Percentage Of Binding Research Articles

Coronil effectively inhibits the interaction of clinically relevant Omicron mutants of SARS-CoV-2 Spike Proteins with human ACE2 receptor

BackgroundAccumulating evidence suggests that the receptor binding domain (RBD) of the SARS-CoV-2 Omicron variant has several times more binding affinity to the human angiotensin-converting enzyme 2 (ACE2) receptor compared to the RBD of the original covid-19 strain. This increased binding affinity of the Omicron variant is responsible for its increased internalization and infectivity. PurposeIn the present study, the impact of Coronil, a tri-herbal formulation of extracts from Withania somnifera, Tinospora cordifolia and Ocimum sanctum on the binding properties of Omicron SARS-CoV-2 variant spike proteins (S proteins) was investigated. MethodsChemical composition of Coronil was determined by the Prominence-XR UHPLC system. The ELISA-based ACE2 binding inhibition assay was performed to delineate the effect of Coronil on the interaction between human ACE2 receptor and different Omicron variant S-proteins such as BA.4/BA5, XBB, BA.2.75.2, BA4.6/BF.7, BA.2.75.2, BQ.1.1 and a recently found spike protein variant JN.1 which is thought to emerge from BA.2.86. ResultsCoronil showed a dose-dependent inhibitory effect on the interactions between ACE2 and receptor binding domains (RBD) of all variants of S-proteins evaluated in this study including the recently emerged, highly transmissible variant spike protein JN.1. Although, Coronil significantly reduced the binding percentage in almost all the variant spike proteins, the maximum inhibition was achieved against BA.4/BA.5 where it inhibited the S protein – ACE2 interaction even at a low concentration of 3 µg/ml (16.6 %). This binding inhibition was further increased to 60.3 and 84.6 % at 100 and 300 µg/ml respectively. ConclusionThis capability of Coronil to inhibit the binding of S-protein variants with ACE2 receptor may interfere with viral binding and internalization resulting in reduced infectivity of these Omicron spike protein variants. Overall, our data underscores the potential of Coronil in combating the various newly emerged Omicron spike protein variants. These findings may provide a basis for further studies of Coronil for its clinical effectiveness against these Omicron variants.

Modification of Vancomycin Structure to Combat against Emerging Vancomycin Resistance

AbstractThe rise of multidrug‐resistant bacteria, such as Enterococcus faecium and Staphylococcus aureus, has compromised the efficacy of glycopeptide antibiotics like vancomycin. Consequently, novel strategies are urgently needed to combat vancomycin‐resistant strains. In this study, novel vancomycin derivatives with disulfide groups targeting the D‐alanyl‐D‐alanine for wild‐type, D‐alanyl‐D‐lactate, and D‐alanyl‐D‐serine regions for resistant strains were designed. Using ChemDraw Pro 12.0, the derivatives were created, and their binding affinities were assessed through molecular docking with AutoDock Vina. Molecular dynamics (MD) simulations were conducted with GROMACS 5.1.4, followed by MM/PBSA and quantum mechanical calculations. Pharmacokinetic properties were evaluated via ADMETlab 3.0. The derivatives showed enhanced binding energies across all target regions, irrespective of aromatic moieties or aliphatic groups. All three derivatives demonstrated higher logP values, improved gastrointestinal absorption, increased plasma protein binding percentages, better tissue distribution, and comparable half‐lives to vancomycin, along with favorable safety profiles. Among the vancomycin derivatives designed, derivative I emerged as a particularly promising candidate against vancomycin‐resistant strains, demonstrating superior binding energies and improved pharmacokinetic properties, thereby making it a strong candidate for further development.

Hybrid Molecules Containing Methotrexate, Vitamin D, and Platinum Derivatives: Synthesis, Characterization, In Vitro Cytotoxicity, In Silico ADME Docking, Molecular Docking and Dynamics.

Designing hybrid-based drugs is one promising strategy for developing effective anticancer drugs that explore combination therapy to enhance treatment efficacy, overcome the development of drug resistance, and lower treatment duration. Bisphosphonates and Vitamin D are commonly administered drugs for the treatment of bone diseases and the prevention of bone metastases. Platinum-based and methotrexate are widely used anticancer drugs in clinics. However, their use is hampered by adverse side effects. Hybrid-based compounds containing either bisphosphonate, vitamin D, platinum-based, or methotrexate were synthesized and characterized using FTIR, 1H-,31P, 13C-NMR, and UHPLC-HRMS which confirmed their successful synthesis. The hydroxyapatite bone binding assay revealed a promising percentage binding affinity of the bisphosphonate hybrid compounds. In vitro cytotoxicity assays on MCF-7 and HT-29 cell lines revealed a promising cytotoxic effect of hybrid 19 at 50 and 100 μg/mL on HT-29 and hybrid 15 on MCF-7 at 100 μg/mL. Molecular docking and dynamics simulation analysis revealed a binding affinity of -9.70 kcal/mol for hybrid 15 against Human 3 alpha-hydroxysteroid dehydrogenase type 3, showing its capability to inhibit Human 3 alpha-hydroxysteroid dehydrogenase type 3. The Swiss ADME, ProTox-II, GUSAR (General Unrestricted Structure-Activity Relationships), and molecular docking and dynamics studies revealed that these compounds are promising anticancer compounds.

