Dendritic Effects of Injectable Biodegradable Thermogels on Pharmacotherapy of Inflammatory Glaucoma-Associated Degradation of Extracellular Matrix

The development of advanced drug delivery systems with extensively sustained release and multiple functions is highly imperative for effective attenuation of the degradation of ocular extracellular matrix that is associated with inflammatory glaucoma. Here, the generation of amine-terminated polyamidoamine dendrimers in an injectable biodegradable thermogel is demonstrated to be important for achieving prolonged drug release profiles and potent anti-inflammatory effects. Among various generations (Gx, x = 0, 1, 3, 5), third-generation G3 is proved as the most effective material for optimizing the synergistic effects of gelatin and poly(N-isopropylacrylamide) and generating a thermogel with the highest biodegradation resistance, the best drug encapsulation/extended-release performance, and the best ability to reduce the elevated expression of inflammatory molecules. A pharmacotherapy based on intracameral injection of thermogels coloaded with pilocarpine and ascorbic acid results in effective alleviation of progressive glaucoma owing to the anti-inflammatory activity and long-acting drug release (above a therapeutic level of 10 µg mL^-1 over 80 days) of thermogels, which simultaneously suppress inflammation and stimulate regeneration of stromal collagen and retinal laminin. These findings on the dendritic effects of rationally designed injectable biomaterials with potent anti-inflammatory effects and controlled drug release demonstrate great promise of their use for pharmacological treatment of progressive glaucoma.

Hcp of the Type VI Secretion System (T6SS) in Acidovorax citrulli Group II Strain Aac5 Has a Dual Role as a Core Structural Protein and an Effector Protein in Colonization, Growth Ability, Competition, Biofilm Formation, and Ferric Iron Absorption

A type VI secretion system (T6SS) gene cluster has been reported in Acidovorax citrulli. Research on the activation conditions, functions, and the interactions between key elements in A. citrulli T6SS is lacking. Hcp (Hemolysin co-regulated protein) is both a structural protein and a secretion protein of T6SS, which makes it a special element. The aims of this study were to determine the role of Hcp and its activated conditions to reveal the functions of T6SS. In virulence and colonization assays of hcp deletion mutant strain Δhcp, tssm (type VI secretion system membrane subunit) deletion mutant strain Δtssm and double mutant ΔhcpΔtssm, population growth was affected but not virulence after injection of cotyledons and seed-to-seedling transmission on watermelon. The population growth of Δhcp and Δtssm were lower than A. citrulli wild type strain Aac5 of A. citrulli group II at early stage but higher at a later stage. Deletion of hcp also affected growth ability in different culture media, and the decline stage of Δhcp was delayed in KB medium. Biofilm formation ability of Δhcp, Δtssm and ΔhcpΔtssm was lower than Aac5 with competition by prey bacteria but higher in KB and M9-Fe3+ medium. Deletion of hcp reduced the competition and survival ability of Aac5. Based on the results of Western blotting and qRT-PCR analyses, Hcp is activated by cell density, competition, ferric irons, and the host plant. The expression levels of genes related to bacterial secretion systems, protein export, and several other pathways, were significantly changed in the Δhcp mutant compared to Aac5 when T6SS was activated at high cell density. Based on transcriptome data, we found that a few candidate effectors need further identification. The phenotypes, activated conditions and transcriptome data all supported the conclusion that although there is only one T6SS gene cluster present in the A. citrulli group II strain Aac5, it related to multiple biological processes, including colonization, growth ability, competition and biofilm formation.

