Correction: Innovative wound management: creating dynamic Alg-Mg/SF hydrogels for controlled Mg2+ release in wound healing.

[This corrects the article DOI: 10.1039/D4RA00793J.].

Innovative wound management: creating dynamic Alg-Mg/SF hydrogels for controlled Mg2+ release in wound healing.

Antibacterial hydrogels have gained considerable attention for soft tissue repair, particularly in preventing infections associated with wound healing. However, developing an antibacterial hydrogel that simultaneously possesses excellent cell affinity and controlled release of metal ions remains challenging. This study introduces an antibacterial hydrogel based on alginate modified with bisphosphonate, forming a coordination complex with magnesium ions. The hydrogel, through an interpenetrating network with silk fibroin, effectively controls the release of magnesium ions and enhances strain resistance. The Alg-Mg/SF hydrogel not only demonstrates outstanding biocompatibility and broad-spectrum antibacterial properties but also stimulates macrophages to secrete anti-inflammatory factors. This advanced Alg-Mg/SF hydrogel provides a convenient therapeutic approach for chronic wound management, showcasing its potential applications in wound healing and other relevant biomedical fields.

Dissecting the HGT network of carbon metabolic genes in soil-borne microbiota.

The microbiota inhabiting soil plays a significant role in essential life-supporting element cycles. Here, we investigated the occurrence of horizontal gene transfer (HGT) and established the HGT network of carbon metabolic genes in 764 soil-borne microbiota genomes. Our study sheds light on the crucial role of HGT components in microbiological diversification that could have far-reaching implications in understanding how these microbial communities adapt to changing environments, ultimately impacting agricultural practices. In the overall HGT network of carbon metabolic genes in soil-borne microbiota, a total of 6,770 nodes and 3,812 edges are present. Among these nodes, phyla Proteobacteria, Actinobacteriota, Bacteroidota, and Firmicutes are predominant. Regarding specific classes, Actinobacteria, Gammaproteobacteria, Alphaproteobacteria, Bacteroidia, Actinomycetia, Betaproteobacteria, and Clostridia are dominant. The Kyoto Encyclopedia of Genes and Genomes (KEGG) functional assignments of glycosyltransferase (18.5%), glycolysis/gluconeogenesis (8.8%), carbohydrate-related transporter (7.9%), fatty acid biosynthesis (6.5%), benzoate degradation (3.1%) and butanoate metabolism (3.0%) are primarily identified. Glycosyltransferase involved in cell wall biosynthesis, glycosylation, and primary/secondary metabolism (with 363 HGT entries), ranks first overwhelmingly in the list of most frequently identified carbon metabolic HGT enzymes, followed by pimeloyl-ACP methyl ester carboxylesterase, alcohol dehydrogenase, and 3-oxoacyl-ACP reductase. Such HGT events mainly occur in the peripheral functions of the carbon metabolic pathway instead of the core section. The inter-microbe HGT genetic traits in soil-borne microbiota genetic sequences that we recognized, as well as their involvement in the metabolism and regulation processes of carbon organic, suggest a pervasive and substantial effect of HGT on the evolution of microbes.

A Comparative Study of Flavonoids and Carotenoids Revealed Metabolite Responses for Various Flower Colorations Between Nicotiana tabacum L. and Nicotiana rustica L.

Tobacco is a model plant for studying flower coloration. Flavonoids and carotenoids were reported to contribute to the flower color in many plants. We investigated the mechanism underlying flower color formation in tobacco by comparing the profiling flavonoids and carotenoids between various species Nicotiana tabacum L. and Nicotiana rustica L., as their flowers commonly presented red (pink) and yellow (orange), respectively. The metabolomes were conducted by UPLC-ESI-MS/MS system. The main findings were as follows: (1) A total of 31 flavonoids and 36 carotenoids were identified in all four cultivars involved in N. tabacum and N. rustica. (2) Flavonoids and carotenoids tended to concentrate in the red flowers (N. tabacum) and yellow flowers (N. rustica), respectively. (3) About eight flavonoids and 12 carotenoids were primarily screened out for metabolic biomarkers, such as the robust biomarker involving kaempferol-3-o-rut, quercetin-glu, rutin, lutein, and ß-carotene. This is the first research of systematic metabolome involving both flavonoids and carotenoids in tobacco flower coloration. The metabolic mechanism concluded that flavonoids and carotenoids mainly contributed to red (pink) and yellow (orange) colors of the tobacco flowers, respectively. Our finding will provide essential insights into characterizing species and modifying flower color in tobacco breeding through genetic improvement or regulation of featured metabolic synthesis.

Tobacco transcription factor bHLH123 improves salt tolerance by activating NADPH oxidase NtRbohE expression.