Antimicrobial peptide LyeTx I mn∆K labeled with 68Ga is a potential PET radiopharmaceutical for molecular imaging of infections

BackgroundAntimicrobial peptides have been radiolabeled and investigated as molecular diagnostic probes due to their propensity to accumulate in infectious sites rather than aseptic inflammatory lesions. LyeTx I is a cationic peptide from the venom of Lycosa erythrognatha, exhibiting significant antimicrobial activity. LyeTx I mn∆K is a shortened derivative of LyeTx I, with an optimized balance between antimicrobial and hemolytic activities. This study reports the first 68Ga-radiolabeling of the DOTA-modified LyeTx I mn∆K and primarily preclinical evaluations of [68Ga]Ga-DOTA(K)-LyeTx I mn∆K as a PET radiopharmaceutical for infection imaging. MethodsDOTA(K)-LyeTx I mn∆K was radiolabeled with freshly eluted 68Ga. Radiochemical yield (RCY), radiochemical purity (RCP), and radiochemical stability (in saline and serum) were evaluated using ascending thin-layer chromatography (TLC) and reversed-phase high-performance liquid chromatography (RP-HPLC). The radiopeptide's lipophilicity was assessed by determining the logarithm of the partition coefficient (Log P). Serum protein binding (SBP) and binding to Staphylococcus aureus (S. aureus) cells were determined in vitro. Ex vivo biodistribution studies and PET/CT imaging were conducted in healthy mice (control) and mice with infection and aseptic inflammation to evaluate the potential of [68Ga]Ga-DOTA(K)-LyeTx I mn∆K as a specific PET radiopharmaceutical for infections. Results[68Ga]Ga-DOTA(K)-LyeTx I mn∆K was obtained with a high RCY (>90 %), and after purification through a Sep-Pak C18 cartridge, the RCP exceeded 99 %. Ascending TLC and RP-HPLC showed that the radiopeptide remained stable for up to 3.0 h in saline solution and up to 1.5 h in murine serum. [68Ga]Ga-DOTA(K)-LyeTx I mn∆K exhibited hydrophilic characteristics (Log P = −2.4 ± 0.1) and low SPB (ranging from 23.3 ± 0.4 % at 5 min of incubation to 10.5 ± 1.1 % at 60 min of incubation). The binding of [68Ga]Ga-DOTA(K)-LyeTx I mn∆K to S. aureus cells was proportional to bacterial concentration, with binding percentages of 8.8 ± 0.5 % (0.5 × 109 CFU.mL−1), 16.2 ± 1.4 % (1.0 × 109 CFU.mL−1), and 62.2 ± 0.6 % (5.0 × 109 CFU.mL−1). Ex vivo biodistribution studies and PET/CT images showed higher radiopeptide uptake at the infection site compared to the aseptic inflammation site; the latter was similar to the control group. Target-to-non-target (T/NT) ratios obtained by ex vivo biodistribution data were approximately 1.0, 1.3, and 3.0 at all investigated time intervals for the control, aseptic inflammation, and infection groups, respectively. Furthermore, T/NT ratios obtained from PET/CT images were 1.1 ± 0.1 for the control group and 1.4 ± 0.1 for the aseptic inflammation group. For the infection group, T/NT ratio was 5.0 ± 0.3, approximately 5 times greater compared to the former groups. ConclusionsThe results suggest the potential of [68Ga]Ga-DOTA(K)-LyeTx I mn∆K as a PET radiopharmaceutical for molecular imaging of infections.

Enantioselective Binding of Proton Pump Inhibitors to Alpha1-Acid Glycoprotein and Human Serum Albumin-A Chromatographic, Spectroscopic, and In Silico Study.

