UNASSIGNED: In this case report, the authors summarize their experience of using hydrogel combined with alginate dressings in the wound care of a patient with grade 4 acute radiation dermatitis. With the combination of hydrogel and alginate dressings, the authors achieved autolytic debridement of the wound and created a moist healing environment to facilitate wound closure. Hydrogel helps the dressing adhere better to the wound bed, ensuring that it does not easily detach during the wound healing process. It also eliminates the need for traditional adhesive tapes for fixation, thus avoiding damage to the fragile skin in the radiation field.The wound gradually decreased in size from an area of 10 × 12 cm, and exudate decreased continuously. The wound completely healed in 20 days with a total of 17 dressing changes. As the wound gradually healed, the patient\'s psychological burden decreased and comfort level increased. The patient expressed satisfaction and hope for the gradual healing of the wound.Thus, the treatment of severe acute radiation dermatitis with hydrogel combined with alginate dressings yields remarkable results, aligning the noninvasive, low-adhesive, absorbent, conformable, and comfortable attributes of optimized wound care. This experience provides a practical foundation for wound management in acute radiation dermatitis and supports clinical application and promotion of the approach.

The two-component system GacS/A and the posttranscriptional control system Rsm constitute a genetic regulation pathway in Gammaproteobacteria; in some species of Pseudomonas, this pathway is part of a multikinase network (MKN) that regulates the activity of the Rsm system. In this network, the activity of GacS is controlled by other kinases. One of the most studied MKNs is the MKN-GacS of Pseudomonas aeruginosa, where GacS is controlled by the kinases RetS and LadS; RetS decreases the kinase activity of GacS, whereas LadS stimulates the activity of the central kinase GacS. Outside of the Pseudomonas genus, the network has been studied only in Azotobacter vinelandii. In this work, we report the study of the RetS kinase of A. vinelandii; as expected, the phenotypes affected in gacS mutants, such as production of alginates, polyhydroxybutyrate, and alkylresorcinols and swimming motility, were also affected in retS mutants. Interestingly, our data indicated that RetS in A. vinelandii acts as a positive regulator of GacA activity. Consistent with this finding, mutation in retS also negatively affected the expression of small regulatory RNAs belonging to the Rsm family. We also confirmed the interaction of RetS with GacS, as well as with the phosphotransfer protein HptB.

BACKGROUND: This study aimed to synthesize dentin powder surface-modified with alginate, a potential substance for dental pulp regeneration, and evaluate its effects on the viability and proliferation of human dental pulp stem cells (hDPSCs) in vitro and its biocompatibility in vivo.
METHODS: In the in vitro phase, dentin powder was synthesized in three size groups (150-250 μm, 250-500 μm, and 500-1000 μm) after demineralization and atelopeptidization which is used to remove dentin collagen telopeptides and eliminate host immune response. Surface modification with alginate was performed and followed by field-emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX), and cell viability and proliferation testing for 14 days with hDPSCs studied. In the in vivo phase, dentin powders were implanted in rat calvarial defects for 8 weeks, and histological analysis was conducted. All nonparametric data were analyzed with the Kruskal- Wallis test, and all the quantitative data were analyzed by one-way ANOVA using SPSS, and P<0.05 was considered statistically significant.
RESULTS: Demineralization and atelopeptidization were successful in all groups. Cell viability was optimal and equal (P>0.05) in all groups. The 500-1000 μm group exhibited significantly higher cell proliferation (P<0.05). Histological assessment shows acceptable biocompatibility in all groups; the angiogenesis score was significantly greater in both 250-500 and 500-1000, and minimal inflammatory response was noted in the 500-1000 μm group, and the amount of newly formed bone in this group was higher than other groups.
CONCLUSIONS: Surface modification of demineralized and atelopeptidized dentin powder with alginate enhanced surface physical properties and cell proliferation while showing great biocompatibility within tissue and reducing the host immune response. These findings hold promise for dentin-pulp complex regeneration.

As a significant structure in activated sludge, extracellular polymeric substances (EPS) hold considerable value regarding resource recovery and applications. The present study aimed to elucidate the relationship between the microbial community and the composition and properties of EPS. A biological nutrient removal (BNR) reactor was set up in the laboratory and controlled under different solid retention times (SRT), altering microbial species within the system. Then EPS was extracted from activated and analyzed by chemical and spectroscopic methods. High-throughput sequencing and metagenomic approaches were employed to investigate bacterial community and metabolic pathways. The results showed that lower SRT with a higher abundance of the family-level Proteobacteria (27.7%-53.5%) favored EPS synthesis, while another dominant group Bacteroidetes (20.0%-32.6%) may not significantly affect EPS synthesis. Furthermore, the abundance of alginates-producing bacteria including Pseudomonas spp. and Azotobacter vinelandii was only 2.53%-6.76% and 1.98%-6.34%, respectively. The alginate synthesis pathway genes Alg8 and Alg44 were also present at very low levels (0.05‱-0.11‱, 0.01‱-0.02‱, respectively). Another important gene related to alginates operons, AlgK, was absent across all the SRT-operated reactors. These findings suggest an impossible and incomplete alginate synthesis pathway within sludge. In light of these results, it can be concluded that EPS does not necessarily contain alginate components.