In plants, reactive oxygen species (ROS) produced following the expression of the respiratory burst oxidase homolog (Rboh) gene are important regulators of stress responses. However, little is known about how plants acclimate to salt stress through the Rboh-derived ROS signaling pathway. Here, we showed that a 400-bp fragment of the tobacco (Nicotiana tabacum) NtRbohE promoter played a critical role in the salt response. Using yeast one-hybrid (Y1H) screens, NtbHLH123, a bHLH transcription factor, was identified as an upstream partner of the NtRbohE promoter. These interactions were confirmed by Y1H, electrophoretic mobility assay, and chromatin immunoprecipitation assays. Overexpression of NtbHLH123 resulted in greater resistance to salt stress, while NtbHLH123-silenced plants had reduced resistance to salt stress. We also found that NtbHLH123 positively regulates the expression of NtRbohE and ROS production soon after salt stress treatment. Moreover, knockout of NtRbohE in the 35S::NtbHLH123 background resulted in reduced expression of ROS-scavenging and salt stress-related genes and salt tolerance, suggesting that NtbHLH123-regulated salt tolerance is dependent on the NtbHLH123-NtRbohE signaling pathway. Our data show that NtbHLH123 is a positive regulator and acts as a molecular switch to control a Rboh-dependent mechanism in response to salt stress in plants.

Obesity related microRNA­424 is regulated by TNF­α in adipocytes.

In recent years, obesity has become a major public health concern. Obesity has been previously associated with low­grade inflammation and TNF­α induction in adipose tissue, which subsequently disrupts adipocyte metabolism. MicroRNAs (miRNAs/miRs) are important metabolic factors and their dysregulation has been associated with obesity­related metabolic syndromes. In fact, it has been directly suggested that miR­424 may be functionally associated with adipogenesis, although its exact role in this process remains unclear. The present study aimed to identify the function of miR­424 in adipogenesis. In the present study, miR­424 expression levels were analyzed during adipogenesis and the differential expression of this miRNA in the adipose tissue of obese and non­obese children was also assessed. Furthermore, the interaction between miR­424 and the adipocytokine TNF­α was determined. Finally, miR­424 target genes and downstream signaling pathways were predicted via bioinformatics and analyzed by performing a luciferase reporter assay to elucidate the functional mechanisms of miR­424 in adipogenesis of visceral adipocytes. The results revealed that the expression levels of miR­424 upregulated in the adipose tissue biopsies from obese children compared with the biopsies of non­obese children. However, in cultured adipocytes, the expression levels of miR­424 were discovered to be gradually downregulated during the adipogenesis process. TNF­α treatment significantly downregulated the expression levels of miR­424 via binding to its promoter region and reducing its transcriptional activity. Through bioinformatic prediction analysis, miR­424 target genes were analyzed, of which several were identified to be involved in signaling pathways that are known to regulate adipogenesis, such as the Wnt signaling pathway. In conclusion, the present study indicated that miR­424 was regulated by TNF­α and served an important role in adipogenesis.

Nanoengineered porous chitosan/CaTiO3 hybrid scaffolds for accelerating Schwann cells growth in peripheral nerve regeneration.

To further improve the property of promoting peripheral nerve regeneration of chitosan materials, CaTiO3 nanoparticles with various concentrations were synthesized in chitosan (CS) solution and formed to porous CS/CaTiO3 hybrid scaffolds. The properties including morphology, wettability, porosity, crystallization intensity and surface charges were characterized, respectively. The influence of the porous CS/CaTiO3 hybrid scaffolds on Schwann cells growth was evaluated. The results showed that the CaTiO3 hybridized CS scaffolds possessed homogeneous nanoparticles distribution with concentration-dependent effect. The hybridization of CaTiO3 nanoparticles could increase the hydrophobicity while reduce the porosity and surface charge density of the porous CS/CaTiO3 hybrid scaffolds The crystal structure of the hybridized scaffolds was mainly the orthorhombic structure of the calcium titanate accompanied by the amorphous phase of chitosan. Culture of Schwann cells indicated that the CS/CaTiO3 hybrid scaffolds with a suitable concentration of CaTiO3 nanoparticles could obviously promote the attachment, proliferation and biological function maintenance of Schwann cells, thus showing potentially great significance towards application in peripheral nerve regeneration.

Nerve growth factor loaded heparin/chitosan scaffolds for accelerating peripheral nerve regeneration.

Artificial chitosan scaffolds have been widely investigated for peripheral nerve regeneration. However, the effect was not as good as that of autologous grafts and therefore could not meet the clinical requirement. In the present study, the nerve growth factor (NGF) loaded heparin/chitosan scaffolds were fabricated via electrostatic interaction for further improving nerve regeneration. The physicochemical properties including morphology, wettability and composition were measured. The heparin immobilization, NGF loading and release were quantitatively and qualitatively characterized, respectively. The effect of NGF loaded heparin/chitosan scaffolds on nerve regeneration was evaluated by Schwann cells culture for different periods. The results showed that the heparin immobilization and NGF loading did not cause the change of bulk properties of chitosan scaffolds except for morphology and wettability. The pre-immobilization of heparin in chitosan scaffolds could enhance the stability of subsequently loaded NGF. The NGF loaded heparin/chitosan scaffolds could obviously improve the attachment and proliferation of Schwann cells in vitro. More importantly, the NGF loaded heparin/chitosan scaffolds could effectively promote the morphology development of Schwann cells. The study may provide a useful experimental basis to design and develop artificial implants for peripheral nerve regeneration and other tissue regeneration.