Redox-dependent functional switching of plant proteins accompanying with their structural changes

Reactive oxygen species (ROS) can be generated during the course of normal aerobic metabolism or when an organism is exposed to a variety of stress conditions. It can cause a widespread damage to intracellular macromolecules and play a causal role in many degenerative diseases. Like other aerobic organisms plants are also equipped with a wide range of antioxidant redox proteins, such as superoxide dismutase, catalase, glutaredoxin, thioredoxin (Trx), Trx reductase, protein disulfide reductase, and other kinds of peroxidases that are usually significant in preventing harmful effects of ROS. To defend plant cells in response to stimuli, a part of redox proteins have shown to play multiple functions through the post-translational modification with a redox-dependent manner. For the alternative switching of their cellular functions, the redox proteins change their protein structures from low molecular weight to high molecular weight (HMW) protein complexes depending on the external stress. The HMW proteins are reported to act as molecular chaperone, which enable the plants to enhance their stress tolerance. In addition, some transcription factors and co-activators have function responding to environmental stresses by redox-dependent structural changes. This review describes the molecular mechanism and physiological significance of the redox proteins, transcription factors and co-activators to protect the plants from environmental stresses through the redox-dependent structural and functional switching of the plant redox proteins.

Rationally Modulating the Functions of Ni3Sn2-NiSnOx Nanocomposite Electrocatalysts towards Enhanced Hydrogen Evolution Reaction

Identifying electrocatalysts with functions of easy dissociation of water, rapid transformation of hydroxyl and facile hydrogen-hydrogen bond formation are indispensable while challenge for realizing efficient alkaline hydrogen evolution reaction (HER). Herein, we presented the design of Ni3Sn2-NiSnOx nanocomposites towards addressing this challenge. We showed that Ni3Sn2 possessed ideal hydrogen adsorption and low hydroxyl adsorption abilities and NiSnOx facilitated water dissociation and hydroxyl transfer process, respectively. Consequently, the fine-tuned interplay of the two functional parts realized the mutual coordination among the multiple functions and led to significantly boosted HER kinetics. Current densities of 10 and 1000 mA cm-2 were obtained at overpotentials of 14 and 165 mV on the optimized catalyst. This work highlights the significance of considering intrinsic interactions between active sites and all pertinent intermediates on obtaining promising electrocatalysts.

Diverse fen plant communities enhance carbon-related multifunctionality, but do not mitigate negative effects of drought

Global change, like droughts, can destabilize the carbon sink function of peatlands, either directly or indirectly through changes in plant community composition. While the effects of drought and plant community composition on individual carbon (C) related processes are well understood, their effect on multiple C-related processes simultaneously-multifunctionality-is poorly known. We studied the effect of drought on four C-related processes (net and gross CO₂ exchange, methane fluxes, and dissolved organic carbon content) in a plant removal experiment. Plant functional type (PFT) removal (graminoids, herbs, Polytrichum spp., incl. combinations) negatively affected multifunctionality; most markedly when all PFTs were removed. Our results corroborate a negative drought effect on C-related multifunctionality. Drought reduced multifunctionality, and this reduction was again largest when all PFTs were removed. Our data further indicate that much of these negative drought effects were carried over and maintained from the initial removal treatment. These results suggest that while a high diversity in plant functional types is associated to high C-related multifunctionality, plant community assembly does not drive the ability of peatlands to withstand the negative impacts of drought on multifunctionality. Hence, to safeguard the carbon cycling function in intact peatlands, the effects of climate change on the functional composition of the peatland plant community needs to be minimized.

Leaky scanning translation generates a second A49 protein that contributes to vaccinia virus virulence

Vaccinia virus (VACV) strain Western Reserve gene A49L encodes a small intracellular protein with a Bcl-2 fold that is expressed early during infection and has multiple functions. A49 co-precipitates with the E3 ubiquitin ligase β-TrCP and thereby prevents ubiquitylation and proteasomal degradation of IκBα, and consequently blocks activation of NF-κB. In a similar way, A49 stabilizes β-catenin, leading to activation of the wnt signalling pathway. However, a VACV strain expressing a mutant A49 that neither co-precipitates with β-TrCP nor inhibits NF-κB activation, is more virulent than a virus lacking A49, indicating that A49 has another function that also contributes to virulence. Here we demonstrate that gene A49L encodes a second, smaller polypeptide that is expressed via leaky scanning translation from methionine 20 and is unable to block NF-κB activation. Viruses engineered to express either only the large protein or only the small A49 protein both have lower virulence than wild-type virus and greater virulence than an A49L deletion mutant. This demonstrates that the small protein contributes to virulence by an unknown mechanism that is independent of NF-κB inhibition. Despite having a large genome with about 200 genes, this study illustrates how VACV makes efficient use of its coding potential and from gene A49L expresses a protein with multiple functions and multiple proteins with different functions.