The enantioselective binding of three proton pump inhibitors (PPIs)-omeprazole, rabeprazole, and lansoprazole-to two key plasma proteins, α1-acid glycoprotein (AGP) and human serum albumin (HSA), was characterized. The interactions between PPI enantiomers and proteins were investigated using a multifaceted analytical approach, including high-performance liquid chromatography (HPLC), fluorescence and UV spectroscopy, as well as in silico molecular docking. HPLC analysis demonstrated that all three PPIs exhibited enantioseparation on an AGP-based chiral stationary phase, suggesting stereoselective binding to AGP, while only lansoprazole showed enantioselective binding on the HSA-based column. Quantitatively, the S-enantiomers of omeprazole and rabeprazole showed higher binding affinity to AGP, while the R-enantiomer of lansoprazole displayed greater affinity for AGP, with a reversal in the elution order observed between the two protein-based columns. Protein binding percentages, calculated via HPLC, were greater than 88% for each enantiomer across both transport proteins, with all enantiomers displaying higher affinity for AGP compared to HSA. Thermodynamic analysis indicated that on the HSA, the more common, enthalpy-controlled enantioseparation was found, while in contrast, on the AGP, entropy-controlled enantioseparation was observed. The study also identified limitations in using fluorescence titration due to the high native fluorescence of the compounds, whereas UV titration was effective for both proteins. The determined logK values were in the range of 4.47-4.83 for AGP and 4.02-4.66 for HSA. Molecular docking supported the experimental findings by revealing the atomic interactions driving the binding process, with the predicted enantiomer elution orders aligning with experimental data. The comprehensive use of these analytical methods provides detailed insights into the enantioselective binding properties of PPIs, contributing to the understanding of their pharmacokinetic differences and aiding in the development of more effective therapeutic strategies.

Iron Deficiency Anemia among Sanitation Workers in a Tertiary Care Hospital: A Cross-sectional Study

ABSTRACT Background: Iron deficiency anemia (IDA) has been the main cause of the health burden in India over the past decade. The aim of the present study was to examine the iron status and prevalence of iron deficiency anemia using biochemical markers among sanitation workers working at a tertiary healthcare center. Methodology: This hospital-based cross-sectional observational study was conducted on 80 sanitation workers for a period of 18 months (age 31–40 years). Dietary intake patterns were collected through the structured questionnaires. Blood samples were analyzed for complete blood count, serum iron level and unsaturated iron binding capacity, and ferritin. Total iron binding capacity and percentage transferrin saturation were calculated. Stool samples were screened for intestinal helminthic ova and cysts of intestinal protozoa. Results: Of the 80 sanitation workers, IDA was found in 38.7%; out of this, mild anemia was found in 16 (20%) participants, while 11.3% and 7.5% participants had moderate and severe anemia, respectively. Higher plasma sTfR levels were observed in women with severe iron depletion than in those with iron sufficiency (median 17.6 versus 15.5 nmol/L; P = 0.001). A statistically significant positive correlation between hemoglobin and serum iron, serum ferritin, and transferrin saturation was found. Hemoglobin was positively correlated with white blood cells, red blood cells, hematocrit, and mean corpuscular hemoglobin. Conclusion: This study highlights the presence of mild IDA among sanitary workers and lower levels of iron intake than the recommended dietary allowance.

Propofol does not alter the protein binding and unbound concentration of lidocaine at clinically targeted plasma concentrations in vitro – A short communication

BackgroundIntravenous lidocaine is increasingly used as an analgesic adjunct during general anaesthesia. Lidocaine is highly protein-bound and changes to binding can alter drug efficacy or toxicity. We aimed to measure the effect of various propofol and lidocaine plasma concentration combinations on the protein binding and concentration of lidocaine in vitro. MethodsKnown targeted concentrations of propofol and lidocaine were added to drug-free human plasma in vitro. Samples were prepared and analysed in various clinically relevant concentration combinations; propofol at 0, 2, 4 and 6 µg/mL, and lidocaine at 1, 3 and 5 µg/mL. The total and unbound concentrations of lidocaine were measured by ultra-high performance liquid chromatography-mass spectrometry and percentage protein binding was determined. Data were presented as mean and standard deviation (SD) and differences between groups analysed. ResultsThe overall mean protein binding of lidocaine was 68.8% (SD 5.5, range 57.5–80.9%). Beta regression analysis revealed no statistically significant difference in lidocaine percentage binding across a range of propofol and lidocaine concentration combinations. ConclusionPropofol did not alter the unbound and free pharmacologically active proportion of lidocaine at different clinically targeted concentrations of propofol and lidocaine in plasma in vitro. The percentage of plasma protein binding of lidocaine in this study was consistent with previously published results.

