Surface Binding Research Articles

Enhanced Adsorption Stability and Biofunction Durability with Phosphonate-Grafted, PEGylated Copolymer on Hydroxyapatite Surface.

Nonfouling surfaces are crucial in applications such as biosensors, medical implants, marine coatings, and drug delivery vehicles. However, their long-term coating stability and robust surface binding strength in physiological media remain challenging. Herein, a phosphonate-grafted, PEGylated copolymer on the hydroxyapatite (HA) surface is proposed to significantly improve the adsorption stability and thus enhance the biofunction durability accordingly. The phosphoryl (-PO3) grafted branch is employed in the functional polymer to facilitate attaching to the HA substrate. In addition, the polymer integrates the nonfouling polymer brushes of poly(ethylene glycol) (PEG) with the cell-adhesive moiety of cyclic Arg-Gly-Asp-d-Phe-Cys peptides (cRGD). A systematic study on the as-synthesized PEGylated graft copolymer indicates a synergistic binding mechanism of the NH2 and PO3 groups to HA, achieving a high surface coverage with desirable adsorption stability. The cRGD/PEGylated copolymers of optimized grafting architecture are proven to effectively adsorb to HA surfaces as a self-assembled copolymer monolayer, showing stability with minimal desorption even in a complex, physiological medium and effectively preventing nonspecific protein adsorption as examined with X-ray photoelectron spectroscopy (XPS) and a quartz crystal microbalance with dissipation (QCM-D). Direct adhesion assays further confirm that the enhanced coating stability and biofunction durability of the phosphonate-grafted, cRGD-PEGylated copolymer can considerably promote osteoblast attachment on HA surfaces, meanwhile preventing microbial adhesion. This research has resulted in a solution of self-assembly polymer structure optimization that exhibits stable nonfouling characteristics.

Four-Channel Ultrasonic Sensor for Bulk Liquid and Biochemical Surface Interrogation.

Custom electronics tailored for ultrasonic applications with four ultrasonic transmit-receive channels and a nominal 25 MHz single channel frequency were developed for ultrasound BAW and SAW biosensor uses. The designed integrated microcontroller, supported by Python with a SciPy library, and the developed system measured the time of flight (TOF) and other wave properties to characterize the acoustic properties of a bulk of the liquid in a microchannel or acoustic properties of biological species attached to an analytic surface in real time. The system can utilize both piezoelectric and capacitive micromachined ultrasound transducers. The device demonstrated a linear response to changes in water salinity. This response was primarily attributed to the time-of-flight (TOF) changes related to the varying solution density. Furthermore, real-time DNA oligonucleotide-based interactions between oligonucleotides immobilized on the device's analytical area and oligonucleotides attached to gold nanoparticles (Au NPs) in the solution were demonstrated. The biological interaction led to an exponential decrease in the acoustic interfacial wave propagating across the interface between the solution and the solid surface of the sensor, the TOF signal. This decrease was attributed to the increase in the effective density of the solution in the vicinity of the sensor's analytical area, as Au NPs modified by oligonucleotides were binding to the analytical area. The utilization of Au NPs in oligonucleotide surface binding yields a considerably stronger sensor signal than previously observed in earlier CMUT-based TOF biosensor prototypes.

Development of a [89Zr]Zr-labeled Human Antibody using a Novel Phage-displayed Human scFv Library.

Tax-interacting protein 1 (TIP1) is a cancer-specific radiation-inducible cell surface antigen that plays a role in cancer progression and resistance to therapy. This study aimed to develop a novel anti-TIP1 human antibody for noninvasive PET imaging in patients with cancer. A phage-displayed single-chain variable fragment (scFv) library was created from healthy donors' blood. High-affinity anti-TIP1 scFvs were selected from the library and engineered to human IgG1. Purified Abs were characterized by size exclusion chromatography high-performance liquid chromatography (SEC-HPLC), native mass spectrometry (native MS), ELISA, BIAcore, and flow cytometry. The labeling of positron emitter [89Zr]Zr to the lead Ab, L111, was optimized using deferoxamine (DFO) chelator. The stability of [89Zr]Zr-DFO-L111 was assessed in human serum. Small animal PET studies were performed in lung cancer tumor models (A549 and H460). We obtained 95% pure L111 by SEC-HPLC. Native MS confirmed the intact mass and glycosylation pattern of L111. Conjugation of three molar equivalents of DFO led to the optimal DFO-to-L111 ratio of 1.05. Radiochemical purity of 99.9% and specific activity of 0.37 MBq/μg was obtained for [89Zr]Zr-DFO-L111. [89Zr]Zr-DFO-L111 was stable in human serum over 7 days. The immunoreactive fraction in cell surface binding studies was 96%. In PET, preinjection with 4 mg/kg cold L111 before [89Zr]Zr-DFO-L111 (7.4 MBq; 20 μg) significantly (P < 0.01) enhanced the tumor-to-muscle standard uptake values (SUVmax) ratios on day 5 compared with day 2 postinjection. L111 Ab targets lung cancer cells in vitro and in vivo. [89Zr]Zr-DFO-L111 is a human antibody that will be evaluated in the first in-human study of safety and PET imaging.

