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Background: Infections caused by biofilm-forming bacteria have significantly linked to dental plaque and caries. The aim of this study is to assess efficacy of some natural compounds in inhibition and eradication of biofilm formed by bacterial isolates from dental infections. Results: Bacterial isolates were recovered from dental plaque/caries and identified using standard microbiological tests and 16S rDNA sequencing. The isolated bacterial strains include Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Klebsiella pneumoniae, and Escherichia coli. The antibiotic susceptibility was determined by disk diffusion method and revealed that the majority of isolates showed high antibiotic resistance, and 61% of isolates were found to be multidrug resistant. The biofilm formation capacity of isolates was investigated using microtiter plate assay. Among the 77 bacterial isolates, seventeen showed moderate biofilm formation capacity, twenty-two showed near-moderate, thirty-four had weak biofilm-forming capacity, and four were non-biofilm producers. The antibiofilm activity of tested compounds (rose and jasmine oils, propolis, vanillin, and vinegar) was evaluated against isolates with highest biofilm-forming capacity. The in vitro antibiofilm ability of tested substances were investigated alone or in combination with each other to evaluate their ability to prevent biofilm formation or destroy preformed single-/multispecies biofilms. Finally, antibiofilm ability of tested combination was evaluated ex vivo on natural teeth. Our results showed that vanillin in combination with rose or jasmine oils showed promising biofilm inhibition and biofilm eradication activities in both the in vitro and ex vivo models. Conclusions: Dental plaque and caries can be successfully prevented using combination of vanillin with rose or jasmine oils, and these compounds can be incorporated in new anticaries dental formulations. [ABSTRACT FROM AUTHOR]

Zn-MOF/bioactive glass nanoparticles were successfully prepared using quick–alkali-modified sol–gel and tested for gentamicin drug delivery. Samples of 0 and 0.8 mol% Zn MOF contents (BG and BG/Zn MOF, respectively) were characterized using XRD, FTIR, TEM, and SEM/EDX. In addition, zeta characteristics and surface area parameters were also evaluated. Moreover, the cell viability of the prepared samples was tested against the osteosarcoma MG-63 cell line to evaluate the ability of prepared samples for bone regeneration. In addition, the antimicrobial activity of glass samples with and without antibiotics was determined against different microorganisms. Finally, the samples were loaded with gentamicin drug, and drug release profile and kinetics were studied too. XRD and FTIR results confirmed the physicochemical properties of the prepared samples. TEM results showed that particles were in the nano-sized range in both samples; however, the presence of Zn MOF increased the dispersity of particles. Both samples were bioactive, as indicated by hydroxyapatite formation on their surfaces. Cytotoxicity estimation of prepared materials exhibited their safe and nontoxic nature. BG/Zn MOF sample demonstrated prolonged drug release and excellent antimicrobial activity in comparison to BG alone. Therefore, the present study provides promising preliminary results regarding the usage of BG/Zn MOF nanoparticles loaded with gentamicin as an effective approach for bone regeneration. Highlights: Bioactive glass doped with zinc-based MOF nanoparticles was prepared and characterized. In vitro bioactivity, antibiotic release profile, and antimicrobial properties were evaluated. Cytotoxicity on osteoblast-like cells was estimated. The produced nanoparticles showed a long-term release of gentamicin drug. The prepared materials had no toxic effect on cells and could be safely used as biocompatible materials for bone regeneration. [ABSTRACT FROM AUTHOR]

The article deals with mesoporous silica nanoparticles that were fabricated as drug carriers for bone infection; the prepared sample was manufactured through the quick alkali-mediated sol-gel technique. Several characterization techniques were applied to meet the study objectives, including Transmittance Electron microscopy (TEM), X-rays, Fourier transform infrared (FTIR), Brunauer Emmett Teller (BET) surface area measurements, and Zetasizer. Moreover, ciprofloxacin was used as a drug model, and the kinetic models of Higuchi were used to study drug release mechanisms. In addition, the cytotoxicity of the mesoporous silica was tested against human bone osteosarcoma cells (MG-63) by MTT assay. This work mainly introduced gamma irradiation as an effective sterilizing technique; moreover, ciprofloxacin loading and release kinetics in Tris buffer solution from the silica nanoparticles were investigated before and after gamma irradiation. The physicochemical features of the mesoporous silica were confirmed by the results obtained from XRD and FTIR measurements. The particle size of the mesoporous silica was less than 15 nm. The cytotoxicity assay results demonstrated that the tested concentrations of the nanoparticles were cytocompatible up to 100 µg/mL towards the MG-63 cells. The in vitro drug release study showed that all samples released the drug via controlled diffusion. Based on these findings, current mesoporous silica may be used to deliver controlled ciprofloxacin for treating bone infection. [ABSTRACT FROM AUTHOR]

