunodotblot is an immunoassay technique that identifies specific proteins or antigens through antibody-antigen interactions, targeting a single contaminant in one reaction. The antigen utilized was dog meat extract (DME) prepared in the laboratory, while the primary antibodies (Ab) against DME were produced in-house using laying hens. Test samples were applied in varying concentrations (5, 10, and 20 µg per spot) onto comb-shaped polyester plastic sheets. A commercial secondary antibody against IgY, labeled with horseradish peroxidase (HRP), served as the detector. The reaction was visually inspected; in cases where dog meat was present, a blue or black spot appeared due to the reaction between the antigen, antibody, enzyme, and substrate. The study demonstrated the successful development of the simplex immunodotblot, which was able to detect dog meat visually at concentrations as low as 5 µg in a laboratory setting. However, further research is required, particularly to adapt the prototype kit for halal food authentication purposes.

Anaphylaxis: A Case Report from Azal hospital, Sana'a, Yemen

Anaphylaxis is a severe life-threatening allergic reaction. This is a type I hypersensitivity reaction. Antibody-antigen reaction induces the release of inflammatory mediators. In this article, we report the case of a 55 years old female patient who presented with generalised urticaria, pruritus, skin edema, fever, abdominal pain, and dyspnea. Investigations showed only neutrophilia. The patient was immediately received intravenous (IV) chlorpheniramine 10 mg and intravenous hydrocortisone 100 mg with a slight response. The patient then received intravenous methylprednisolone 500 mg with dramatic improvement. This drug was administered once daily for three consecutive days.

A Microfluidic Biosensor for Quantitative Detection of Salmonella in Traditional Chinese Medicine.

Microbial contamination is an important factor threatening the safety of Chinese medicine preparations, and microfluidic detection methods have demonstrated excellent advantages in the application of rapid bacterial detection. In our study, a novel optical biosensor was developed for the rapid and sensitive detection of Salmonella in traditional Chinese medicine on a microfluidic chip. Immune gold@platinum nanocatalysts (Au@PtNCs) were utilized for specific bacterial labeling, while magnetic nano-beads (MNBs) with a novel high-gradient magnetic field were employed for the specific capture of bacteria. The immune MNBs, immune Au@PtNCs, and bacterial samples were introduced into a novel passive microfluidic micromixer for full mixing, resulting in the formation of a double-antibody sandwich structure due to antigen-antibody immune reactions. Subsequently, the mixture flowed into the reaction cell, where the MNBs-Salmonella-Au@PtNCs complex was captured by the magnetic field. After washing, hydrogen peroxide-tetramethylbenzidine substrate (H2O2-TMB) was added, reacting with the Au@PtNCs peroxidase to produce a blue reaction product. This entire process was automated using a portable device, and Salmonella concentration was analyzed via a phone application. This simple biosensor has good specificity with a detection range of 9 × 101-9 × 105 CFU/mL and can detect Salmonella concentrations as low as 90 CFU/mL within 74 min. The average recoveries of the spiked samples ranged from 76.8% to 109.5.

Bovine Serum Albumin-Capped Fluorescent Copper Nanocluster Incorporated with 2D-Molybdenum Disulfide Nanosheets as a FRET-Based Immune Probe for the "Turn-On" Detection of cTnT.

Cardiovascular disease is the primary cause of mortality worldwide, as stated by the World Health Organization. We utilized the red fluorescence emitted by copper nanoclusters (CuNCs) to detect cardiac Troponin T (cTnT). We designed a fluorescent probe to detect cTnT using an on-off-on technique. The cTnT antibody was coupled on the surface of a bovine serum albumin-capped CuNC (Ab-BSA©CuNC) MoS2 nanosheet, efficiently quenching the luminescence of Ab-BSA©CuNCs due to their high affinity and binding interaction by establishing an Ab-BSA©CuNC/MoS2 platform. The luminescence of Ab-BSA©CuNCs was restored due to the antigen-antibody interaction. With a detection limit of 9.4 pg/mL, a linear relationship between the luminescence intensity concentrations of cTnT was observed in the 0.161-1.57 ng/mL ranges. Additionally, the efficacy of the developed technique to measure cTnT in blood serum samples was evaluated, and it exhibited a good recovery percentage.

