Antimicrobial Protection Research Articles

Effects of lipopolysaccharide-induced inflammation on hypoxia and inflammatory gene expression pathways of the rat testis

BackgroundBacterial infection and inflammation of the testis impairs fertility, yet an understanding of inflammatory responses of the testis is incomplete. We are interested in identifying gene pathways involved in the detection and clearance of infectious microbes in the male reproductive tract. In previous studies in our lab focused on hypoxia-responsive genes of the testis, preliminary experiments suggested that genes classically categorized as hypoxia genes are also activated during antimicrobial responses. The purpose of this study was to identify hypoxia and inflammatory gene pathways that contribute to antimicrobial protection of the testis and to consider possible cross-talk and interactions between these pathways. Inflammation was induced in Sprague-Dawley rats using P. aeruginosa or E. coli lipopolysaccharide (LPS). Levels of hypoxia-inducible factor-1 (HIF-1α) protein and nuclear factor kappa B (NF-κB) were measured, and hypoxia and inflammatory gene expression patterns in testis were analyzed by gene expression profiling using real-time quantitative PCR arrays.ResultsIn LPS-treated rats, HIF-1α protein increased with no change in Hif-1α mRNA. Western Blot analysis also demonstrated no change in NF-κB and inhibitory NFKB alpha (IκBα) protein levels following LPS treatment. Five hypoxia pathway genes (Angptl4, Egr1, Ier3, Pai1, and Glut1), and 11 inflammatory pathway genes (Ccl12, Cc13, Cd14, Cxcl10, Icam1, Il10, Il1b, Il6, Nfkbia, Tlr2, Tnf) up-regulated after 3 h of inflammation. Angptl4, Ccl12, Cc13, Cd14, Egr1, Nfkbia, Tlr2, and Tnf remained elevated at 6 h. Six genes were up-regulated at 6 h only (Bhlhe40, C3, Jak2, Nlrp3, Slc11a1, Tlr1). One gene (Tlr5) was down-regulated after 3 h and no genes at 6 h. Electrophoretic mobility shift assay results suggest a decrease in NF-κB binding activity following LPS treatment.ConclusionsTesticular HIF-1α is up-regulated following LPS-induced inflammation. In contrast to other tissues, in which HIF-1α is up-regulated through transcriptional activation via NF-κB, we conclude that HIF-1α in the testis is not up-regulated through an increase in Hif-1α mRNA or through NF-κB-dependent mechanisms. Hypoxia pathway genes and genes involved in Toll-like receptor (TLR) and cytokine-mediated signaling comprise major functional categories of up-regulated genes, demonstrating that both hypoxia and classic inflammatory pathways are involved in inflammatory responses of the testis.

Enhancement of agricultural produce quality and storability using citral-based edible coatings; the valuable effect of nano-emulsification in a solid-state delivery on fresh-cut melons model.

Emulsification approach is widely employed to deliver beneficial agents to liquid food products, whereas utilizing emulsions with solid food is scarce. In this research, coarse and nano emulsions of citral were prepared and embedded in chitosan or carboxymethyl cellulose (CMC) polysaccharides to form active edible coatings for solid-state delivery. Polysaccharides stabilized the emulsions by electrostatic interactions, while chitosan also prevented coalescence. The nano emulsion based films showed a more organized and dense morphology (E-SEM), higher water vapor barrier, better mechanical features (strength, elasticity and Young modulus) than the coarse ones. When applied on a solid food model, fresh-cut melons, the nanoemulsified edible coatings demonstrated a superior antimicrobial protection (up to a 5-log reduction) and significantly extended product's storability (up to 13 days). The presented approach could be further employed for the delivery of other beneficial agents (nutrients, aroma, antimicrobial, antioxidants) to solid food products, contributing a general progress in this field.