Pyrrole-Terminated Ionic Liquid Surfactant: One Molecule with Multiple Functions for Controlled Synthesis of Diverse Multispecies Co-Doped Porous Hollow Carbon Spheres

Rationally and efficiently controlling chemical composition, microstructure, and morphology of carbon nanomaterials plays a crucial role in significantly enhancing their functional properties and expending their applications. In this work, a novel strategy for simultaneously controlling these structural parameters was developed on the base of a multifunctional precursor approach, in which the precursor not only serves as carbon source and structure-directing agent, but also contains two heteroatom doping sites. As exemplified by using pyrrole-terminated ionic liquid surfactant as such precursor, in conjunction with sol-gel chemistry this strategy allows for efficiently producing well-defined hollow carbon spheres with controlled microstructure and chemical compositions. Remarkably, the dual-doping sites in confined silica channels provide an exciting opportunity and flexibility to access various doped carbons through simply anion exchange or altering the used oxidative polymerization agent, especially the multispecies codoped materials by combination of the two doping modes. All the results indicate that the described strategy may open up a new avenue for efficiently synthesizing functional carbon materials with highly controllable capability.

Neuropsychological Assessment of a New Computerized Cognitive Task that Was Developed to Train Several Cognitive Functions Simultaneously

Recent studies have indicated that computerized cognitive training is effective as therapy for reducing the cognitive decline with aging and the dysfunction associated with neuropsychiatric illness. Although cognitive trainings that targets a specific function and multi-domain cognitive training have both been shown to have significant effects, we need one simple behavioral training paradigm to improve multiple domains of cognitive functions easily and simultaneously. We had developed a new computerized task that seeks to engage the cognitive functions of planning, mental calculation, and divergent thinking based on a working memory task in a single task. The purpose of this study was to assess the cognitive features of our new task by comparing the scores of seven known neuropsychological batteries in healthy elderly subjects. The relationships between performance in our task and the scores obtained by the neuropsychological batteries were examined. The percentage of correct performance on our task was correlated with the scores on the category fluency test, the digit span backward task, and the Trail making test B. Stepwise multiple regression analyses revealed that the scores on the category fluency test and the Trail making test B showed significant positive correlations with the percentage of correct performance on our task. Although the present study did not show high correlations between the percentage of correct performance on our task and working memory functions as a primary target, we observed mid-level correlations between the percentage of correct performance on our task and functions for divided attention and word fluency. Our new task requires not only working memory, but also attention and divergent thinking. Thus, this task might be a useful tool for training multiple cognitive functions simultaneously.

The role of isoprene in insect herbivory

Several hypotheses have previously been proposed to explain the function of isoprene in plants, including its ability to protect the leaf metabolic machinery from transient high temperature1,2 and from oxidative stress.3 Isoprene may also serve as a metabolic overflow mechanism for carbon or photosynthetic energy4-6 and may promote flowering in neighbouring plants.7 We have reported recently that isoprene can be detected by a herbivore, Manduca sexta, and that it directly deters them from feeding, with an isoprene emission threshold level of <6 nmol m(-2) s(-1).8 We demonstrated this using both in vivo experiments, using isoprene-emitting transgenic tobacco plants (Nicotiana tabacum cv. Samsun) and non-emitting azygous control plants, and in vitro experiments, using an artificial (isoprene-emitting and non-emitting control) diet. Here we discuss the potential role of isoprene in plant-herbivore interactions and the possibility that isoprene actually serves multiple purposes in plants.

