RESULTS: The ternary nanocomposite containing conducting polymer polypyrrole, cobalt oxide, and silver nanoparticles showed potent antimicrobial effects against these pathogens. The antibacterial assay showed that PPy-Co3O4-AgNPs exhibited significant bactericidal activity against neuropathogenic E. coli K1 at only 8 μg/mL as compared to individual components of the nanocomposite, whereas a 70 % inhibition of A. castellanii viability was observed at 50 μg/mL. Moreover, PPy-Co3O4-AgNPs were found to have minimal cytotoxicity against human keratinocytes HaCaT cells in vitro even at higher concentration (50 μg/mL), and also reduced the microbes-mediated cytopathogenicity against host cells.

CONCLUSION: These results demonstrate that PPy-Co3O4-AgNPs hold promise in the development of novel antimicrobial nanomaterials for biomedical applications.

OBJECTIVE: In the current study, aqueous extract of Thymus vulgaris (T. vulgaris) was used to synthesize the AgNPs using green synthesis techniques followed by checking the effectiveness and various biological activities of these AgNPs.

METHODS: At first, the plant samples were proceeded for extraction of aqueous extracts followed by chromatography studies to measure the phenolics and flavonoids. The synthesis and characterization of AgNPs were done using green synthesis techniques and were confirmed using Fourier transform infra-red (FT-IR) spectroscopy, UV-visible spectroscopy, scanning electron microscope (SEM), zeta potential, zeta sizer and X-Ray diffraction (XRD) analysis. After confirmation of synthesized AgNPs, various biological activities were checked.

RESULTS: The chromatography analysis detected nine compounds accounting for 100% of the total amount of plant constituents. The FT-IR, UV-vis spectra, SEM, zeta potential, zeta sizer and XRD analysis confirmed the synthesis of AgNPs and the variety of chemical components present on the surface of synthesized AgNPs in the plant extract. The antioxidant activity of AgNPs showed 92% inhibition at the concentration of at 1000 µg/mL. A greater inhibitory effect in anti-diabetic analysis was observed with synthesized AgNPs as compared to the standard AgNPs. The hemolytic activity was low, but despite low concentrations of hemolysis activity, AgNPs proved not to be toxic or biocompatible. The anti-inflammatory activity of AgNPs was observed by in-vitro and in-vivo approaches in range at various concentrations, while maximum inhibition occurs at 1000 µg (77.31%).

METHODS: AgNP-K 1:1 was synthesized with 1 mM kaempferol, whereas AgNP-K 1:2 with 2 mM kaempferol. The characterization of AgNP-K 1:1 and AgNP-K 1:2 was performed using UV-visible spectroscopy (UV-Vis), Zetasizer, transmission electron microscopy (TEM), scanning electron microscopy-dispersive X-ray spectrometer (SEM-EDX), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy. The antibacterial activities of five samples (AgNP-K 1:1, AgNP-K 1:2, commercial AgNPs, kaempferol, and vancomycin) at different concentrations (1.25, 2.5, 5, and 10 mg/mL) against MRSA were determined via disc diffusion assay (DDA), minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) assay, and time-kill assay.

PURPOSE: The purpose of this in vitro study was to assess the antimicrobial effect of sub 10-nm AgNPs in maxillofacial silicone against Staphylococcus aureus, Candida albicans, and mixed species biofilms containing both and to test the effectiveness of different AgNP concentrations against all 3 biofilms in vitro.

MATERIAL AND METHODS: Silicone disks (M511; Technovent Ltd) containing 0.0% (control), 0.1%, and 0.5% AgNPs were fabricated and treated with S. aureus, C. albicans, and mixed species strains of both in 24-well culture plates containing appropriate media. Each well received a 0.1-mL aliquot of the standardized suspension of microorganisms. The plates were incubated for 21 consecutive days, and colony-forming units per milliliter (CFU/mL) were measured on the first, third, fifth, seventh, fifteenth, and twenty-first day with the Miles and Misra method. Data were analyzed by 2-way ANOVA and the paired t test to evaluate the relationship between AgNP concentration, microbial strain, and time (α=.05). Mean CFU/mL differences for each time and for each biofilm category were assessed by repeated measure ANOVA.