Hydrothermal growing of cluster-like ZnO nanoparticles without crystal seeding on PET films via dopamine anchor

Growing of ZnO nanoparticles on PET films without crystal seeding has been achieved by employing polydopamine as the anchor. The PDA layer was formed on the surface of PET film by the polymerization of dopamine. The PDA-PET was dipped into zinc precursors for hydrothermal growth of ZnO nanoparticles. Cluster-like ZnO nanoparticles were obtained and the special structure was affected by the growing time and zinc ion concentration. The surface morphology, structure and properties were characterized, and the functions including antimicrobial activity and UV protection of the ZnO-coated PET film were investigated. The developed facile hydrothermal approach without seeding will benefit the development of UV resistant and antimicrobial PET films.

The antimicrobial protection hypothesis of Alzheimer's disease

ObjectiveWe explore here a novel model for amyloidogenesis in Alzheimer's disease (AD). This new perspective on AD amyloidosis seeks to provide a rational framework for incorporating recent and seemingly independent findings on the antimicrobial role of β-amyloid and emerging experimental, genetic, and epidemiological data, suggesting innate immune-mediated inflammation propagates AD neurodegeneration. BackgroundAD pathology is characterized by cerebral deposition of amyloid-β protein (Aβ) as β-amyloid. Genetic studies have confirmed the key role of Aβ in AD, revealing that mutation-mediated shifts in the peptides generation lead to early onset familial Alzheimer's disease. However, Aβ generation appears normal for the majority of AD patients, who lack early onset familial Alzheimer's disease mutations. In prevailing models of nonfamilial AD, individual genetics and age-associated changes in brain milieu promote an intrinsically abnormal propensity of Aβ for self-association. However, emerging findings are increasingly inconsistent with characterization of Aβ oligomerization as a nonphysiological and exclusively pathological activity. Recent studies suggest Aβ is an ancient, highly conserved effector molecule of innate immunity. Moreover, Aβ oligomerization and β-amyloid generation appear to be important innate immune pathways that mediate pathogen entrapment and protect against infection. New AD amyloidogenesis modelRecent findings on inflammation-mediated neurodegeneration and the role of Aβ in immunity have led to emergence of the “Antimicrobial Protection Hypothesis” of AD. In this model, β-amyloid deposition is an early innate immune response to genuine, or mistakenly perceived, immunochallenge. Aβ first entraps and neutralizes invading pathogens in β-amyloid. Aβ fibrillization drives neuroinflammatory pathways that help fight the infection and clear β-amyloid/pathogen deposits. In AD, chronic activation of this pathway leads to sustained inflammation and neurodegeneration. Mounting data link elevated brain microbe levels with AD. The Antimicrobial Protection Hypothesis reveals how increased brain microbial burden may directly exacerbate β-amyloid deposition, inflammation, and AD progression. Amyloid cascade hypothesisIn the antimicrobial protection model, the modality of Aβ's pathophysiology is shifted from abnormal stochastic behavior toward dysregulated innate immune response. However, β-amyloid deposition in AD still leads to neurodegeneration. Thus, the new model extends but remains broadly consistent with the Amyloid Cascade Hypothesis and overwhelming data showing the primacy of Aβ in AD pathology.

OR-050 The Development of a Protein Powder Product with an integrated solution for Active Population

Objective Sports nutrition is expanding from professional athletes to a broader spectrum of consumers focused on fitness and improving overall wellness. The recommendation of combining exercise and healthy diet has been highlighted by Health China 2030 and National Nutrition Planning, leading to increased embrace of active lifestyle among Chinese people. Along with the increasing involvement in sports comes with concerns on decreasing resting metabolic rate due to weight loss, impaired joint health and post-exercise immunological response. To confront the above-mentioned challenges, we aimed to develop a product with an integrated solution to support fitness goals while diminishing exercise-related concerns.
 Methods Literature review was conducted for core ingredient screen, followed by in vitro studies to substantiate and compare efficacy of ingredients from various resources. Muscle protein synthesis was measured in myotubes during the differentiation and fusion of C2C12 myocytes. Myotube fusion density was quantified by ImageJ, an image processing program, subsequent to myotube staining.
 Results Muscle mass gain enhances resting metabolic rate. It has been shown that whey protein supplementation at 20 g/d significantly increased lean muscle synthesis rate in post-exercise subjects. The efficacy of whey protein powder sourced from different resources were compared by conducting in vitro studies. A large body of evidence has shown that collagen peptide supplementation can mitigate joint pain and maintain joint health in athletic population. Yeast β-glucan was spotlighted as an immunity enhancer with antimicrobial protection and benefit in minimizing post-exercise immunosuppression. 
 Conclusions A protein powder containing over 20 g/serving whey protein, combining with collagen peptide and yeast β-glucan may convey beneficial effects in muscle synthesis, as well as protective effects against joint pain and post-exercise immunosuppression among active population. The combination of the above-mentioned ingredients could provide a well-round solution to confront the challenges that met by most active population.