Photophobotaxis in the filamentous cyanobacterium Phormidium lacuna: Mechanisms and implications for photosynthesis-based light direction sensing.

Cyanobacterium Phormidium lacuna filaments move from dark to illuminated areas by twitching motility. Time-lapse recordings demonstrated that this photophobotaxis response was based on random movements with movement reversion at the light-dark border. The filaments in the illuminated area form a biofilm attached to the surface. The wild-type and the pixJ and cphA mutants were investigated for photophobotaxis at diverse wavelengths and intensities. CphA is a cyanobacterial phytochrome; PixJ is a biliprotein with a methyl-accepting chemotaxis domain and is regarded as a phototaxis photoreceptor in other species. The cphA mutant exhibited reduced biofilm surface binding. The pixJ mutant was characterized as a negative photophobotaxis regulator and not as a light direction sensor. 3-(3,4-dichlorophenyl)1,1-dimethylurea (DCMU) blocks electron transfer in PS II. At concentrations of 100 and 1000 μM DCMU, photophobotaxis was inhibited to a greater extent than motility, suggesting that PSII has a role in photophobotaxis. We argue that the intracellular concentrations of regular photoreceptors, including CphA or PixJ, are too small for a filament to sense rapid light intensity changes in very weak light. Three arguments, specific inhibition by DCMU, broad spectral sensitivity, and sensitivity against weak light, support photosynthesis pigments for use as photophobotaxis sensors.

P911 Development and Characterization of SPY002, a Novel Extended Half-life Monoclonal Antibody Drug Candidate Targeting TL1A for the Treatment of IBD

Abstract Background Tumor necrosis factor (TNF)-like ligand 1A (TL1A) mediates a broad spectrum of pro-inflammatory and fibrotic effects and is implicated in the pathogenesis of several immunologic disorders. Blockade of the interaction of TL1A with its cognate receptor, DR3, has been shown to ameliorate disease activity patients with Crohn’s disease (CD) and ulcerative colitis (UC). SPY002 is a novel, extended half-life fully human IgG1 monoclonal antibody (mAb) that binds soluble TL1A with high affinity and specificity, and potently inhibits TL1A-mediated signaling. Methods SPY002 was evaluated in multiple in vitro and ex vivo assays compared to other clinical anti-TL1A mAbs (PRA023/MK-7240, RVT-3101, and TEV-48574). Binding affinity to soluble TL1A was determined by surface plasmon resonance (SPR) and binding to membrane-bound TL1A was confirmed by flow cytometry (FACS). Competitive blockade of TL1A binding to cell-surface DR3 was determined by FACS, and competition against the decoy receptor, DcR3, was evaluated by ELISA. The binding epitope of SPY002 was determined using cryogenic electron microscopy. TF-1 cell apoptosis and a primary human whole blood-based assay measuring IFNg secretion were used to assess functional blockade of exogenously added TL1A. Half-life extension was measured via pharmacokinetic analysis in both Tg276 transgenic mice (hemizygous for human FcRn) and cynomolgus monkeys given a single bolus of SPY002 by intravenous and/or subcutaneous administration. Results SPY002 binds specifically to monomeric and trimeric TL1A and not to related TNF super family proteins TNF, FasL, TRAIL, or LIGHT. SPY002 demonstrates sub-nanomolar affinity for soluble TL1A and binds to TL1A over-expressed on the surface of human embryonic kidney (HEK) cells. SPY002 potently inhibits both TL1A-induced apoptosis of TF-1 cells and TL1A-induced secretion of IFNg in human whole blood, with IC50 values comparable to those of RVT-3101 and TEV-48574, and a substantially lower IC50 than that of PRA023/MK-7240. The half-life of SPY002 is significantly extended in Tg276 mice compared to RVT-3101. In cynomolgus monkeys, the half-life of SPY002 is at least 18 days, compared to an observed half-life of 9-12 days for RVT-3101 and PRA023/MK-7240. Conclusion SPY002 exhibits high selectivity and affinity for TL1A, demonstrates effective blockade of the TL1A interaction with DR3, and potently inhibits downstream cellular signaling. With an extended half-life in NHP, SPY002 demonstrates therapeutic potential for effective and safe treatment of CD and UC with the advantage of infrequent SC dosing. Further preclinical and clinical studies are warranted to demonstrate this potential.

