Silver nanoparticles have been widely used in medicinal and biological fields. Their biological evaluation is an important researchful field. In this paper are summarized the status quo of nano-hydroxyapatite biological evaluation at home and abroad. Although silver nanoparticles showed good biological compatibility when they were tested by contrast to ISO 10993 standards, some reports have proved that many medical devices loaded with silver could release silver ions (Ag+) which could translocate in blood circulation and cumulate in some organs such as liver and kidney. It may induce hepatotoxicity or renal toxicity and may lead to death in some situation extremely exposed to a certain dose of Ag+. The dimension of silver nanoparticles is close to silver ions and some reports have proved that they could translocate in body, so it is suggested that silver nanoparticles should induce the same toxicity with silver ions. In addition, silver nanoparticles have shown cytotoxicity in some experiment in vitro. But the mechanisms of its cytotoxity are not clear; it may attribute to the silver ions that release from silver nanoparticles or to the silver nanoparticles that permeate through cell membrane. Hence, there are some potential anxieties for the biological safety of silver nanoparticles.
Metal Nanoparticles ; toxicity ; Silver ; toxicity

To address the controversial issue of the toxicity of dental alloys and silver nanoparticles in medical applications, an in vivo-like LO2 3-D model was constructed within polyvinylidene fluoride hollow fiber materials to mimic the microenvironment of liver tissue. The use of microscopy methods and the measurement of liver-specific functions optimized the model for best cell performances and also proved the superiority of the 3-D LO2 model when compared with the traditional monolayer model. Toxicity tests were conducted using the newly constructed model, finding that four dental castings coated with silver nanoparticles were toxic to human hepatocytes after cell viability assays. In general, the toxicity of both the castings and the coated silver nanoparticles aggravated as time increased, yet the nanoparticles attenuated the general toxicity by preventing metal ion release, especially at high concentrations.
Cells, Cultured ; Dental Casting Technique ; Hepatocytes/drug effects* ; Humans ; Metal Nanoparticles/toxicity* ; Silver/toxicity* ; Toxicity Tests

Nanosilver antibiotic devices for gynecological external use are the third-class products of medical devices, whose biological safety and efficiency should be strictly controlled. But there is not yet the national standard or industry standard for the products to control the production process, so their testing method of biological evaluation mainly refers to GB/T16886 "The Guide to Implementation of Biological Evaluation of Medical Devices". To control the biological safety effectively, it's necessary to work out the testing items and methods of the biological evaluation for such products.
Animals ; Anti-Bacterial Agents ; toxicity ; BALB 3T3 Cells ; Equipment and Supplies ; adverse effects ; Female ; Male ; Mice ; Nanostructures ; Rabbits ; Silver ; toxicity ; Toxicity Tests ; methods

OBJECTIVEThis study aims to compare and determine a kind of nano-hydroxyapatite composite material with good antibacterial efficacy on Enterococcusfaecalis (E. faecalis) in vitro.

METHODSWe investigated the antimicrobial activity of four kinds of nano-hydroxyapatite composites, namely, silver/hydroxyapatite composite nanoparticles (Ag/nHA), yttrium/hydroxyapatite composite nanoparticles (Yi/nHA), cerium/hydroxyapatite composite nanoparticles (Ce/nHA), and hydroxyapatite nanoparticles (nHA), against E. faecalis in vitro using the agar diffusion and broth dilution method by measuring the growth inhibition zone and the minimum inhibitory concentration (MIC), respectively.

RESULTSThe agar diffusion test results showed that Ag/nHA displayed an obvious growth inhibition zone, whereas Yi/nHA, Ce/nHA, and nHA showed no influence on E. faecalis. The MIC value of Ag/nHA was 1.0 g.L-1, and the three other materials had no effect on E.faecalis even at the high concentration of 32.0 g.L-1.

