Antimicrobial Effects Research Articles

H2O2 Self‐Supplying CaO2/POM@MOF Bimodal Nanogeneration Materials for Photothermal and Chemodynamic Synergistic Antimicrobials

ABSTRACTThe emergence of bacterial resistance has a negative impact on the conventional antimicrobial treatments, and research into the development of the new antimicrobial materials is of great significance. Multimodal synergistic antimicrobial materials exert better antimicrobial effects compared with a single modality. In recent years, Polyoxometalate (POM) has shown great potential in the biomedical field due to its high catalytic activity and high photothermal conversion ability. However, owing to its small surface area, its applications have been greatly limited. Herein, we designed a H2O2 self‐supplied CDT and PTT bimodal nanogeneration material (i.e., CaO2/POM@MOF) possessing a larger surface area for the treatment of the bacterial infections, in which CaO2 could release O2 and H2O2 in the weakly acidic microenvironment of bacterial infection and the dual catalytic site of POM@MOF could enhance the CDT reaction to generate ROS, resulting in the bacterial oxidative stress and the leakage of the bacterial contents, and the exposure to the NIR light generates localized high temperature that cause the rupture of bacterial cell membranes and the denaturation of their proteins. Meanwhile, the superior stability of POM@MOF can release fewer metal ions to improve its biocompatibility. The in vitro antimicrobial experiments demonstrated that CaO2/POM@MOF possessed the combined CDT and PTT effect and exhibited excellent antimicrobial efficacy. This work presents a promising strategy to combat the bacterial infections.

Antimicrobial Effects of Orthodontic Molar Tube Coated with ZnO Nanoparticles Using Electrophoretic Deposition Method: A Randomized Clinical Trial.

This study aimed to evaluate the antimicrobial effect of coated orthodontic molar tubes (COMT) with zinc oxide nanoparticles (ZnO NPs) using an electrophoretic deposition method (EPD) and to evaluate the orthodontic molar tubes (OMT) bond failure rate. Seventy-two orthodontic molar tubes (OMTs) for second molars were divided into two groups 36 each; one group coated with ZnO NPs and the other control negative uncoated. The OMT was coated using the EPD method with ZnO NPs in a concentration of 10g/l. The OMTs were randomly allocated using a split-mouth, cross-quadrant design. After 2weeks of appliance placement, swabs were taken from the surface of the OMTs for microbial assessment against Streptococcus mutans, Lactobacillus acidophilus, and total bacterial counts; additionally, plaque and gingival indices were assessed. The patient was followed for 3months to evaluate the bond failure rate. The COMT showed a statistically significant reduction in total bacterial accounts, S. mutans, and L. acidophilus compared to UOMT (P < 0.001). Furthermore, the plaque and gingival indices near COMT were significantly less than that of UOMT. The bond failure rate was not significant between the COMT and UOMT. The COMT with ZnO NPs has potent antibacterial activity against the tested pathogens with a reduction in the amount of plaque accumulation. The use of the EPD method was feasible without adverse effects on theorthodontic molar tubes bond failure rate.

Transition metal homoeostasis is key to metabolism and drug tolerance of Mycobacterium abscessus

