Semi-Biosynthetic Production of Surface-Binding Adhesive Antimicrobial Peptides Using Intein-Mediated Protein Ligation.

Microbial infections remain a global health concern, calling for the urgent need to implement effective prevention measures. Antimicrobial peptides (AMPs) have been extensively studied as potential antimicrobial coating agents. However, an efficient and economical method for AMP production is lacking. Here, we synthesized the direct coating adhesive AMP, NKC-DOPA5, composed of NKC, a potent AMP, and repeats of the adhesive amino acid 3,4-dihydroxyphenylalanine (DOPA) via an intein-mediated protein ligation strategy. NKC was expressed as a soluble fusion protein His-NKC-GyrA (HNG) in Escherichia coli, comprising an N-terminal 6× His-tag and a C-terminal Mxe GyrA intein. The HNG protein was efficiently produced in a 500-L fermenter, with a titer of 1.63 g/L. The NKC-thioester was released from the purified HNG fusion protein by thiol attack and subsequently ligated with chemically synthesized Cys-DOPA5. The ligated peptide His-NKC-Cys-DOPA5 was obtained at a yield of 88.7%. The purified His-NKC-Cys-DOPA5 possessed surface-binding and antimicrobial properties identical to those of the peptide obtained via solid-phase peptide synthesis. His-NKC-Cys-DOPA5 can be applied as a practical and functional antimicrobial coating to various materials, such as medical devices and home appliances.

Finding Cortical Subregions Regarding the Dorsal Language Pathway Based on the Structural Connectivity.

Although the language-related fiber pathways in the human brain, such as the superior longitudinal fasciculus (SLF) and arcuate fasciculus (AF), are already well-known, understanding more sophisticated cortical regions connected by the fiber tracts is essential to scrutinize the structural connectivity of language circuits. With the regions of interest that were selected based on the Brainnetome atlas, the fiber orientation distribution estimation method for tractography was used to produce further elaborate connectivity information. The results indicated that both fiber bundles had two distinct connections with the prefrontal cortex (PFC). The SLF-II and dorsal AF are mainly connected to the rostrodorsal part of the inferior parietal cortex (IPC) and lateral part of the fusiform gyrus with the inferior frontal junction (IFJ), respectively. In contrast, the SLF-III and ventral AF were primarily linked to the anterior part of the supramarginal gyrus and superior part of the temporal cortex with the inferior frontal cortex, including the Broca's area. Moreover, the IFJ in the PFC, which has rarely been emphasized as a language-related subregion, also had the strongest connectivity with the previously known language-related subregions among the PFC; consequently, we proposed that these specific regions are interconnected via the SLF and AF within the PFC, IPC, and temporal cortex as language-related circuitry.

Modulation of Solvation Structure and Electrode Work Function by an Ultrathin Layer of Polymer of Intrinsic Microporosity in Zinc Ion Batteries.

Zinc ion batteries are promising candidates for large-scale energy storage systems. However, they suffer from the critical problems of insufficient cycling stability due to internal short-circuiting by zinc dendrites and zinc metal orphaning. In this work, a polymer of intrinsic microporosity (PIM-1) is reported as an ion regulating layer and an interface modulator, which promotes a uniform Zn plating and stripping process. According to spectroscopic analyses and computational calculations, PIM-1 enhances the reaction kinetics of a Zn metal electrode by altering the solvation structure of Zn2+ ions and increasing the work function of the Zn surface. As a result, the PIM-1 coating significantly improves the cyclability (1700 h at 0.5 mA cm-2 ) and Coulombic efficiency (99.6% at 3 mA cm-2 ) of the Zn/Zn2+ redox reaction. Moreover, the PIM-1 coated Zn operates for more than 200 h at 70% Zn utilization even under 10 mA cm-2 and 110 h at 95% Zn utilization of the Zn metal electrode. A Zn||V2 O5 full cell employing the PIM-1 layer exhibits seven times longer cycle life compared to the cell using bare Zn. The findings in this report demonstrate the potential of microporous materials as a key ingredient in the design of reversible Zn electrodes.

Adhesive Antimicrobial Peptides Containing 3,4-Dihydroxy-L-Phenylalanine Residues for Direct One-Step Surface Coating.

Bacterial colonization and transmission via surfaces increase the risk of infection. In this study, we design and employ novel adhesive antimicrobial peptides to prevent bacterial contamination of surfaces. Repeats of 3,4-dihydroxy-L-phenylalanine (DOPA) were added to the C-terminus of NKC, a potent synthetic antimicrobial peptide, and the adhesiveness and antibacterial properties of the resulting peptides are evaluated. The peptide is successfully immobilized on polystyrene, titanium, and polydimethylsiloxane surfaces within 10 min in a one-step coating process with no prior surface functionalization. The antibacterial effectiveness of the NKC-DOPA5-coated polystyrene, titanium, and polydimethylsiloxane surfaces is confirmed by complete inhibition of the growth of Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus within 2 h. The stability of the peptide coated on the substrate surface is maintained for 84 days, as confirmed by its bactericidal activity. Additionally, the NKC-DOPA5-coated polystyrene, titanium, and polydimethylsiloxane surfaces show no cytotoxicity toward the human keratinocyte cell line HaCaT. The antimicrobial properties of the peptide-coated surfaces are confirmed in a subcutaneous implantation animal model. The adhesive antimicrobial peptide developed in this study exhibits potential as an antimicrobial surface-coating agent for efficiently killing a broad spectrum of bacteria on contact.