This work was aiming to design novel bio-composite (BC) materials based on microwave-prepared AuNPs-loaded Zeolite-A (ZA-Au) and nano-hydroxyapatite (HA). Ciprofloxacin drug was uploaded onto the BC entities to provide a potential treatment for osteomyelitis. The prepared BCs containing the lowest and highest (10 and 40%) active weight ratios of ZA-Au were prepared and coded as ZA-Au-10 and ZA-Au-40, respectively. The XRD, FTIR, TEM, and SEM supported with EDX technique were used for samples characterization. Both bio-mixtures were able to induce hydroxyapatite layer after immersion into SBF for 15 days. Cytotoxic evaluation of all prepared materials indicated their safe and nontoxic nature. Both BCs showed significant improvement in their drug release profiles and rates, compared to either parent constituents (HA or ZA-Au). The total cumulative amounts of released antibiotic from ZA-Au-10 and ZA-Au-40 were 1.324 ± 0.21 and 1.218 ± 0.13 mg, respectively. The application of the Higuchi square root model on the drug release profiles for both BCs specified the diffusion-controlled manner for the drug elution. This novel BC will combine the high bioactivity of the nano-HA with the given strength and defined porosity of the zeolite structure, to help effectively in delivering the drug in a regular and prolonged manner. Overall, the formed novel bio-composites are cost-effective and proved to be highly efficient as a controlled drug delivery system for ciprofloxacin. [ABSTRACT FROM AUTHOR]

The present study aimed to prepare controlled drug delivery systems based on gelatin-agarose scaffold and its modification by the addition of glass nanoparticles. Three different scaffolds were prepared and coded according to their glass contents (0, 20, and 40 wt.%) as PG0, PG20, and PG40, respectively. They were characterized by the SEM/EDX and FT-IR. Glass nanoparticles addition improved the ability of the scaffolds to precipitate a hydroxyapatite layer on their surfaces. The total quantities of the drug taken by the scaffolds PG0, PG20, and PG40 were 38.82 ± 0.4, 39.22 ± 0.3, and 38.78 ± 0.3 mg, respectively. The final cumulative amounts of release drug of scaffolds PG0, PG20 and PG40 during the whole release experiments (24 days) were 4.98 ± 1.15, 8.23 ± 1.20, and 14.45 ± 1.62 mg, respectively. Incorporation of glass nanoparticles in the scaffolds improved their drug release profiles and rates. Application of different mathematical models on the drug release profile of the scaffolds indicated that ciprofloxacin was released through diffusion-controlled and/or dissolution-controlled modes. The proposed scaffolds could serve as a potential osteomyelitis treatment. [ABSTRACT FROM AUTHOR]

Nano bioactive glasses in the system; 70 SiO2–10 P2O5–(20–x) CaO–xCuO (x = 0, 3 and 5% mol%), were synthesized by the rapid alkali sol–gel method. The dual effect of incorporating 0, 3, and 5 mol% of CuO (replacing CaO) and gamma irradiation on nanobioactive glasses structure were studied. The bioactivity, cytotoxicity and promotion in wound healing of fibroblast cells (BJ-1) were studied. The results showed that the unirradiated and irradiated samples were able to form hydroxyapatite layer on their surfaces in SBF after 30 days. Scratch-wound healing assay also, indicated that the samples which incorporating 3 mol% of CuO with or without gamma irradiation had the highest wound closure rate (99.1%, and 98.1%, respectively). The result of cytotoxic assay demonstrated that 100 μg/mL of 0, 3 mol% of CuO before and after gamma irradiation showed non-significant decrease (p > 0.05) in the mean viability percentage towards BJ.1 cells. Therefore, these compositions could be suitable for wound healing applications. [ABSTRACT FROM AUTHOR]

