OBJECTIVE: To characterize the silver in chitosan antibacterial gel, and to establish a method for the determination of silver content in samples. METHODS: The silver in the samples was analysed by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and single particle inductively coupled plasma mass spectrometry (SP-ICP-MS). Microwave digestion was adopted to digest the chitosan antibacterial gel, and then the content of silver was determined by flame atomic absorption spectrometry. RESULTS: The analysises showed that the particle size of silver in chitosan antibacterial gel was about 150~ 200 nm. The silver showed good linearity in the concentration range of 25~250 μg/L (y=0.000 35x+0.001 7, r=0.999 9). The recovery rate (n=9) was 98.5%. CONCLUSIONS SEM, EDS and SP-ICP-MS can be used for the characterization of silver particles in chitosan antibacterial gel. Microwave digestion-flame atomic absorption spectrophotometry method is simple, practicable, high precision and high quantitative accuracy, which is suitable for the quantitative analysis of silver in chitosan antibacterial gel.
Anti-Bacterial Agents/pharmacology* ; Chitosan/chemistry* ; Microwaves ; Particle Size ; Silver

Using three-dimensional printing to produce antibacterial wound dressing is a new topic that will change the production style of wound dressing industry. Combining with post-3D-printed process, a desktop fused deposition molding equipment can be used to produce wound dressing containing polyvinyl alcohol, alginate and chitosan. The wound dressing produced by FDM has good aspects of absorbency, moisture vapour transmission rate and mechanical property. After loaded with antibacterial agent iodine and silver nano particle, the antibacterial activity rate increases to 99% and it is suitable to use as antibacterial wound dressing. This method affects the production of wound dressing to a more cost-effective way, and provides a possible individualized treatment for patient in the future.
Alginates ; chemistry ; Anti-Bacterial Agents ; administration & dosage ; Bacteria ; drug effects ; Bandages ; economics ; standards ; Chitosan ; chemistry ; Humans ; Iodine ; administration & dosage ; pharmacology ; Nanoparticles ; administration & dosage ; Polyvinyl Alcohol ; chemistry ; Printing, Three-Dimensional ; Silver ; administration & dosage ; pharmacology ; Wound Healing

Biosynthesis of silver and other metallic nanoparticles is one of the emerging research area in the field of science and technology due to their potentiality, especially in the field of nano-biotechnology and biomedical sciences in order to develop nanomedicine. In our present study, Penicillium decumbens (MTCC-2494) was brought from Institute of Microbial Technology (IMTECH) Chandigarh and employed for extracellular biological synthesis of silver nanoparticles. Ag-NPs formation was appeared with a dark brown color inside the conical flask. Characterization of Ag-NPs were done by UV-Spectrophotometric analysis which showed absorption peak at 430 nm determines the presence of nanoparticles, Fourier transform infrared (FT-IR) spectroscopic analysis, showed amines and amides are the possible proteins involved in the stabilization of nanoparticles as capping agent. Atomic force Microscopy (AFM) confirmed the particle are spherical, size was around 30 to 60 nm and also the roughness of nanoparticles. Field emission scanning electron microscopy (FE-SEM) showed the topology of the nanoparticles and were spherical in shape. The biosynthesis process was found fast, ecofriendly and cost effective. Nano-silver particle was found to have a broad antimicrobial activity and also it showed good enhancement of antimicrobial activity of Carbenicillin, Piperacillin, Cefixime, Amoxicillin, Ofloxacin and Sparfloxacin in a synergistic mode. These Ag-NPs showed good anti-cancer activity at 80 μg·mL(-1)upon 24 hours of incubation and toxicity increases upon 48 hours of incubation against A-549 human lung cancer cell line and the synergistic formulation of the antibiotic with the synthesized nanoparticles was found more effective against the pathogenic bacteria studied.
Anti-Bacterial Agents ; metabolism ; pharmacology ; Antineoplastic Agents ; metabolism ; pharmacology ; Bacteria ; drug effects ; Cell Line, Tumor ; Humans ; Lung Neoplasms ; drug therapy ; Metal Nanoparticles ; chemistry ; Microbial Sensitivity Tests ; Penicillium ; metabolism ; Silver ; metabolism ; pharmacology

