Zn-(0-1.6)Mg (in wt.%) alloys were prepared by hot extrusion at 300 °C. The structure, mechanical properties and in vitro biocompatibility of the alloys were investigated. The hot-extruded magnesium-based WE43 alloy was used as a control. Mechanical properties were evaluated by hardness, compressive and tensile testing. The cytotoxicity, genotoxicity (comet assay) and mutagenicity (Ames test) of the alloy extracts and ZnCl2 solutions were evaluated with the use of murine fibroblasts L929 and human osteosarcoma cell line U-2 OS. The microstructure of the Zn alloys consisted of recrystallized Zn grains of 12 μm in size and fine Mg2Zn11 particles arranged parallel to the hot extrusion direction. Mechanical tests revealed that the hardness and strength increased with increasing Mg concentration. The Zn-0.8 Mg alloys showed the best combination of tensile mechanical properties (tensile yield strength of 203 MPa, ultimate tensile strength of 301 MPa and elongation of 15%). At higher Mg concentrations the plasticity of Zn-Mg alloys was deteriorated. Cytotoxicity tests with alloy extracts and ZnCl2 solutions proved the maximum safe Zn(2+) concentrations of 120 μM and 80 μM for the U-2 OS and L929 cell lines, respectively. Ames test with extracts of alloys indicated that the extracts were not mutagenic. The comet assay demonstrated that 1-day extracts of alloys were not genotoxic for U-2 OS and L929 cell lines after 1-day incubation.
- MeSH
- biokompatibilní materiály chemie toxicita MeSH
- hořčík chemie toxicita MeSH
- kultivované buňky MeSH
- lidé MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- poškození DNA účinky léků MeSH
- slitiny chemie toxicita MeSH
- viabilita buněk účinky léků MeSH
- zinek chemie toxicita MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Metal-related genes (afe_0654, afe_0671, afe_0674, afe_1143, afe_1144, and afe_2126) were cloned to identify whether those genes existed in Acidithiobacillus ferrooxidans strain DC (A. ferrooxidans DC). The deduced amino acid sequences of those genes were analyzed by bioinformatics. The tolerance levels of A. ferrooxidans DC to Mn(2+), Zn(2+), and Cd(2+) were determined, which were 0.52, 0.42, and 0.16 mol/L for ferrous iron-grown cells and 0.38, 0.18, and 0.08 mol/L for sulfur-grown cells, respectively. Real-time quantitative PCR was employed to analyze the transcriptional levels of the metal-related genes when ferrous iron- and sulfur-grown cells of A. ferrooxidans DC, respectively, exposed to Mn(2+), Zn(2+), and Cd(2+). The metal-related genes were up-regulated when A. ferrooxidans DC exposed to Mn(2+). When A. ferrooxidans DC exposed to Zn(2+), the metal-related genes were up-regulated in sulfur-grown cells; afe_0654 and afe_0674 were down-regulated, and the others were up-regulated in ferrous iron-grown cells. Afe_2126 was down-regulated, and the others were up-regulated when A. ferrooxidans DC exposed to Cd(2+). According to experimental results and bioinformatics analysis, the proteins encoded by afe_0654 and afe_0674 may relate with Mn(2+) and Cd(2+) efflux. It needed further study whether they relate with Zn(2+) transport. Proteins encoded by afe_0671, afe_1143, and afe_1144 may relate with the efflux of Mn(2+), Zn(2+), and Cd(2+). The protein encoded by afe_2126 may relate with Mn(2+) and Zn(2+) efflux and Cd(2+) uptake.
- MeSH
- Acidithiobacillus účinky léků genetika růst a vývoj MeSH
- bakteriální geny MeSH
- bakteriální proteiny genetika metabolismus MeSH
- biologický transport MeSH
- hořčík metabolismus toxicita MeSH
- klonování DNA MeSH
- kovy metabolismus toxicita MeSH
- kvantitativní polymerázová řetězová reakce MeSH
- mangan metabolismus toxicita MeSH
- mikrobiální testy citlivosti MeSH
- regulace genové exprese u bakterií účinky léků MeSH
- sekvenční analýza DNA MeSH
- síra metabolismus MeSH
- stanovení celkové genové exprese MeSH
- výpočetní biologie MeSH
- zinek metabolismus toxicita MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
