Regulation of astrocyte activity and immune response on graphene oxide-coated titanium by electrophoretic deposition.

Introduction: Astrocytes play crucial role in modulating immune response in the damaged central nervous system. Numerous studies have investigated the relationship between immune responses in astrocytes and brain diseases. However, the potential application of nanomaterials for alleviating neuroinflammation induced by astrocytes remains unexplored. Method: In this study, we utilized electrophoretic deposition (EPD) to coat graphene oxide (GO) onto titanium (Ti) to enhance the bioactivity of Ti. Results: We confirmed that GO-Ti could improve cell adhesion and proliferation of astrocytes with upregulated integrins and glial fibrillary acidic protein (GFAP) expression. Moreover, we observed that astrocytes on GO-Ti exhibited a heightened immune response when exposed to lipopolysaccharide (LPS). Although pro-inflammatory cytokines increased, anti-inflammatory cytokines and brain-derived neurotrophic factors involved in neuroprotective effects were also augmented through nuclear localization of the yes-associated protein (YAP) and nuclear factor kappa B (NF-κB). Discussion: Taken together, GO-Ti could enhance the neuroprotective function of astrocytes by upregulating the expression of anti-inflammatory cytokines and neuroprotective factors with improved cell adhesion and viability. Consequently, our findings suggest that GO-Ti has the potential to induce neuroprotective effects by regulating cell activity.

Influence of MXene Particles with a Stacked-Lamellar Structure on Osteogenic Differentiation of Human Mesenchymal Stem Cells.

MXenes with a two-dimensional (2D) structure have attracted attention as potential biomedical materials. In this study, Ti3C2 MXene particles with 2D-lamellar structures were intercalated and their potential as a biomaterial was evaluated using human mesenchymal stem cells. Intercalated MXene was characterized in terms of microstructure, phase composition, and size. Cell proliferation experiments with MXene particles confirmed that concentrations >50 µg/mL were cytotoxic, while concentrations <20 µg/mL promoted osteogenic differentiation. Moreover, MXene effectively facilitated the early and late osteogenic gene expression.

Hymenobacter radiodurans sp. nov., isolated from soil in the Republic of Korea.

A bacterial strain, designated 17J36-26T, was isolated from the UV-irradiated soil from Jeju Island, South Korea. Cells are Gram negative, strictly aerobic, non-motile, non-spore forming, rod shaped, and catalase and oxidase positive. The major fatty acids of strain 17J36-26T were summed feature 4 (17:1 iso I/17:1 anteiso B), summed feature 3 (16:1 ω6c/16:1 ω7c), C16:1 ω5c and iso-C15:0. The polar lipid profile contained phosphatidylethanolamine, unidentified aminophospholipid, phospholipids and four unidentified lipids. The G+C content of the strain 17J36-26T was 62.6 mol%. The 16S rRNA gene sequence analysis showed that strain 17J36-26T was phylogenetically related to Hymenobacter qilianensis DK6-37T and Hymenobacter roseosalivarius AA718T (97.5% and 96.8% sequence similarity, respectively). Strain 17J36-26T showed resistance to UV radiation. Both average nucleotide identity (ANI) and in silico DNA-DNA hybridization (isDDH) values between strains 17J36-26T and type strains of Hymenobacter species were lower than the cut-off (≥ 95-96% for ANI and ≥ 70% for isDDH) to define a bacterial new species. The polyphasic approach using genotypic, phenotypic and chemotaxonomic data showed that strain 17J36-26T could be distinguished from its phylogenetically related species, and thus, the strain representative of a novel species within the genus Hymenobacter, for which the name Hymenobacter radiodurans sp. nov. (type strain 17J36-26T = KCTC 62269T = JCM 33185T) is proposed.

Flaviaesturariibacter flavus sp. nov., isolated from soil in Jeju Island.

