Plasmon Resonance Research Articles

Aqueous phase Localized Surface Plasmon Resonance based Hydrogen sensing using Mixed colloidal Ag and PdAu nanoparticles

Hydrogen sensing is critical for its role in clean energy technologies. Herein, a colloidal Ag-PdAu ternary system as an efficient Localized Surface Plasmon Resonance (LSPR)-based sensor is first proposed for H2 sensing in aqueous environments. Upon exposure to H2, the system exhibits a significant LSPR peak shift of 42 nm within just 10 min, with no observable response to N2 under identical conditions.

High salt-resistant and robust MXene@oleylamine/PET composite nonwoven for efficient and long-term solar desalination

2D transition metal carbides/nitrides/carbonitrides (MXenes) have received extensive attention in solar seawater desalination due to their hydrophilicity, 100 % photothermal conversion efficiency, and efficient light-trapping by enhancing localized surface plasmon resonance (LSPR). Nevertheless, the easily oxidizable characteristics of MXenes, along with salt accumulation and structural weakness impede their practical application in solar-driven interfacial evaporators. Herein, a hydrophobic MXene@oleylamine/polyethylene terephthalate (MXene@OAm/PET) nonwoven with long-term operational stability is fabricated via firmly chemical cross-linking between oleylamine (OAm) modified MXene (MXene@OAm) and NH2-PEG-COOH treated PET nonwoven (PEG-PET). The MXene@OAm endows excellent oxidation resistance and hydrophobicity. The prepared MXene@OAm/PET nonwoven which exhibits broad-spectrum solar absorption and high efficiency, can achieve an average evaporation rate in 3.5 wt% NaCl solution at 1.26 kg·m−2·h−1 and no seeable salt deposition during 15 irradiation cycles for 8 h a day indicates its superior salt resistance and long-term stability. Most importantly, after being soaked in 3.5 wt% NaCl solution for 40 days, the evaporation rate of MXene@OAm/PET nonwoven still remains stable at around 1.22 kg·m−2·h−1, indicating the significant potential of this prepared nonwoven for long-term seawater desalination and its suitability for industrial applications. Even in industrial wastewater, the evaporation rate can reach 1.27 kg·m−2·h−1. This work demonstrates a successful strategy for achieving high efficiency, stability, and superior salt resistance, which can be potentially utilized in seawater desalination and wastewater treatment.

Tuneability and optimum functionality of plasmonic transparent conducting oxide-Ag core-shell nanostructures

Tunning localized surface plasmon resonance (LSPR) in transparent conducting oxides (TCO) has a great impact on various LSPR-based technologies. In addition to the commonly reported mechanisms used for tunning LSPR in TCOs (e.g., size, shape, carrier density modifications via intrinsic and extrinsic doping), integrating them in core-shell structures provides an additional degree of freedom to expand its tunability, enhance its functionality, and widen its versatility through application-oriented core-shell geometrical optimization. In this work, we explore the tuneability and functionality of two TCO nanostructures; indium doped tin oxide (ITO) and gallium doped zinc oxide (GZO) encapsulated with silver shell within the extended theoretical Mie theory formalism. The effect of core and shell sizes on LSPR peak position and line width as well as absorption and scattering coefficients is numerically investigated. Simulations showed that LSPRs of ITO-Ag and GZO-Ag core-shell nanostructures have great tunning capabilities, spanning from VIS to IR spectral range including therapeutic window of human tissue and essential solar energy spectrum. Potential functionality as refractive index sensor (RIS) and solar energy absorber (SEA) are examined using appropriate figure of merits (FoM). Simulations indicate that a geometrically optimized core-shell architecture with exceptional FoMs for RIS and SEA can be realized. Contrary to carrier density manipulation, integrating TCO cores to metallic shells proves to be an effective approach to enhance tunability and optimize functionality for high performance TCO-based plasmonic devices, with minimum impact on the inherited physical and chemical properties of the used TCO-core materials.