Silver nanoparticles are considered as good antimicrobial agent. AgNPs were synthesized by mixing silver nitrate solution with citrus sinesis extract for 2 h at 37 °C and analyzed by UV-visible spectra, SEM, XRD, and FTIR. AgNPs were tested against B. subtilis, Shigella, S. aureus, and E. coli. Minimum inhibitory concentration of AgNPs was 20 µg/mL for B. subtilis and Shigella and 30 µg/mL for S. aureus and E. coli. Antibiofilm activity (80% to 90%) was observed at 25 µg/mL. AgNPs were stable for five months with sustained antimicrobial activity. Biosynthesized AgNPs can be used to inhibit food poisoning microbial growth.
Anti-Bacterial Agents ; pharmacology ; Bacillus subtilis ; drug effects ; Bacteria ; drug effects ; Citrus sinensis ; chemistry ; Escherichia coli ; drug effects ; Foodborne Diseases ; prevention & control ; Metal Nanoparticles ; analysis ; Plant Extracts ; pharmacology ; Shigella ; drug effects ; Silver ; pharmacology ; Staphylococcus aureus ; drug effects

This study reported the obtainment of the full-length cDNA of Salvia miltiorrhiza hairy roots (Abbr: SmHDR, GenBank number: JX233817), via extracting Salvia miltiorrhiza hairy roots total RNA, designing specific primers according to the transcriptome data and using the RACE strategy, and then analyzed it with bioinformatics approaches. On this basis, using the real-time PCR to detect SmHDR gene expression after Ag+ induction, and testing tanshinones contents of corresponding samples by UPLC. SmHDR has 1 647 nucleotides, and an open reading frame (ORF) encoding a protein of 463 amino acid residues. The deduced protein has isoelectric point (pI) of 5.72 and a calculated molecular weight about 51.88 kD. In the secondary structure, the percentage of alpha helix, beta turn and random coil were 35.64%, 20.30% and 44.06%, respectively. Sequence alignment and phylogenetic analysis demonstrated that SmHDR had relative close relationship to the HDR of Picrorhiza kurrooa, similar to HDR from other species of plants. Real time PCR results indicated that elicitor of Ag+ stimulated the increase of mRNA expression of SmHDR. At the same time, results of ultra performance liquid chromatography (UPLC), used to examine the accumulation of diterpenoid tanshinones in hairy roots, showed that the contents of diterpenoid tanshinones in hairy roots of Salvia miltiorrhiza were increased dramatically at 12 h after treated with Ag+, and then decreased significantly. This result showed a positive correlation between the levels of mRNA expression and tanshinones accumulation in Salvia miltiorrhiza stimulated by Ag+. The content of tanshinones was gradually raised, and it had an obvious increase at 120 h. The bioinformatics analysis and gene expression indicated that SmHDR might be involved in tanshinones biosynthesis, which laid the foundation for further study of secondary metabolic regulation mechanism of tanshinones.
Amino Acid Sequence ; Cloning, Molecular ; DNA, Complementary ; genetics ; Diterpenes, Abietane ; biosynthesis ; metabolism ; Gene Expression Regulation, Plant ; Open Reading Frames ; Oxidoreductases ; chemistry ; genetics ; metabolism ; Phylogeny ; Plant Roots ; genetics ; metabolism ; Plants, Medicinal ; genetics ; metabolism ; Protein Structure, Secondary ; RNA, Messenger ; metabolism ; Salvia miltiorrhiza ; genetics ; metabolism ; Sequence Alignment ; Silver Nitrate ; pharmacology ; Synthetic Biology

OBJECTIVETo synthesize silver nanopaticles from leaves extract of Eucalyptus chapmaniana (E. chapmaniana) and test the antimicrobial of the nanoparticles against different pathogenic bacteria, yeast and its toxicity against human acute promyelocytic leukemia (HL-60) cell line.