EVALUATION OF CARIOGENIC SITUATION IN CHILDREN WITH TYPE 1 DIABETES MELLITUS GIVEN THE MINERALIZING POTENTIAL OF SALIVA AND ENAMEL RESISTANCE

Aim.This study was conducted to evaluate the caries resistance of hard tooh tissues and the state of the calcium and phosphorus metabolism in children with type 1 diabetes mellitus given the mineralizing potential of saliva and antimicrobial protection of the oral cavity.Materials and methods. There was conducted a general clinical, dental, laboratory examination of 127 children with type 1 diabetes mellitus aged 7 to 12 years with the endocrinopathy experience from eight months to ten years. The obtained data were compared with the results of the examination of 37 "healthy" and "practically healthy" children of this age category. When assessing the dental status of children, were used the hygienic index (Y.A. Fedorov, V.V. Volodkina, 1970), the CFE/ cf index (WHO Expert Committee, 1962), the simplified hygienic index OHI-S (Green, Vermillion, 1964). The intensity of the enamel demineralization processes was assessed using the enamel resistance test (V.R. Okushko, L.I. Kosavera, 1984) and vital staining (L.A. Aksamit, 1978). The electrometry of hard tooth tissues was carried out by the electrodiagnostic apparatus "Dent Est" (V.K. Leontiev, G.G. Ivanova, 1985).The laboratory diagnostics of the salivary indicators included the study of calcium (total, ionized), inorganic phosphorus, alkaline phosphatase, osteocalcin, parathyroid hormone, 25-hydroxyvitamin D3, lactoferrin. The microcrystallization and mineralizing potential of saliva were determined according to Leus P.A. (1997).Results.At the early stages of type 1 diabetes mellitus development children have a compensated and subcompensated form of the carious process, the increase in the enamel permeability, a slight predominance of the demineralization processes over the remineralization processes in solid tooth tissues. It indicates that self-regulation of the mineral metabolism mechanisms takes place while maintaining the physiological remineralizing properties of saliva. At a late stage of type 1 diabetes mellitus development a high intensity and decompensated form of the carious lesions are established as well as low structural and functional enamel resistance and pronounced processes of hard tooth tissues demineralization. The emergence of this complex in children with the experience of endocrinopathy for more than five years indicates the depletion of salivary gland functionality, the disturbance of mobilization salivary systems in response to the occurrence of the cariogenic situation in the oral cavity, the change in calcium homeostasis, the decrease in enamel resistance to organic acids and the absence of saliva crystallization.Conclusion.The growing positive dynamics of index growth in children with long-term type 1 diabetes mellitus, indicating the deterioration of the dental status, requires adherence to the principles of rational nutrition, quarterly professional caries preventive measures using modern and effective oral care products, the introduction of active forms of hygienic training and education taking into account the mineralizing potential of saliva as well as careful monitoring of the acquired manual skills.

Drug-Loaded Halloysite Nanotube-Reinforced Electrospun Alginate-Based Nanofibrous Scaffolds with Sustained Antimicrobial Protection.