Tuning Energy Transfer Pathways in Halide Perovskite-Dye Hybrids through Bandgap Engineering.

Lead halide perovskite nanocrystals, which offer rich photochemistry, have the potential to capture photons over a wide range of the visible and infrared spectrum for photocatalytic, optoelectronic, and photon conversion applications. Energy transfer from the perovskite nanocrystal to an acceptor dye in the form of a triplet or singlet state offers additional opportunities to tune the properties of the semiconductor-dye hybrid and extend excited-state lifetimes. We have now successfully established the key factors that dictate triplet energy transfer between excited CsPbI3 and surface-bound rhodamine dyes using absorption and emission spectroscopies. The pendant groups on the acceptor dyes influence surface binding to the nanocrystals, which in turn dictate the energy transfer kinetics, as well as the efficiency of energy transfer. Of the three rhodamine dyes investigated (rhodamine B, rhodamine B isothiocyanate, and rose Bengal), the CsPbI3-rose Bengal hybrid with the strongest binding showed the highest triplet energy transfer efficiency (96%) with a rate constant of 1 × 109 s-1. This triplet energy transfer rate constant is nearly 2 orders of magnitude slower than the singlet energy transfer observed for the pure-bromide CsPbBr3-rose Bengal hybrid (1.1 × 1011 s-1). Intriguingly, although the single-halide CsPbBr3 and CsPbI3 nanocrystals selectively populate singlet and triplet excited states of rose Bengal, respectively, the mixed halide perovskites were able to generate a mixture of both singlet and triplet excited states. By tuning the bromide/iodide ratio and thus bandgap energy in CsPb(Br1-xIx)3 compositions, the percentage of singlets vs triplets delivered to the acceptor dye was systematically tuned from 0 to 100%. The excited-state properties of halide perovskite-molecular hybrids discussed here provide new ways to modulate singlet and triplet energy transfer in semiconductor-molecular dye hybrids through acceptor functionalization and donor bandgap engineering.

Phase Control and Singlet Energy Transfer Enabled by Trimethylamine Modified Boron Dipyrromethene for Stable CsPbBr3 Quantum Wells

AbstractThe phase distribution and organic spacer cations play pivotal roles in determining the emission performance and stability of perovskite quantum wells (QWs). Here, we propose a universal molecular regulation strategy to tailor phase distribution and enhance the stability of CsPbBr3 QWs. The capability of sterically hindered ligands with formidable surface binding groups is underscored in directing CsPbBr3 growth and refining phase distribution. With trimethylamine modified boron dipyrromethene (BDP‐TMA) ligand as a representative, the BDP‐TMA driven can precisely control phase distribution and passivate defects of CsPbBr3. Notably, BDP‐TMA acts as a co‐spacer organic entity in obtained BDP‐TMA‐CsPbBr3, facilitating efficient singlet energy transfer and tailoring the luminescence to produce a distinctive bluish‐white emission. The BDP‐TMA‐CsPbBr3 demonstrates significant phase stability under water exposure, light irradiation, and moderate temperature. Interestingly, BDP‐TMA‐CsPbBr3 exhibits the thermally‐induced dynamic fluorescence control at elevated temperatures, which can be achieved feasible for advanced information encryption. This discovery paves the way for the exploration of perovskite QWs in applications like temperature sensing, anti‐counterfeiting, and other advanced optical smart technologies.