Effect of different pectin sources and structures on the stability of cyanidin-3-O-glucoside (C3G)

The physicochemical properties of cyanidin-3-O-glucoside (C3G) were investigated after binding with pectin from different sources (apple and peach) and fractions (water-soluble fraction (WSF), chelator soluble fraction (CSF) and sodium carbonate soluble fraction (NSF)). Apple WSF and peach CSF were high esterification degree pectin (DE) (63.23% and 55.66%). CSF of both AP and PP was abundant in HG and exhibited a much more linear structure than WSF and NSF. The maximum binding percentage was obtained at pH 2.0 for apple pectin (AP) (46%–50%) and at pH 3.5 for peach pectin (PP) (50%–54%). Binding with both pectins increased the color stability of C3G at pH 2.0. High DE pectin increased C3G light stability by reducing the degradation rate (0.03 h−1) compared to C3G alone (0.05 h−1). All the pectins reduced the thermal degradation rate of C3G, thus exhibiting a protective effect. A negative correlation was found between the relative RG I area and the particle size of the pectin-C3G complexes. Pectin played a leading role in the ζ-potential change.

Novel ultrasensitive automated kinetic exclusion assay for measurement of plasma levels of soluble PD-L1, the predictive and prognostic biomarker in cancer patients treated with immune checkpoint inhibitors

Recently, the blood plasma or serum levels of soluble programmed death protein 1 (PD-L1), but not tissue PD-L1 expression level, have been proposed as an effective predictive and prognostic biomarker in patients treated with immune checkpoint inhibitors for different types of cancers. The quantification of soluble PD-L1 in blood will provide a quick evaluation of patients’ immune status; however, the available assays have limitations in their sensitivity, reproducibility, and accuracy for use in clinical settings. To overcome these problems, this study was dedicated to developing an ultrasensitive automated flow-based kinetic exclusion assay (KinExA) for the accurate and precise measurement of soluble PD-L1 in plasma. The assay was developed with the assistance of KinExA™ 3200 biosensor. In this assay, PD-L1 in its calibrator or plasma sample solution was pre-equilibrated with anti-PD-L1 monoclonal antibody. The equilibrated mixture solution was then passed rapidly over PD-L1 protein that has been coated onto polymethylmethacrylate beads consolidated as a microcolumn in the observation cell of the KinExA™ biosensor. The free anti- PD-L1 antibody was bound to the immobilized PD-L1, however, the unbound molecules were removed from the beads microcolumn by flushing the system with phosphate-buffered saline. Fluorescein-labeled secondary antibody was passed rapidly over the beads, and the fluorescence signals were monitored during the flow of the labeled antibody through the beads. The calibration curve was generated by plotting the binding percentages as a function of PD-L1 concentrations in its sample solution. The working range of the assay with very a good correlation coefficient on a 4-parameter equation (r = 0.9992) was 0.5 − 100 pg mL─1. The assay limit of detection and quantitation were 0.15 and 0.5 pg mL─1, respectively. The recovery values of plasma-spiked PD-L1 were in the range of 96.4–104.3 % (±3.7–6.2 %). The precision of the assay was satisfactory; the values of the coefficient of variations did not exceed 6.2 % for both intra- and inter-day precision. The automated analysis by the proposed KinExA facilitates the processing of many specimens in clinical settings. The overall performance of the proposed KinExA is superior to the available assays for plasma levels of soluble PD-L1. The proposed assay is anticipated to have a great value in the measurement of PD-L1 where a more confident result is needed.

Anionic Dye Removal with a Thin Cationic Polyaniline Coating on Cellulosic Biomaterial.

This paper reports the development of novel adsorbent materials using polyaniline (PANI) grafted onto Posidonia (POS) fibers, aimed at efficiently removing phenol red (PSP), an anionic dye, from aqueous solutions. The synthesis involved the copolymerization of aniline grafted on the surface of the POS and aniline monomer in solution, resulting in a chemically bound thin PANI layer on the POS bioadsorbent. Structural characteristics and binding affinities of these adsorbents with PANI under its emeraldine salt (POS@PANI-ES) or emeraldine base (POS@PANI-EB) forms are reported. The rapid adsorption kinetics observed are attributed to enhanced accessibility to PANI adsorption sites on the POS surface. The binding percentages of PSP to POS@PANI-ES and POS@PANI-EB materials were found to be 97 and 50%, respectively, after 15 min of contact time. The Langmuir model for localized adsorption sites and the Volmer model for nonlocalized adsorption as a mobile layer were fitted to the experimental adsorption isotherms of PSP to POS@PANI-EB and POS@PANI-ES, yielding the thermodynamic parameters of adsorption. The adsorption capacities of PSP on POS@PANI-EB and POS@PANI-ES were 37.8 and 71.5 μmol g-1, respectively. The adsorption of PSP remained above 80% at moderate salt concentrations of around 0.1 mol L-1; however, higher concentrations of NaCl and CaCl2 in PSP solutions significantly reduced the adsorption on POS@PANI-ES.

Exploring the viability of Zeatin as a prospective therapeutic candidate for investigating the complex interplay between severe acute respiratory syndrome coronavirus (SARS-CoV) and Alzheimer's disease.