UNASSIGNED: Although the mechanism is unclear, Pseudomonas aeruginosa (PA) infection directly affects the frequency of acute exacerbations in patients with bronchiectasis. The aims of this article are to analyze the genetic mutation characteristics of the algUmucABD operon in PA, isolated from hospitalized patients with bronchiectasis, and to explore independent risk factors for frequent acute exacerbations of bronchiectasis.
UNASSIGNED: Based on the number of acute exacerbations that occurred in the past year, these patients with bronchiectasis were divided into those with frequent acute exacerbations (Group A) and those with non-frequent acute exacerbations (Group B). We identified the distribution of mucoid phenotypes (MPs) and alginate morphotypes (AMs) in PA, and classified them into I-IV categories based on their different AMs; otherwise, the gene mutation types (GMTs) of the algUmucABD operon were tested. Subsequently, the relationship between GMT, MP, and AM and the independent risk factors for frequent acute exacerbations in patients with bronchiectasis were explored.
UNASSIGNED: A total of 93 patients and 75 PA strains, from January 2019 to August 2023, were included in this study. The MP and AM distributions of PA were as follows: 64 strains (85.33%) of mucoid (the AMs were 38 strains of type I, 3 strains of type II, and 23 strains of type IV) and 11 strains of non-mucoid (the AM was type III only). Mucoid PA with algU, mucA, mucB, and mucD mutations accounted for 19.61%, 74.51%, 31.37%, and 50.98%, respectively. GMT was divided into the following: mucA mutations only, mucA combined with other gene mutations, other gene mutations without mucA mutations, and without gene mutations. In 91.7% of PA with type I of AM, only mucA mutations occurred, and in both separate MP and AM, the GMT differences were statistically significant. Lastly, the number of lung lobes with bronchiectasis and the number of PA with mucA mutations only were the independent risk factors for frequent acute exacerbations.
UNASSIGNED: The mucA mutation was primarily responsible for the mucoid of MP and type I of AM in PA, and it was also an independent risk factor for frequent exacerbations of bronchiectasis.

To achieve the optimal alginate-based oral formulation for delivery of hydrophobic drugs, on the basis of previous research, we further optimized the synthesis process parameters of alginate-g-oleylamine derivatives (Ugi-FOlT) and explored the effects of different degrees of substitution (DSs) on the molecular self-assembly properties of Ugi-FOlT, as well as the in vitro cytotoxicity and drug release behavior of Ugi-FOlT. The resultant Ugi-FOlT exhibited good amphiphilic properties with the critical micelle concentration (CMC) ranging from 0.043 mg/mL to 0.091 mg/mL, which decreased with the increase in the DS of Ugi-FOlT. Furthermore, Ugi-FOlT was able to self-assemble into spherical micellar aggregates in aqueous solution, whose sizes and zeta potentials with various DSs measured by dynamic light scattering (DLS) were in the range of 653 ± 25~710 ± 40 nm and -58.2 ± 1.92~-48.9 ± 2.86 mV, respectively. In addition, RAW 264.7 macrophages were used for MTT assay to evaluate the in vitro cytotoxicity of Ugi-FOlT in the range of 100~500 μg/mL, and the results indicated good cytocompatibility for Ugi-FOlT. Ugi-FOlT micellar aggregates with favorable stability also showed a certain sustained and pH-responsive release behavior for the hydrophobic drug ibuprofen (IBU). Meanwhile, it is feasible to control the drug release rate by regulating the DS of Ugi-FOlT. The influence of different DSs on the properties of Ugi-FOlT is helpful to fully understand the relationship between the micromolecular structure of Ugi-FOlT and its macroscopic properties.

Chitosan, alginate, and chitosan-alginate (50:50) mixed hydrogels were prepared by freeze casting, freeze-drying, and subsequent physical cross-linking. Chitosan was cross-linked with citrate and alginate with calcium ions, while the mixed gels were cross-linked with both cross-linking agents. Both cryogels and xerogels were obtained by lyophilization and drying of the hydrogels. We investigated the effect of the chemical composition and the physical state of gels on the gel structure and sorption of model dyes. Alginate and mixed gels cross-linked with Ca2+ ions sorbed 80-95% of cationic dye from the solutions. The chitosan gels are primarily capable of adsorbing anionic dyes, but at near-neutral pH, their capacity is lower than that of alginate gels, showing 50-60% dye sorption. In the case of alginate gels, the dye sorption capacity of xerogels, cryogels, and hydrogels was the same, but for chitosan gels, the hydrogels adsorbed slightly less dye than the dried gels.