Phase Control and Singlet Energy Transfer Enabled by Trimethylamine Modified Boron Dipyrromethene for Stable CsPbBr3 Quantum Wells.

The phase distribution and organic spacer cations play pivotal roles in determining the emission performance and stability of perovskite quantum wells (QWs). Here, we propose a universal molecular regulation strategy to tailor phase distribution and enhance the stability of CsPbBr3 QWs. The capability of sterically hindered ligands with formidable surface binding groups is underscored in directing CsPbBr3 growth and refining phase distribution. With trimethylamine modified boron dipyrromethene (BDP-TMA) ligand as a representative, the BDP-TMA driven can precisely control phase distribution and passivate defects of CsPbBr3 . Notably, BDP-TMA acts as a co-spacer organic entity in obtained BDP-TMA-CsPbBr3 , facilitating efficient singlet energy transfer and tailoring the luminescence to produce a distinctive bluish-white emission. The BDP-TMA-CsPbBr3 demonstrates significant phase stability under water exposure, light irradiation, and moderate temperature. Interestingly, BDP-TMA-CsPbBr3 exhibits the thermally-induced dynamic fluorescence control at elevated temperatures, which can be achieved feasible for advanced information encryption. This discovery paves the way for the exploration of perovskite QWs in applications like temperature sensing, anti-counterfeiting, and other advanced optical smart technologies.

Calculation of oxide sputter yields

An existing semi-empirical model to calculate the compound sputter yields is used to fit a large set of literature data on oxide sputter yields which consists of data for 21 different materials, and 65 datasets. The dedicated fitting procedure enables to link the surface binding energy of the metal and oxygen atoms with the oxide cohesive energy. This approach resolves a long standing problem in the research community on the accurate prediction of oxide sputter yields.

Insight on the stability of methane hydrate in montmorillonite slits by molecular dynamics simulations

The extent of interactions between clay surfaces and water molecules and their impact on hydrate stability in clay reservoirs have been a source of debate. This study employs molecular dynamics simulations to investigate the stability of methane hydrates in montmorillonite slits at various temperatures, focusing on the surface influence scale, bound water molecule distribution characteristics, and binding strength. The results reveal that hydrates in close proximity to the clay surface exhibit lower stability and higher decomposition susceptibility due to the hydrophilic nature of the surface, which leads to water molecule aggregation, driving methane molecules away during decomposition. Furthermore, we compare the charged and neutral tetrahedral layer surfaces of montmorillonite and find that the quasi-liquid layer on the neutral tetrahedral layer surface is thinner, with persisting semicage structures within the vacancies of the Si-O rings. These variations in surface influence range and binding strength can be attributed to intermolecular Coulomb interactions and charge redistribution at the interface. These research findings provide valuable molecular insights into the microscopic characteristics and behavior of hydrates within clay slits.

Interactions Between Silver Nanoparticles and Culture Medium Biomolecules with Dose and Time Dependencies.

The interaction between silver nanoparticles (AgNPs) and molecules producing coronas plays a key role in cytotoxicity mechanisms. Once adsorbed coronas determine the destiny of nanomaterials in vivo, their effective deployment in the biomedical field requires a comprehensive understanding of the dynamic interactions of biomolecules with nanoparticles. In this work, we characterized 40nm AgNPs in three different nutritional cell media at different molar concentrations and incubation times to study the binding mechanism of molecules on surface nanoparticles. In addition, their cytotoxic effects have been studied in three cell lineages used as tissue regeneration models: FN1, HUV-EC-C, RAW 264.7. According to the data, when biomolecules from DMEM medium were in contact with AgNPs, agglomeration and precipitation occurred. However, FBS medium proteins indicated the formation of coronas over the nanoparticles. Nonetheless, little adsorption of molecules around the nanoparticles was observed when compared to DMEM supplemented with 10% FBS. These findings indicate that when nanoparticles and bioproteins from supplemented media interact, inorganic salts from DMEM contribute to produce large bio-coronas, the size of which varies with the concentration and time. The static quenching mechanism was shown to be responsible for the fluorescence quenching of the bioprotein aggregates on the AgNPs surface. The calculated bioprotein-nanoparticle surface binding constants were on the order of 105M-1 at 37°C, with hydrophobic interactions driven by enthalpy and entropy playing a role, as confirmed by thermodynamic analysis. Cytotoxicity data showed a systematic degrowth in the viable cell population as the number of nanoparticles increased and the diameter of coronas decreased. Cytotoxic intervals associated with half decrease of cell population were established for AgNPs molar concentration of 75µM for 24h and 50µM for 48h. In summary, through the cytotoxicity mechanism of bio-coronas we are able to manipulate cells' expansion rates to promote specific processes, such inflammatory mechanisms, at different time instants.