Single layered Ag/NiO plasmonic nanocoatings: A new green synthesis method for selective solar absorber

This study presents the synthesis of environmentally benign, single-layered spectrally selective Ag/NiO nanocoating absorbers using a green synthesis method. Various characterization techniques, including Rutherford backscattering spectroscopy (RBS), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM), were used to examine the effects of plasmonic Ag concentration on the structural, chemical composition, and surface morphology of the nanocomposites. The optical properties of the deposited nanocoatings were investigated using a UV–Vis-NIR spectrophotometer in the solar spectrum region (300–2500 nm) and an FT-IR spectrophotometer in the infrared wavelength region (3000–20,000 nm). XRD results confirmed the coexistence of a face-centered cubic phase of Ag and NiO in the Ag/NiO nanocermet thin films. SEM and TEM topography revealed uniformly distributed nanosphere NiO thin films and cubic Ag metal with better dispersibility and crystallization. The RBS spectrum of the samples showed a homogeneous distribution of Ni, Ag, and O atoms throughout the coatings. Ag/NiO nanocoatings deposited with 8 wt% Ag content exhibited excellent solar absorptance (α) = 0.95 and thermal emittance of (ɛ) of 0.08. This enhancement is primarily attributed to the localized surface plasmon resonance (LSPR) effect associated with the embedded Ag nanoparticles, which facilitates more effective utilization of light.

Localized surface plasmon resonance effect-mediated in-situ photochemical–formation of H2O2 for high epoxidation performance over LaSrCoNiO6 nanoparticles

Selective aerobic epoxidation of allylic alcohols and olefins presents a promising solution to the modern chemical industry. However, the development of non-noble metal catalysts with superior catalytic performance for this reaction remains a significant challenge. This study introduces a plasmonic photothermal-catalytic system centered around nano LaSrCoNiO6 (LSCNi-N) catalyst, enabling the epoxidation of cinnamyl alcohol and styrene mediated by LSPR effect under visible light illumination (>420 nm). This catalyst exhibits superior epoxidation catalytic performance, with selectivities of up to 72.3 % in a 93.4 % conversion of cinnamyl alcohol and 91.8 % selectivity of styrene oxide at almost 100 % conversion of styrene. Mechanistic studies reveal that the high selectivity derives from the in-situ photochemical formation of H2O2 mediated by the localized surface plasmon resonance effect of LSCNi-N and hole scavenger effect of cinnamyl alcohol. These findings highlight the potential of designing plasmonic transition-metal oxidic catalysts to overcome challenges in selectively synthesizing fine chemicals through visible light catalysis.

TiN/TiO2 embedded in ReS2 nanoflowers with wide light absorption and multi-interfacial charge transfer for efficient photocatalytic hydrogen generation

The design of functional materials with efficient light absorption and charge separation is crucial for photocatalytic energy conversion. Herein, a plasmonic TiN/TiO2/ReS2 ternary hybrid is prepared, which exhibits exceptional photocatalytic activity caused by the plasmon-mediated light absorption and multi-interfacial charge separation. The ternary hybrids were synthesized by heating TiN, Re, and S sources at high pressure and temperature. The TiN was partially oxidized to form TiN/TiO2 hybrids, which were then embedded in ReS2 nanoflowers through Ti-S bonds, creating a 3D flower-like structure with multiple interfaces. The plasmon resonance of TiN and the bandgap excitations of ReS2 and TiO2 endow the hybrids with efficient light absorption in UV–VIS-NIR region. Additionally, the novel embedded structure and the multiple interfaces between TiN, TiO2, and ReS2 facilitate the formation of built-in electric fields and multi-channel charge transfer, which efficiently quicken photoinduced carriers’ migration and hot electron injection. Consequently, the TiN/TiO2/ReS2 hybrids demonstrate a high-efficiency photocatalytic hydrogen generation rate, which is 12.1 times that of commercial P25. Notably, the hybrids also exhibit high photocatalytic activity under near-infrared light irradiation. This study offers innovative insights into the design of photocatalysts and suggests that the prepared materials could be utilized in solar-driven energy conversion applications.