The Application of Molecularly Imprinted Polymers in Forensic Toxicology: Issues and Perspectives

Molecularly imprinted polymers (MIPs) are synthetic receptors designed to selectively bind specific molecules, mimicking natural antibody–antigen interactions. Produced through polymerization around a target molecule (template), MIPs create imprints that confer high specificity and binding affinity upon template removal. Initially developed in the 1970s with organic polymers, MIPs now play critical roles in separation sciences, catalysis, drug delivery, and sensor technology. In forensic science, MIPs offer potential for sample preparation, pre-concentration, and analyte detection, especially with complex biological and non-biological matrices. They exhibit superior stability under extreme conditions, enabling their use in challenging forensic contexts such as detecting new psychoactive substances or trace explosives. Despite advantages like reusability and high selectivity, MIPs face limitations in forensic analysis due to their complex synthesis, potential template leakage, and non-specific binding. Moreover, the lack of standardized protocols limits their mainstream adoption, as forensic applications require validated, reproducible methods. This review systematically assesses MIPs in forensic toxicology, focusing on their current capabilities, limitations, and potential for broader integration into forensic workflows. Future research should address standardization and evaluate MIPs’ effectiveness in diverse forensic applications to realize their full potential.

A bio-nano-engineered platform fabricated from cerium oxide-carbon nanoparticles stabilized with chitosan for label-free sensing of a lung cancer biomarker.

Herein, we report a label-free cancer biosensor designed for carcinoembryonic antigen (CEA) detection using a nanohybrid comprising CeO2 nanoparticles, carbon nanoparticles (CNPs), and chitosan (Ch). CeO2 nanoparticles were prepared using a simple green synthesis process. A thin film of the CeO2-CNPs-Ch nanohybrid was formed on indium tin oxide (ITO)-coated glass plates that endowed a high surface area, excellent stability, and good adsorption for the efficient loading of CEA antibodies. Quantitative and selective determination of CEA antigen was achieved by immobilizing monoclonal CEA antibodies (anti-CEA) on the CeO2-CNPs-Ch/ITO platform. The electrochemical response of the anti-CEA/CeO2-CNPs-Ch/ITO immunoelectrode was evaluated in a label-free immunoassay format using differential pulse voltammetry (DPV). The response studies of immunoelectrodes indicated wider linearity with respect to the CEA concentration in the range of 0.05-100 ng mL-1. The electrochemical cancer biosensor exhibited a higher sensitivity of 22.40 μA cm-2 per decade change in concentration along with storage stability for up to 35 days. The limit of detection (LOD) was 0.037 ng mL-1. Furthermore, this cancer biosensor exhibited good specificity and reproducibility. Thus, the proposed CeO2-CNPs-Ch nanocomposite-based platform provides an efficient method for the analysis of other antigen-antibody interactions and biomolecule detection. The efficacy of the anti-CEA/CeO2-CNPs-Ch/ITO immunoelectrode was further examined by measuring CEA levels in human serum.

Label-free electrochemical assessment of human serum and cancer cells to determine the folate receptor cancer biomarker.

The folate receptor (FR) is a well-known biomarker that is overexpressed in many cancer cells, making it a valuable target for cancer diagnostics and therapeutic strategies. However, identifying cancer biomarkers remains a challenge due to factors such as lengthy procedures, high costs, and low sensitivity. This study presents the development of a novel, cost-effective biosensor designed for the detection of FR. To overcome the limitations of traditional immunological methods, which rely on antigen-antibody interactions, we utilized a charge-based affinity approach. Folic acid (FA) was conjugated with poly (diallyl dimethylammonium chloride) (PDDA) using an EDC-NHS linker on the surface of multi-walled carbon nanotubes. The biosensor enabled electrochemical detection of FR through differential pulse voltammetry (DPV), achieving an impressive detection limit of 1.6pg/mL and a dynamic range of 1-10,000ng/mL. Additionally, the biosensor exhibited excellent stability (30days), high selectivity, and repeatability (RSD=3.14%, n=5). This work presents a promising strategy for developing ligand-receptor-based biosensors. It paves the way for future applications in cancer diagnostics and biosystem interfaces, offering high performance and practical advantages.