Halloysite nanotube (HNT)-reinforced alginate-based nanofibrous scaffolds were successfully fabricated by electrospinning to mimic the natural extracellular matrix (ECM) structure which is beneficial for tissue regeneration. An antiseptic drug, cephalexin (CEF)-loaded HNT, was incorporated into the alginate-based matrix to obtain sustained antimicrobial protection and robust mechanical properties, the key criteria for tissue engineering applications. Electron microscopic imaging and drug release studies revealed that CEF had penetrated into the lumen space of the HNT and also deposited on the outer walls, with a total loading capacity of 30 wt %. Moreover, the diameter of alginate-based nanofibers of the scaffolds ranged from 40 to 522 nm with well-aligned HNTs, resulting in superior mechanical properties. For instance, the addition of 5% (w/w) HNT improved the tensile strength (σ) and elastic modulus by 3-fold and 2-fold, respectively, compared to those of the alginate-based scaffolds without HNT. The fabricated scaffolds exhibited remarkable antimicrobial properties against both Gram-negative and Gram-positive bacteria, and the cytotoxicity studies confirmed the nontoxicity of the fabricated scaffolds. Drug release kinetics showed that CEF inside HNTs diffuses within 24 h and that the diffusion of the drug is delayed by 7 days once the CEF-loaded HNTs are incorporated into the alginate-based nanofibers. These fabricated alginate-based electrospun scaffolds with enhanced mechanical properties and sustained antimicrobial protection hold great potential to be used as artificial ECM scaffolds for tissue engineering applications.

Self-assembling antimicrobial peptides on nanotubular titanium surfaces coated with calcium phosphate for local therapy

Bacterial infection is a serious medical problem leading to implant failure. The current antibiotic based therapies rise concerns due to bacterial resistance. The family of antimicrobial peptides (AMP) is one of the promising candidates as local therapy agents due to their broad-spectrum activity. Despite AMPs receive increasing attention to treat infection, their effective delivery to the implantation site has been limited. Here, we developed an engineered dual functional peptide which delivers AMP as a biomolecular therapeutic agent onto calcium phosphate (Ca-P) deposited nanotubular titanium surfaces. Dual functionality of the peptide was achieved by combining a hydroxyapatite binding peptide-1 (HABP1) with an AMP using a flexible linker. HABP functionality of the peptide provided a self-coating property onto the nano-topographies that are designed to improve osteointegration capability, while AMP offered an antimicrobial protection onto the implant surface. We successfully deposited calcium phosphate minerals on nanotubular titanium oxide surface using pulse electrochemical deposition (PECD) and characterized the minerals by XRD, FT-IR, FE-SEM. Antimicrobial activity of the engineered peptide was tested against S. mutans (gram- positive) and E. coli (gram-negative) both in solution and on the Ca-P coated nanotubular titanium surface. In solution activity of AMP and dual functional peptide have the same Minimum Inhibitory Concentration (MIC) (32 mg/mL). The peptide also resulted in the reduction of the number of bacteria both for E.coli and S. mutans compare to control groups on the surface. Antimicrobial features of dual functional peptides are strongly correlated with their structures suggesting tunability in design through linkers regions. The dual-function peptide offers single-step solution for implant surface functionalization that could be applicable to any implant surface having different topographies.

THE ROLE OF ARGININE DEIMINASE FROM STREPTOCOCCUS PYOGENES IN INHIBITION MACROPHAGES NITROGEN MONOXIDE (NO) SYNTHESIS

The protective role of macrophages closely related to the production of bactericidal molecules, in which nitrogen monoxide (NO) play an important role. Arginine serves as a substrate for inducible NO synthase (iNOS) in course of NO production. Expression and activity of iNOS are regulated by the availability of the substrate (arginine) in the intercellular space. The bacterial enzyme arginine deiminase also uses arginine as a substrate, causing its deficiency for host cells. The aim of this study was to confirm the possible role of arginine deiminase from S. pyogenes in inhibiting NO synthesis by macrophages. For this purpose, a comparative study was made of the effect on the synthesis of NO by macrophages of the products of destruction of two strains: the initial S. pyogenes M49-16 and the isogenic mutant S. pyogenes M49-16 delArcA with the inactivated arginine deiminase gene (arcA). It has been shown that the ability of S. pyogenes M49-16 to inhibit production of NO by macrophages depends on its arginine deiminase activity because the isogenous mutant of S. pyogenes M49-16 delArcA with the inactivated gene arcA has lost its ability to inhibit NO synthesis. This allows us to consider the effects of S. pyogenes M49-16 as effects of arginine deiminase. An analysis of the inhibitory mechanisms of the enzyme showed that suppression of NO synthesis was not associated with the effect of destruction products of S. pyogenes M49-16 on the viability of macrophages. According to data of flow cytometry, incubation of cells in the presence of S. pyogenes destruction products of the original and mutant strains did not affect the level of iNOS expression, i.e. did not alter synthesis or stability of this enzyme. At the same time, the decrease in NO production under the influence of the original S. pyogenes strain M49-16 correlated with a decrease in the content of arginine in the culture medium. When exogenous arginine to the culture medium was added, the effect of the original strain of the suppression of NO production was declined. This confirms that the depletion of arginine is the main mechanism of the inhibitory effect of arginine deiminase on the production of NO by macrophages. The deficiency of NO production in the course of streptococcal infection can lead to a weakening of bactericidal activity of macrophages and to a decrease in the effectiveness of antimicrobial protection.