AbstractAntimicrobial resistance (AMR) is one of the major challenges humans are facing this century. Understanding the mechanisms behind the rise of AMR is therefore crucial to tackling this global threat. The presence of transition metals is one of the growth-limiting factors for both environmental and pathogenic bacteria, and the mechanisms that bacteria use to adapt to and survive under transition metal toxicity resemble those correlated with the rise of AMR. A deeper understanding of transition metal toxicity and its potential as an antimicrobial agent will expand our knowledge of AMR and assist the development of therapeutic strategies. In this study, we investigate the antimicrobial effect of two transition metal ions, namely cobalt (Co2+) and nickel (Ni2+), on the non-tuberculous environmental mycobacterium and the opportunistic human pathogen Mycobacterium abscessus. The minimum inhibitory concentrations of Co2+ and Ni2+ on M. abscessus were first quantified and their impact on the bacterial intracellular metallome was investigated. A multi-omics strategy that combines transcriptomics, bioenergetics, metabolomics, and phenotypic assays was designed to further investigate the mechanisms behind the effects of transition metals. We show that transition metals induced growth defect and changes in transcriptome and carbon metabolism in M. abscessus, while the induction of the glyoxylate shunt and the WhiB7 regulon in response to metal stresses could be the key response that led to higher AMR levels. Meanwhile, transition metal treatment alters the bacterial response to clinically relevant antibiotics and enhances the uptake of clarithromycin into bacterial cells, leading to increased efficacy. This work provides insights into the tolerance mechanisms of M. abscessus to transition metal toxicity and demonstrates the possibility of using transition metals to adjuvant the efficacy of currently using antimicrobials against M. abscessus infections.

Fabrication of kenaf fiber reinforced boron carbide fillers embedded epoxy matrix composite – An antimicrobial and structural analysis

This study investigates the incorporation of boron carbide (B4C) filler particulates into a kenaf fiber-reinforced epoxy matrix to explore its potential in lightweight applications, focusing on antimicrobial effectiveness, mechanical integrity, thermal properties, and microstructural characteristics. The composite material was formulated by blending varying seven different concentrations of boron carbide (0–50 g) and kenaf fibers (KFs) with an epoxy resin, aiming to achieve a balance between mechanical strength and minimal weight. Antimicrobial test revealed that the composite material, consisting of kenaf fiber reinforced with B4C particulates, exhibited significant antibacterial activity against common pathogens. Mechanical testing indicated that the addition of boron carbide and kenaf fibers significantly improved the tensile strength and flexural rigidity of the composites. Specifically, enhancements in tensile strength and flexural modulus were quantitatively analyzed, showing notable increases compared to the base epoxy resin. Scanning Electron Microscopy (SEM) was employed to examine the fracture surfaces following mechanical testing, revealing improved interfacial bonding between the kenaf fibers and the epoxy matrix due to the presence of boron carbide. This microscopic analysis also highlighted areas where stress distribution was optimized, contributing to the composite's enhanced mechanical properties.

Microbial Growth Inhibition Effect, Polyphenolic Profile, and Antioxidative Capacity of Plant Powders in Minced Pork and Beef

Consumer interest in healthier meat products has grown in recent years. Therefore, the use of plant powders as natural preservatives in the composition of pork and beef products could be an alternative to traditional meat products. This study aimed to assess the effect of different powders, such as blackcurrant, chokeberry, rowan berries, apple, tomato, garlic, and rhubarb, on the microbial growth dynamics in minced pork and beef during refrigerated storage. The total counts of aerobic microorganisms, Pseudomonas spp., yeasts, and molds were examined according to ISO methods. The polyphenolic profiles of plant powders and supplemented minced pork and beef samples were determined by HPLC-MS. The antioxidative capacity of the plant powders was analyzed using a spectrophotometric method. The findings of the study revealed that supplemented minced pork and beef samples had similar polyphenolic profiles and microbial growth dynamics. The highest antioxidative capacity was observed for anthocyanin-rich berry powders. In both minced pork and beef, rhubarb powder was the most effective plant material for inhibiting microbial growth, followed by blackcurrant pomace powder. In conclusion, all of the plant powders used in the present study can be used for the valorization of minced meat products, providing both antimicrobial and antioxidant effects.

