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

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

Sterols are one of the active classes of compounds in Inonotus obliquus for their effective therapy of many diseases. In field environment, this fungus accumulates large amount of sterols. In cultured mycelia, however, this class of compounds is less accumulated. For analyzing the factors responsible for differing sterol composition, the field-grown and cultured mycelia were extracted with 80% ethanol at room temperature and total sterols were prepared using silicon gel column chromatography followed by identification using either GC-MS or spectroscopic methods. For culturing Inonotus obliquus, the seed culture was grown either in basic medium consisting of glucose (2%), yeast extract (0.5%), KH2PO4 (0.01%), MgSO4.7H20 (0.05%) and distilled water at pH 6.5, or the basic medium supplemented with serial concentrations of AgNO3. The results indicated that field-grown mycelia contained lanosterol and inotodiol (comprised 45. 47% and 25. 36% of the total sterols, respectively) and other 10 sterols (comprising the remaining 30.17%) including ergosterol biosynthetic intermediates such as 24-methylene dihydrolanosterol, 4,4-dimethylfecosterol, 4-methyl fecosterol, fecosterol and episterol. Column chromatography also led to the isolation of lanosterol, Inotodiol, trametenolic acid, foscoparianol B and a new triterpenoid foscoparianol D in field-grown mycelia. In comparison, the cultured mycelia only contained three sterols with ergosterol as the predominant one (82.20%). Lanosterol only accounted for 3.68%. Supplementing Ag+ into the culture at 0.28 micromol x L(-1) greatly enhanced content of lanosterol (accounting for 56.81%) and decreased the content of ergosterol (18.5%) together with the presence of intermediates for ergosterol biosynthesis. These results suggested that the sterol composition in mycelia of the fungus can be diversified by supplementing substances inhibiting enzymatic process towards the synthesis of ergosterol. Harsh growth conditions in field environment (i.e. temperature variation, UV irradiation etc.) can delay the synthesis of ergosterol and hereby diversify the sterol composition in the mycelia of Inonotus obliquus.
Basidiomycota ; chemistry ; growth & development ; Culture Media ; pharmacology ; Culture Techniques ; Ergosterol ; biosynthesis ; Gas Chromatography-Mass Spectrometry ; Lanosterol ; analogs & derivatives ; biosynthesis ; Mycelium ; chemistry ; Silver Nitrate ; pharmacology

In the present paper, in-situ preparation of silver nanoparticles have been conducted in 3D network structure of BC membrane through liquid phase chemical deoxidization method. The characterization of products was investigated using scanning electron microscopy (SEM), infrared spectroscopy (IR), energy dispersion spectrometry (SEM-EDS). The absorbing water capacity and preserving water capacity of substitutes and the antibacterial capacities of antibacterial agent-loaded artificial skin were tested. The results showed the silver nanoparticles were approximately spherical particles with an average diameter of 45nm, and were noted to have excellent sterilizing efficacy the efficiency of against Escherichia coli, yeast and Candida albicans.
Anti-Bacterial Agents ; pharmacology ; Bacteria ; chemistry ; Candida albicans ; drug effects ; Cellulose ; chemistry ; Escherichia coli ; drug effects ; Humans ; Metal Nanoparticles ; chemistry ; Microbial Sensitivity Tests ; Silver ; Skin, Artificial

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

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

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

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 investigate the synergistic effects of a biotic elicitor yeast extract and different abiotic elicitors (Ag+, Co2+ and alpha-amino isobutyric acid) on the production of tanshinones in Salvia miltiorrhiza hairy root.

METHODDifferent elicitors and their combinations were added to S. miltiorrhiza hairy root culture and the contents of three major tanshinones (crypotanshinone, tanshinone I and tanshinone II A) were analyzed by HPLC.

RESULTThe combinations of yeast extract with different abiotic elicitors had notable synergistic effects on the tanshinone I and tanshinone II A production but not on crypotanshinone. The combination of yeast extract and Ag+ (300 micromol x L(-1)) yielded the highest tanshinone I content, which was nearly 14-fold of the control, and the synergistic elicitation coefficient was 3.0. The combination of yeast extract and Co2+ (100 micromol L(-1)) led to the highest tanshinone IIA content, which was about 14.5-fold of the control, and the synergistic elicitation coefficient was 2.1. Only yeast extract combined with alpha-amino isobutyric acid (200 micromol x L(-1)) increased the crypotanshinone content more effectively than single elicitors. The highest crypotanshinone content was 1.28 mg x g(-1), about 30-fold of the control with a synergistic elicitation coefficient of 1.3.

CONCLUSIONThe elicitation by the combination of a biotic elicitor and an abiotic elicitor can generate a synergistic effect, which is more effective than single elicitors to promote secondary metabolite production in plant tissue cultures.

Aminoisobutyric Acids ; pharmacology ; Bioreactors ; Cobalt ; pharmacology ; Culture Media ; Culture Techniques ; Diterpenes, Abietane ; Drug Synergism ; Phenanthrenes ; metabolism ; Plant Roots ; growth & development ; metabolism ; Plants, Medicinal ; growth & development ; metabolism ; Saccharomyces cerevisiae ; chemistry ; Salvia miltiorrhiza ; growth & development ; metabolism ; Silver ; pharmacology