CONCLUSIONAg/nHA display a potential antimicrobial efficacy to planktonic E.faecalis. Whereas, the three other kinds of nano-hydroxyapatite composites (Yi/nHA, Ce/nHA, nHA) show no influence.

Anti-Bacterial Agents ; pharmacology ; Anti-Infective Agents ; Durapatite ; pharmacology ; Enterococcus faecalis ; drug effects ; Microbial Sensitivity Tests ; Nanocomposites ; toxicity ; Silver

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

OBJECTIVETo evaluate the biocompatibility of nano-silver base inorganic antibacterial agents and compare the cytotoxicity in vitro among six types of nano-silver base inorganic antibacterial agents.

METHODSFUMAT T200-4, HN300, Novaron, Kangwang, MOD and SR1000 were diluted to different concentrations, such as 100 g/L, 50 g/L, 25 g/L and 12.5 g/L. The cytotoxicity in vitro of these agents on rat's fibroblast was assayed with MTT method. And the grades of cytotoxicity were compared.

RESULTSHigh concentrations of nano-silver base inorganic antibacterial agents had cytotoxic effects on rat's fibroblasts L-929. As the concentration decreased, the cytotoxicity decreased. No cytotoxic effects were observed at or below the concentration of 25 g/L. FUMAT T200-4, Kongwang and SR1000, with the carrier of phosphate zirconium, had less cytotoxity than the others.

CONCLUSIONSNano-Silver base inorganic antibacterial agents, such as FUMAT T200-4, Kangwang, SR1000, have good biocompatibility. And they have the possibility of clinical application. The safe concentration of these agents is at or below 25 g/L.

Animals ; Anti-Bacterial Agents ; administration & dosage ; toxicity ; Cell Line ; Dose-Response Relationship, Drug ; Drug Evaluation, Preclinical ; Fibroblasts ; drug effects ; Nanostructures ; administration & dosage ; toxicity ; Rats ; Silver Compounds ; administration & dosage ; classification ; toxicity

OBJECTIVETo detect cobalt chromium alloy antimicrobial coating silver of the surface structure and the cell toxicity in order to provide a theoretical basis for clinical application.

METHODSPlasma spraying technique was adopted to prepare cobalt chromium alloy antimicrobial coating silver. Scanning electron microscopy, energy dispersive analysis and X-ray diffraction analysis were used to evaluate the surface properties. The methyl thiazolyl tetrazolium and flow cytometry method was adopted to test the L929 cell proliferation and the influence of the cell cycle.

RESULTSThe surface of the coating was uniform and compact, combined perfectly with substrate material. The content of the surface was mainly Ag, Cr and a small amount of Ag(2)O, Cr(2)O(3). After cobalt chromium alloy was cultured in leach liquor for 1, 2 and 3 days, the statistical result showed that there was no significant different between the three groups. The cytotoxic level of negative control group was level 0 at each time point and that of other groups was level 1 at each time point. There was no significant difference between cobalt chromium alloy and cobalt chromium alloy antimicrobial coating silver in cell toxicity (P > 0.05). There was no statistical significance of the influence on cell cycle between cobalt chromium alloy with Ag coating [the G2's rate of cell cycle was (8.23 ± 0.39)%] and cobalt chromium alloy group [the G2's rate of cell cycle was (8.70 ± 0.46)%] (P > 0.05).

CONCLUSIONSThe surface of the coating was stable and there was no significant difference between cobalt chromium alloy widely used in clinic and cobalt chromium alloy with Ag coating of the influence on proliferation of L929 cell and cell cycle, the cell compatibility of cobalt chromium with Ag coating is well.

Animals ; Cell Cycle ; drug effects ; Cell Line ; Cell Proliferation ; drug effects ; Chromium Alloys ; chemistry ; toxicity ; Dental Casting Technique ; Fibroblasts ; cytology ; drug effects ; Mice ; Microscopy, Electron, Scanning ; Silver ; chemistry ; toxicity ; Surface Properties ; X-Ray Diffraction