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Stem cells opened great opportunity to overcome diseases that conventional therapy had only limited success. Use of scaffolds made from biomaterials not only helps handling of stem cells for delivery or transplantation but also supports enhanced cell survival. Likewise, cell encapsulation can provide stability for living animal cells even in a state of separateness. Although various chemical reactions were tried to encapsulate stolid microbial cells such as yeasts, a culture environment for the growth of animal cells allows only highly biocompatible reactions. Therefore, the animal cells were mostly encapsulated in hydrogels, which resulted in enhanced cell survival. Interestingly, major findings of chemistry on biological interfaces demonstrate that cell encapsulation in hydrogels have a further a competence for modulating cell characteristics that can go beyond just enhancing the cell survival. In this review, we present a comprehensive overview on the chemical reactions applied to hydrogel‐based cell encapsulation and their effects on the characteristics and behavior of living animal cells. Stem‐cell‐based cell therapy is a promising strategy for regenerative medicine. Since cells are expanded by in vitro culture and subsequently transplanted to in vivo milieu, they are devoid of micro‐environmental niche, thereby decreasing cell activity and survival. Hydrogel‐based encapsulation of stem/tissue progenitor cells not only provides cytoprotective effect to enhance cell survival, but also influences various aspects of cell activities, including differentiation tendency, migration, paracrine activity, and integration with adjacent tissues. This review demonstrates several aspects of cell encapsulation in hydrogel to maximize the functionality of cells for the therapeutic purposes. [ABSTRACT FROM AUTHOR]

The article discusses a study on the coating process of yeast cells with antimicrobial chitosan through layer-by-layer (LbL) assembly. Topics include the antimicrobial properties of chitosan, the cytocompatibility of LbL components which are the requirements for successful coating and the potential application of antimicrobial materials to cell surface modification.

We demonstrated a new type of visible light-induced photocatalyst, comprising fluorescein molecules, TiO 2 , and gold nanoparticles anchored onto polymer fibers. The synthesized fiber composite was fully characterized by thermogravimetric analysis, scanning electron microscopy, transmission electron microscopy, FT-IR spectroscopy, contact angle measurement, and fluorescence microscopy. Under sunlight and visible light irradiation, the photocatalytic activity of the tricomponent system showed 2–3 times greater photodegradation efficiency for methylene blue than a representative photocatalyst, Degussa P25. [ABSTRACT FROM AUTHOR]

The article discusses the optimization of the cytocompatible silica coating conditions for screening of mammalian HeLa cells in silicification conditions. Topics discussed include the stringent selection of material for the manipulation of mammalian cells and the process coating of individual HeLa cells with silica in cytocompatible conditions.

Abstract: Chemical surface modification of neuron-surface interfaces is essential for the development of biologically active and functional neural interfaces. Different types of surface modification schemes are required to derivatize either electrode or insulator surfaces, which limits the surface chemistry based neural interface design. Herein, we report a novel and powerful approach for modifying neuron-surface interfaces using mussel-inspired polymer (‘polydopamine film(polyDA)’) for generating effective chemical platforms on both electrode and insulator surfaces simultaneously. We applied polyDAs to common neural interface surfaces (gold, glass, platinum, indium tin oxide, liquid crystal polymer) and subsequently functionalized them by covalently linking biomolecules. The surfaces coated with polyDAs exhibited uniform and reproducible surface properties and they all became neuron-adhesive after linking with poly-d-lysine. In addition, polydopamine-coated microelectrode arrays were readily functional such that spontaneous and evoked neural activities could be recorded from cultured neuronal networks. We have successfully showed that a novel polyDA can be effectively used for the neural interface design. [Copyright &y& Elsevier]

Inspired by biosilicification of glass sponges, we designed a catalytic peptide, which formed silica structures in the imidazole-buffered solution. The peptide was adsorbed selectively onto the surface of yeast cells, and the bioinspired silicification led to the formation of a cytoprotective silica shell on individual yeast cells. [ABSTRACT FROM AUTHOR]

Single-cell nanoencapsulation (SCNE) has great potential in the enhancement of therapeutic effects of probiotic microbes. However, the material scope has been limited to water-soluble compounds to avoid non-biocompatible organic solvents that are harmful to living cells. In this work, the SCNE of probiotic Lactobacillus acidophilus with water-insoluble luteolin and Fe3+ ions is achieved by the vortex-assisted, biphasic water–oil system. The process creates L. acidophilus nanoencapsulated in the luteolin-Fe3+ shells that empower the cells with extrinsic properties, such as resistance to lysozyme attack, anti-ROS ability, and α-amylase-inhibition activity, as well as sustaining viability under acidic conditions. The proposed protocol, embracing water-insoluble flavonoids as shell components in SCNE, will be an advanced add-on to the chemical toolbox for the manipulation of living cells at the single-cell level. [ABSTRACT FROM AUTHOR]

Presents information on a study which examined self-assembly in quasi-two-dimensional mesoscale system of hexagonal plates using capillary forces. Design of the system; Experimental methods; Results and discussion; Conclusions.