A Gram-stain-negative, non-motile and yellow-colored bacterium, designated 17J68-12T, was isolated from soil in Jeju Island, Korea. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain 17J68-12T formed a distinct lineage within the family Chitinophagaceae and was mostly related to members of Flaviaesturariibacter luteus (97.5%), Flaviaesturariibacter amylovorans (96.8%) and Flaviaesturariibacter terrae (96.8%). Growth was observed at 18-42 °C (optimum 30 °C) in R2A broth at pH 7.0. The major cellular fatty acids of the strain 17J68-12 T were summed feature 3 (C16:1 ω6c and/or C16:1 ω7c), summed feature 1 (C15:1 iso-H and/or C13:0 3-OH), and iso-C15:0. The predominant respiratory quinones are MK-7 and MK-6. The major polar lipid was identified as phosphatidylethanolamine. Based on biochemical, chemotaxonomic and phylogenetic characteristics, the strain 17J68-12T represents a novel bacterial species within the family Chitinophagaceae, for which the name Flaviaesturariibacter flavus sp. nov. is proposed. The type strain of Flaviaesturariibacter flavus is 17J68-12T (= KCTC 62219T = JCM 33179T).

Nocardioides jejuensis sp. nov., isolated from soil.

A Gram-stain positive, asporogenous, aerobic, white -coloured bacterium, designated 18JY15-6T, was isolated from soil from Jeju Island, Korea. Pairwise analysis of the 16S rRNA gene sequence of strain 18JY15-6T indicated high similarity to Nocardioides phosphati DSM 104026T (97.4%), Marmoricola terrae KACC 17308T (96.7%) and Nocardioides jensenii KCTC 0074BPT (96.6%). Phylogenetic analysis revealed that strain 18JY15-6T formed a distinct lineage within the family Nocardioidaceae and is closely related to members of the genus Nocardioides. Genome sequencing of strain 18JY15-6T revealed 3221 total genes, including 3162 protein coding genes, 59 RNA and 31 pseudogenes. Growth was observed at 18-37 °C (optimal 30 °C) in R2A medium at pH 7.0. The major cellular fatty acids of strain 18JY15-6T were identified as C16:0, C18:1ω9c, C18:0 10-methyl, tuberculostearic and C17:0. The fatty acid profile of strain 18JY15-6T was more dissimilar when compared with M. terrae. The only respiratory quinone present was found to be MK-8(H4). The major polar lipids are diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and phosphatidylcholine. The results of phylogenetic, biochemical and chemotaxonomic characterisation allow the differentiation of strain 18JY15-6T from N. phosphati WYH11-7T, M. terrae JOS5-1T and N. jensenii NBRC 14755T which supports the conclusion that this strain represents a novel species of the genus Nocardioides, for which we propose the name Nocardioides jejuensis sp. nov. The type strain of Nocardioides jejuensis is 18JY15-6T (= KCTC 49105T = JCM 33182T).

Flavisolibacter galbus sp. nov., isolated from soil in Jeju Island.

A Gram-stain negative, non-motile, and yellow-coloured bacterium, designated 17J28-26T, was isolated from soil in Jeju Island, Korea. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain 17J28-26T formed a distinct lineage within the family Chitinophagaceae (order Chitinophagales, class Chitinophagia), and is closely related to Flavisolibacter ginsenosidimutans (96.8% 16S rRNA gene sequence similarity), and Flavisolibacter ginsengisoli (96.6%). Growth was observed at 18-37 °C (optimum 30 °C) in R2A medium at pH 7.0. The major cellular fatty acids of strain 17J28-26T were summed feature 3 (C16:1 ω6c and/or C16:1 ω7c), and iso-C15:0. The predominant respiratory quinone was MK-7. The major polar lipid was identified as phosphatidylethanolamine. Based on biochemical, chemotaxonomic and phylogenetic characteristics, strain 17J28-26T represents a novel bacterial species within the family Chitinophagaceae, for which the name Flavisolibacter galbus sp. nov. is proposed. The type strain of Flavisolibacter galbus is 17J28-26T (= KCTC 62222T = JCM 33203T).