METHODSTen milliliter of leaves extract was mixed with 90 mL of 0.01 mmol/mL or 0.02 mmol/mL aqueous AgNO3 and exposed to sun light for 1 h. A change from yellowish to reddish brown color was observed. Characterization using UV-vis spectrophotometery and X-ray diffraction analysis were performed. Antimicrobial activity against six microorganisms was tested using well diffusion method and cytoxicity test using 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide, a yellow tetrazole was obtained on the human leukemia cell line (HL-60).

RESULTSUV-vis spectral analysis showed silver surface plasmon resonance band at 413 nm. X-ray diffraction showed that the particles were crystalline in nature with face centered cubic structure of the bulk silver with broad beaks at 38.50° and 44.76°. The synthesized silver nanoparticles efficiently inhibited various pathogenic organisms and reduced viability of the HL-60 cells in a dose-dependent manner.

CONCLUSIONSIt has been demonstrated that the extract of E. chapmaniana leaves are capable of producing silver nanoparticles extracellularly and the Ag nanoparticles are quite stable in solution. Further studies are needed to fully characterize the toxicity and the mechanisms involved with the antimicrobial and anticancer activity of these particles.

Anti-Infective Agents ; chemical synthesis ; pharmacology ; toxicity ; Bacteria ; drug effects ; Candida albicans ; drug effects ; Cell Line, Tumor ; Eucalyptus ; chemistry ; Humans ; Metal Nanoparticles ; chemistry ; toxicity ; Plant Extracts ; chemistry ; pharmacology ; toxicity ; Plant Leaves ; chemistry ; Silver ; pharmacology ; toxicity

Phagocytosis or endocytosis by macrophages is critical to the uptake of fine particles, including nanoparticles, in order to initiate toxic effects in cells. Here, our data enhance the understanding of the process of internalization of silver nanoparticles by macrophages. When macrophages were pre-treated with inhibitors to phagocytosis, caveolin-mediated endocytosis, or clathrin-mediated endocytosis, prior to exposure to silver nanoparticles, Interleukin-8 (IL-8) production was inhibited. Although cell death was not reduced, the inflammatory response by macrophages was compromised by phagocytosis and endocytosis inhibitors.
Cell Line ; Cell Survival/drug effects ; Endocytosis/*physiology ; Humans ; Interleukin-8/*metabolism ; Macrophages/drug effects/*metabolism ; Metal Nanoparticles/*chemistry ; Phagocytosis/*physiology ; Silver/*chemistry/pharmacology

OBJECTIVETo synthesize the ecofriendly nanoparticles, which is viewed as an alternative to the chemical method which initiated the use of microbes like bacteria and fungi in their synthesis.

METHODSThe current study uses the endophytic bacterium Bacillus cereus isolated from the Garcinia xanthochymus to synthesize the silver nanoparticles (AgNPs). The AgNPs were synthesized by reduction of silver nitrate solution by the endophytic bacterium after incubation for 3-5 d at room temperature. The synthesis was initially observed by colour change from pale white to brown which was confirmed by UV-Vis spectroscopy. The AgNPs were further characterized using FTIR, SEM-EDX and TEM analyses.

RESULTSThe synthesized nanoparticles were found to be spherical with the size in the range of 20-40 nm which showed a slight aggregation. The energy-dispersive spectra of the nanoparticle dispersion confirmed the presence of elemental silver. The AgNPs were found to have antibacterial activity against a few pathogenic bacteria like Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhi and Klebsiella pneumoniae.

CONCLUSIONSThe endophytic bacteria identified as Bacillus cereus was able to synthesize silver nanoparticles with potential antibacterial activity.