The present research aims to explore the intricate link between SARS-CoV infection and susceptibility to Alzheimer's disease, focusing on the role of APOE4, a genetic factor associated with both conditions. Our research aims to uncover shared molecular pathways, considering APOE4's impact on lipid metabolism, immune responses, and neuroinflammation relevant to COVID-19 and AD. The Chyawanprash phytocompounds were subjected to in-silico ADMET profiling and Zeatin a neuroprotective cytokinin emerged as a promising regulator of the ACE2-SPIKE complex as it exhibits favourable pharmacological attributes, presenting as a non-substrate for Permeability glycoprotein, low Protein Binding Percentage, and distinctive toxicity endpoints. Therapeutic candidate. Zeatin's robust binding disrupts the intricate APOE4-ACE2-SPIKE interplay (AAS), offering a potential therapeutic avenue that is further corroborated by Molecular dynamic simulation as the system remained stable without any major fluctuation throughout the 100ns simulation. The AAS binding free energy, determined as -124.849 +/- 15.513 KJ/mol using MMPBSA assay, reveals significant contributions to complex stability from amino acids including, GLN41: 1.211kcal/mol, GLU340: 1.188kcal/mol, ALA344: 1.198kcal/mol, while ARG38: 2.011kcal/mol establishes pivotal strong bonds integral to the interaction between AAS and Zeatin. Rigorous cytotoxicity assessments reveal Zeatin's safety profile, highlighting its inhibitory effect on LN18 cell viability that sharply decreases to 32.47% at 200µg/ml, underscoring its modulatory impact on cellular metabolism. These findings enhance our understanding of the convergent mechanisms linking SARS-CoV and AD, providing valuable insights for potential therapeutic interventions. Further research is warranted to elucidate the specific pathways and molecular mechanisms through which zeatin exerts its protective effects.

P1081 Pharmacokinetics and immunogenicity of the ustekinumab biosimilar candidate ABP 654 in patients with moderate-to-severe plaque psoriasis

Abstract Background ABP 654 is being developed as a biosimilar candidate to ustekinumab reference product (RP), a biologic agent used in the treatment of certain chronic, immune-mediated, inflammatory diseases. Previously, we reported no clinically meaningful differences in efficacy or safety between ABP 654 and ustekinumab RP in a 52-week randomised, double-blinded, active-controlled study in patients with moderate-to-severe plaque psoriasis. Here, we describe the pharmacokinetics (PK) and anti-drug antibody (ADA) results from the same study. Methods A total of 563 patients were randomised in a 1:1 ratio to receive ABP 654 or ustekinumab RP at a subcutaneous dose of 45 mg (baseline body weight [BW] ≤ 100 kg) or 90 mg (baseline BW > 100 kg) (Fig. 1). Serum samples for PK and ADA evaluations were collected at various timepoints. Concentrations of ABP 654 and ustekinumab RP were measured using an electrochemiluminescent (ECL) assay based on the Meso Scale Discovery platform. All ADA samples were tested in a validated binding, acid-dissociation ECL assay. Samples testing positive for binding antibodies were evaluated for neutralising ADA in a validated ECL-based affinity capture elution assay. Results From baseline to Week 52, the geometric least-squares (LS) means of trough serum concentrations were similar between the ABP 654 and ustekinumab RP groups. In addition, the geometric LS means of serum concentrations were similar post Week 28 for patients (ABP 654, n=25 and ustekinumab RP, n=34) who received dose intensification. Of patients with a post-baseline ADA result through Week 28, 52 (18.6%) patients in the ABP 654 group and 104 (37.1%) patients in the ustekinumab RP group tested positive for binding ADAs. Of these, 24 (8.6%) patients in the ABP 654 group and 50 (17.9%) patients in the ustekinumab RP group tested positive for neutralising ADAs. For dose intensification patients with a post-baseline result post Week 28, no patients in the ABP 654 group tested positive for binding or neutralising ADAs, and 2 (5.9%) patients in the ustekinumab RP group tested positive for binding and neutralising ADAs. Conclusion Throughout the study, serum trough concentrations remained comparable between ABP 654 and ustekinumab RP. While the percentages of binding and neutralising ADAs were numerically lower for the ABP 654 group compared with the ustekinumab RP group through Week 28 (and in patients who received dose intensification), the available clinical efficacy, safety, and PK data suggest that these differences were not clinically impactful. Overall, the results support a conclusion of no clinically meaningful differences between ABP 654 and ustekinumab RP.

