جستجوی مقالات مرتبط با کلیدواژه "نانوذره tio2" در نشریات گروه "پزشکی"

Today, titanium dioxide (TiO2) nanoparticles present extensive therapeutic applications. The present study was conducted to investigate the cytotoxicity of TiO2 on colon cancer cell line (HT29), and analyze the expression of caspase-3 and 9 genes. The present experimental study used the MTT assay to examine the cytotoxicity of 3.125, 6.25, 12.5, 25, 50 and 100 µg/ml concentrations of TiO2 nanoparticles on cell line HT29. After the treatment of HT29 cells with IC50 concentration of TiO2, the gene expression levels of caspase-3 and caspase-9 were investigated and compared with the reference gene of GAPDH using real time PCR. DAPI staining and flow cytometry were ultimately used to confirm apoptosis in HT29 cells. The treatment of HT29 cells with different concentrations of TiO2 showed that TiO2 nanoparticles at 50 and 100 µg/ml concentrations present the highest cytotoxicity, which was statistically significant (P<0.05). Moreover, the expression of caspase-3 gene was found to be significantly upregulated by 2.0±69.13 (P<0.001) and that of caspase-9 gene by 3.0±46.29 (P<0.001) in HT29 cell lines treated with TiO2 nanoparticles for 24 hours. The results of DAPI staining and flow cytometry also confirmed apoptosis in HT29 cells. According to the obtained results, TiO2 nanoparticles can be recommended as prospective medicinal candidates for pharmaceutical purposes, although further studies are required in this field.

Background and Among different cancers, breast cancer has a high prevalence among women and radiotherapy is used as a treatment modality in which radio sensitizers are used to increase its efficiency. Nanoparticles are such sensitizers that enhance the efficiency of radiotherapy via creation of free radicals and induction of oxidative stress. This study aimed at evaluating the synergistic effect of radiation therapy and TiO2 nanoparticles on animal models of breast cancer.
After induction of breast adenocarcinoma tumors in Balb/C, the animals were divided into several groups as control, rutile and anatase injections at 5mg/kg and 10mg/kg doses/with and without radiotherapy. Then, the efficiency of treatment was evaluated.
In groups receiving anatase nanoparticles with and without radiation, the values for tumor volume, relative volume and relative volume percentage showed a small increase and a considerable reduction, respectively. In rutile groups with and without radiation, these values showed a small increase and a considerable increase, respectively. IR value reduced to negative value and then increased to zero and positive in anatase groups with and without radiation. This parameter had little changes in rutile groups with and without radiation.
Titanium dioxide nanoparticles increased sensitivity of tumor cells to radiation therapy due to ROS production. Compared with rutile crystals, anatase crystals have intense effect because of having a larger surface area and higher photocatalytic activity.

Surfactants or surface active agents are organic chemicals that accumulate at the interface gas-liquid or liquid Wax, change the properties of water by reducing the surface tension of water, they speed up the cleaning process. Direct discharge of raw sewage or treated effluent, detergents into the environment and pollution, water resources and rising costs are reduced in quality. The purpose of this study is to evaluate the performance of Leca-containing titanium dioxide nanoparticles for the removal of the surfactant from wastewater. This study is an experiment one at which batch experiments were performed using a Photocatalytic reactor. To study the preparation and properties of catalytic adsorbent Leca to increase the efficiency of titanium dioxide (Tio2) was used. Parameters (3, 5, 7, 9, 11) pH, amount of adsorbent (0.25-2 g/L), surfactant concentration (25-200 mg/L) and contact time (15-120 min) was evaluated by Leca- corrective Adsorbent. Experiments on synthetic examples and in optimal conditions, on real samples were also performed. Surfactant concentration is measured with a spectrophotometer model (shimadzu UV-1800) was performed at a wavelength nm467. The maximum removal of surfactant through Leca- modified in aqueous solutions of synthetic SDS in optimal conditions (contact time 30 min, pH =5, the value of 1 g/L of adsorbent and initial concentration of surfactant is 100 mg/L) at a rate of 98% in the same samples the actual result was 87%. The process of adsorption followed second-order kinetic model and the adsorption isotherm data (R2 =0.984) was more consistent. The results showed that the Leca-containing nanoparticles of titanium dioxide can be used as an effective adsorbent for the removal of anionic surfactants from aqueous solutions used.