Sample-to-answer point-of-care testing platform for quantitative detection of small molecules in blood using a smartphone-and microfluidic-based nanoplasmonic biosensor

Rapid and ultrasensitive detection of small molecules is of great significance in point-of-care testing (POCT) for health management and biomarker detection for many diseases. In this study, a novel POCT device integrated with a metasurface plasmon resonance (MetaSPR) chip with diffusion film enhancement was designed and controlled by a smartphone app for small molecule ultrasensitive detection based on competitive immunoassays. In this method, the sample competes with the antigen immobilized on the chip, and labeled antibodies are pumped from the sample pad to the chip for multiplexed and sample-to-answer analysis of blood. The entire process of detection is 14.3-fold less time (210 s in total) compared to an enzyme-linked immunosorbent assay (ELISA). For this assay, the limit of detection was 0.36 ppt and 1.05 ppt for testosterone and 25-hydroxyvitamin D3, respectively, and showed 100- to 1000-fold greater sensitivity than that of ELISA. Collectively, the data suggest that this novel POCT platform, based on a MetaSPR biosensor, provides ultrasensitive, rapid, regenerable, versatile, and real-time quantitative analysis for applications in health management and early diagnosis.

Plasmon-Enhanced Photoelectrochemistry of Photosystem II on a Hierarchical Tin Oxide Electrode for Ultrasensitive Detection of 17β-Estradiol.

Despite its excellent efficiency in natural photosynthesis, the utilization of photosystem II (PSII)-based artificial photoelectrochemical (PEC) systems for analytical purposes is hindered due to the low enzyme loading density and ineffective electron transfer (ET) processes. Here, we present a straightforward and effective approach to prepare a PSII-based biohybrid photoanode with remarkable photoresponse, enabled by the use of a hierarchically structured inverse-opal tin oxide (IO-SnO2) electrode combined with gold nanoparticles (Au NPs). The porous, carbon-containing IO-SnO2 structure allows for a high density and photoactivity loading of PSII complexes, while also providing strong electrical coupling between the protein film and the electrode. A new electron transfer pathway mediated by Au NPs was identified at the protein-electrode interface, which efficiently shuttles the photogenerated electrons from the enzyme to the IO-SnO2 electrode. Furthermore, the PEC response of the electrode was significantly enhanced by the surface plasmon resonance (SPR) effect of Au NPs. Upon light irradiation, this PSII-based photoanode exhibited an impressively high and stable photocurrent output, which was utilized to fabricate an aptasensor for 17β-Estradiol (E2) detection. Under optimal conditions, a detection limit of 0.33 pM was obtained, along with a broad detection range from 15 pM to 30 nM. The applicability of the aptasensor was assessed by measuring E2 in water and urine samples, demonstrating its feasibility in environmental monitoring and clinical tests.

Tetradecyl 2,3-Dihydroxybenzoate Improves Cognitive Function in AD Mice by Modulating Autophagy and Inflammation Through IPA and Hsc70 Targeting.

