Farnoosh Haghighi, Shahla Roudbar Mohammdi, Parisa Mohammadi, Mehdi Eskandari,
Volume 15, Issue 1 (4-2012)
Abstract
Background: Candida albicans is the fourth common cause of chronic fungal infections that cause both mucosal and deep tissue infections. Nowadays, mortality and morbidity due to C .albicans infections via medical devices, such as catheter and implants, are increasing. Therefore, finding new methods of combating such infectious agents seems necessary. In this study antifungal effects of titanium dioxide nanoparticles and photocatalyst TiO2 nanoparticles on C .albicans biofilms were investigated.
Materials and Methods: In this experimental study, TiO2 nanoparticles were synthesized and exposed to UV ray with 370 nm wavelength. Biofilms of C. albicans were developed on flat-bottomed 96-well microtiter plates, and antifungal effects of TiO2 and photocatalyst TiO2 nanoparticles were evaluated. Data were analyzed by t-test using SPSS software.
Results: MIC50 of photocatalyst TiO2 nanoparticles was 1.9 µg/ml and its MIC90 was 2.74 µg/ml while MFC was determined to be 3.37 µg/ml. Biofilms inhibitory concentration of TiO2 nanoparticles, photocatalyst TiO2 nanoparticles, and fluconazole for susceptible strains were 5.14, 4.54, and 4 µg/ml, respectively. These values for the fluconazole resistant strains were 5.35, 4.88, and 8 µg/ml, respectively.
Conclusion: Photocatalyst TiO2 nanoparticles showed a suitable antifungal property against C. albicans biofilms compared with fluconazole. Thus it can be a new strategy in prevention of fungal biofilms, especially those formed on the surface of medical devices.
Reza Tajik, Hasan Asilian Mohabadi, Ali Khavanin, Ahmad Joneidi Jafari, Ardalan Soleimanian,
Volume 15, Issue 8 (1-2013)
Abstract
Background: Poly chlorinated biphenyls (PBCs) are the group of organic chemical materials that have a great chemical stability. These compounds are hazardous pollutants which pose various occupational and environmental problems. This study was conducted to determine the effect of microwave rays, hydrogen peroxide, Tio2 catalyst, and ethanol on the decomposition of PBCs. Materials and Methods: In this experimental study, a vessel reactor (250ml volume)that was connected with a tube connector to thecondensor system was used. A microwave oven with a fixed frequency of 2450 MHZ was used to provide microwave irradiation and ray powers used at 540, 720 and 900w. pH and temperature of the samples were continuously monitored and the experiments were repeated three times. Askarel oils were analyzed by GC-ECD. Results: The mean of total PCBS degradation at 540, 720, and 900w was 83.88±1.63, 89.27±2.44, and 95.98±0.81%, respectively. The mean of total PCBS degradation in terms of ratio to solvent with oil transformer in 1:1, 2:1, and 3:1 was 53.8±3.26, 79.04±1.24, and 95.08±1.69%, respectively. The mean of total PCBS degradation in terms of not using H2o2/Tio2 and using H2O2 (20%) and 0.05, 0.1, 0.15, and 0.2 g of Tio2 concurrently was 71.47±0.81, 87.9±2.16, 89.48±1.69, 91.7±1.24, and 93.07±3.09 %, respectively. Conclusion: Using microwave irradiation in the presence of H2O2 oxidant and Tio2 catalyst leads to the reduction of PCBS.