CERVICAL MUCUS NEUTROPHILS FUNCTIONAL STATUS INTERACTION WITH THE SPECIES COMPOSITION OF VAGINAL LACTOBACILLI IN PREGNANT WOMEN

Aim. Of the study is to assess cervical mucus neutrophils functional status depend on dominant lactobacillus strain in I trimester of pregnancy women. Material and methods. We definded 40 lactobacillus strains obtained from the genital tract of the pregnant women. We used mass spectrometry analysis to identify vaginal lactobacilli and evaluated biofilm formation. Also, we studied cervical mucus neutrophils viability, lysosomal activity, spontaneous and induced NBT test (Nitroblue Tetrazolium test), ability to absorb the latex particles. Isolated strains were divided into 3 groups depending on presence or absence of vaginal or cervical channel infectious diseases. Results. We identified 5 lactobacilli types: L. jensenii, L. mspatus, L. аcidophilus, L. gasseri, L. delbrueckii among 40 definded strains. We determined different intensity of phagocytosis depending on dominant strain in normocenosis. With the L. crispatus prevalence demonstrated the least intensity of phagocytosis compared with L. acidophilus and L.jensenii. Lactobacilli able to intensively produce biomatrix in condition of genital infection. Thus blocking antigenic potential and result in absence of NBT-reducing power of neutrophilic granulocytes and reduction antimicrobial protection of pregnant women genital tract mucosa. Conclusion. The indicators of neutrophils functional status depend on dominant lactobacilli strain in I trimester of pregnancy women.

UV protection and antimicrobial finish on cotton khadi fabric using a mixture of nanoparticles of zinc oxide and poly-hydroxy-amino methyl silicone

A different percentage of nanoparticles of zinc oxide dispersed in a newer amino-silicone binder (poly-hydroxy-amino methyl silicone) were applied to bleached cotton khadi (handloom woven from handspun yarns) fabric to impart both ultraviolet protection and an antimicrobial finish in one step using the pad-dry-cure method, instead of using two processes for two different finishes. Amongst the varying dosages of nanoparticles of zinc oxide (1% to 5%) on the weight of fabric dispersed in poly-hydroxy-amino methyl silicone (2–10%) owf, 1% nanoparticles of zinc oxide and 4% poly-hydroxy-amino methyl silicone show ultraviolet protection factor 10 and 93–95% antibacterial reduction, whereas a 4% poly-hydroxy-amino methyl silicone and 5% nanoparticles of zinc oxide combination yields ultraviolet protection factor 20 and 99% antibacterial reduction. Thus, nanoparticles of zinc oxide at the level of 5% application with 4% poly-hydroxy-amino methyl silicone gives the best antimicrobial (99% bacterial reduction) and ultraviolet protection factor value of 20, balanced with 15–20% loss of fabric tenacity. Fourier transform infrared spectroscopy analysis reveals a complex formation between cellulose/oxy-cellulose and poly-hydroxy-amino methyl silicone that embeds nanoparticles of zinc oxide within it. Supporting reaction mechanisms proposed for both energy dispersive spectroscopy and atomic absorption spectrophotometry results further confirm the presence of zinc, potassium, and silicon on the treated cotton fabric. A wash stability test also shows the stability of the antimicrobial treatment for up to five wash cycles with 96% bacterial reduction and retention of ultraviolet protection factor of 15 after five washes. Thus, this single step combining ultraviolet protective and antimicrobial finishing of cotton fabric may be used for eco-fashion garments to protect the human skin from ultraviolet light and microbes alongside its possible uses in medical textiles to protect human body parts.