Drug development for Alzheimer's disease (AD) treatment is challenging due to its complex pathogenesis. Tetradecyl 2,3-dihydroxybenzoate (ABG-001), a leading compound identified in our prior research, has shown promising NGF-mimicking activity and anti-aging properties. In the present study, both high-fat diet (HFD)-induced AD mice and naturally aging AD mice were used to evaluate anti-AD effects. Meanwhile, RNA-sequences, Western blotting, immunofluorescence staining, enzyme-linked immunosorbent assay (ELISA), cellular thermal shift assay (CETSA), drug affinity-responsive target stability (DARTS) assay, construction of expression plasmid and protein purification, surface plasmon resonance (SPR) analysis, and 16S rRNA sequence analysis were used to identify the target protein of ABG-001 and clarify the mechanism of action for this molecule. ABG-001 effectively mitigates the memory dysfunction in both HFD-induced AD mice and naturally aging AD mice. The therapeutic effect of ABG-001 is attributed to its ability to promote neurogenesis, activate chaperone-mediated autophagy (CMA), and reduce neuronal inflammation. Additionally, ABG-001 positively influenced the gut microbiota, enhancing the production of indole-3-propionic acid (IPA), which is capable of crossing the blood-brain barrier (BBB) and contributes to neuronal regeneration. Furthermore, our research revealed that IPA, linked to the anti-AD properties of ABG-001, targets the heat shock cognate 70 kDa protein (Hsc70) and regulates the Hsc70/PKM2/HK2/LC3 and FOXO3a/SIRT1 signaling pathways. ABG-001 improves the memory dysfunction of AD mice by modulating autophagy and inflammation through IPA and Hsc70 targeting. These findings offer a novel approach for treating neurodegenerative diseases, focusing on the modification of the gut microbiota and metabolites coupled with anti-aging strategies.

Polyfluorene-based conjugated nanocomposites with in-situ gold nanoparticles: Synthesis via rational chemical passivation and characterization of supramolecular fibrillar structures

We present a rational and innovative chemical approach for synthesizing and characterizing conjugated polymer nanocomposites as direct passivation of gold nanoparticles (AuNPs), highlighting intrinsic morphologies and distinct photophysical properties in the solid state. The pioneering synthesis of polyfluorene with thiol, LaPPS79.10, revolutionized its application as a direct passivator of AuNPs, resulting in stable nanocomposites with the capacity for storage in the dry state and subsequent redispersion in organic solvent. The presence of AuNPs with average diameters of 3.5 ± 1.3 nm induced the formation of an interconnected fibrillar supramolecular network (ribbon-like) and several microdomains in the nanocomposite (LaPPS79.10+AuNPs), correlated by XRD, TEM and SEM measurements. Characterization of the polyfluorene precursor derivative, LaPPS10, revealed bundle-like morphologies with aggregation-induced emission (AIE). Introducing thiol groups into the intermediate structure induced polymer chain organization (LaPPS79.10), leading to unique straw-like and lenticular bundle morphologies, disrupting the non-planar π-π packing and quenching the emission, a case of aggregation-caused quenching (ACQ). In LaPPS79.10+AuNPs, the proximity of the π system to the Au localized surface plasmon resonance (LSPR) resulted in high absorption, negligible self-absorption, and efficient emission quenching, as well as improved thermal resistance compared to the original polymer. The unprecedented discovery of the properties resulting from the electronic interaction between the π system of the AuNPs passivating polymer and the effects of plasmonic resonance represents a significant advance in nanoscience, opening new perspectives for exciting applications in organic photovoltaic devices and metamaterials.

High-Performance BlueP/WS2 Heterostructure-Based GO-Coated Surface Plasmon Resonance Biosensor for Rapid Detection of Cancer Cells

High-Performance BlueP/WS2 Heterostructure-Based GO-Coated Surface Plasmon Resonance Biosensor for Rapid Detection of Cancer Cells

Visual colorimetric immunosensor for sensitive detection of 4-Chlorophenoxyacetic based on TMB2+-mediated etching of Au NRs

4-Chlorophenoxyacetic acid (4-CPA), a synthetic plant regulator, has been banned due to its cumulative toxicity to humans. However, unqualified sampling remains common in the market. To address the poor sensitivity of 4-CPA antibodies reported previously, a highly sensitive monoclonal antibody specific to 4-CPA was produced by redesigning and synthesizing a novel hapten in this study. Additionally, a visual colorimetric immunosensor based on TMB2+ mediated etching of gold nanorods (Au NRs) was developed. The ∆λ of the localized surface plasmon resonance (LSPR) peak exhibited a linear dependence on the 4-CPA concentration in the range of 0.2–6.25 ng mL−1, with a low limit of detection (LOD) of 0.2 ng mL−1. Recovery tests (85.0% to 108%) and HPLC validation demonstrated the immunosensor’s accuracy and precision. This visual colorimetric immunosensor illustrates significant potential for rapid detection of 4-CPA in biological environments.