Highlights from the article: After confirming the reasonable performance of our GCN model, we deleted each one from the 12 atom features and trained the feature-deleted models with the same protocol as before in order to understand the contribution of individual atom features to the aqueous solubility.

Nanoencapsulation of living cells within artificial shells is a powerful approach for augmenting the inherent capacity of cells and enabling the acquisition of extrinsic functions. However, the current state of the field requires the development of nanoshells that can dynamically sense and adapt to environmental changes by undergoing transformations in form and composition. This paper reports the compositional transformation of an enzyme‐embedded nanoshell of Fe3+‐trimesic acid complex to an iron phosphate shell in phosphate‐containing media. The cytocompatible transformation allows the nanoshells to release functional molecules without loss of activities and biorecognition, while preserving the initial shell properties, such as cytoprotection. Demonstrations include the lysis and killing of Escherichia coli by lysozyme, and the secretion of interleukin‐2 by Jurkat T cells in response to paracrine stimulation by antibodies. This work on micrometric Transformers will benefit the creation of cell‐in‐shell nanobiohybrids that can interact with their surroundings in active and adaptive ways. [ABSTRACT FROM AUTHOR]

Although deep‐learning (DL) models suggest unprecedented prediction capabilities in tackling various chemical problems, their demonstrated tasks have so far been limited to the scalar properties including the magnitude of vectorial properties, such as molecular dipole moments. A rotation‐equivariant MolNet_Equi model, proposed in this paper, understands and recognizes the molecular rotation in the 3D Euclidean space, and exhibits the ability to predict directional dipole moments in the rotation‐sensitive mode, as well as showing superior performance for the prediction of scalar properties. Three consecutive operations of molecular rotation RM ${\left(R\left(M\right)\right)}$ , dipole‐moment prediction φμRM ${\left({\phi{} }_{\mu }\left(R\left(M\right)\right)\right)}$ , and dipole‐moment inverse‐rotation R-1φμRM ${\left({R}^{-1}\left({\phi{} }_{\mu }\left(R\left(M\right)\right)\right)\right)}$ do not alter the original prediction of the total dipole moment of a molecule φμM ${\left({\phi{} }_{\mu }\right(M\left)\right)}$ , assuring the rotational equivariance of MolNet_Equi. Furthermore, MolNet_Equi faithfully predicts the absolute direction of dipole moments given molecular poses, albeit the model has been trained only with the information on dipole‐moment magnitudes, not directions. This work highlights the potential of incorporating fundamental yet crucial chemical rules and concepts into DL models, leading to the development of chemically intuitive models. [ABSTRACT FROM AUTHOR]

(–)‐Cannabidiol (CBD), a nonpsychoactive compound isolated from the Cannabis genus, has recently emerged as a promising research subject in neuroscience due to its potential therapeutic benefits against neurological disorders. However, there has been limited fundamental understanding of how CBD affects neuronal development, such as neurite outgrowth and axonal branching, at the cell level. This work investigates the effects of CBD on the early development of primary hippocampal neurons in a noncontact neuron‐astrocyte coculture system. The immunocytochemical and quantitative analyses indicate that CBD of 10 μM promotes neurite growth, including neurite elongation and arborization, and accelerates the process of axon specification. The CBD treatment to the coculture system leads to noticeable increases in the longest‐neurite length, primary‐neurite number, and branch‐point number, as well as the population of axon‐determined neurons. The results provide informative insights into the therapeutic potential of CBD in neurological disorders, such as Alzheimer's disease. [ABSTRACT FROM AUTHOR]

Describes the combination of microcontact printing and surface-initiated ring-opening metathesis polymerization to generate patterned polymers on surfaces. Application of the patterns as reactive ion etching resists; Identification of reliable, flexible process that can be used to generate patterned polymer films on technologically important surfaces.

Cell–ECM interactions (ECM=extracellular matrix) can keep the cells alive through the activation of intracellular survival signaling pathways. When cells are detached from ECM stroma, the cells enter an attachment‐deprived state, which is devoid of extracellular signals that trigger the activation of survival signaling pathways. Therefore, single cells in the detached state eventually undergo anoikis, a type of cell death induced by an attachment‐deprived state. Cell encapsulation can provide a signaling que for the cells in an attachment‐deprived state to activate survival signaling pathways. Depending on the purpose of application, cells are encapsulated in their single‐cellular or multicellular states. The Minireview by E. Lee et al. on page 15725 ff. summarizes the current research strategies of cell encapsulation in the perspective for future applications. [ABSTRACT FROM AUTHOR]

Inspiration from the iron gall ink leads to the efficient formation of Fe(iii)–tannic acid coacervate particles inside the phase-separated microdroplets that are derived from the aqueous PEG/dextran liquid–liquid phase separation system. This hierarchical self-assembly, in aid of the protein affinity of tannic acid, makes it possible to compartmentalize and condense proteins into a localized, compact space in the microdroplets. [ABSTRACT FROM AUTHOR]