High-throughput specificity profiling of antibody libraries using ribosome display and microfluidics.

In this work, we developed PolyMap (polyclonal mapping), a high-throughput method for mapping protein-protein interactions. We demonstrated the mapping of thousands of antigen-antibody interactions between diverse antibody libraries isolated from convalescent and vaccinated COVID-19 donors and a set of clinically relevant SARS-CoV-2 spike variants. We identified over 150 antibodies with a variety of distinctive binding patterns toward the antigen variants and found a broader binding profile, including targeting of the Omicron variant, in the antibody repertoires of more recent donors. We then used these data to select mixtures of a small number of clones with complementary reactivity that together provide strong potency and broad neutralization. PolyMap is a generalizable platform that can be used for one-pot epitope mapping, immune repertoire profiling, and therapeutic design and, in the future, could be expanded to other families of interacting proteins.

AntiBinder: utilizing bidirectional attention and hybrid encoding for precise antibody-antigen interaction prediction.

Antibodies play a key role in medical diagnostics and therapeutics. Accurately predicting antibody-antigen binding is essential for developing effective treatments. Traditional protein-protein interaction prediction methods often fall short because they do not account for the unique structural and dynamic properties of antibodies and antigens. In this study, we present AntiBinder, a novel predictive model specifically designed to address these challenges. AntiBinder integrates the unique structural and sequence characteristics of antibodies and antigens into its framework and employs a bidirectional cross-attention mechanism to automatically learn the intrinsic mechanisms of antigen-antibody binding, eliminating the need for manual feature engineering. Our comprehensive experiments, which include predicting interactions between known antigens and new antibodies, predicting the binding of previously unseen antigens, and predicting cross-species antigen-antibody interactions, demonstrate that AntiBinder outperforms existing state-of-the-art methods. Notably, AntiBinder excels in predicting interactions with unseen antigens and maintains a reasonable level of predictive capability in challenging cross-species prediction tasks. AntiBinder's ability to model complex antigen-antibody interactions highlights its potential applications in biomedical research and therapeutic development, including the design of vaccines and antibody therapies for rapidly emerging infectious diseases.

Detection of Antibody-Antigen Interactions with Electrochemical Biosensor Based on Bipolar Phenomenon

Introduction We propose a new biosensor based on the bipolar phenomenon. The bipolar phenomenon polarizes a conductor (bipolar electrode, BPE) inserted into an electric field formed between driving electrodes (DEs) connected to an external power source. Electrochemical biosensing using the bipolar phenomenon for detecting biomolecules has recently been reported. In biosensing, BPE separates the molecular recognition site from the detection site. This feature is scalable and enables the exploration of new detection reactions. Therefore, the bipolar phenomenon shows potential as a new tool for biosensors. Here, we demonstrate the electrochemical biosensor with a simple design using an open BPE. The biosensor detects C-reactive protein (CRP) by electrochemical impedance measurement under non-faradic conditions. Experimental Gold electrodes (10 mm × 10 mm) were immersed in 10 mM 3-mercaptopropionic acid (MPA) solution for 1 h to form an MPA self-assembled monolayer. The carboxyl groups of the MPA monolayer were treated with 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride/N-hydroxysuccinimide (0.2 M/0.1 M). Subsequently, the electrodes were incubated with 10 µg/mL of anti-CRP antibody in 0.1 M phosphate buffer (PB, pH 7.0) to immobilize the antibody. Following the blocking treatment, the electrodes were exposed to 10 μg/mL CRP in 0.1 M PB at 37°C for 0-2 h to react with CRP. For impedance measurements, Pt-black-coated gold wires were used as the DEs and connected to an impedance analyzer. The BPE was placed at the bottom of an electrochemical cell filled with 0.1 M PB (pH 7.0), and the DE was positioned directly above the BPE (refer to Fig. 1A). The measurements were performed in a frequency range from 1 Hz to 8 MHz, with an amplitude of 0.1 V and a DC bias voltage of 0 V. Results and Discussion Figure 1B shows the relationship between CRP immobilization time and impedance value at 1 kHz. A linear decrease in impedance was observed during the immobilization time of 0-1 h, which caused the increased in capacitance of the BPE surface resulting from the increased amount of immobilized CRP. Over 1 h of immobilization, the impedance change slowed down, indicating the saturation of CRP immobilization. These results suggest that the sensor developed in this study detects the antigen-antibody reaction on the BPE through impedance change. Figure 1