The ESAT-6-like secretion system (ESS) of Staphylococcus aureus plays a significant role in persistent infections. EssB is a highly conserved bitopic ESS protein comprising a cytosolic N-terminus, single transmembrane helix and a C-terminus located on the trans-side of the membrane. Six systematic truncations covering various domains of EssB were constructed, followed by bacterial two-hybrid screening of their interaction with EsaA, another conserved integral membrane component of the ESS pathway. Results show that the transmembrane domain of EssB is critical for heterodimerization with EsaA. In vivo crosslinking followed by Western blot analysis revealed high molecular weight species when wild-type EssB and EsaA were crosslinked, but this band was not detected in the absence of the transmembrane domain of EssB. Heterologous overproduction of EssB, EsaA and five other components of the ESS pathway in Escherichia coli BL21(DE3), followed by fractionation experiments led to a remarkable increase in the periplasmic protein content, suggesting the assembly of partially regulated secretion mechanism. These data identify the transmembrane domain of EssB as indispensable for interaction with EsaA, thereby facilitating protein secretion across bacterial membranes in a fashion that requires other components of the ESS pathway. [ABSTRACT FROM AUTHOR]

Abstract: The main aim of the work was the fabrication of novel silver releasing nanocomposite scaffolds, for bone treatment, by the gas foaming/particulate-leaching technique. Silver doped bioactive glass nanoparticles were used as a filler, to provide the scaffolds with bioactivity, as well as anti-bacterial properties. Nanocomposite scaffolds containing 0, 20 and 40wt% glass contents were prepared and coded as PAg0, PAg20 and PAg40, respectively. The scaffolds were characterized by SEM/EDXA, FTIR and TGA. Examination of SEM microphotographs showed that, the produced scaffolds had well interconnected structures. For PAg0, PAg20 and PAg40, the maximum pore sizes were about 250, 150 and 100μm, respectively, while their porosities % were 92%, 89% and 83%, respectively. Degradation studies were carried out, by incubating the scaffolds in simulated body fluid, for a month. Results revealed the possibility to modulate and improve the degradation of the scaffolds by increasing their glass contents. The final weight losses measured for PAg0, PAg20 and PAg40 were 12.76%, 14.61% and 17.42%, respectively. On the other hand, the highest water absorption values recorded for those scaffolds were 61.89%, 240.36% and 270.87%, respectively, indicating that, the addition of glass nanoparticles to the scaffolds improved their water absorption abilities. Both PAg20 and PAg40 induced an apatite layer on their surfaces, had anti-bacterial effect in agar plates, and their silver releasing profiles followed a diffusion-controlled mechanism. Therefore they could be used for bone treatment. [Copyright &y& Elsevier]

Ce-containing bioactive glasses are known to decrease reactive oxygen activities inside the body. That is because of their excellent catalytic activities which come from the fast interchange of Ce3+/Ce4+ oxidation states. This research was mainly aimed at preparing new Ce-doped nano-bioactive glasses based on 60SiO2-(10-x)B2O3-25CaO-5P2O5-xCeO2, in mole% (x = 0 and 5 mol%) as multifunctional bone fillings. Moreover, the glasses were used as a delivery system for ciprofloxacin to intensely solve the bone infection complications. Nevertheless, there were no previous works studied of the nature immersing solution effect on the drug release behavior from Ce-doped nano-bioactive glass carriers. Therefore, phosphate-free and phosphate-containing buffer solutions with/without superoxide species (H2O2) were used to investigate the efficacy of this drug delivery system in different environment. The results showed that Ce addition enhanced the formation of apatite layer and cell viability. Moreover, the percentage of released drug was apparently affected by the glass composition and nature of soaking fluid, specifically, in the media containing superoxide species (H2O2). In conclusion, the prepared Ce-doped glass nanoparticles illustrated multifunctional bone filling material, but when it intended to be utilized as a drug delivery system, the nature of surrounding medium have to be taken into consideration. [ABSTRACT FROM AUTHOR]

Survey and population density of the olive bark borer, Phloeotribus scarabaeoides (Bern.) (Coleoptera: Scolytidae), and its associated parasitoids were carried out at Fayoum Governorate, Egypt during the two successive years 2008 and 2009. Six species of hymenopterous parasitoids were recorded i.e. Cheiropachus quadrum L. Eurytoma morio Bohemen., Raphitelus maculates Walker. Cerocephala cornigera Westw., Cephalonomia sp. and Dendrosoter protuberans Ness. D. protuberans was recorded for the first time on P. scarabaeoidesn in Egypt. P. scarabaeoides had two peaks in 2008 and 2009, while the parasitoids had one peak in 2008 and 2 peaks in 2009. C. quadrum was the dominant parasitoid in both seasons, with a relative density of 75.8 and 39.7, respectively. In 2008, percentage of parasitism ranged between 0.2 and 52.9%, while in 2009 it ranged between 0.07 and 29.9%. Highest percentages of parasitism (52.9% and 29.9%) were recorded in January 2008 and February 2009, respectively. [ABSTRACT FROM AUTHOR]