Paenibacillus albus sp. nov., a UV radiation-resistant bacterium isolated from soil in Korea.

A novel Gram-stain-positive, motile, white color and endospore-forming bacterium, designated 18JY67-1T, was isolated from soil in Jeju Island, Korea. The strain grow at 15-42 °C (optimum 30 °C) in R2A medium at pH (6.0-9.5) (optimum 7.5). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain 18JY67-1T formed a distinct lineage within the family Paenibacillaceae (order Bacillales, class Bacilli), and was closely related to Paenibacillus rhizoryzae (KP675984; 96.9% 16S rRNA gene sequence similarity). The major cellular fatty acids of the strain 18JY67-1T were C16:0 and anteiso-C15:0. The predominant respiratory quinones were MK-7. The major polar lipid was identified as diphosphatidylglycerol. On the basis of phenotypic, chemotaxonomic and genotypic properties clearly indicated that isolate 18JY67-1T represents a novel species within the genus Paenibacillus, for which the name Paenibacillus flavus sp. nov. is proposed. The type strain of Paenibacillus flavus is 18JY67-1T (= KCTC 33959T = JCM 33184T).

Cohnella candidum sp. nov., radiation-resistant bacterium from soil.

A Gram-stain positive, endospore-forming, circular, convex, cream colored, designated strain 18JY8-7T, was isolated from soil collected in Jeju Island, South Korea. Phylogenetic analysis using 16S rRNA gene sequences showed that strain 18JY8-7T formed a distinct lineage within the family Paenibacillaceae (order Bacillales, class Bacilli), and is closely related to Cohnella rhizosphaerae (96.1%, sequence similarity) and Cohnella xylanilytica (96.0%). Optimal growth occurred at 30 °C, pH 6.5 and in the absence of NaCl. The predominant cellular fatty acids were anteiso-C15:0 and iso-C16:0. The major respiratory quinone was MK-7. The polar lipids profile comprised of diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylethanolamine. The DNA G + C content was 57.0 mol %. The genotypic and phenotypic analyses revealed the differentiation of strain 18JY8-7T from all recognized Cohenella species. The strain 18JY8-7T, therefore represents a novel bacterial species within the family Paenibacillaceae, for which the name Cohnella candidum sp. nov. is proposed. The type strain is 18JY8-7T (= KCTC 33969T = JCM 33199T).

Deinococcus irradiatisoli sp. nov., isolated from gamma ray-irradiated soil.

Strain 17bor-2T, a gamma-resistant, pink-to-red-coloured, aerobic, catalase-positive, oxidase-negative and Gram-stain-negative bacterium, was isolated from gamma ray-irradiated soil. The isolate grew aerobically at 18-37 °C (optimum, 28-30 °C), pH 6.0-8.0 (pH 6.5-7.5) and in the presence of 0-1 % (w/v) NaCl (0 % NaCl). Phylogenetic analysis based on its 16S rRNA gene sequence indicated that strain 17bor-2T belonged to the genus Deinococcus with a highest sequence similarity of 96.4 % to Deinococcus alpinitundrae ME-04-04-52T. The major fatty acids of the strain were summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), C16 : 0 and cyclo C17 : 0. The only respiratory quinone was MK-8. The major polar lipids of the strain were phosphoglycolipid, aminophospholipid and an unknown glycolipid. The DNA G+C content of strain 17bor-2T was 62.8 mol%. On the basis of its phenotypic, genotypic and chemotaxonomic characteristics, strain 17bor-2T should be classified as a novel species in the genus Deinococcus, for which the name Deinococcusirradiatisoli sp. nov. is proposed. The type strain is 17bor-2T (=KCTC 33907T=NBRC 113037T).

Pontibacter terrae sp. nov., isolated from soil.