The anti-inflammatory effect of a magnoliae cortex and Zea mays L. extract mixture in a canine model of ligature-induced periodontitis

BackgroundPeriodontitis is common in dogs. It is characterized by destruction of the supporting tissues of the teeth due to the host-immune response triggered by plaque. Magnoliae cortex and Zea mays L. extract showed anti-inflammatory and anti-microbial effects, respectively. This study aimed to evaluate improvement in periodontitis following the administration of Magnoliae cortex and Zea mays L. extract in dogs. Periodontitis was experimentally induced in 10 beagle dogs. Five dogs were administered 40 mg of Magnoliae cortex extract and 20 mg of Zea mays L. extract orally once per day for 2 months (MZ group), whereas the other group received empty gelatin capsules (control group). Periodontal clinical parameters, complete blood count, serum chemistry parameters, and tissue inflammatory cytokines and chemokine expression were assessed before and after combined oral extracts administration.ResultsThe complete blood count and serum chemistry results of all dogs were within normal ranges. Gingival inflammation in MZ group was significantly better than that in the control group at 4 and 8 weeks post-medication (PM; p < 0.05). The periodontal pocket depth and clinical attachment loss at 8 weeks PM in the MZ group were significantly lower than the baseline values (p < 0.05). The incidence of bleeding on probing in the MZ group was significantly lower than that in the control group at 4 weeks PM (p < 0.05). Throughout the medication period, the percentages of CD4 + and CD8 + T cells were higher and lower, respectively, in the MZ group. However, these differences were only significant at 8 weeks PM. The expression of the inflammatory cytokines IL-1β, IL-6, IL-17, and TNF-α and the chemokine IL-8 in the inflamed tissues was lower in the MZ group, and the two groups showed a significant difference in TNF-α expression.ConclusionsCombined administration of Magnoliae cortex and Zea mays L. extract improved the clinical symptoms of periodontal disease in dogs. This beneficial effect may be partly due to the inhibitory effects of these extracts on the inflammatory response.

Single acute and repeated subacute toxicity evaluations of Annona atemoya leaf extract with in vitro anti-inflammatory potential

The nutraceutical and biological potential of Annona atemoya, a fruiting plant, has been reported. We and others have demonstrated that A. atemoya leaf extract (AAL) has various pharmacological properties, such as antioxidant, antimicrobial, and neuroprotective effects. However, knowledge about the safety and potential toxicity of AAL remains limited. We aimed to assess the potential toxicity of AAL using acute and repeated subacute oral toxicity tests in rats. In both acute and repeated subacute toxicity test, no AAL-related behavioral abnormalities or changes in mortality, food intake, body weight were observed up to a dosage of 2000 mg/kg, indicating that the median lethal dose of AAL is higher than 2000 mg/kg. In subacute toxicity tests, no significant changes in hematological and biochemical parameters, urinalysis results, and histopathological variables were observed. Therefore, the no-observed-adverse-effect level (NOAEL) of orally administered AAL was estimated to be 2000 mg/kg/day in male and female rats. We also examined the effect of AAL on the inflammatory reaction in lipopolysaccharide (LPS)-stimulated BV-2 cells. AAL treatment significantly inhibited the LPS-stimulated increases in the levels of nitric oxide (NO) and inflammatory cytokines, implying that AAL has an anti-inflammatory effect. Quality control analysis revealed that two marker compounds, rutin and isoquercitrin, were present at 27.570 and 4.322 mg/g, respectively, in a freeze-dried AAL sample and were completely eluted within 27 min. The extraction recovery was 99.47–103.80%, and the precision was ≤2.79%. Overall, these findings suggest the safety, anti-inflammatory activity, and standardization of AAL.

Enhancing Antibacterial Efficacy: Synergistic Effects of Citrus aurantium Essential Oil Mixtures against Escherichia coli for Food Preservation