Crystallization and Optical Behaviour of Nanocomposite Sol-Gel TiO2:Ag Films.

Sol-gel spin coating method was employed for depositing TiO2 and Ag-doped TiO2 films. The effects of Ag doping and the annealing temperatures (300-600 °C) were studied with respect to their structural, morphological, vibrational, and optical properties. Field Emission Scanning Electron microscopy (FESEM) investigation exhibited the grained, compact structures of TiO2-based films. Ag incorporation resulted in a rougher film surface. X-ray diffraction (XRD) results confirmed the formation of Ag nanoparticles and AgO phase, along with anatase and rutile TiO2, strongly depending on Ag concentration and technological conditions. AgO fraction diminished after high temperature annealing above 500 °C. The vibrational properties were characterized by Fourier Transform Infrared (FTIR) spectroscopy. It was found that silver presence induced changes in IR bands of TiO2 films. UV-VIS spectroscopy revealed that the embedment of Ag NPs in titania matrix resulted in higher absorbance across the visible spectral range due to local surface plasmon resonance (LSPR). Ag doping reduced the optical band gap of sol-gel TiO2 films. The optical and plasmonic modifications of TiO2:Ag thin films by the number of layers and different technological conditions (thermal and UV treatment) are discussed.

Crystal structure of the HMGA AT-hook 1 domain bound to the minor groove of AT-rich DNA and inhibition by antikinetoplastid drugs

High mobility group (HMG) proteins are intrinsically disordered nuclear non-histone chromosomal proteins that play an essential role in many biological processes by regulating the expression of numerous genes in eukaryote cells. HMGA proteins contain three DNA binding motifs, the “AT-hooks”, that bind preferentially to AT-rich sequences in the minor groove of B-form DNA. Understanding the interactions of AT-hook domains with DNA is very relevant from a medical point of view because HMGA proteins are involved in different conditions including cancer and parasitic diseases. We present here the first crystal structure (1.40 Å resolution) of the HMGA AT-hook 1 domain, bound to the minor groove of AT-rich DNA. In contrast to AT-hook 3 which bends DNA and shows a larger minor groove widening, AT-hook 1 binds neighbouring DNA molecules and displays moderate widening of DNA upon binding. The binding affinity and thermodynamics of binding were studied in solution with surface plasmon resonance (SPR)-biosensor and isothermal titration calorimetry (ITC) experiments. AT-hook 1 forms an entropy-driven 2:1 complex with (TTAA)2-containing DNA with relatively slow kinetics of association/dissociation. We show that N-phenylbenzamide-derived antikinetoplastid compounds (1–3) bind strongly and specifically to the minor groove of AT-DNA and compete with AT-hook 1 for binding. The central core of the molecule is the basis for the observed sequence selectivity of these compounds. These findings provide clues regarding a possible mode of action of DNA minor groove binding compounds that are relevant to major neglected tropical diseases such as leishmaniasis and trypanosomiasis.

Enhancing sensitivity to oxaliplatin in tongue squamous cell carcinoma: mechanistic insights and therapeutic potential of DHA combination therapy.