De novo characterization of Phenacoccus solenopsis transcriptome and analysis of gene expression profiling during development and hormone biosynthesis

The cotton mealybug Phenacoccus solenopsis is a devastating pest of cotton causing tremendous loss in the yield of crops each year. Widespread physiological and biological studies on P. solenopsis have been carried out, but the lack of genetic information has constrained our understanding of the molecular mechanisms behind its growth and development. To understand and characterize the different developmental stages, RNA-Seq platform was used to execute de-novo transcriptome assembly and differential gene expression profiling for the eggs, first, second, third instar and adult female stages. About 182.67 million reads were assembled into 93,781 unigenes with an average length of 871.4 bp and an N50 length of 1899 bp. These unigenes sequences were annotated and classified by performing NCBI non-redundant (Nr) database, Kyoto Encyclopedia of Genes and Genomes (KEGG) and Clusters of Orthologous Groups (COG), Gene ontology (GO), the Swiss-Prot protein database (Swiss-Prot), and nearest related organism Acyrthosiphon pisum (pea aphid) database. To get more information regarding the process of metamorphosis, we performed a pairwise comparison of four developmental stages and obtained 29,415 differentially expressed genes. Some of the differentially expressed genes were associated with functional protein synthesis, anti-microbial protection, development and hormone biosynthesis. Functional pathway enrichment analysis of differentially expressed genes showed the positive correlation with specific physiological activities of each stage, and these results were confirmed by qRT-PCR experiments. This study gives a valuable genomics resource of P. solenopsis covering all its developmental stages and will promote future studies on biological processes at the molecular level.

Growing ZnO Nanoparticles on Polydopamine-Templated Cotton Fabrics for Durable Antimicrobial Activity and UV Protection.

This work aims to develop durable functional cotton fabrics by growing zinc oxide (ZnO) nanoparticles on polydopamine (PDA) templates. ZnO nanoparticles were grown on the PDA-templated cotton fabrics by the hydrothermal method at room temperature. The surface morphology, chemical composition, and crystalline structure of the ZnO-coated cotton fabrics were characterized by scanning electron microscope (SEM) with energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The ZnO nanoparticles were found to disperse evenly on the surface of cotton fabrics. The ultraviolet (UV) protection factor (UPF) value of the ZnO-coated cotton fabrics was maintained at 122.5, and 99% reduction in bacterial load was observed against Gluconobacter cerinus even after five cycles of laundering. The PDA was found to be effective in fixing the ZnO seeds tightly on the surface of cotton fabrics, resulting in excellent durability of the coating of ZnO nanoparticles.

Anticancer, antimicrobial, and DNA protection analysis of novel 2,4-dihydroxyquinoline dyes

A new series of 2,4-dihydroxyquinoline derived disazo dyes has been synthesized by the reaction of 5-amino-4-phenylazo-3-methyl-1H-pyrazole derivatives with 2,4-dihydroxyquinoline. The structures of the obtained dyes were identified by various spectrophotometric methods such as FT-IR, 1H-NMR, and elemental analysis. The synthesized compounds were also examined for different biological activities, including DNA protection, antimicrobial, and anticancer activities. Compound 3b was found most effective on Gram-positive bacteria. A DNA protection assay was applied to all compounds, and it was found that compounds 3h and 3j had a high capacity for binding to DNA. Besides, compounds 3h and 3j showed cytotoxicity against HeLa and PC3 cancer cell lines. These compounds could potentially be used as drugs or drug additives based on their effects on bacterial and cancer cell lines.