Essential oils (EOs) from various medicinal and aromatic plants are known for their diverse biological activities, including their antimicrobial effects. Citrus aurantium EO is traditionally used for therapeutic benefits due to its high content of bioactive compounds. Therefore, this study focuses on its potential use as a food preservative by investigating the combined antibacterial properties of EOs from leaves (EO1), flowers (EO2), and small branches (EO3) of Citrus aurantium against six bacterial strains by the agar disk diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) methods. The chemical compositions of the EOs were analysed by gas chromatography–mass spectrometry (GC-MS) and revealed the presence of numerous compounds responsible for their antimicrobial properties. The MIC values for the EOs were 3.12 mg/mL, 4.23 mg/mL, and 1.89 mg/mL, for EO1, EO2 and EO3, respectively, while the MBC values were 12.5 mg/mL, 6.25 mg/mL, and 6.25 mg/mL, respectively. A simplex centroid design was created to analyse the effect of the individual and combined EOs against E. coli. The combined EOs showed enhanced antibacterial activity compared to the individual oils, suggesting a synergistic effect (e.g., trial 9 with an MIC of 0.21 mg/mL), allowing the use of lower EO concentrations and reducing potential negative effects on food flavour and aroma. Additionally, the practical application of investigated EOs (at concentrations twice the MIC) was investigated in raw chicken meat stored at 4 °C for 21 days. The EOs, individually and in combination, effectively extended the shelf life of the meat by inhibiting bacterial growth (total bacterial count of less than 1 × 104 CFU/g in the treated samples compared to 7 × 107 CFU/g in the control on day 21 of storage). The study underlines the potential of C. aurantium EOs as natural preservatives that represent a sustainable and effective alternative to synthetic chemicals in food preservation.

An Overview of the Phytochemical and Therapeutic Potential of Wrightia Tinctoria

Introduction: Several natural phytomedicines derived from Chinese herbs demonstrate a wide range of pharmacological effects. Wrightia tinctoria (WT) is a small deciduous tree known as sweet indrajao. It belongs to the Apocynaceae family. Many diseases have been treated with this plant's phytoconstituents, such as skin disorders, dysenteric, diarrhea, and hair treatments. In addition, the therapeutic elements of WT demonstrate significant anti-inflammatory and anti-dandruff properties. However, there is a difference between this plant's preclinical and clinical significance. The purpose of this study is to collect and evaluate the various chemical, medicinal, and pharmacological characteristics of WT in relation to multiple disorders using preclinical evidence. This will serve as a valuable foundation for researchers to explore its effectiveness in clinical trials further. Materials and Methods: A comprehensive search was conducted across several databases, including PubMed, Web of Science, Scopus, Academic Journals Embase, Google Scholar, and Science Direct. The search utilized specific keywords such as "Wrightia tinctoria" as well as terms like "Traditional Chinese Medicine," "Pharmacological activities," "Anti-cancer," "Anti-viral," "Anti-microbial," "Anti-psoriatic," "Anti-Inflammatory," "Quercetin" and their combinations mainly from 1993 to 2024. Results: The pharmacological and therapeutic potential of WT is gathered and summarized based on existing research reports. WT substances consist of various phytoconstituents, including flavonoids, steroids, alkaloids, volatile oils, esters, and others. These components are primarily responsible for the various pharmacological effects of WT, such as anti-oxidant, anti-bacterial, antifungal, anti-diabetic, anti-cancer, anti-microbial, anti-inflammatory, and anti-ulcer effects. Conclusion: This review focuses on current research findings regarding WT's therapeutic potential and pharmacological activities. Additionally, it addresses the major safety and toxicity issues related to WT.

Biotransformation of Xanthohumol by Entomopathogenic Filamentous Fungi.

Xanthohumol (1) is a major prenylated flavonoid in hops (Humulus lupulus L.) which exhibits a broad spectrum of health-promoting and therapeutic activities, including anti-inflammatory, antioxidant, antimicrobial, and anticancer effects. However, due to its lipophilic nature, it is poorly soluble in water and barely absorbed from the gastrointestinal tract, which greatly limits its therapeutic potential. One method of increasing the solubility of active compounds is their conjugation to polar molecules, such as sugars. Sugar moiety introduced into the flavonoid molecule significantly increases polarity, which results in better water solubility and often leads to greater bioavailability. Entomopathogenic fungi are well known for their ability to catalyze O-glycosylation reactions. Therefore, we investigated the ability of selected entomopathogenic filamentous fungi to biotransform xanthohumol (1). As a result of the experiments, one aglycone (2) and five glycosides (3-7) were obtained. The obtained (2″E)-4″-hydroxyxanthohumol 4'-O-β-D-(4‴-O-methyl)-glucopyranoside (5) has never been described in the literature so far. Interestingly, in addition to the expected glycosylation reactions, the tested fungi also catalyzed chalcone-flavanone cyclization reactions, which demonstrates chalcone isomerase-like activity, an enzyme typically found in plants. All these findings undoubtedly indicate that entomopathogenic filamentous fungi are still an underexploited pool of novel enzymes.