Squamous cell carcinoma of the tongue, a common and aggressive malignancy, poses a substantial threat to health and well-being. Despite the promising results of combination therapy with dihydroartemisinin (DHA) and oxaliplatin (Oxa) in various cancers, its effectiveness in treating tongue squamous cell carcinoma had not been explored prior to this study. Our research found that DHA significantly enhances the sensitivity of tongue squamous cell carcinoma cells to Oxa, even at very low concentrations. The combination treatment was observed to modulate the activity of CDK1 and Cyclin B1, arresting the cell cycle in the G2 phase. Additionally, it reduces mitochondrial membrane potential, prompting the release of cytochrome c and activating cleaved caspase-3, which promotes apoptosis. Notably, surface plasmon resonance and immunoprecipitation experiments revealed that DHA targets and attenuates CDK1 modification, weakening its interaction with STAT3 protein. This leads to reduced expression of anti-apoptotic genes and facilitates programmed cell death in CAL-27 cells. The findings underscore the potential of DHA and Oxa as a potent therapeutic strategy for tongue squamous cell carcinoma, opening avenues for clinical application and further exploration into its mechanistic pathways.

Dielectric Surface-Based Biosensors for Enhanced Detection of Biomolecular Interactions: Advances and Applications

Surface plasmon resonance (SPR) biosensors are extensively utilized for analyzing molecular interactions due to their high sensitivity and label-free detection capabilities. Recent innovations in surface-sensitive biosensors with dielectric surfaces address the inherent limitations associated with traditional gold surfaces, such as thermal effects and biocompatibility issues, which can impede broader applications. This review examines state-of-the-art biosensor configurations, including total internal reflection, optical waveguide, photonic crystal resonators, Bloch surface wave biosensors, and surface electrochemical biosensors, which can enhance analyte signals and augment the molecular detection efficiency at the sensor interface. These technological advancements not only improve the resolution of binding kinetics analysis and single-molecule detection but also extend the analytical capabilities of these systems. Additionally, this review explores prospective advancements in augmenting field enhancement and incorporating multimodal sensing functionalities, emphasizing the significant potential of these sophisticated biosensing technologies to profoundly enhance our understanding of molecular interactions.

Formononetin Induces Ferroptosis in Activated Hepatic Stellate Cells to Attenuate Liver Fibrosis by Targeting NADPH Oxidase 4.

Ferroptosis is a newly discovered type of cell death that exerts a crucial role in hepatic fibrosis. Formononetin (FMN), a natural isoflavone compound mainly isolated from Spatholobus suberectus Dunn, shows multiple biological activities, including antioxidant, anti-inflammatory, and hepatoprotection. This research aims to explore the regulatory mechanism of FMN in liver fibrosis and the relationship between NADPH oxidase 4 (NOX4) and ferroptosis. The effects of FMN on HSC ferroptosis were evaluated in rat model of CCl4-induced hepatic fibrosis. In vitro, N-acetyl-L-cysteine (NAC) and deferoxamine (DFO) were used to block ferroptosis and then explored the anti-fibrotic effect of FMN. The target protein of FMN was identified by bio-orthogonal click chemistry reaction as well as drug affinity responsive target stability (DARTS), cellular thermal shift (CETSA), surface plasmon resonance (SPR) assays, and isothermal titration calorimetry (ITC) analysis. Here, we found that FMN exerted anti-fibrotic effects via inducing ferroptosis in activated HSCs. NAC and DFO prevented FMN-induced ferroptotic cell death and collagen reduction. Furthermore, FMN bound directly to NOX4 through possible active amino acid residues sites, and increased NOX4-based NADPH oxidase activity to enhance levels of NADP+/NADPH, thus promoting ferroptosis of activated HSCs and relieving liver fibrosis. These results demonstrate that the direct target and mechanism by which FMN improves liver fibrosis, suggesting that FMN may be a natural candidate for further development of liver fibrosis therapy.