Coordination-driven self-assembly of metal–ligand complexes is a powerful nanoarchitectonic tool for particle engineering, but its usability is limited when using two immiscible coating components. This paper reports that simple vortexing of a biphasic system of Fe3+ ions in water and flavonoids in oil forms nanoshells on individual particles, thereby enabling the utilization of water-insoluble ligands as coating materials. Mechanistic studies suggest that the biphasic mass-transfer equilibrium of flavonoid-Fe3+ species controls the shell formation, with the oil phase acting as a reservoir of coating precursors for continuous coating. The versatility and convenience of our method expand the chemical toolbox for modulating particle–material interfaces. [ABSTRACT FROM AUTHOR]

Magnetic functionalization of living cells has intensively been investigated with the aim of various bioapplications such as selective separation, targeting, and localization of the cells by using an external magnetic field. However, the magnetism has not been introduced to individual living cells through the in situ chemical reactions because of harsh conditions required for synthesis of magnetic materials. In this work, magnetic iron oxide was formed on the surface of living cells by optimizing reactions conditions to be mild sufficiently enough to sustain cell viability. Specifically, the reactive LbL strategy led to formation of magnetically responsive yeast cells with iron oxide shells. This facile and direct post-magnetization method would be a useful tool for remote manipulation of living cells with magnetic interactions, which is an important technique for the integration of cell-based circuits and the isolation of cell in microfluidic devices. [ABSTRACT FROM AUTHOR]

One-step fabrication method for thin films and shells is developed with nature-derived eggshell membrane hydrolysates (ESMHs) and coffee melanoidins (CMs) that have been discarded as food waste. The nature-derived polymeric materials, ESMHs and CMs, prove highly biocompatible with living cells, and the one-step method enables cytocompatible construction of cell-in-shell nanobiohybrid structures. Nanometric ESMH-CM shells are formed on individual probiotic Lactobacillus acidophilus, without any noticeable decrease in viability, and the ESMH-CM shells effectively protected L. acidophilus in the simulated gastric fluid (SGF). The cytoprotection power is further enhanced by Fe3+-mediated shell augmentation. For example, after 2 h of incubation in SGF, the viability of native L. acidophilus is 30%, whereas nanoencapsulated L. acidophilus, armed with the Fe3+-fortified ESMH-CM shells, show 79% in viability. The simple, time-efficient, and easy-to-process method developed in this work would contribute to many technological developments, including microbial biotherapeutics, as well as waste upcycling. [ABSTRACT FROM AUTHOR]

ABSTRACT Activation-free copolymeric films possessing high selectivity to target proteins and low biofouling background are prepared via controlled radical polymerization. The copolymeric films are generated by surface-initiated activators regenerated by electron transfer atom transfer radical polymerization (SI-ARGET ATRP) of N-acryloxysuccinimide (NAS) and oligo(ethylene glycol) methyl ether methacrylate (OEGMEMA) by controlling the molar feed ratio of the two monomers. The formation of copolymeric films is characterized by ellipsometry, contact angle goniometry, FTIR spectroscopy, and X-ray photoelectron spectroscopy. The prepared copolymeric films are biotinylated without an activation step. Biotin-streptavidin association is employed as a model system to investigate both selective binding and the relevant signal-to-noise ( S/N) ratio. When the molar feed ratio of NAS and OEGMEMA is 2:8, the copolymeric film is optimized to give the highest S/N ratio (339.8) according to surface plasmon resonance studies. The highly selective bioconjugation is used to generate micropatterns of rhodamine-conjugated streptavidin on the copolymeric film. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 329-337 [ABSTRACT FROM AUTHOR]

Most graph neural networks (GNNs) in deep‐learning chemistry collect and update atom and molecule features from the fed atom (and, in some cases, bond) features, basically based on the two‐dimensional (2D) graph representation of 3D molecules. However, the 2D‐based models do not faithfully represent 3D molecules and their physicochemical properties, exemplified by the overlooked field effect that is a "through‐space" effect, not a "through‐bond" effect. We propose a GNN model, denoted as MolNet, which accommodates the 3D non‐bond information in a molecule, via a noncovalent adjacency matrix A‾ , and also bond‐strength information from a weighted bond matrix B. Comparative studies show that MolNet outperforms various baseline GNN models and gives a state‐of‐the‐art performance in the classification task of BACE dataset and regression task of ESOL dataset. This work suggests a future direction for the construction of deep‐learning models that are chemically intuitive and compatible with the existing chemistry concepts and tools. [ABSTRACT FROM AUTHOR]

Back and forth: Enzymatic, reversible polymerization on gold surfaces was efficiently carried out from surface ‐ tethered self ‐ priming oligodeoxynucleotides in a sequence ‐ specific fashion by using two kinds of enzymes. Taq DNA polymerase, acting as a catalyst, facilitated DNA polymerization, and DNA restriction enzymes cut DNA polymers from the surface. [ABSTRACT FROM AUTHOR]