Asthma Phenotyping Via Multiplex Detection of Cytokines on an Electrochemical Sensor

Asthma, a complex and diverse lung condition, is typically associated with chronic airway inflammation. Asthma classification has traditionally relied on clinical symptoms and treatment response. As our understanding of asthma’s heterogeneity grows, phenotyping has become a focus. Cytokines, essential chemical messengers in the immune system, play a pivotal role in the mediation of chronic diseases. They facilitate communication between immune cells and directly impact inflammation. Various cytokines have been implicated in asthma pathogenesis. Leveraging cytokines for asthma phenotyping is valuable, as identifying and quantifying these inflammatory mediators can lead to more precise, targeted treatments. To achieve this, we have developed a customizable electrochemical platform for multiplexed detection of select cytokines for non-invasive cytokine detection in saliva. This platform rapidly detects cytokines within physiological ranges and will aid physicians in asthma phenotyping and treatment planning especially for severe asthmatics.The detection platform leverages subtle changes in impedance at the electrode-electrolyte interface as a function of the chemical interaction between specific antibody-antigen interactions to establish a calibration dose response curve. The platform’s capability to detect and quantify the cytokines in human saliva is demonstrated through spike and recovery experiments.

Molecularly imprinted biomimetic plasmonic sensor decorated with gold nanoparticles for selective and sensitive detection of bisphenol A

Molecularly imprinted polymers inspired by antigen-antibody interactions have received substantial interest as a biomimetic artificial receptor system in environmental applications. Herein, we present a molecularly imprinted surface plasmon resonance sensor integrated with gold nanoparticles for the identification of bisphenol A (BPA), an endocrine-disrupting chemical. We synthesized BPA-imprinted nanofilm consisting of amino acid-based functional monomers to selectively detect BPA from synthetic wastewater samples. BPA-spiked synthetic wastewater samples were analyzed to ensure the method's reliability and feasibility. Under ideal conditions, the suggested approach performed well in terms of analytical performance to bisphenol A, with a wide linear range of 0.1 to 10 µg/L and LOD of 10 ng/L. The sensor results align well with the Langmuir adsorption model. It has also been shown that repeated use of the sensor can be achieved. According to selectivity studies, bisphenol A adsorbed within the imprinted cavities favorably compared to 4-nitrophenol and phenol. The produced bisphenol A-imprinted surface plasmon resonance sensor provides improved sensitivity based on the signal amplification strategy, unconjugated sensing without the need for labelling, real-time sensing, low sample consumption rates, quantifiable assessment, and outstanding kinetic rate constant calculation in actual samples. Also, because the produced sensor is reusable with relative standard deviations (RSD)<1.25, indicating the sensor's precision, the surface plasmon resonance-based biomimetic BPA sensor is simple to practice and a cost-effective option.

Synthesis and application of electrospun polyvinylidene fluoride/polyvinylidene glycol nanofibrous membrane for enhanced biomarker detection in immunochromatography assay

