Malate-Based Biodegradable Scaffolds Activate Cellular Energetic Metabolism for Accelerated Wound Healing

A Targeted Core-Shell ZIF-8/Au@Fe3O4 Platform with Multiple Antibacterial Pathways for Infected Skin Wound Regeneration

Bacterial infections seriously retard skin wound healing. To enhance the antibacterial efficiency and subsequent skin regeneration, a core-shell structured therapeutic platform, named FZAM, was designed with multiple antimicrobial pathways. FZAM consists of nanosized Fe3O4 as the core and ZIF-8 loaded with Au nanoparticles (NPs) and maltodextrin as the shell. Fe3O4 and Au NPs form a heterojunction that generates hyperthermia and abundant reactive oxide species (ROS) under near-infrared (NIR) irradiation. This heterojunction also exhibits outstanding peroxidase-like activity. When bacteria invade, maltodextrin plays a targeting effect to increase the interaction between FZAM and bacteria, and with the synergistic action of NIR-induced hyperthermia and ROS as well as Zn2+ from ZIF-8, FZAM kills more than 99% of bacteria at 200 μg mL-1. Fortunately, FZAM is cytocompatible and even promotes the biofunctions of fibroblasts and endothelial cells. In infected skin wound models, FZAM sterilizes bacteria with NIR irradiation and subsequently reduces the inflammatory response and accelerates skin regeneration. This work provides a core-shell structured therapy platform for treating infection with the assistance of NIR irradiation and helping skin wound healing.

Identification of GDP as a small inhibitory molecule in HepG2 cells by non‑targeted metabolomics analysis

Identifying the mechanism by which lipid metabolism regulates cancer may offer a novel approach for therapeutic intervention. It has previously been identified that a lipid metabolism-related factor, namely fatty acid hydroxylase domain containing 2 (FAXDC2), is downregulated in various types of cancer, and inhibits the proliferation and migration of liver cancer cells through a mechanism associated with ERK. The liver is important for lipid metabolism, and FAXDC2 is involved in the synthesis of cholesterol and sphingomyelin. However, the functional mechanism by which FAXDC2 influences liver cancer cells through metabolic processes and ERK signaling remains unclear. Therefore, the present study induced the overexpression of FAXDC2 in HepG2 liver cancer cells and performed a metabolomics analysis. This identified guanosine diphosphate (GDP) as a significantly altered metabolite. Using AlphaFold3, a robust interaction was predicted between FAXDC2 and GDP, which lead to the hypothesis that GDP may mediate the inhibitory effects of FAXDC2 on liver cancer cells by directly modulating the functional properties of the cells, thereby influencing their behavior and progression. Cell Counting Kit-8 assays were used to study the impact of elevated GDP concentrations on HepG2 cell growth. The results revealed a gradual reduction in the viability of HepG2 cells as the GDP concentration increased. In addition, western blotting showed that GDP treatment was accompanied by a significant downregulation of cyclin dependent kinase 4 and cyclin D1 expression levels, and Transwell experiments revealed that GDP treatment significantly decreased the invasion of HepG2 cells. Treatment with GDP also significantly inhibited the expression of ERK. In summary, the present study is the first to indicate that GDP is a metabolic small molecule with inhibitory activity in cancer cells, which has previously been overlooked in tumor metabolic reprogramming. The study findings offer new insights and strategies for the diagnosis and treatment of liver cancer, and potentially other types of cancer.

Reprogramming metabolic microenvironment for nerve regeneration via waterborne polylactic acid-polyurethane copolymer scaffolds