The possibility of lateral extension of conjugation withina covalentlygrafted molecular layer by a scanning probe-based method was tested.A molecular layer derived from ω-(N-pyrrolyl)propanolwas formed on n-type Si(111) surface. Application of large samplebiases greater than ±4 V during conductive atomic force microscope(AFM) scans under vacuum resulted in changes of mechanical and electricalcharacteristics of the molecular layer: the tip–sample conductancewas increased greatly, the friction was reduced significantly, andthe surface potential of the scanned area was increased. The reductionin friction could be attributed to molecular linking formed withinthe layer. The increased conductance suggested extended conjugationamong the pyrrolyl end groups. Therefore, it was inferred that thebiased AFM scan successfully induced local polymerization/oligomerizationwithin the covalently grafted molecular layer. [ABSTRACT FROM AUTHOR]

This work proposes the use of IN−A (IN: identity matrix; A: adjacency matrix), instead of IN+A, the normalized form of which has intensively been used for the construction of graph convolutional networks (GCNs), in deep‐learning chemistry. The performance of the GCN model with D−1/2IN−AD−1/2 in its convolution step is at least on a par with the vanilla GCN that uses D~−1/2IN+AD~−1/2 (D~: degree matrix of IN+A) in various chemistry datasets, such as FreeSolv, ESOL, lipophilicity, and blood–brain barrier penetration datasets. It could be seen that the use of IN−A might be more chemically intuitive than the use of IN+A, potentially embracing the information on bond properties, such as dipole moment, and functional groups in a molecule. This work suggests unavoidable necessity of tackling molecular‐representation problems in deep‐learning chemistry from unprecedented angles of view for advanced development and construction of chemically intuitive deep‐learning models. [ABSTRACT FROM AUTHOR]

This work proposes the data augmentation by molecular rotation, with consideration that the protein‐ligand binding events are rotation‐variant. As a proof‐of‐concept, known active (i. e., 1‐labeled) ligands to human β‐secretase 1 (BACE‐1) are rotated for the generation of 0‐labeled data, and the rotation‐dependent prediction accuracy of 3D graph convolutional network (3DGCN) is investigated after data augmentation. The data augmentation makes the orientation‐recognizing ability of 3DGCN improved significantly in the classification task for BACE‐1/ligand binding. Furthermore, the data‐augmented 3DGCN has a capability for predicting active ligands from a candidate dataset, via improved performance of orientation recognition, which would be applied to virtual drug screening and discovery. [ABSTRACT FROM AUTHOR]

The manipulation of cell surfaces in anchorage‐dependent cells can help overcome difficulties presented during cell handling and application. Silica‐based protective mechanisms existing in free‐floating microorganisms may be used as inspiration for sustaining human cell survival in suspension. Gathering on this, herein human adipose‐derived mesenchymal stem cells (hASCs) are partially coated with a hard silica layer that operates as a supporting platform for individual cells in suspension. Inspired by the organic templates involved in biosilicification, a novel chitosan (CHT) derivative displaying fully natural quaternary amine moieties is synthetized via a rapid, one‐pot strategy. Silicification is promoted on individual hASCs surfaces via a two‐step process: a priming step onto previously adhered cell with this CHT derivative, followed by a biocompatible sol–gel process. hASCs holding a silica backpack exhibit enhanced cell survival in suspension conditions and can spread and acquire a more adherent phenotype. This new protocol for cell‐surface modification also provides a new generation of hybrid materials with functionalization of the silica backpack, which can be applied to different areas such as tissue engineering, biosensing, drug delivery, and targeted cell‐based therapies. [ABSTRACT FROM AUTHOR]

Examines the arrays of self-assembled monolayers (SAM) to inhibit bacterial adhesion. Efficacy of inhibitors using SAM; Adhesion of uropathogenic Escherichia coli by binding; Discussion on cell adhesion and binding ligands for protein.

3D graph convolutional network (3DGCN) is a graph neural network (GNN) variant that utilizes the 3D bond information on molecules for chemical tasks. In 3DGCN, the pooling operation extracts the molecular features from the atomic features for molecule embedding and dimensionality reduction. In this work, we investigated the pooling effects on the performance of 3DGCN in the classification of protein–ligand binding events, especially when a ligand is rotated with respect to a target protein in the 3D Cartesian coordinate. 3DGCN showed the general ability for recognizing the ligand rotation, and its prediction accuracy was found to be pooling‐dependent. For example, 3DGCN with max pooling did not recognize the rotations of known active ligands for human β‐secretase 1 faithfully, compared with the other pooling operations (sum, avg, and set2set). This work would contribute to augmented architecture evolution of 3DGCN for the chemical tasks that require the 3D molecular information including chirality. [ABSTRACT FROM AUTHOR]