Immunochromatography assay (ICA) stands as a pioneering point-of-care testing (POCT) method, leveraging the simplicity, portability, and versatility of dry-strip testing method, chromatographic and antigen-antibody immunological reaction. Despite its numerous advantages, the shortcomings like low sensitivity, limited matrix, restricted matrix compatibility, and uncontrollable chromatographic rates, have hindered the ICA application. To overcome the aforementioned challenges, we proposed constructing a novel ICA strip based on homemade hydrophilic, flexible membranes to replace the commercially available nitrocellulose (NC). The key to the innovation lies in the spinning solution of a blend of poly (vinylidene fluoride) (PVDF) and polyethylene glycol (PEG), which is made into a nanofibrous membrane named EPVDF/PEG membrane by electrostatic spinning technique. This membrane, due to its high specific surface area and high porosity, can be loaded with more detection reagents than normal substrates, increasing the reaction time and achieving improved detection sensitivity. This membrane also has adjustable chromatographic rate, high protein loading capacity, good biocompatibility and excellent colouring ability. As a result, the established EPVDF/PEG-based ICA strips demonstrate an ultralow detection limit, as low as 0.5 mIU∙mL−1 when human chorionic gonadotropin (HCG) serves as the biomarker model, which is a 50-fold increase in detection sensitivity compared to commercial strips. Furthermore, EPVDF/PEG-based ICA strips can be produced on a large scale for the availability of efficient and mature electrospinning technologies. In summary, this work offers a transformative advancement in ICA development, potentially opening new horizons for sensitive biomarker detection.

Prediction of antibody-antigen interaction based on backbone aware with invariant point attention.

Antibodies play a crucial role in disease treatment, leveraging their ability to selectively interact with the specific antigen. However, screening antibody gene sequences for target antigens via biological experiments is extremely time-consuming and labor-intensive. Several computational methods have been developed to predict antibody-antigen interaction while suffering from the lack of characterizing the underlying structure of the antibody. Beneficial from the recent breakthroughs in deep learning for antibody structure prediction, we propose a novel neural network architecture to predict antibody-antigen interaction. We first introduce AbAgIPA: an antibody structure prediction network to obtain the antibody backbone structure, where the structural features of antibodies and antigens are encoded into representation vectors according to the amino acid physicochemical features and Invariant Point Attention (IPA) computation methods. Finally, the antibody-antigen interaction is predicted by global max pooling, feature concatenation, and a fully connected layer. We evaluated our method on antigen diversity and antigen-specific antibody-antigen interaction datasets. Additionally, our model exhibits a commendable level of interpretability, essential for understanding underlying interaction mechanisms. Quantitative experimental results demonstrate that the new neural network architecture significantly outperforms the best sequence-based methods as well as the methods based on residue contact maps and graph convolution networks (GCNs). The source code is freely available on GitHub at https://github.com/gmthu66/AbAgIPA .

A Comparative Study of the Rate of Helicobacter pylori infection Using Three Diagnostic Techniques among Patients in Rivers State

Background: Approximately 89% of gastric cancers are attributable to H. pylori infection, however, only 1 in 5 patients survive longer than 5 years after diagnosis. Evidence has shown that screening and eradication of H. pylori in young adults would be cost-effective and could prevent 1 gastric cancer in every 4 to 6 cases. Diagnostic tests used to detect Helicobacter pylori are either invasive or noninvasive methods. These tests have varying sensitivity and specificity, having about 90% accuracy in the diagnosis of H. pylori infection in clinical practice. Aim: This study aims at detecting Helicobacter pylori using antibody-antigen, stool antigen and polymerase chain reaction (PCR) and to compare the infection rate among the different diagnostic techniques. Methodology: This was a cross-sectional study. The participants included attendants to tertiary and private hospitals in Port Harcourt metropolis for medical treatment. Blood and stool samples were collected from one hundred and eighty (180) subjects aged 1 to 60 years and above. Ethical approval for the study was obtained from the Rivers State University Teaching Hospital Ethics Committee. Convenience sampling technique was deployed. Samples were collected from subjects who consented to the study. All samples collected were analyzed in Medical Microbiology Laboratory, Rivers State Teaching Hospital and subsequently, molecular analysis was carried out. Results: The blood antibodies test (serology) method shows a greater number of positive cases (43.9%) than stool antigen method (8.3%). Also, out of the 75% stool antigen positive samples, subjected to more specific PCR, only 25% were positive. There was a significant difference (p-value of &lt;0.001) in sensitivity between antigen and serology, there was also a significant difference (p-value of &lt;0.025) between antigen and PCR result outcomes. Conclusion: The study has shown that there is a notable variation in the diagnosis of H pylori among the laboratory techniques used.