Diverse fen plant communities enhance carbon-related multifunctionality, but do not mitigate negative effects of drought

Global change, like droughts, can destabilize the carbon sink function of peatlands, either directly or indirectly through changes in plant community composition. While the effects of drought and plant community composition on individual carbon (C) related processes are well understood, their effect on multiple C-related processes simultaneously-multifunctionality-is poorly known. We studied the effect of drought on four C-related processes (net and gross CO₂ exchange, methane fluxes, and dissolved organic carbon content) in a plant removal experiment. Plant functional type (PFT) removal (graminoids, herbs, Polytrichum spp., incl. combinations) negatively affected multifunctionality; most markedly when all PFTs were removed. Our results corroborate a negative drought effect on C-related multifunctionality. Drought reduced multifunctionality, and this reduction was again largest when all PFTs were removed. Our data further indicate that much of these negative drought effects were carried over and maintained from the initial removal treatment. These results suggest that while a high diversity in plant functional types is associated to high C-related multifunctionality, plant community assembly does not drive the ability of peatlands to withstand the negative impacts of drought on multifunctionality. Hence, to safeguard the carbon cycling function in intact peatlands, the effects of climate change on the functional composition of the peatland plant community needs to be minimized.

The Energy Landscape Perspective: Encoding Structure and Function for Biomolecules

The energy landscape perspective is outlined with particular reference to biomolecules that perform multiple functions. We associate these multifunctional molecules with multifunnel energy landscapes, illustrated by some selected examples, where understanding the organisation of the landscape has provided new insight into function. Conformational selection and induced fit may provide alternative routes to realisation of multifunctionality, exploiting the possibility of environmental control and distinct binding modes.

Electrospun Fenoprofen/Polycaprolactone @ Tranexamic Acid/Hydroxyapatite Nanofibers as Orthopedic Hemostasis Dressings

Dressings with multiple functional performances (such as hemostasis, promoting regeneration, analgesia, and anti-inflammatory effects) are highly desired in orthopedic surgery. Herein, several new kinds of medicated nanofibers loaded with several active ingredients for providing multiple functions were prepared using the modified coaxial electrospinning processes. With an electrospinnable solution composed of polycaprolactone and fenoprofen as the core working fluid, several different types of unspinnable fluids (including pure solvent, nanosuspension containing tranexamic acid and hydroxyapatite, and dilute polymeric solution comprising tranexamic acid, hydroxyapatite, and polyvinylpyrrolidone) were explored to implement the modified coaxial processes for creating the multifunctional nanofibers. Their morphologies and inner structures were assessed through scanning and transmission electron microscopes, which all showed a linear format without the discerned beads or spindles and a diameter smaller than 1.0 μm, and some of them had incomplete core-shell nanostructures, represented by the symbol @. Additionally, strange details about the sheaths' topographies were observed, which included cracks, adhesions, and embedded nanoparticles. XRD and FTIR verified that the drugs tranexamic acid and fenoprofen presented in the nanofibers in an amorphous state, which resulted from the fine compatibility among the involved components. All the prepared samples were demonstrated to have a fine hydrophilic property and exhibited a lower water contact angle smaller than 40° in 300 ms. In vitro dissolution tests indicated that fenoprofen was released in a sustained manner over 6 h through a typical Fickian diffusion mechanism. Hemostatic tests verified that the intentional distribution of tranexamic acid on the shell sections was able to endow a rapid hemostatic effect within 60 s.

Healable, Recyclable, and Ultra-Tough Waterborne Polyurethane Elastomer Achieved through High-Density Hydrogen Bonding Cross-Linking Strategy