Hydrating cleansing: efficacy and tolerability of new formulations with hyaluronic acid 0.2% for intimate hygiene in the woman in fertile age and menopause

Dehydration of genital areas, known as vaginal dryness, frequently affects woman's life, from fertile to postmenopausal period, and must be treated with specific products, including proper intimate cleansing. Based on that, two new cleanser formulations, characterized by Hyaluronic Acid 0.2% as main ingredient, have been developed (Hyalo Gyn® Intimo Active and Hyalo Gyn® Intimo Advance), with the aim to provide an effective hydration of the vaginal, vulvar, perianal and anal areas beyond guaranteeing daily intimate hygiene. The two intimate cleansing mousses have been formulated in mousse and differentiated, in terms of ingredients, accordingly to the different physiological conditions and female needs of fertile age and menopause respectively. Clinical trials conducted on women of childbearing age and menopause showed that daily cleansing with these intimate washes promotes hydration of vaginal tissues thanks to the presence of hyaluronic acid. In particular, the cleansing mousse for fertile women gives also a soothing effect, offers antimicrobial protection and a long lasting feeling of freshness. The cleansing mousse for menopausal women provides a freshness sensation, improves elasticity and tonicity and exerts an anti-smell and anti-oxidative effect.

EPD of Novel Nanostructured Silica Coatings: Processing and Applications

Specific designed silver-doped glazes have already been used for antimicrobial coating applications in ceramic consumer oriented industry; however, comprehensive use of silver-based agents in ceramic glazes presents issues of clouding, crazing, discoloration, and other undesirable consequences to the glaze aesthetics as well as severe cost problems. Accordingly, there is a need for low-cost and high quality glazes and coatings that offer persistent built-in antimicrobial protection. Here we show that electrophoretic deposition, based on membrane templating, may answer these requests of realization of micro-topological design of glazings, while offering at the same time a wide library of available antimicrobial efficient nanomaterials to be incorporated into the micro-structured glazes. As consequence, these coatings are particularly suited for applications where interaction with pathogens in liquid solutions or gas-phase atmospheres has to be favoured. Strategies on the integration of microstructured coatings into devices with applicative purposes in consumer ceramics and sanitary ware products, are presented.

Antibacterial activity of male and female sperm-storage organs in ants.

Bacteria can damage sperm and thus reduce the reproductive success of both males and females; selection should therefore favour the evolution of antimicrobial protection. Eusocial hymenopterans might be particularly affected by such bacterial infections because of their mating ecology. In both sexes, mating is restricted to a short window early in the adult stage; there are no further chances to mate later in life. Males die shortly after mating, but queens use the acquired sperm to fertilise their eggs for years, sometimes decades. The reproductive success of both sexes is, thus, ultimately sperm-limited, which maintains strong selection for high sperm viability before and after storage. We tested the antibacterial activity of the contents of the male and female sperm-storage organs - the accessory testes and the spermatheca, respectively. As our study species, we used the bacterium Escherichia coli and the garden ant Lasius niger, whose queens can live for several decades. Our results provide the first empirical evidence that male and female sperm-storage organs display different antibacterial activity. While the contents of the accessory testes actually enhanced bacterial growth, the contents of the spermatheca strongly inhibited it. Furthermore, mating appears to activate the general immune system in queens. However, antimicrobial activity in both the spermatheca and the control tissue (head-thorax homogenate) declined rapidly post-mating, consistent with a trade-off between immunity and reproduction. Overall, this study suggests that ejaculates undergo an immune 'flush' at the time of mating, allowing storage of sperm cells free of bacteria.

Antimicrobial activity of American cranberry extract in the antimicrobial protection of minced pork meat