Evident from numerous studies, cysteine plays a crucial role in cellular function. Reactions with analyte also enables for molecular recognition to adhere to molecular therapeutic potential; integration between synthetic probes therefore allows for a potentially deep therapy-related interogation of biological systems (theranostics). The development of molecular cysteine probes with extremely accurate detection is still a key challenge for the field. The development of water-soluble organic molecular fluorescent probes able to efficiently distinguish common biothiols such as cysteine (Cys), homocysteine (Hcy) and glutathione (GSH) by chemical recognition means i.e. by (binding, cleavage) in biological systems is a greatly sought research challenge due to the similarity of the small sulfhydryl-containing species. Herein, we have developed a water-soluble and highly cell viable fluorescent organic molecule (log P = 0.82) for the selective detection of cysteine. The probe (Myco-Cys) shows a "turn-on" response with the cleavage ester linkage of the methacrylate as cysteine is encountered in solution. The probe shows strong fluorescence enhancement (16.5-fold) when treated with Cys (1 equiv., 10 μM) compared to closely related species such as amino acids, including HCy/GSH, and the limit of detection was determined as 45.0 nM. DFT calculations helped confirm the photomechanism of Myco-Cys. Furthermore, the sensing ability of the probe was demonstrated by living cell assays through the use of confocal fluorescence microscopy. Myco-Cys could selectively detect cysteine among biothiols. Myco-Cys was able to monitor the cysteine level, apart from the oxidative stress present in the form of H2O2 in A549 cells. [ABSTRACT FROM AUTHOR]

The article discusses a study which developed a method for fabricating silica thin films on gold substrates using a rationally designed molecule as a catalytic templates. Topics covered include the synthesis of a catalytic molecule, histidine-conjugated thiol, the experimental procedure for the formation of silica thin films, and the catalytic activity of histidine-terminated self-assembled monolayers (His-SAM) compared with that of amine-SAM.

In this paper, we present synthesis of a novel carboxybetaine l -3,4-dihydroxyphenylalanine derivative (CB -DOPA) and its excellent antifouling properties to inhibit bacterial adhesion. We optimized the coating efficiency by controlling oxidation-induced polymerization with various oxidants in an alkaline environment. The surface coating was investigated by water contact angle goniometry, ellipsometry, X-ray photoelectron spectroscopy, atomic force microscopy, and FT-IR spectroscopy. Among the conditions examined, the optimal condition was the sodium periodate-mediated oxidation, which achieved the highest CB -DOPA coating efficiency. The optimized CB -DOPA coating was applied to a variety of substrates, including gold, titanium dioxide, stainless steel, poly(tetrafluoroethylene), and polyurethane. Compared with bare controls, CB -DOPA-coated substrates showed high resistance to the adhesion of Escherichia coli. [Display omitted] • A novel carboxybetaine L-DOPA derivative (CB -DOPA) was designed and synthesized. • Simple one-step, dip coating method was established. • The CB -DOPA coatings showed high resistance to bacterial adhesion. • The optimized CB -DOPA coating could be applied to a variety of substrates. [ABSTRACT FROM AUTHOR]

Development of deep-learning models for intermolecular noncovalent (NC) interactions between proteins and ligands has great potential in the chemical and pharmaceutical tasks, including structure–activity relationship and drug design. It still remains an open question how to convert the three-dimensional, structural information of a protein–ligand complex into a graph representation in the graph neural networks (GNNs). It is also difficult to know whether a trained GNN model learns the NC interactions properly. Herein, we propose a GNN architecture that learns two distinct graphs—one for the intramolecular covalent bonds in a protein and a ligand, and the other for the intermolecular NC interactions between the protein and the ligand—separately by the corresponding covalent and NC convolutional layers. The graph separation has some advantages, such as independent evaluation on the contribution of each convolutional step to the prediction of dissociation constants, and facile analysis of graph-building strategies for the NC interactions. In addition to its prediction performance that is comparable to that of a state-of-the art model, the analysis with an explainability strategy of layer-wise relevance propagation shows that our model successfully predicts the important characteristics of the NC interactions, especially in the aspect of hydrogen bonding, in the chemical interpretation of protein–ligand binding. [ABSTRACT FROM AUTHOR]

Rapid degradation of Fe3+-tannic acid films is achieved under mild conditions via ascorbic acid-mediated Fe3+ reduction, which overcomes the problems in the disassembly of a metal–organic complex including slow reaction rates and reaction incompatibility with living cells. The strategy of reductive disassembly is applied to degradable single-cell nanoencapsulation, providing an advanced tool for tightly controlling and manipulating the cell–material interface. [ABSTRACT FROM AUTHOR]

We report a simple method of enhancing electric conductance in nanogap devices without any additional treatments, such as silver-enhancing process. The low electric conductance after selective immobilization of biofunctionalized gold nanoparticles in the gap region was greatly enhanced by repeated I-V scans at relatively high voltage ranges of -5 to 5 V, which was attributed to the formation of a new conduction pathway across the gap. The higher conduction state of the nanogap device showed a very stable I-V curve, which was used as an excellent measure of the existence of prostate-specific antigen. [ABSTRACT FROM AUTHOR]