Unraveling the orientation of an enzyme adsorbed onto a metal-organic framework.

Bio-conversion of lignocellulosic biomass to bioethanol fuel is a highly desirable yet challenging objective because of the low catalytic activity and high cost of β-glucosidase (BGL). Recently, ZIF-8, an emerging organic porous material, has been proposed as a promising candidate for enzyme immobilization to improve associated activity and stability. However, the underlying interaction mechanism of binding BGL on the ZIF-8 surface is yet to be clarified. Here, the adsorption of BGL onto ZIF-8 is explored for the first time by molecular dynamics simulations. The results show that BGL adsorbs on the ZIF-8 surface with a "back-on" orientation. The adsorption free energy analysis shows that the adsorption process is enthalpy driven. In addition, the electrostatic interaction between negatively charged residues and Zn2+ on the surface of ZIF-8 is found to play a decisive role in surface binding, which accounts for 98% of the total interaction energy. The secondary structure of BGL is not affected despite the strong adsorption, suggesting the good biocompatibility of ZIF-8. This study not only provides a reliable theoretical insight into understanding the interaction mechanism between BGL and ZIF-8, but also helps the rational design of ZIF-8-based materials for bio-related applications.

Optimality and cooperativity in superselective surface binding by multivalent DNA nanostars.

Weak multivalent interactions govern a large variety of biological processes like cell-cell adhesion and virus-host interactions. These systems distinguish sharply between surfaces based on receptor density, known as superselectivity. Present experimental studies typically involve tens or hundreds of interactions, resulting in a high entropic contribution leading to high selectivities. However, if, and if so how, systems with few ligands, such as multi-domain proteins and bacteriophages binding to their host, show superselective behavior is an open question. Here, we address this question with a multivalent experimental model system based on star shaped branched DNA nanostructures (DNA nanostars) with each branch featuring a single stranded overhang that binds to complementary receptors on a target surface. Each DNA nanostar possesses a fluorophore, to directly visualize DNA nanostar surface adsorption by total internal reflection fluorescence microscopy (TIRFM). We observe that DNA nanostars can bind superselectively to surfaces and bind optimally at a valency of three, for a given binding strength and concentration. We explain this optimum by extending the current theory with interactions between DNA nanostar binding sites (ligands). Our results add to the understanding of multivalent interactions, by identifying cooperative mechanisms that lead to optimal selectivity, and providing quantitative values for the relevant parameters. These findings inspire additional design rules which improve future work on selective targeting in directed drug delivery.

Artificial intelligence driven molecule adsorption prediction (AIMAP) applied to chirality recognition of amino acid adsorption on metals.

Predicting the adsorption structure of molecules has long been a challenging topic given the coupled complexity of surface binding sites and molecule flexibility. Here, we develop AIMAP, an Artificial Intelligence Driven Molecule Adsorption Prediction tool, to achieve the general-purpose end-to-end prediction of molecule adsorption structures. AIMAP features efficient exploration of the global potential energy surface of the adsorption system based on global neural network (G-NN) potential, by rapidly screening qualified adsorption patterns and fine searching using stochastic surface walking (SSW) global optimization. We demonstrate the AIMAP efficiency in constructing the Cu-HCNO6 adsorption database, encompassing 1 182 351 distinct adsorption configurations of 9592 molecules on three copper surfaces. AIMAP is then utilized to identify the best adsorption structure for 18 amino acids (AAs) on achiral Cu surfaces and the chiral Cu(3,1,17) S surface. We find that AAs chemisorb on copper surfaces in their highest deprotonated state, through both the carboxylate-amino skeleton and side groups. The chiral recognition is identified for the d-preference of Asp, Glu, and Tyr, and l-preference for His. The physical origin for the enantiospecific adsorption is thus rationalized, pointing to the critical role of the competitive adsorption between functional side groups and the carboxylate-amino skeleton at surface low-coordination sites.