Track-Density Ratio Mapping With Fiber Types in the Cerebral Cortex Using Diffusion-Weighted MRI.

The nerve fibers are divided into three categories: projection, commissural, and association fibers. This study demonstrated a novel cortical mapping method based on these three fiber categories using MR tractography data. The MR fiber-track data were extracted using the diffusion-weighted 3T-MRI data from 19 individuals' Human Connectome Project dataset. Anatomical MR images in each dataset were parcellated using FreeSurfer software and Brainnetome atlas. The 5 million extracted tracks per subject by MRtrix software were classified based on the basic cortical structure (cortical area in the left and right hemisphere, subcortical area), after the tracks validation procedure. The number of terminals for each categorized track per unit-sized cortical area (1 mm3) was defined as the track-density in that cortical area. Track-density ratio mapping with fiber types was achieved by mapping the density-dependent color intensity for each categorized tracks with a different primary color. The mapping results showed a highly localized, unique density ratio map determined by fiber types. Furthermore, the quantitative group data analysis based on the parcellation information revealed that the majority of nerve fibers in the brain are association fibers, particularly in temporal, inferior parietal, and occipital lobes, while the projection and commissural fibers were mainly located in the superior part of the brain. Hemispheric asymmetries in the fiber density were also observed, such as long association fiber in the Broca's and Wernicke's areas. We believe this new dimensional brain mapping information allows us to further understand brain anatomy, function.

Controlled Synthesis of Metal-Organic Frameworks in Scalable Open-Porous Contactor for Maximizing Carbon Capture Efficiency.

Metal-organic frameworks (MOFs) are a class of microporous materials that have been highlighted with fast and selective sorption of gas molecules; however, they are at least partially unstable in the scale-up process. Here, we report a rational shaping of MOFs in a scalable architecture of fiber sorbent. The long-standing stability challenge of MOFs was resolved by using stable metal oxide precursors that are subject to controlled surface oxide dissolution-growth chemistry during the Mg-based MOF synthesis. Highly uniform MOF crystals are synthesized along with the open-porous fiber sorbents networks, showing unprecedented cyclic CO2 capacities in both flue gas and direct air capture (DAC) conditions. The same chemistry enables an in situ flow synthesis of Mg-MOF fiber sorbents, providing a scalable pathway for MOF synthesis in an inert condition with minimal handling steps. This modular approach can serve both as a reaction stage for enhanced MOF fiber sorbent synthesis and as a "process-ready" separation device.

Errors according to the number of registered markers used in navigation-assisted surgery of the mandible.

BACKGROUND: The aim of this study was to evaluate the accuracy of navigation according to the number of markers in terms of target registration errors (TREs) at each anatomical location during the registration process of the navigation system for the mandible. METHODS: The TREs were measured in five different experiments, varying only in the number of registration reference markers, which ranged from three to seven. To measure the TREs according to the number of registration reference markers, two experimental navigation devices were used: 1) Cbyon navigation surgery equipment 2) Polaris optical tracker. Both experiments were conducted to obtain the TREs at the anatomical locations of the mandible according to the number of registration markers during the navigation process. Statistical analysis was performed using the SPSS 23.0 software. RESULTS: At all anatomical locations, errors were 2 mm or less. Further, significant differences in the target errors measured by the Cbyon system were found according to the number of registration markers. Significant differences in the target errors measured by the Polaris optical tracker were found according to the registration markers at the posterior border only. In both groups, the target errors did not decrease as the number of registration markers increased. CONCLUSIONS: This study demonstrates that an increase in the number of registration markers is not associated with a decrease in the TRE, and that a specific number of registration markers could reduce the TREs at each anatomical site. It is important to determine the minimum number of image registration markers at which the smallest TRE would be observed for different surgical sites.

VEGF siRNA Delivery by a Cancer-Specific Cell-Penetrating Peptide.

RNA interference provides an effective tool for developing antitumor therapies. Cell-penetrating peptides (CPPs) are delivery vectors widely used to efficiently transport small-interfering RNA (siRNA) to intracellular targets. In this study, we investigated the efficacy of the cancer-specific CPP carrier BR2 to specifically transport siRNA to cancer-target cells. Our results showed that BR2 formed a complex with anti-vascular endothelial growth factor siRNA (siVEGF) that exhibited the appropriate size and surface charge for in vivo treatment. Additionally, the BR2-VEGF siRNA complex exhibited significant serum stability and high levels of gene-silencing effects in vitro. Moreover, the transfection efficiency of the complex into a cancer cell line was higher than that observed in non-cancer cell lines, resulting in downregulated intracellular VEGF levels in HeLa cells and comprehensively improved antitumor efficacy in the absence of significant toxicity. These results indicated that BR2 has significant potential for the safe, efficient, and specific delivery of siRNA for diverse applications.