RESUMO
OBJECTIVES: Nanoparticles induce oxidative stress in cells and damage them through the cell membrane and DNA damage, eventually resulting in cell death. This study aimed to evaluate the effect of titanium dioxide (TiO2) nanoparticles on apoptosis induction and invasion of gastric cancer cell line, MKN-45. METHODS: We used the MTT assay to assess proliferation of MKN-45 gastric cancer cells after exposure to different forms of TiO2 nanoparticles including amorph, brookite, anatase, and rutile coated with polyethylene glycol (PEG) and bovine serum albumin (BSA). Ethidium bromide and acridine orange staining were used to visualize cancer cell apoptosis, and the wound healing assay technique (migration test) was used to assay cancer cell invasion. RESULTS: Viability and proliferation of cancer cells in the presence of various forms of TiO2 nanoparticles were reduced (p ≤ 0.050). This reduction in cell proliferation and viability was directly related to concentration and duration of exposure to nanoparticles. Induction of cell death was seen in all groups (p ≤ 0.050). Increased cell invasion was seen in PEG-amorph TiO2 group compared to the control group. Cell invasion was decreased only in the brookite BSA group (p ≤ 0.050). CONCLUSIONS: Various forms of TiO2 nanoparticles reduced cell proliferation and induced apoptosis in cancer cells. Some forms of TiO2 nanoparticles such as brookite BSA also inhibited cell invasion. PEG-amorph TiO2 nanoparticles increased cell invasion. These differences seem to be due to the effects of different configurations of TiO2 nanoparticles. TiO2 may provide a new strategy for cancer treatment and more studies are needed.
RESUMO
OBJECTIVES: Due to increasing cardiac disease and its mortality rate, the frequency of cardiac imaging has grown and, as a result, interventional cardiologists potentially receive high radiation doses in cardiac examinations. This study aimed to assess the knowledge, attitude, and practice (KAP) level of radiation protection (RP) among interventional radiology staff in Iranian health care centers across the country. METHODS: We used a validated questionnaire survey consisting of 30 multiple-choice questions to perform a cross-sectional study. Participants were healthcare personnel working professionally with radiation at different levels (i.e., secretary, radiology technologists, nurse, and physician). The questionnaire was divided into three sections to assess KAP regarding RP. RESULTS: Significant differences exist in RP KAP mean scores based on educational age (p < 0.050). There was no significant difference in RP KAP mean scores when looking at sex, practice age, and hospital type (p > 0.050). We found a significant difference between RP KAP mean scores and different regions (p < 0.050). CONCLUSIONS: Educational and practice age, sex, type of hospital, and geographical region affect he KAP of interventional radiology staff regarding RP. Since many of the subjective radiation harms for both medical team and patients, this can be easily controlled and prevented; a checkup for personnel of interventional radiology departments, considering samples from different parts of the country with different levels of education, continuous training, and practical courses may help map the status of KAP. The results of this study may also help authorized health physics officers design strategic plans to enhance the quality of such services in radiation departments.