Herb-Nanoparticle Hybrid System for Improved Oral Delivery Efficiency to Alleviate Breast Cancer Lung Metastasis.

Metastasis is a complex process involving multiple factors and stages, in which tumor cells and the tumor microenvironment (TME) play significant roles. A combination of orally bioavailable therapeutic agents that target both tumor cells and TME is conducive to prevent or impede the progression of metastasis, especially when undetectable. However, sequentially overcoming intestinal barriers, ensuring biodistribution in tumors and metastatic tissues, and enhancing therapeutic effects required for efficient therapy remain challenging. Inspired by the unique chemical features of natural herbs, we propose an oral herb-nanoparticle hybrid system (HNS) formed through the self-binding of Platycodon grandiflorum-Curcuma zedoaria (HG), a herb pair/group used in clinical practice to treat breast cancer metastasis, to lipid-polymer nanoparticles (LPNs) loaded with silibinin. The molecular structure responsible for HG association with LPNs was assessed using surface-enhanced Raman spectroscopy for HNS surface chemistry characterization. Moreover, the molecular class of HG was identified using UPLC-Orbitrap-MS/MS to further confirm the surface binding. Mucus diffusion and in vivo biodistribution were evaluated using in vitro multiple-particle tracking and environment-responsive fluorescence probe in 4T1 tumor-bearing mice, respectively. The alleviation of breast cancer metastasis was assessed in 4T1 tumor-bearing mice, and the underlying mechanism was investigated. The HNS reduced particle-mucus interactions by altering hydrophilicity and surface characteristics compared to LPNs. The epithelium transportation of HNS and absorption through Peyer's patch in mice were improved, promoting their biodistribution in the lung and tumor tissues. Furthermore, the HNS alleviated lung metastasis by inducing cell apoptosis and regulating the expression of MMP-9 and TGF-β1, which altered the TME in 4T1 tumor-bearing mice. HNS provides an appealing system with multi-component binding of herbal medicine to facilitate both oral nanoparticle delivery efficiency and the alleviation of lung metastasis. This strategy may potentially help improve treatment for patients with breast cancer.

Mechanistic study of the atomic layer deposition of cobalt: a combined mass spectrometric and computational approach.

Cobaltcarbonyl-tert-butylacetylene (CCTBA) is a conventional precursor for the selective atomic layer deposition of Co onto silicon surfaces. However, a limited understanding of the deposition mechanism of such cobalt precursors curbs rational improvements on their design for increased efficiency and tuneable selectivity. The impact of using a less reactive internal alkyne instead of a terminal alkyne was investigated using experimental and computational methods. Using electrospray-ionization mass spectrometry, the formation of CCTBA analogs and their gas phase decomposition pathways were studied. Decomposition experiments show very similar decomposition pathways between the two complexes. The internal alkyne dissociates from the Co complex at slightly lower energies than the terminal alkyne, suggesting that an internal alkynyl ligand may be more suited to low temperature ALD. In addition, transition state calculations using the nudged elastic band method confirm an increased reaction barrier between the internal alkyne and the Si-H surface bonds on Si(111). These results suggests that using a less reactive internal alkyne will result in fewer embedded carbon impurities during deposition onto Si wafers. DFT calculations using the PBE functional and periodic boundary conditions also predict increased surface binding with the metal centers of the internal alkynyl complex.

Cyanoremediation of heavy metals (As(v), Cd(ii), Cr(vi), Pb(ii)) by live cyanobacteria (Anabaena variabilis, and Synechocystis sp.): an eco-sustainable technology.