Study on the mechanism of ROS-induced oxidative stress injury and the broad-spectrum antimicrobial performance of nickel ion-doped V6O13 powder

In this study, pure V6O13 and nickel ion-doped V6O13 powders were synthesized by a simple hydrothermal-calcination method, and their broad-spectrum antimicrobial properties and mechanisms were investigated. The crystal structure, morphology, and chemical state of the powders were thoroughly analyzed by XRD, SEM, TEM, XPS, and UV–Vis. Their antimicrobial properties and mechanisms were evaluated by the ring of inhibition, bio-SEM, live-dead cell staining, ROS detection, and protein leakage experiments. The results showed that nickel ion doping modulated the oxygen defects of V6O13, generating more reactive oxygen species and leading to more severe oxidative stress, resulting in a broad-spectrum and highly efficient antimicrobial effect. This study also revealed the antimicrobial mechanism based on oxygen defect -induced ROS production, which caused cellular oxidative stress damage, leading to leakage of intracellular substances and cell death. This study not only demonstrates the potential of V6O13 as an efficient antimicrobial agent but also provides a strong experimental basis and theoretical support for the engineering design and optimization of novel antimicrobial materials by modulating material defects through ion doping.

Honey Phytochemicals: Bioactive Agents With Therapeutic Potential for Dermatological Disorders.

Honey has been reported to have a range of biological activities including antimicrobial, immunomodulatory, and wound healing effects. Indeed, medical-grade honey is currently used in hospitals for the clinical management of wound infections. Honey is also of scientific interest for its therapeutic effects on other dermatological disorders such as atopic dermatitis, rosacea, and skin cancer. Recent studies have uncovered that honey contains a range of phytochemicals including flavonoids, dicarboxylic acids, coumarins, and phenolic acids. In this review, PubMed was used to search the scientific literature on the biological properties of honey phytochemicals in relation to dermatological disorders and to evaluate their potential as bioactive agents, drugs, or cosmeceuticals for the treatment of skin disease. The review revealed that phytochemicals found in honey have antimicrobial, anti-inflammatory, antiaging, antioxidant, anticancer, depigmenting, photoprotective, wound healing, and skin barrier enhancing properties. Although further high-quality studies are required to establish clinical efficacy, these findings suggest that honey phytochemicals may have the potential to be used as bioactive agents for the management of a range of dermatological disorders including wounds, psoriasis, atopic dermatitis, vitiligo, rosacea, and skin cancer.

Unveiling the inactivation mechanisms of different viruses in sludge anaerobic digestion based on factors identification and damage analysis

Despite anaerobic digestion having potential for pathogen reduction in sewage sludge, the behaviors of viruses as the primary health concern are rarely studied. This study investigated the inactivation kinetics and mechanisms of four typical virus surrogates with different structures in mesophilic (MAD) and thermophilic (TAD) anaerobic digestion of sludge. Virus inactivation in MAD was virus-type-dependent correspondingly to different function loss. Temperature drove the faster inactivation proceeding for enveloped Phi6, while temperature and ammonia were the critical inactivation factors for nonenveloped MS2, causing genome degradation and protein functional damage. Interaction with sludge solids played critical role in DNA viruses T4 and Phix174 inactivation via inducing host binding function damage. By comparison, TAD enhanced viral protein denaturation, bringing efficient inactivation with reducing heterogeneity among nonenveloped viruses. These insights into unique virus behaviors in anaerobic digestion systems can provide guidance for developing more effective disinfection protocols and improving sludge biosafety.