The Role of Zinc on Liver Fibrosis by Modulating ZIP14 Expression Throughout Epigenetic Regulatory Mechanisms

Zinc plays a pivotal role in tissue regeneration and maintenance being as a central cofactor in a plethora of enzymatic activities. Hypozincemia is commonly seen with chronic liver disease and is associated with an increased risk of liver fibrosis development and hepatocellular carcinoma. Previously favorable effects of zinc supplementation on liver fibrosis have been shown. However, the underlying mechanism of this effect is not elucidated. Liver fibrosis was induced in mice by using CCl4 injection, followed by treatment with zinc chloride (ZnCl2) both at fibrotic and sham groups, and their hepatocytes were isolated. Our results showed that the administration of ZnCl2 restored the depleted cytosolic zinc levels in the hepatocytes isolated from the fibrotic group. Also, alpha-smooth muscle actin (αSMA) expression in hepatocytes was decreased, indicating a reversal of the fibrotic process. Notably, ZIP14 expression significantly increased in the fibrotic group following ZnCl2 treatment, whereas in the sham group ZIP14 expression decreased. Chromatin immunoprecipitation (ChIP) experiments revealed an increased binding percentage of Metal-regulatory transcription factor 1 (MTF1) on ZIP14 promoter in the hepatocytes isolated from fibrotic mice compared to the sham group after ZnCl2 administration. In the same group, the binding percentage of the histone deacetylase HDAC4 on ZIP14 promoter decreased. Our results suggest that the ZnCl2 treatment ameliorates liver fibrosis by elevating intracellular zinc levels through MTF1-mediated regulation of ZIP14 expression and the reduction of ZIP14 deacetylation via HDAC4. The restoration of intracellular zinc concentrations and the modulation of ZIP14 expression by zinc orchestrated through MTF1 and HDAC4, appear to be essential determinants of the therapeutic response in hepatic fibrosis. These findings pave the way for potential novel interventions targeting zinc-related pathways for the treatment of liver fibrosis and associated conditions.

The differential non-covalent binding of epicatechin and chlorogenic acid to ovotransferrin and the enhancing efficiency of immunomodulatory activity

Seeking safe and environmentally friendly natural immunomodulators is a pressing requirement of humanity. This study investigated the differential binding characteristics of two polar polyphenols (PP), namely epicatechin (EC) and chlorogenic acid (CA), to ovotransferrin (OVT), and explored the relationship between structural transformations and immunomodulatory activity of OVT-PP complexes. Results showed that CA exhibited a stronger affinity for OVT than EC, mainly driven by hydrogen bonds and van der Waals forces. Complexation-induced conformational variations in OVT, including static fluorescence quenching, increased microenvironment polarity surrounding tryptophan and tyrosine residues, and the transition from disordered α-helix to stable β-sheet. Furthermore, the structural conformation transformation of OVT-PP complexes facilitated the enhancement of immunomodulatory activity, with the OVT-CA (10:2) complex demonstrating the best immunomodulatory activity. Principal component analysis (PCA) and Pearson correlation analysis revealed the immunomodulatory activities of the OVT-PP complexes were influenced by surface hydrophobicity (negatively correlated), β-sheet percentage and polyphenol binding constants. It could be inferred that PP complexation increased the surface polarity of OVT, consequently enhancing its immunomodulatory activity by promoting cell membrane affinity and antigen recognition. This study provides valuable guidance for effectively utilizing polyphenol-protein complexes in enhancing immunomodulatory activity.

Adsorption and removal of polystyrene nanoplastics from water by green-engineered clays

Human exposure to micro- and nanoplastics (MNPs) commonly occurs through the consumption of contaminated drinking water. Among these, polystyrene (PS) is well-characterized and is one of the most abundant MNPs, accounting for 10 % of total plastics. Previous studies have focused on carbonaceous materials to remove MNPs by filtration, but most of the work has involved microplastics since nanoplastics (NPs) are smaller in size and more difficult to measure and remove. To address this need, green-engineered chlorophyll-amended sodium and calcium montmorillonites (SMCH and CMCH) were tested for their ability to bind and detoxify parent and fluorescently labeled PSNP using in vitro, in silico, and in vivo assays. In vitro dosimetry, isothermal analyses, thermodynamics, and adsorption/desorption kinetic models demonstrated 1) high binding capacities (173–190 g/kg), 2) high affinities (103), and 3) chemisorption as suggested by low desorption (≤42 %) and high Gibbs free energy and enthalpy (>|−20| kJ/mol) in the Langmuir and pseudo-second-order models. Computational dynamics simulations for 30 and 40 monomeric units of PSNP depicted that chlorophyll amendments increased the binding percentage and contributed to the sustained binding. Also, 64 % of PSNP bind to both the head and tail of chlorophyll aggregates, rather than the head or tail only. Fluorescent PSNP at 100 nm and 30 nm that were exposed to Hydra vulgaris showed concentration-dependent toxicity at 20–100 µg/mL. Importantly, the inclusion of 0.05–0.3 % CMCH and SMCH significantly (p ≤ 0.01) and dose-dependently reduced PSNP toxicity in morphological changes and feeding rate. The bioassay validated the in vitro and in silico predictions about adsorption efficacy and mechanisms and suggested that CMCH and SMCH are efficacious binders for PSNP in water.