The cyanoremediation technique for heavy metal (HM) removal from wastewater using live cyanobacteria is promising to reduce the pollution risk both for the environment and human health. In this study, two widely recognized freshwater cyanobacteria, Anabaena variabilis and Synechocystis sp., were used to explore their efficacy in HM (As(v), Cd(ii), Cr(vi), Pb(ii)) removal. The different optimum adsorption conditions were pH 8 and 7.5 for A. variabilis and Synechocystis sp., respectively, but the temperature (25 °C) and contact time (48 hours) were the same for both strains. Under these specified conditions, A. variabilis exhibited the capability to remove 25% of As(v), 78% of Cd(ii), 54% of Cr(vi), and 17% of Pb(ii), whereas Synechocystis sp. removed 77% of As(v), 57% of Cd(ii), 91% of Cr(vi), and 77% of Pb(ii) at different initial concentrations. Metal diversity interfered negatively with cyanobacterial growth, especially Cd(ii) and As(v), as measured by OD730, dry biomass, chlorophyll a, and carotenoid production for both strains. Fourier transform infrared spectrum (FT-IR) analysis revealed the existence of diverse surface binding sites for HM adsorption, stemming from proteins and polysaccharides. Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS) confirmed the presence of HMs on the surface of the cyanobacterial cells. Finally, the zeta potential results indicating alterations in the surface negative charges elucidated the adsorption mechanisms involved in the HM removal by both cyanobacteria. These results provided a comprehensive understanding of the HM adsorption mechanism by cyanobacteria, offering valuable theoretical insights that can be extrapolated to enhance our comprehension of the cyanoremediation mechanisms by various other cyanobacterial strains.

Development of therapeutic monoclonal antibodies against DKK1 peptide-HLA-A2 complex to treat human cancers

BackgroundTargeted immunotherapy with monoclonal antibodies (mAbs) is an effective and safe method for the treatment of malignancies. Development of mAbs with improved cytotoxicity, targeting new and known tumor-associated antigens, therefore...

Anion-tuning in cobalt chalcogenides for a comparative study on electro-oxidation of glucose

Electronic structure modulation is of great important to enhance the electrocatalytic ability for glucose oxidation and follow up the electrochemical sensing performance. In this work, Co3X4 (X = O, S, Se) synthesized by oxidation, sulfurization and selenylation of ZIF-67 precursor, respectively, are served as electrocatalysts and then modified on conductive indium tin oxide (ITO) to construct sensing electrodes. The Co3S4/ITO electrode shows a highest sensitivity of 1109.9 μA−1 mM−1 cm−2 when compared with those of the Co3Se4/ITO electrode (515.9 μA−1 mM−1 cm−2), Co3O4/ITO electrode (227.7 μA−1 mM−1 cm−2), and even the relative reported sensing electrodes, enabling more efficient electro-oxidation of glucose by S substitution in Co3X4. The experimental characterization and theoretical calculation elucidate that tuning the anion components in cobalt chalcogenides can modulate their electrochemical active surface area, hydrophilicity, electrical conductivity and binding energies for glucose adsorption, in turn, the electrocatalytic ability. This work provides not only an effective strategy for performance improvement but also a significant understanding of how the anion component of electrocatalyst affect their glucose oxidation ability.

A reusable graphene oxide aerogel for pre-concentrating and recovering uranium from water and valorisation of spent material in a cementitious material

Graphene oxide is an excellent substrate for pre-concentrating and recovering uranium in water. However, the need for scalable and affordable methods for producing graphene oxide has hindered its field applications. Besides, a sustainable strategy is required to recycle spent adsorbents and prevent them from entering the waste stream. In these contexts, this paper describes the application of graphene oxide aerogel (GOA) produced from graphite through a single-step combustion route for pre-concentrating and recovering uranium in water. The method allows GOA production in bulk quantity at 8–10 times less cost than prevalent Modified Hummer's graphene oxide (HGO). The paper also demonstrates using spent GOA as an active admixture in mortar to improve its mechanical properties. The physicochemical properties of the GOA and mechanistic details of uranium surface bindings were studied thoroughly. GOA showed enhanced uranium adsorption capacity (278 mg/g) compared to HGO due to abundant hydroxyl, carboxyl, and epoxy groups on GOA. However, the presence of HCO3− in water reduced uranium uptake due to highly water-soluble uranium-carbonate complexes such as (UO2)2CO3(OH)3−,UO2(CO3)34−, and UO2(CO3)22−. The addition of the spent GOA improved the cement mortar's compressive strength by 15 % compared to the pristine cube and arrested the leaching of residual uranium. The GOA addition and associated enhancement in compressive strength help to save cement and lower CO2 emissions. In short, the present work addresses the critical challenges of using GOA in pre-concentrating and recovering aqueous uranium, such as bulk production, production cost, and spent materials disposal.