Anti-Bacterial Agents ; chemistry ; pharmacology ; Bacillus cereus ; drug effects ; isolation & purification ; Escherichia coli ; drug effects ; Garcinia ; chemistry ; Klebsiella pneumoniae ; drug effects ; Metal Nanoparticles ; chemistry ; Microbial Sensitivity Tests ; Nanoparticles ; chemistry ; Phytotherapy ; methods ; Plant Extracts ; chemistry ; pharmacology ; Pseudomonas aeruginosa ; drug effects ; Silver ; chemistry ; pharmacology ; Staphylococcus aureus ; drug effects

OBJECTIVETo determine the amount of silver in silver-loaded coral hydroxyapatite (Ag(+)-CHA) bone substitute and its impact on the biocompatibility of this material with mouse embryonic osteoblast cells.

METHODSAg(+)-CHA was prepared by immersing coral hydroxyapatite in a serial concentration of silver nitrate solutions. The amount of silver in the prepared Ag(+)-CHA was measured by inductively coupled plasma atomic emission spectrometry (ICP-AES). The viability of MC3T3-E1 cells incubated with Ag(+)-CHA was measured by MTT colorimetric assay, and the cell growth and morphological changes were observed by inverted phase-contrast microscope and confocal laser scanning microscope.

RESULTSThe amount of silver loading in the bone substitutes prepared by immersion in 1×10(-2), 1×10(-3), 5×10(-4), 10(-4), 8×10(-5), and 5×10(-5) mol/L silver nitrate solutions were 4127.67∓47.35, 167.90∓11.00, 83.42∓4.51, 30.20∓2.32, 22.39∓4.09, and 15.11∓0.55 µg/g, respectively. A low silver content in the material (prepared with silver nitrate solution of less than 8×10(-5) mol/L) showed no significant inhibitory effect on the growth of MC3T3-E1 cells or produced noticeable cytotoxic effect. On the materials prepared with 8×10(-5) and 10(-5) mol/L silver nitrate solution, the osteoblasts displayed active proliferation similar to those incubated on materials without silver loading. The confluent cells showed a normal fusiform morphology with tight arrangement.

CONCLUSIONAg(+)-CHA with low silver content has a good biocompability and can promote the proliferation and growth of MC3T3-E1 cells in vitro, suggesting the clinical potential of this material as a anti-infection bone substitute.

3T3 Cells ; Animals ; Anthozoa ; chemistry ; Anti-Bacterial Agents ; analysis ; pharmacology ; Biocompatible Materials ; chemistry ; pharmacology ; Bone Substitutes ; chemistry ; pharmacology ; Cells, Cultured ; Durapatite ; chemistry ; pharmacology ; Materials Testing ; Mice ; Silver ; analysis ; chemistry ; pharmacology

We tried to find the effects of the application of the antibacterial solution containing silver ions on the surface of the denture soft lining material. We selected the right concentration of the silver-containing solution and coated a soft lining material with the solution so that the soft lining material could be antibacterial. The antibacterial solution containing silver ions was prepared by sol-gel method. MIC of C. a and S. a were tested by broth dilution test. The surface property and thickness were tested after coated. The in vitro antibacterial ratio against C. a and S. a were demonstrated by the method of plate-counting. A film was formed after coating, while the adequacy was not changed. Antibacterial ratio of 0.64 mg/ml group against C. a was 90.82%, and that against S. a was 94.96% in 24 hours, respectively. It was found that the antibacterial property of the soft lining material can be acquired by coating this antibacterial solution with silver ion, without changing the adequacy.
Anti-Bacterial Agents ; chemistry ; pharmacology ; Candida albicans ; drug effects ; Denture Cleansers ; pharmacology ; Denture Liners ; microbiology ; Membranes, Artificial ; Microbial Sensitivity Tests ; Silver ; pharmacology ; Staphylococcus aureus ; drug effects