Decoding the interaction mechanism between bis(2-methyl-3-furyl) disulfide and oral mucin

The interactions between mucin and aroma compounds have been shown to affect aroma perception. This study aimed to investigate the binding behavior between mucin and bis(2-methyl-3-furyl) disulfide and reveal the interaction mechanism at different pH levels. Based on our results, the binding percentages between mucin and bis(2-methyl-3-furyl) disulfide ranged from 37.03 % to 71.87 % at different contents. The complexes formation between mucin and bis(2-methyl-3-furyl) disulfide was confirmed by turbidity, particle size, zeta-potential, and surface hydrophobicity analyses. According to the results of multispectral techniques and molecular dynamic simulation, mucin could interact with bis(2-methyl-3-furyl) disulfide by hydrogen bonding, hydrophobic interactions, and van der Waals force. Furthermore, the binding constants of mucin to bis(2-methyl-3-furyl) disulfide were 1.26 × 103, 1.14 × 103, and 9.13 × 103 L mol−1 at pH 5.0, 7.0, and 8.5, respectively. These findings contribute to the comprehensive knowledge on the interaction mechanism between bis(2-methyl-3-furyl) disulfide and mucin, providing insights for flavor modulation in meat products.

Radiochemical and biological assessments of a PSMA-I&S cold kit for fast and inexpensive 99mTc-labeling for SPECT imaging and radioguided surgery in prostate cancer.

The expression of prostate-specific membrane antigen (PSMA) is upregulated in prostate cancer (PCa) cells and PSMA-ligands have been radiolabeled and used as radiopharmaceuticals for targeted radionuclide therapy (TRT), single photon emission computed tomography (SPECT) or positron emission tomography (PET) molecular imaging, and radioguided surgery in PCa patients. Herein, we aimed at radiolabeling the PSMA-I&S cold kit with 99mTc, resulting in a radiopharmaceutical with high radiochemical yield (RCY) and stability for SPECT imaging and radioguided surgery in PCa malignancies. Various pre-clinical assays were conducted to evaluate the [99mTc]Tc-PSMA-I&S obtained by the cold kit. These assays included assessments of RCY, radiochemical stability in saline, lipophilicity, serum protein binding (SPB), affinity for LNCaP-PCa cells (binding and internalization studies), and ex vivo biodistribution profile in naive and LNCaP-PCa-bearing mice. The radiopharmaceutical was obtained with good RCY (92.05% ± 2.20%) and remained stable for 6h. The lipophilicity was determined to be -2.41 ± 0.06, while the SPB was ∼97%. The binding percentages to LNCaP cells were 9.41% ± 0.57% (1h) and 10.45% ± 0.45% (4h), with 63.12 ± 0.93 (1h) and 65.72% ± 1.28% (4h) of the bound material being internalized. Blocking assays, employing an excess of unlabeled PSMA-I&S, resulted in a reduction in the binding percentage by 2.6 times. The ex vivo biodistribution profile confirmed high accumulation of [99mTc]Tc-PSMA-I&S in the tumor and the tumor-to-contralateral muscle ratio was ∼6.5. In conclusion, [99mTc]Tc-PSMA-I&S was successfully obtained by radiolabeling the cold kit using freshly eluted [99mTc]NaTcO4, exhibiting good RCY and radiochemical stability. The preclinical assays demonstrated that the radiopharmaceutical shows favorable characteristics for SPECT imaging and radioguided surgery in PCa patients.

Abstract 066: Decoy Peptide Attenuates The Syndrome Of preeclampsia In A Rodent Model