(−)‐Cannabidiol ((−)‐CBD), a non‐psychoactive phytocannabinoid from Cannabis, and its structural analogs have received growing attention in recent years because of their potential therapeutic benefits, including neuroprotective, anti‐epileptic, anti‐inflammatory, anxiolytic, and anti‐cancer properties. (−)‐CBD and its analogs have been obtained mainly based on extraction from the natural source; however, the conventional extraction‐based methods have some drawbacks, such as poor quality control along with purification difficulty. Chemical‐synthetic strategies for (−)‐CBD could tackle these issues, and, additionally, generate novel (−)‐CBD analogs that exhibit advanced biological activities. This review concisely summarizes the historic and recent milestones in the synthetic strategies for (−)‐CBD and its analogs. [ABSTRACT FROM AUTHOR]

• AMPAs, markers of nerve agents were extracted by polymeric thin film. • In-situ derivatization and the HS-SPME were performed on poly(META) thin film. • AMPAs were detected by GC–MS without an elution step. • The method was successfully applied to the 35th OPCW proficiency test sample. A headspace solid-phase microextraction (HS-SPME) method, involving solid-phase extraction and in-situ derivatization using polymeric thin film, was developed for the gas chromatography-mass spectrometry (GC–MS) analysis of the degradation products of nerve agents. The solid-phase extraction (SPE) was performed using poly([2-(Methacryloyloxy)ethyl]trimethylammonium chloride) film on a gold plate prepared via surface-initiated polymerization. The extracted analytes were directly derivatized with N,O -bis(trimethylsilyl)trifluoroacetamide (BSTFA) on the plate. Various parameters like fiber type, headspace time, temperature, and amount of BSTFA were optimized. Under the optimized conditions, the relative standard deviations (RSDs) were in the range 7.0–13.1% and the limits of detection (LODs) were measured to be between 10 and 20 pg mL−1. The application of the developed method was tested using the 35th Organization for Prohibition of Chemical Weapons (OPCW) proficiency test sample. [ABSTRACT FROM AUTHOR]

The possibility of exposure to botulinum neurotoxin (BoNT), a powerful and potential bioterrorism agent, is considered to be ever increasing. The current gold-standard assay, live-mouse lethality, exhibits high sensitivity but has limitations including long assay times, whereas other assays evince rapidity but lack factors such as real-time monitoring or portability. In this study, we aimed to devise a novel detection system that could detect BoNT at below-nanomolar concentrations in the form of a stretchable biosensor. We used a field-effect transistor with a p-type channel and electrodes, along with a channel comprising aligned carbon nanotube layers to detect the type E light chain of BoNT (BoNT/E-Lc). The detection of BoNT/E-Lc entailed observing the cleavage of a unique peptide and the specific bonding between BoNT/E-Lc and antibody BoNT/E-Lc (Anti-BoNT/E-Lc). The unique peptide was cleaved by 60 pM BoNT/E-Lc; notably, 52 fM BoNT/E-Lc was detected within 1 min in the device with the antibody in the bent state. These results demonstrated that an all-carbon nanotube-based device (all-CNT-based device) could be produced without a complicated fabrication process and could be used as a biosensor with high sensitivity, suggesting its potential development as a wearable BoNT biosensor. [ABSTRACT FROM AUTHOR]

Abstract In this study, a simple solid-phase extraction (SPE) technique was developed to extract organophosphonic acids as degradation products of nerve agents from aqueous samples for identification by instrumental analyses such as FT-IR, TOF-SIMs and GC-MS. To selectively extract the organophosphonic acids, we synthesized an anion exchange polymer film on a gold plate using surface-initiated controlled radical polymerization with 2-[(methacryloyloxy)ethyl]trimethylammonium chloride. Extraction of the organophosphonic acids onto the plates was successfully confirmed by polarized angle fourier transformation-infra red (FT-IR) spectroscopy, X-ray photoelectron spectroscopy, and time-of-flight secondary ion mass spectrometry analyses. The limit of detection of the developed SPE method satisfied the detection limit of Chemical Warfare Agents verification criteria by FT-IR analysis. After optimization, the detection limit values were found to be between 0.1 and 0.4 µg mL−1, and the recovery ranged from 50% to 110% in aqueous solution containing various interference. In addition, the SPE process was successfully applied to the detection of pinacolyl methylphosphonic acid, the degradation product of soman, in the 35th Organization for Prohibition of Chemical Weapons proficiency test sample. Graphical abstract fx1 Highlights • Degradation products of nerve agents were easily extracted by thin-film SPE. • The polymeric film was formed by surface-initiated controlled radical polymerization. • Markers of CWAs were detected by FT-IR, XPS, and ToF-SIMS without an elution step. • Polymer-based SPE was successfully applied to the 35th OPCW proficiency test sample. [ABSTRACT FROM AUTHOR]