A RAPIDLY COLORIMETRIC DETECTION OF ARSENIC AND MERCURY IONS BASED ON SURFACE PLASMON RESONANCE ABSORBANCES OF FUNCTIONALIZED AuNPs IN COSMETICS

In this study, a novel colorimetric method is developed for the detection of arsenic and mercury ions, utilizing the surface plasmon resonance (SPR) properties of AuNPs ([Formula: see text] nanoparticles) functionalized with APT ([Formula: see text]-(3-aminophenyl) tetrazole). Theoretical calculations confirm the findings from UV–Visible spectroscopy and transmission electron microscopy analyses, indicating that APT is electrostatically bound to the surfaces of the AuNPs. The introduction of [Formula: see text] and [Formula: see text] ions triggers a coordination reaction with APT, resulting in a reduced interparticle distance among the AuNPs. This change leads to a visible color shift of the solution from wine red to bluish-gray. The detection limits for [Formula: see text] and [Formula: see text] are determined to be 0.6 and 0.24 [Formula: see text] g⋅[Formula: see text], respectively, distinguishable to the naked eye. A robust linear correlation is observed between the absorbance ratios and the ion concentrations, with correlation coefficients ([Formula: see text]) of 0.990 for [Formula: see text] and 0.998 for [Formula: see text]. These findings demonstrate that AuNPs functionalized with APT are effective for the quantitative analysis of arsenic and mercury ions. The sensor exhibits high selectivity and excellent resistance to interference, indicating its potential applicability for monitoring [Formula: see text] and [Formula: see text] in tap water and cosmetic products.

Structural insights into epitope-paratope interactions of a monoclonal antibody targeting CEACAM5-expressing tumors

Carcinoembryonic antigen-related cell adhesion molecules (CEACAMs) are overexpressed in some tumor types. The antibody-drug conjugate tusamitamab ravtansine specifically recognizes the A3-B3 domains of human CEACAM5 (hCEACAM5). To understand this specificity, here we map the epitope-paratope interface between the A3-B3 domains of hCEACAM5 (hCEACAM5A3-B3) and the antigen-binding fragment of tusamitamab (tusa Fab). We use hydrogen/deuterium exchange mass spectrometry to identify the tusa Fab paratope, which involves heavy chain (HC) residues 101–109 and light chain residues 48–54 and 88–104. Using surface plasmon resonance, we demonstrate that alanine variants of HC residues 96–108 abolish binding to hCEACAM5, suggesting that these residues are critical for tusa-Fab–antigen complex formation. The cryogenic electron microscopy structure of the hCEACAM5A3-B3- tusa Fab complex (3.11 Å overall resolution) reveals a discontinuous epitope involving residues in the A3-B3 domains and an N-linked mannose at residue Asn612. Conformational constraints on the epitope-paratope interface enable tusamitamab to target hCEACAM5A3-B3 and distinguish CEACAM5 from other CEACAMs.

Identification of fibrinogen as a plasma protein binding partner for lecanemab biosimilar IgG.

Recombinant monoclonal therapeutic antibodies like lecanemab, which target amyloid beta in Alzheimer's disease, offer a promising approach for modifying the disease progression. Due to its relatively short half-life, lecanemab administered as a bi-monthly infusion (typically 10 mg/kg) has a relatively brief half-life. Interaction with abundant plasma proteins binder in the bloodstream can affect pharmacokinetics of drugs, including their half-life. In this study, we investigated potential plasma protein binding (PPB) interaction to lecanemab using lecanemab biosimilar. Lecanemab biosimilar used in this study was based on publicly available sequences. ELISA and western blotting were used to assess lecanemab biosimilar immunoreactivity in the fractions of human plasma obtained through size exclusion chromatography. The binding of lecanemab biosimilar to candidate plasma binders was confirmed by western blotting, ELISA, and surface plasmon resonance analysis. Using a combination of equilibrium dialysis, ELISA, and western blotting in human plasma, we first describe the presence of likely PPB partners to lecanemab biosimilar and then identify fibrinogen as one of them. Utilizing surface plasmon resonance, we confirmed that lecanemab biosimilar does bind to fibrinogen, although with lower affinity than to monomeric amyloid beta. In the context of lecanemab therapy, these results imply that fibrinogen levels could impact the levels of free antibodies in the bloodstream and that fibrinogen might serve as a reservoir for lecanemab. More broadly, these results indicate that PPB may be an important consideration when clinically utilizing therapeutic antibodies in neurodegenerative disease.