Background: Preeclampsia (preE) is a serious complication of pregnancy manifested by high blood pressure, proteinuria, and edema. In a previous study, we demonstrated that circulating levels of soluble (pro)renin receptor ((P)RR) were elevated at delivery in patients with preE, and that both plasma and placental (pro)renin were elevated in preE patients and in a rat model of preE. Decapeptide based on this handle-region sequence (handle-region peptides or HRP) can block binding of (pro)renin to (P)RR. Objective: The goal of this study is to develop and characterize HRP as an innovative treatment for preE. Methods and Materials: The human extravillous cytotrophoblast (CTB) cell line Sw-71 used in these studies was derived from first trimester chorionic villous tissue. (P)RR (2 nM) was incubated in 1.0 mL medium with the receptor-expressing CTB cells for 0, 6, 12, 18, or 24 hours, followed by renin activity assay to determine the percent binding and activation of (P)RR. Female Sprague-Dawley rats (200-250 g, first-time pregnant with confirmation by vaginal plug, Harlan) are randomly assigned to three groups (n=8 per group): 1) NP: normal pregnant rats; 2) PDS: pregnant animals injected initially with 12.5 mg of DOCA in a depot form intraperitoneally, followed by a weekly injection of 6.5 mg, and whose drinking water was replaced with 0.9% saline; 3) PDS-HRP: rats administered DOCA and saline as for Group 2, and also given HRP (10 mg/kg, i.p.) daily from day 10 through day 20 of pregnancy. Results: (Pro)renin was non-proteolytically activated by binding to (P)RR on the cell membrane of CTB cells, while HRP inhibited binding and attenuated activation of (P)RR. The HRP decoy peptide normalizes blood pressure, proteinuria, and birth numbers in DOCA model of preE. When HRP was administered following the onset of hypertension, the BP, proteinuria, and number of pups were normalized to control normal pregnancy. Conclusions: HRP inhibits the binding of (pro)renin to (P)RR. This study in animal model of preE suggests HRP blockade of (P)RR can attenuate the disease. (P)RR and (pro)renin levels are elevated in preE patients and in their placenta, as well as in a rat model of preE. This data suggests HRP as a potential therapeutic for intervention of RAS signaling in preE.

Comprehensive Biological, Photodegradation, Density Functional Theory, and Docking Exploration of Zn(II) and Mn(II) complexes of Piroxicam

AbstractThe biological evaluation of coordination complexes is an active research area ascribed to structural modification and synergistic action due to metal ions. The mononuclear complexes of Zn(II) and Mn(II) piroxicam were evaluated for their encyclopedic biological activities, DFT, and docking exploration. Different antioxidant methods were used to assess their antioxidant potential. DNA cleavage and protein binding properties of the complexes were monitored through gel electrophoresis and UV‐visible spectrophotometry. The low IC50 value of both complexes implies more potency than the piroxicam. The percent cleavage and binding constant values indicated that the complexes bind with DNA and BSA more efficiently than the piroxicam. In SD rats, complexes were screened for analgesic, anti‐anxiety, anti‐inflammatory, and anti‐hyperglycemic effects. The complexes demonstrated statistically significant results for in‐vivo analysis. Photodegradation results of the metal complexes under UV lamp exhibited abrupt degradation than the piroxicam. Docking results also validate a better propensity of both complexes to bind with DNA and BSA. Hydrogen bonding and Van der Waals forces play a key role in stabilizing complexes in DNA and BSA binding pockets. These metal complexes have evident therapeutic potential more than piroxicam and could be promising drugs for relieving pain, anxiety, inflammation, and associated comorbidities with good pharmacodynamic properties.

Radiolabeling, Quality Control, and Cell Binding Studies of New 99mTc-Labeled Bisphosphonates: 99mTc-Ibandronate Sodium.

Early detection of bone cancer is critical for treating symptoms, minimizing pain, and increasing overall quality of life. It is critical to develop novel radiopharmaceuticals with high labeling efficiency and stability for the diagnosis of bone cancer. This research aims to design a novel radiopharmaceutical that may be used to diagnose bone cancer. In this study, ibandronate sodium (IBD), a bisphosphonate analog, was radiolabeled with technetium-99m [99mTc] and quality control tests on the newly developed radiopharmaceutical ([99mTc]Tc-IBD) were performed using radioactive thin layer chromatography. After that, the incorporation of [99mTc]Tc-IBD into hydroxyapatite (HA) crystals and a human bone osteosarcoma cell line (U2OS) was tested. According to the results obtained, optimal radiolabeling procedure was obtained for [99mTc]Tc-IBD with 200 μg.mL-1 IBD, 20 μg stannous chloride, and 99mTc with 37 MBq radioactivity. The reaction mixture was adjusted to pH 5.5 and incubated at room temperature for 15 min. The radiochemical purity of [99mTc]Tc-IBD was found to be greater than 95% at room temperature for up to 6 h. Additionally, chromatography analysis showed >95% [99mTc]Tc-IBD complex formation with promising stability for up to 24 h in saline and up to 2 h in cell medium. The percentage binding of IBD to HA was 83.70 ± 3.67 and the logP of [99mTc]Tc-IBD was -1.1014. The radiolabeled complex exhibited a higher rate of cell incorporation to U2OS cells compared to Reduced/Hydrolyzed 99mTcO4 -. The newly produced radiopharmaceutical is very promising according to the results of in vitro cell culture, HA binding, and quality studies, and will be a step forward for further studies in nuclear medicine for bone cancer diagnostics.