Antimicrobial, Optical, and Mechanical Properties of Saliva-Contaminated Silver–Zeolite Nanoparticle-Incorporated Dental Acrylic Resins

Background and Purpose: This study aimed to evaluate the flexural strength, color change and antimicrobial effect of silver–zeolite nanoparticles (NPs) in acrylic resin materials. Methods: Fifty-six disc-shaped acrylic resin samples were divided into four groups (n = 7) according to concentrations of silver–zeolite NPs (0%, 2%, 4%, 5%). Discs were contaminated with C. albicans and S. mutans. The antimicrobial effect was tested by inoculating contaminated discs on Tryptic soy agar (TSA), Sabouraud Dextrose Agar (SDA), Tryptic soy broth (TSB), and Sabouraud dextrose broth (SDB). Forty rectangular 65 × 10 × 2.5 mm acrylic resin specimens were also classified into four groups (n = 10) according to concentrations of silver–zeolite NPs. For the color change, L, a, and b values of rectangular specimens were examined with a spectrophotometer. A three-point bending test was also performed using a Devotrans device to determine the flexural bond strength of rectangular specimens. Scanning electron microscope analysis (SEM/EDX analysis) was also performed. Results: In this study, the antimicrobial effect increased with the concentration of silver–zeolite NPs added to acrylic resin discs. In our study, adding 2% silver–zeolite NPs was more effective against C. albicans. The antimicrobial effect against S. mutans increased with concentration of silver–zeolite NPs (&lt;0.001). The colonization of C. albicans was significantly reduced by silver–zeolite NPs. A significant increase was observed in the color change as the nanoparticle percentage ratio increased (p &lt; 0.001). The flexural strength values of the groups containing 2% and 4% nanoparticles were found to be clinically acceptable. Conclusions: The study showed that bacterial and fungal colonization is significantly reduced by adding silver–zeolite nanoparticles to acrylic resin discs. Based on its antimicrobial, physical, and mechanical properties, we recommend adding 2% silver–zeolite nanoparticles to the acrylic resin material for optimal results.

Synthesis, Spectral Characterization and Biological, DNA Binding, Molecular Docking and ADMET Studies of a New Benzyl (Z)-N’-((E)- 3-Ethoxy-2-Hydroxybenzylidene) Carbamohydrazonothioate and Its Co (II), Ni (II), Cu (II) and Zn (II) Metal Complexes Derived From S-Benzyl Thiosemicabazide-Salicylaldehyde.

This study presents the synthesis, characterization, and biological evaluation of metal complexes derived from benzyl carbamohydrazonothioate. The ligand was synthesized through a condensation reaction and subsequently complexed with various metal ions, including Cu(II), Ni(II), Co(II), and Zn(II). The resulting metal complexes were characterized using a range of spectroscopic techniques, including FT-IR, UV-Vis, and NMR spectroscopy, confirming the successful coordination of the metal ions with the ligand. The structural elucidation was further supported by elemental analysis and molar conductance measurements. The biological activities of the synthesized complexes were evaluated for their antibacterial, antifungal, and antioxidant properties. The results indicated that the metal complexes exhibited enhanced biological activities compared to the free ligand, suggesting their potential as effective antimicrobial and antioxidant agents. This study highlights the significance of metal complexation in enhancing the biological efficacy of organic ligands.