A bacterial strain, designated 17SD1-15T, was isolated from soil. Cells of this strain were Gram-stain-negative and aerobic rods. The major fatty acids of strain 17SD1-15T were iso-C15 : 0 and summed feature 4 (anteiso-C17 : 1 B and/or iso-C17 : 1 I). The polar lipids were phosphatidylethanolamine, one phospholipid and five unidentified lipids. The G+C content of the genomic DNA of strain 17SD1-15T was 49.0 mol%. The 16S rRNA gene sequence analysis showed that strain 17SD1-15T was phylogenetically related to Pontibacter saemangeumensis GCM0142T, Pontibacter korlensis X14-1T, Pontibacter yuliensis H9XT, Pontibacter diazotrophicus H4XT and Pontibacter humi SWU8T (98.3, 96.4, 96.4, 96.4 and 96.0 % sequence similarity, respectively). DNA-DNA relatedness between 17SD1-15T and the most closely related type strain of Pontibacter species was 42.9±0.8 %. The low level of DNA-DNA relatedness identified strain 17SD1-15T as a member of a novel species in the genus Pontibacter. The results of genotypic and phenotypic data, including chemotaxonomic traits, showed that strain 17SD1-15T could be distinguished from its phylogenetically related species. Therefore, strain 17SD1-15T represents a novel species within the genus Pontibacter, for which the name Pontibacter terrae sp. nov. is proposed, with the type strain 17SD1-15T (=KCTC 52915T=NBRC 113057T).

Roseomonas radiodurans sp. nov., a gamma-radiation-resistant bacterium isolated from gamma ray-irradiated soil.

A bacterial strain, designated 17Sr1-1T, was isolated from gamma ray-irradiated soil. Cells of this strain were Gram-stain-negative, strictly aerobic, motile and non-spore-forming rods. Growth occurred at 18-42 ˚C and pH 6.0-8.0, but no growth occurred at 2 % NaCl concentration. The major fatty acids of strain 17Sr1-1T were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), iso-C17 : 1ω5c and C16 : 0. The polar lipid profile contained diphosphatidylglycerol, glycolipid, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol and four unidentified lipids. The G+C content of the genomic DNA of 17Sr1-1T was 71.9 mol%. The 16S rRNA gene sequence analysis showed that strain 17Sr1-1T was phylogenetically related to Roseomonas pecuniae N75T and Roseomonas rosea 173-96T (96.6 and 96.3 % sequence similarity, respectively). The genotypic and phenotypic data showed that strain 17Sr1-1T could be distinguished from its phylogenetically related species, and that this strain represented a novel species within the genus Roseomonas, for which the name Roseomonas radiodurans sp. nov. (type strain 17Sr1-1T=KCTC 52899T=NBRC 112872T) is proposed as the first reported gamma ray-resistant Roseomonas species.

Adhaeribacter swui sp. nov., isolated from wet mud.

Strain 17mud1-7T, a pink, aerobic, catalase-positive, oxidase-positive and Gram-reaction-negative bacterium, was isolated from wet mud. The isolate grew aerobically at 18-37 °C (optimum 28 °C), at pH 6.0-8.0 (optimum pH 7.0) and in the presence of 0-1 % (w/v) NaCl (optimum 0 % NaCl). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain 17mud1-7T belonged to the genus Adhaeribacter with highest sequence similarity of 96.4 % to Adhaeribacter aerophilus 6424S-25T. The strain showed the typical chemotaxonomic characteristics of the genus Adhaeribacter, with the presence of menaquinone MK-7 as the respiratory quinone, and summed feature 4 (composed of iso-C17 : 1 I/anteiso-C17 : 1 B), iso-C15 : 0 and C16 : 1ω5c as the major fatty acids are. The polar lipid profile contained two aminophosphoglycolipids, two glycolipids and three unidentified lipids. The DNA G+C content of strain 17mud1-7T was 45.9 mol%. Strain 17mud1-7T should thus be classified as representing a novel species in the genus Adhaeribacter, for which the name Adhaeribacter swui sp. nov. is proposed. The type strain is 17mud1-7T (=KCTC 52873T=NBRC 112824T).