Alginate oligosaccharides (AOSs), which are an attractive feed additive for animal production, exhibit pleiotropic bioactivities. In the present study, we investigated graded doses of AOS-mediated alterations in the physiological responses of piglets by determining the intestinal architecture, barrier function, and microbiota. A total of 144 weaned piglets were allocated into four dietary treatments in a completely random design, which included a control diet (CON) and three treated diets formulated with 250 mg/kg (AOS250), 500 mg/kg (AOS500), and 1000 mg/kg AOS (AOS1000), respectively. The trial was carried out for 28 days. Our results showed that AOS treatment reinforced the intestinal barrier function by increasing the ileal villus height, density, and fold, as well as the expression of tight junction proteins, especially at the dose of 500 mg/kg AOS. Meanwhile, supplementations with AOSs showed positive effects on enhancing antioxidant capacity and alleviating intestinal inflammation by elevating the levels of antioxidant enzymes and inhibiting excessive inflammatory cytokines. The DESeq2 analysis showed that AOS supplementation inhibited the growth of harmful bacteria Helicobacter and Escherichia_Shigella and enhanced the relative abundance of Faecalibacterium and Veillonella. Collectively, these findings suggested that AOSs have beneficial effects on growth performance, antioxidant capacity, and gut health in piglets.

Bacterial infections already pose a significant threat to skin wounds, especially in diabetic patients who have difficulty healing wounds. However, wound or bacterial infections are known to produce excess reactive oxygen species (ROS), and hypoxia may further hinder wound healing and the development of chronic wounds. In this study, a multifunctional hydrogel for ROS scavenging and bacterial inhibition was developed by cross-linking polyvinyl alcohol (PVA) and sodium alginate (SA) with graphene oxide (GO) loaded with silver-platinum hybrid nanoparticles (GO@Ag-Pt). The PVA/SA hydrogel loaded with GO@Ag-Pt exhibited the ability to scavenge different types of ROS, generate O2, and kill a broad spectrum of bacteria in vitro. The silver-platinum hybrid nanoparticles significantly increased the antibacterial ability against Escherichia coli and Staphylococcus aureus compared with silver nanoparticles (AgNps). GO@Ag-Pt loaded hydrogel was effective in treating infections caused by S.aureus, thereby significantly promoting wound healing during the inflammatory phase. Hydrogel therapy significantly reduced the level of ROS and alleviated inflammation levels. Notably, our ROS-scavenging, antibacterial hydrogels can be used to effectively treat various types of wounds, including difficult-to-heal diabetic wounds with bacterial infections. Thus, this study proposes an effective strategy for various chronic wound healing based on ROS clearance and bacteriostatic hydrogels.

(+)4-cholesten-3-one has been proved to have potential wound healing effect in the process of wound regeneration. This study aimed to evaluate the effect of (+)4-cholesten-3-one/sodium alginate/gelatin on skin injury and reveal its potential molecular mechanism. First, we prepared sodium alginate/gelatin hydrogel (SA/Gel hydrogel) with different ratios and tested their characteristics. Based on these results, different concentrations of (+)4-cholesten-3-one were added into SA/Gel hydrogel. A full-thickness skin injury model was successfully established to evaluate wound healing activityin vivo. HE staining and Masson staining were used to evaluate the thickness of granulation tissue and collagen deposition level. Immunohistochemical staining and immunofluorescence staining were applied to detect the level of revascularization and proliferation in each group of wounds. Western blot, quantitative-PCR and immunofluorescence staining were used to detect the expression of proteins related to Wnt/β-catenin signaling pathway in each group of wounds.In vitroresults showed that the hydrogel not only created a 3D structure for cell adhesion and growth, but also exhibited good swelling ability, excellent degradability and favorable bio-compatibility. Most importantly,in vivoexperiments further indicated that (+)4-cholesten-3-one/SA/Gel hydrogel effectively enhanced wound healing. The effectiveness is due to its superior abilities in accelerating healing process, granulation tissue regeneration, collagen deposition, promoting angiogenesis, tissue proliferation, as well as fibroblast activation and differentiation. The underlying mechanism was related to the Wnt/β-catenin signaling pathway. This study highlighted that (+)4-cholesten-3-one/SA/Gel hydrogel holds promise as a wound healing dressing in future clinical applications.