Cell metabolism, as the key driver of inflammation, revascularization and even subsequent tissue regeneration, is controlled by and also conversely influenced by signal transduction. Incorporation of cell metabolism into tissue engineering research holds immense potential for in-situ treatment repair and further understanding of the host-biomaterial cues in body response. In this study, an anti-inflammatory waterborne polyurethane scaffold incorporated with poly-l-lactic acid (PLLA) block was served to repair nerve injuries (LAx-WPU). Lactate was released through the degradation of LAx-WPU scaffolds, and the content increased with the addition of PLLA block over the degradation times. Thenceforth, the production of adenosine triphosphate (ATP) in primary neurons and neuronal axon growth were achieved by taking up lactate through monocarboxylate transporters (MCT2) for energy metabolism under glucose-free environment treated with LAx-WPU degradation solution. After LAx-WPU was implanted to repair brain nerve defects in rats, filamentous neurons elongation, rapid vascularization, and nerve tissue regeneration were realized up to 28 days with the positive expression of microtubule-associated protein (MAP2), β-tubulin (Tuj1), and platelet endothelial cell adhesion molecule (CD31) in the scaffolds. Results highlighted that the LAx-WPU scaffolds up-regulated not only the ATP-ADP-AMP purine metabolism compounds to mainly bridge neuroactive ligand-receptor interaction genes, cAMP pathway genes, and calcium pathway genes for neurocytes but also the ATP-GMP purine metabolism to angiogenesis in Gene Ontology (GO) analysis. Further analysis in reverse showed axonal regeneration is restrained by the inhibition of MCT2, proving LAx-WPU promoted nerve repair depended on lactate for energy. Therefore, LAx-WPU scaffolds construct an expected way to modulate the metabolic microenvironment for inducing nerve regeneration by intrinsic biomaterial metabolism cues without any bioactive factors.

Metabolomics Provides New Insights into the Mechanisms of Wolbachia-Induced Plant Defense in Cotton Mites

Endosymbiotic bacteria play a significant role in the co-evolution of insects and plants. However, whether they induce or inhibit host plant defense responses remains unclear. In this study, non-targeted metabolomic sequencing was performed on cotton leaves fed with Wolbachia-infected and uninfected spider mites using parthenogenetic backcrossing and antibiotic treatment methods. A total of 55 differential metabolites were identified, which involved lipids, phenylpropanoids, and polyketides. KEGG pathway enrichment analysis revealed seven significantly enriched metabolic pathways. Among them, flavonoid and flavonol biosynthesis, glycerophospholipid metabolism, and ether lipid metabolism showed extremely significant differences. In Wolbachia-infected cotton leaves, the flavonoid biosynthesis pathway was significantly up-regulated, including quercetin and myricetin, suggesting that the plant produces more secondary metabolites to enhance its defense capability. Glycerophosphocholine (GPC) and sn-glycerol-3-phosphoethanolamine (PE) were significantly down-regulated, suggesting that Wolbachia may impair the integrity and function of plant cell membranes. The downregulation of lysine and the upregulation of L-malic acid indicated that Wolbachia infection may shorten the lifespan of spider mites. At various developmental stages of the spider mites, Wolbachia infection increased the expression of detoxification metabolism-related genes, including gene families such as cytochrome P450, glutathione S-transferase, carboxylesterase, and ABC transporters, thereby enhancing the detoxification capability of the host spider mites. This study provides a theoretical basis for further elucidating the mechanisms by which endosymbiotic bacteria induce plant defense responses and expands the theoretical framework of insect-plant co-evolution.

A Cutting-Edge Multilayer Nanofiber Wound Dressing: Design, Synthesis, and Investigation for Enhanced Wound Healing In Vitro and In Vivo

Wounds, disruptions in normal anatomy, are classified as acute or chronic. The choice of wound treatment relies significantly on dressing materials. Electrospun nanofibrous materials offer promising applications in wound healing, featuring a substantial surface area, close mimicry of the natural extracellular matrix, and adjustable water resistance, air permeability, and drug release. This research endeavors to formulate an innovative three-layered nanofibrous wound dressing using the electrospinning technique with the primary objectives of enhancing patient well-being, exhibiting antimicrobial characteristics, and expediting wound healing. The designed dressing comprises nanofibers of polyurethane (PU), quercetin (Q)-loaded polyethylene glycol (PEG), polyvinyl alcohol (PVA), and gelatin. Characterization of individual layers and the integrated wound dressing was conducted through SEM and FT-IR analyses. The efficacy of the nanofibrous wound dressing was assessed through in vitro human cell culture and in vivo rat wound models. The anti-toxic effects of nanofiber wound dressing on human epithelial and keratin cells have been proven. In vitro wound models in 24-well plates were utilized to assess the impact on wound healing rates. Photographic documentation of wound closure was performed at the different treatment hours, revealing complete closure of the wounds by the end of the 48th hour. Rats with 2 × 1 cm wounds were treated with the nanofibrous dressings, and wound healing progress was observed over a 14-day period. qRT-PCR was employed to analyze MMP-9, TIMP1, COL1A1, PDGFA, and VEGFC mRNA expressions. With its contemporary design surpassing existing treatments, the nanofiber wound dressing stands out for its wound-healing acceleration and antibacterial properties.