The spatial distribution of cell‐surface glycoconjugates in the brain changes continuously, reflecting neurophysiology especially in the developing phase, but their functions and fates mostly remain unexplored. Their spatiotemporal distribution is particularly important in polarized neuronal cells, such as cerebral cortical neurons composed of a soma and neurites. In this work, we dually labeled sialic acid (Sia5Ac) and N‐acetylgalactosamine/glucosamine (GalNAc/GlcNAc) by a neurocompatible strategy of metabolic glycan labeling, metabolism‐by‐tissues (MbT), and obtained the multiplexed information on their spatiotemporal distribution on polarized cortical neurons. The analyses showed the preferentially distinct distribution of each saccharide set at the late developmental stage after randomized, heterogeneous distribution at the early stage, suggesting that Sia5Ac and GalNAc/GlcNAc are translocated anisotropically during neuronal development. Simultaneous metabolic labeling of sialic acid and N‐acetylgalactosamine/glucosamine glycans in primary cortical neurons via a neurocompatible strategy of MbT (metabolism‐by‐tissues) showed the glycoconjugate‐specific spatial distributions at the late developmental stage (8 DIV) after randomized, heterogeneous distribution at the early stage (2 DIV). [ABSTRACT FROM AUTHOR]

This work examines the development of primary neurons and astrocytes on thoroughly controlled functional groups. Negatively charged surfaces presenting carboxylate (COO–) or sulfonate (SO3–) groups prove beneficial to neuronal behavior, in spite of their supposed repulsive electrostatic interactions with cellular membranes. The adhesion and survival of primary hippocampal neurons on negatively charged surfaces are comparable to or slightly better than those on positively charged (poly-d-lysine-coated) surfaces, and neuritogenesis and neurite outgrowth are accelerated on COO– and SO3– surfaces. Moreover, such favorable influences of the negatively charged surfaces are only seen in neurons but not for astrocytes. Our results indicate that the in vitro developmental behavior of primary hippocampal neurons is sophisticatedly modulated by angstrom-sized differences in chemical structure or the charge density of the surface. We believe that this work provides new implications for understanding neuron–material interfaces as well as for establishing new ways to fabricate neuro-active surfaces. [ABSTRACT FROM AUTHOR]

Lymphocytes, such as T cells and natural killer (NK) cells, have therapeutic promise in adoptive cell transfer (ACT) therapy, where the cells are activated and expanded in vitro and then infused into a patient. However, the in vitro preservation of labile lymphocytes during transfer, manipulation, and storage has been one of the bottlenecks in the development and commercialization of therapeutic lymphocytes. Herein, we suggest a cell-in-shell (or artificial spore) strategy to enhance the cell viability in the practical settings, while maintaining biological activities for therapeutic efficacy. A durable titanium oxide (TiO2) shell is formed on individual Jurkat T cells, and the CD3 and other antigens on cell surfaces remain accessible to the antibodies. Interleukin-2 (IL-2) secretion is also not hampered by the shell formation. This work suggests a chemical toolbox for effectively preserving lymphocytes in vitro and developing the lymphocyte-based cancer immunotherapy. [ABSTRACT FROM AUTHOR]

Lymphocytes, such as T cells and natural killer (NK) cells, have therapeutic promise in adoptive cell transfer (ACT) therapy, where the cells are activated and expanded in vitro and then infused into a patient. However, the in vitro preservation of labile lymphocytes during transfer, manipulation, and storage has been one of the bottlenecks in the development and commercialization of therapeutic lymphocytes. Herein, we suggest a cell-in-shell (or artificial spore) strategy to enhance the cell viability in the practical settings, while maintaining biological activities for therapeutic efficacy. A durable titanium oxide (TiO2) shell is formed on individual Jurkat T cells, and the CD3 and other antigens on cell surfaces remain accessible to the antibodies. Interleukin-2 (IL-2) secretion is also not hampered by the shell formation. This work suggests a chemical toolbox for effectively preserving lymphocytes in vitro and developing the lymphocyte-based cancer immunotherapy. [ABSTRACT FROM AUTHOR]

Herein we demonstrate a systematic investigation of chemically functionalizable, non-biofouling agarose films over large-area glass surfaces. Agarose films, prepared with various concentrations of aqueous agarose, were activated by using periodate oxidation to generate aldehyde groups at the termini of the agarose chains. The non-biofouling efficacy and binding capabilities of the activated films were evaluated by using protein and cellular patterning, performed by using a microarrayer, microcontact printing, and micromolding in capillaries. Characterization by using a fluorescence slide scanner and a scanning-probe microscope revealed that the pore sizes of the agarose films played an important role in achieving desirable film performance; the 0.2 wt % agarose film exhibited the optimum efficacy in this work. [ABSTRACT FROM AUTHOR]