With the increasing popularity of elastomers in industry and daily life, their high performance and functionality have attracted widespread attention. However, it is a great challenge for them to possess both high mechanical properties and excellent healing and recovery capabilities due to the limitations of the preparation methods and the intrinsic microstructure of the elastomers. In this study, a strategy of ice-controlled interfacial stepwise cross-linking was proposed to prepare the waterborne polyurethane-based elastomers with ultrahigh-density hydrogen bonding interaction achieved by enhancing the utilization rate of phenol hydroxyl groups of tannic acid to the maximum extent. The elastomers have incredible mechanical properties, including ultrahigh toughness of 1.03 GJ m-3 (which represents the highest level among polyurethane elastomers prepared through common processing techniques to date), extremely high true fracture stress of ∼1.9 GPa, world-record fracture energy of 520 kJ m-2, and exciting multiple functional characteristics, such as highly efficient self-healing ability of 10 min, high resistance to physical damage and chemical corrosion, broad temperature and frequency damping effects, good shape memory effect, and excellent melt-processing recyclability and solvent recyclability. These robust multifunctional elastomers represent considerable potential in various fields, from defense and military industry and civil transportation to precision manufacturing, etc.

Facile Formation of Multifunctional Biomimetic Hydrogel Fibers for Sensing Applications

To face the challenges in preparing hydrogel fibers with complex structures and functions, this study utilized a microfluidic coaxial co-extrusion technique to successfully form functional hydrogel fibers through rapid ionic crosslinking. Functional hydrogel fibers with complex structures, including linear fibers, core-shell structure fibers, embedded helical channels, hollow tubes, and necklaces, were generated by adjusting the composition of internal and external phases. The characteristic parameters of the hydrogel fibers (inner and outer diameter, helix generation position, pitch, etc.) were achieved by adjusting the flow rate of the internal and external phases. As biocompatible materials, hydrogel fibers were endowed with electrical conductivity, temperature sensitivity, mechanical enhancement, and freeze resistance, allowing for their use as temperature sensors for human respiratory monitoring and other biomimetic application developments. The hydrogel fibers had a conductivity of up to 22.71 S/m, a response time to respiration of 37 ms, a recovery time of 1.956 s, and could improve the strength of respiration; the tensile strength at break up to 8.081 MPa, elongation at break up to 159%, and temperature coefficient of resistance (TCR) up to -13.080% °C-1 were better than the existing related research.

Multiple roles of released c-type cytochromes in tuning electron transport and physiological status of Geobacter sulfurreducens

Dissimilatory metal-reducing bacteria (DMRB) can transfer electrons to extracellular insoluble electron acceptors and play important roles in geochemical cycling, biocorrosion, environmental remediation, and bioenergy generation. c-type cytochromes (c-Cyts) are synthesized by DMRB and usually transported to the cell surface to form modularized electron transport conduits through protein assembly, while some of them are released as extracellularly free-moving electron carriers in growth to promote electron transport. However, the type of these released c-Cyts, the timing of their release, and the functions they perform have not been unrevealed yet. In this work, after characterizing the types of c-Cyts released by Geobacter sulfurreducens under a variety of cultivation conditions, we found that these c-Cyts accumulated up to micromolar concentrations in the surrounding medium and conserved their chemical activities. Further studies demonstrated that the presence of c-Cyts accelerated the process of microbial extracellular electron transfer and mediated long-distance electron transfer. In particular, the presence of c-Cyts promoted the microbial respiration and affected the physiological state of the microbial community. In addition, c-Cyts were observed to be adsorbed on the surface of insoluble electron acceptors and modify electron acceptors. These results reveal the overlooked multiple roles of the released c-Cyts in acting as public goods, delivering electrons, modifying electron acceptors, and even regulating bacterial community structure in natural and artificial environments.

Versatility of electrospun Janus wound dressings

Electrospun nanofibers produced through single-fluid blending processes have successfully demonstrated their potential as highly effective wound dressings. However, electrospun Janus nanofibers, in which various chambers can be designed to load different active pharmaceutical ingredients into different polymeric matrices, are further exhibiting their versatility for promoting wound healing. This commentary declares that wound dressings always need multiple functional performances to promote wound healing. Janus nanofibers have their unique advantages, with different parts interacting with their environments, thereby providing a versatile platform for developing novel wound dressings. Two recent examples, each with a different preparation strategy for developing novel wound dressings, are discussed, and the promising future of Janus nanofibers in wound dressing applications is highlighted.