The aim of the study was to determine the content of bioactive ingredients in the American cranberry extracts (Vaccinium macrocarpon), the antimicrobial activity of these extracts and the efficiency of the selected extract in minced pork meat together with its sensory evaluation. Three extracts were made: aqueous (w-FACE), ethanol (e-FACE) and aqueous-ethanol (we-FACE). The content of bioactive components was tested by HPLC. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were determined against ten Gram-negative bacteria strains and six Gram-positive bacterial strains by serial macrodilution method. Minced pork meat with or without addition of 2.5% w-FACE was inoculated with four pathogenic strains (Escherichia coli, Salmonella Enteritidis, Listeria monocytogenes and Staphylococcus aureus) and stored at 4°C for 6 days. In 0, 2, 4 and 6 day, the number of bacteria was determined by plate method. Sensory evaluation of meat samples with and without in-FACE included general appearance and smell. All extracts contained organic acids (p-coumarin, benzoic, chlorogenic and coffee) and flavone (quercetin, miristin, epicatechin and isorhamnetin). E-FACE also contains ursolic acid. The MIC/MBC values of the extracts were in the range of 1.56-6.25 (3.13-25.0) mg/ml against Gram-positive bacteria and 6.25-12.5 (6.25-25.0) mg/ml against Gram-negative bacteria. Statistically significant (p ≤ 0.05) inhibition of growth of all pathogens in minced pork meat containing in-FACE was found. The 2.5% w-FACE had no significant effect (p ≤ 0.05) on the initial sensory characteristics of minced pork meat and after 4 and 6 days of storage was significantly higher than that of FACE-free meat. The results of the study suggest the possibility of using an aqueous extract of cranberry fruit as a natural preservative of minced pork meat..

Mesoporous Silica and Organosilica Nanoparticles: Physical Chemistry, Biosafety, Delivery Strategies, and Biomedical Applications.

Predetermining the physico-chemical properties, biosafety, and stimuli-responsiveness of nanomaterials in biological environments is essential for safe and effective biomedical applications. At the forefront of biomedical research, mesoporous silica nanoparticles and mesoporous organosilica nanoparticles are increasingly investigated to predict their biological outcome by materials design. In this review, it is first chronicled that how the nanomaterial design of pure silica, partially hybridized organosilica, and fully hybridized organosilica (periodic mesoporous organosilicas) governs not only the physico-chemical properties but also the biosafety of the nanoparticles. The impact of the hybridization on the biocompatibility, protein corona, biodistribution, biodegradability, and clearance of the silica-based particles is described. Then, the influence of the surface engineering, the framework hybridization, as well as the morphology of the particles, on the ability to load and controllably deliver drugs under internal biological stimuli (e.g., pH, redox, enzymes) and external noninvasive stimuli (e.g., light, magnetic, ultrasound) are presented. To conclude, trends in the biomedical applications of silica and organosilica nanovectors are delineated, such as unconventional bioimaging techniques, large cargo delivery, combination therapy, gaseous molecule delivery, antimicrobial protection, and Alzheimer's disease therapy.

Antimicrobial protection of minced pork meat with the use of Swamp Cranberry (Vaccinium oxycoccos L.) fruit and pomace extracts.

The objective of the study was to determine the antimicrobial activity of Swamp Cranberry (Vaccinium oxycoccos) fruit and pomace extracts (FSCE and PSCE) and their efficiency in minced pork meat. Ethanol (96 and 40%) and water were used for raw material extraction. Organic acids, flavonols, terpenes and stilbenes composition of the extracts was determined using HPLC. Minimal inhibitory concentration and minimum bactericidal/fungicidal concentration were determined for bacteria and fungi strains using the broth macrodilution method. The growth inhibition of Staphylococcus aureus, Listeria monocytogenes, Salmonella Enteritidis, and Escherichia coli in inoculated fresh minced pork meat containing 2.5% we-PSCE or we-FSCE (prepared by using 40% ethanol) were evaluated within 6days of refrigeration storage. Swamp Cranberry pomace extracts contained stilbenes and more organics acids and flavonols than fruit extracts. Extracts inhibited Gram-positive bacteria strains stronger than Gram-negative, regardless of used raw material. The extracts did not show antifungal activity. Water-ethanol extracts (we-FSCE and we-PSCE) had stronger antibacterial properties than ethanolic extracts (e-FSCE and e-PSCE) and aqueous extracts (w-FSCE and w-PSCE). A 2.5% addition of we-PSCE or we-FSCE to minced pork meat resulted in a reduction of the number of pathogenic cells by 4 log cycles after 4days of refrigeration storage. Baked burgers containing 2.5% of these extracts obtained high ratings for color, taste, odor, juiciness, and overall acceptability that did not differ statistically from control samples. Extracts from Swamp Cranberry constitute interesting candidates for natural preservatives of minced pork meat.