Assessment of some parameters of the chemical composition of Thymus kotschyanus Boiss. Growing in different ecological zones of the Republic of Armenia

Background: Thymus kotschyanus Boiss., commonly known as thyme, is a small semi-shrub valued for its aromatic and medicinal properties. Found throughout the Middle East and the Caucasus, it adapts to various ecological conditions and is rich in biologically active compounds, including essential oils, flavonoids, and phenolic acids. Its diverse chemical profile has made it a focus of pharmacological research for its antimicrobial, antioxidant, and anti-inflammatory effects, highlighting its potential therapeutic applications. Objective: The study aimed to investigate the bioactive compounds in wild T. kotschyanus Boiss. plants grown under diverse ecological conditions, with an emphasis on how these compounds change in response to varying environmental contexts. Materials and Methods: The chemical composition of Thymus kotschyanus Boiss. was investigated during its flowering phenophase. Aerial parts of plants were collected from the Tavush (40°880518N, 45°427958E) and Kotayk (40°17’56"N, 44°33’15"E) regions in Armenia between 2021 and 2023. The study focused on analyzing ash and moisture content, phytochemical screening, and mineral content. Results: The ethanolic extracts of Thymus kotschyanus Boiss from both regions contained a diverse array of bioactive compounds, including coumarins, flavonoids, alkaloids, tannins, phenols, carbohydrates, proteins, and saponins. Plants from the Tavush region exhibited a moisture content 1.83% higher than those from the Kotayk region, reflecting a 36.1% increase. Similarly, the ash content was 1.3% higher in Tavush plants, resulting in a 17.1% increase compared to Kotayk plants. Analysis of macro- and microminerals revealed that potassium was the most abundant macromineral, followed by calcium, magnesium, phosphorus, and sodium. Among the microminerals, iron had the highest concentration, followed by zinc and copper. Conclusion: The study demonstrated significant differences in the biologically active compounds, mineral composition, moisture, and ash content of T. kotschyanus Boiss. from different ecological zones in Armenia. Plants from the Tavush region exhibited higher moisture and ash content, as well as elevated levels of vitamins A and C, phenolic content, and essential minerals such as calcium, magnesium, sodium, potassium, and phosphorus, compared to those from the Kotayk region. These findings underscore the impact of environmental conditions on the quality and composition of T. kotschyanus Boiss., highlighting its potential as a valuable source of biologically active compounds and essential minerals. Keywords: aromatic plants, bioactive compounds, essential minerals, wild thyme, T. kotschyanus Boiss

The Antimicrobial Effect of the Incorporation of Inorganic Substances into Heat-Cured Denture Base Resins—A Systematic Review

The Antimicrobial Effect of the Incorporation of Inorganic Substances into Heat-Cured Denture Base Resins—A Systematic Review

Antibacterial and Healing Efficacy of Mangiferin-Loaded Silver Nanoparticle and Chitosan-Alginate Membrane Dressings

Mangiferin, a bioactive constituent of Mangifera indica (family Anacardiaceae), has an impressive therapeutic profile, having antioxidant, anti-inflammatory, analgesic, antibacterial, and immunomodulatory properties capable of possessing wound healing potential. Our investigation aims to isolate and characterize mangiferin, green synthesis of silver nanoparticles (Ag-NPs) and production of chitosan alginate (Cs/Alg) film dressing loaded with mangiferin Ag-NPs and assess antibacterial and wound-healing properties against infected excision and burn wounds. The isolated mangiferin was authenticated by estimating melting point, thin layer chromatography (TLC), fourier-transform infrared spectroscopy (FTIR), and high-performance liquid chromatography (HPLC). Ag-NPs were green synthesized and characterized by UV-visible, particle size, zeta potential (ZP), entrapment efficiency (%EE), scanning electron microscope (SEM), transmission electron microscope (TEM), and stability study. Chitosan alginate membrane dressing was prepared by incorporating mangiferin Ag-NPs, and film thickness, pH, film weight, water intake capacity, and in-vitro drug release parameters were estimated. Among the four mangiferin Ag-NP batches, MN3 formed stable polydispersity spherical Ag-NPs with smaller particle size and high %EE. Mangiferin-loaded Cs/Alg film MN-CM4 showed significantly higher (p &lt; 0.001) drug content, wettability, release profile, and favorable pH changes. The mangiferin Ag-NPs embedded Cs/Alg film dressing showed a significantly high antimicrobial effect against the gram-positive bacterial strain of S. aureus, commonly found in wounds. MN3 and MN-CM4 treatment showed the shortest epithelialization period and enhanced wound closure. The hydroxyproline content has significantly (p &lt; 0.001) increased, and myeloperoxidase content was reduced by MN3 and MN-CM4 treatment. MN-CM4 treatment showed complete re-epithelialization reduced inflammatory cells with thicker and denser collagen fiber deposition. The effectiveness of the Cs/Alg film of mangiferin Ag-NPs dressing has a synergistic effect on promoting speedy wound healing. The Cs/Alg film of mangiferin Ag-NPs showed rapid wound healing against infected and burned wounds, enhanced collagen synthesis, and anti-inflammatory and antibacterial efficacy.