The blood-type-mismatch problem, in addition to shortage of blood donation, in blood transfusion has prompted the researchers to develop universal blood that does not require blood typing. In this work, the "cell-in-shell" (i.e., artificial spore) approach is utilized to shield the immune-provoking epitopes on the surface of red blood cells (RBCs). Individual RBCs are successfully coated with supramolecular metal-organic coordination complex of ferric ion (FeIII) and tannic acid (TA). The use of isotonic saline (0.85% NaCl) is found to be critical in the formation of stable, reasonably thick (20 nm) shells on RBCs without any aggregation and hemolysis. The formed "RBC-in-shell" structures maintain their original shapes, and effectively attenuate the antibody-mediated agglutination. Moreover, the oxygen-carrying capability of RBCs is not deteriorated after shell formation. This work suggests a simple but fast method for generating immune-camouflaged RBCs, which would contribute to the development of universal blood. [ABSTRACT FROM AUTHOR]

A cytocompatible method of surface-initiated, activator regenerated by electron transfer, atom transfer radical polymerization (SI-ARGET ATRP) is developed for engineering cell surfaces with synthetic polymers. Dopamine-based ATRP initiators are used for both introducing the ATRP initiator onto chemically complex cell surfaces uniformly (by the material-independent coating property of polydopamine) and protecting the cells from radical attack during polymerization (by the radical-scavenging property of polydopamine). Synthetic polymers are grafted onto the surface of individual yeast cells without significant loss of cell viability, and the uniform and dense grafting is confirmed by various characterization methods including agglutination assay and cell-division studies. This work will provide a strategic approach to the generation of living cell-polymer hybrid structures and open the door to their application in multitude of areas, such as sensor technology, catalysis, theranostics, and cell therapy. [ABSTRACT FROM AUTHOR]

A cytocompatible method of surface-initiated, activator regenerated by electron transfer, atom transfer radical polymerization (SI-ARGET ATRP) is developed for engineering cell surfaces with synthetic polymers. Dopamine-based ATRP initiators are used for both introducing the ATRP initiator onto chemically complex cell surfaces uniformly (by the material-independent coating property of polydopamine) and protecting the cells from radical attack during polymerization (by the radical-scavenging property of polydopamine). Synthetic polymers are grafted onto the surface of individual yeast cells without significant loss of cell viability, and the uniform and dense grafting is confirmed by various characterization methods including agglutination assay and cell-division studies. This work will provide a strategic approach to the generation of living cell-polymer hybrid structures and open the door to their application in multitude of areas, such as sensor technology, catalysis, theranostics, and cell therapy. [ABSTRACT FROM AUTHOR]

Cell nanoencapsulation, generating cell-in-shell structures ('artificial spores'), provides a chemical toolbox for controlling the cellular behaviors and functional characteristics of individual cells. Among the shell materials studied so far, naturally occurring polyphenolic compounds, including polydopamine and tannic acid, have intensively been employed in cell-surface engineering, because their material-independent coating property eliminates an extra priming step for inducing subsequent shell formation. Albeit successful in generating cell-in-shell structures, the coating of polyphenolic compounds generally requires alkaline conditions and/or high salt conditions, which are not compatible with certain cell types. In this work, we demonstrate that the nanocoating of individual cells with a plant-derived phenolic compound, pyrogallol (1,2,3-trihydroxybenzene), occurs at mildly alkaline pH of 7.8 in an isotonic buffer. Three different cell types (anucleate, microbial, and mammalian cells) are coated with pyrogallol without noticeable decrease in cell viability. The protocol developed in this work could be applied to other polyphenolic compounds, and, considering the many polyphenols identified as a coating material, provides an advanced chemical tool in cell-surface engineering. [ABSTRACT FROM AUTHOR]

Herein, we present a simple readout of the binding between a chemical drug and its target proteins in the cytoplasm by using a two-step bioorthogonal labeling method combined with spatially-localized expression of proteins. Dasatinib was modified with trans-cyclooctene (TCO), and its cytoplasmic target kinases were expressed in intracellular compartments, such as endosomes and F-actins. After bioorthogonal labeling, the colocalization between Dasatinib and its target proteins was observed in intracellular compartments. [ABSTRACT FROM AUTHOR]

We demonstrated protein and cellular patterning with a soft lithography technique using poly[2-aminoethyl methacrylate- co-oligo(ethylene glycol) methacrylate] films on gold surfaces without employing a backfilling process. The backfilling process plays an important role in successfully generating biopatterns; however, it has potential disadvantages in several interesting research and technical applications. To overcome the issue, a copolymer system having highly reactive functional groups and bioinert properties was introduced through a surface-initiated controlled radical polymerization with 2-aminoethyl methacrylate hydrochloride (AMA) and oligo(ethylene glycol) methacrylate (OEGMA). The prepared poly(AMA- co-OEGMA) film was fully characterized, and among the films having different thicknesses, the 35 nm-thick biotinylated, poly(AMA- co-OEGMA) film exhibited an optimum performance, such as the lowest nonspecific adsorption and the highest specific binding capability toward proteins. [ABSTRACT FROM AUTHOR]