Oxygen vacancy-dependent synergistic disinfection of antibiotic-resistant bacteria by BiOBr nanoflower induced H2O2 activation

Antibiotic-resistant bacteria (ARB) and antibiotic-resistant genes (ARGs) pose a significant threat to both ecosystems and human health. Owing to the excellent catalytic activity, eco-safety, and convenience for defect engineering, BiOBr with oxygen vacancies (OVs) of different density thus were fabricated and employed to activate H2O2 for ARB disinfection/ARGs degradation in present study. We found that BiOBr with OVs of appropriate density induced via ethanol reduction (BOB-E) could effectively activate H2O2, achieving excellent ARB disinfection and ARGs degradation efficiency. Moreover, this disinfection system exhibited remarkable tolerance to complex water environments and actual water conditions. In-situ characterization and theoretical calculations revealed that OVs in BOB-E could effectively capture and activate aqueous H2O2 into HO· and O2·−. The generated reactive oxygen species combined with electron transfer could damage the cell membrane system and degrade genetic materials of ARB, leading to effective disinfection. The impressive reusability, high performance achieved in two immobilized reaction systems (packed column and baffled ditch reactor), excellent degradation of emerging organic pollutants supported the feasibility of BOB-E/H2O2 system towards practical water decontamination. Overall, this study not only provides insights into fabrication of bismuth-based catalysts for efficient ARB disinfection/ARGs degradation via OVs regulation, but also paves the way for their practical applications.

Decontamination Potential of Ultraviolet Type C Radiation in Water Treatment Systems: Targeting Microbial Inactivation

Access to safe water and sanitation is a critical global challenge, posing significant health risks worldwide due to waterborne diseases. This study investigates the efficacy of ultraviolet type C radiation as a disinfection method for improving water quality. The research elucidates UV-C’s mechanism of action, highlighting its ability to disrupt DNA and RNA replication, thereby inactivating pathogens. Furthermore, the study analyses the influence of key factors on UV-C disinfection effectiveness, including water turbidity and the presence of dissolved organic matter, which can attenuate UV-C penetration and reduce treatment efficiency. The experimental results demonstrate a substantial reduction in microbial content following UV-C treatment. River water samples exhibited a 57.143% reduction in microbial load, while well water samples showed a 50% reduction. Notably, Escherichia coli (E. coli) concentrations decreased significantly, with an 83.33% reduction in well water and a 62.5% reduction in borehole water. This study makes a novel contribution to the understanding of UV-C disinfection by identifying the presence of resistant organisms, including Adenoviruses, Bacterial spores, and the Protozoan Acanthamoeba, in water samples. This finding expands the scope of UV-C research beyond easily culturable bacteria. To address this challenge, future investigations should explore synergistic disinfection strategies, such as combining UV-C treatment with advanced oxidation processes. Optimising UV-C system designs and developing robust, real-time monitoring systems capable of detecting and quantifying known and emerging UV-resistant pathogens are crucial for ensuring comprehensive water decontamination.