Functional bioinspired nanocomposites for anticancer activity with generation of reactive oxygen species.

Cancer is a debilitating and deadly disease caused by the uncontrolled growth of aberrant cell populations. This disease cannot always be controlled with traditional therapies and medicines. Different medicines are being used for this purpose, however these medicines have their side effects and are harmful to healthy cells. A better way to cure cancer disease is by limiting the agglomeration of cancer cells, minimizing their growth and their population by destroying these harmful cells. This could be achieved by controlling the function of mitochondria and DNA in cancer cells with the use of biocompatible materials with tuneable physical properties. Accordingly, research is ongoing as to the use of nanomaterials and nanotechnology in medicine. Zinc oxide semiconductor nanoparticles have displayed good anticancer behaviour. They have unique properties such as biocompatibility, good stability, and are environmentally friendly. Owing to these characteristics, they are focused on biological applications such as drug delivery and cancer therapy. In the present research work, zinc oxide, titanium dioxide nanoparticles and titanium oxide-zinc oxide nanocomposites were successfully trailed for anti-cancer activity. Pure zinc oxide nanoparticles (ZnO NPs), titanium dioxide nanoparticles (TiO2 NPs) and their nanocomposites (TiO2+ZnO NPs) were prepared by the co-precipitation technique. The structural properties were investigated by X-ray diffraction, which confirmed the Wurtzite structure of pure ZnO NPs. The morphology of the NPs was checked by scanning electron microscopy. For incident light having a higher energy band gap of nanomaterials, the electrons are excited to the conduction band and these electrons generate reactive oxygen species (ROS). The efficacy of these nanomaterials was checked by exposing the NPs to the human liver cancer cell HepG2. The MTT assay describes anticancer activity via cell viability. The cell viability of composites was observed to be greater than pure ZnO NPs. Their results showed that the structure of ZnO NPs remains the same with composites of TiO2 NPs, but the band gap of the composite was intermediate for individual samples. It also showed that the anticancer activity of composites was also less than pure ZnO NPs which is due to the reduction of ROS generation. This is observed that nanocomposites of ZnO and TiO2 could be effective in the development of a treatment of human liver cancer cells.

Radiation absorbed dose for cobalt-60 gamma source in phantoms for different materials.

Current practices in radiation therapy required high doses of radiation to be delivered with increased accuracy. Treatment planning task is exercised till an optimum dose distribution is achieved. The present reported work was performed to compare the various aspects of the cobalt-60 radiation beam therapy with fixed source-surface distance 70cm incident normally. This study was conducted in May 2012 at the Department of Radiation Physics of MD Anderson Cancer Centre, University of Texas, Houston, United States. Radiation doses were calculated in a solid phantom as well as in water phantom at different square field sizes and depths. It was noted that the rate of absorbed dose increased with the increase in the field size and decreased with the increase in depths. The rate of absorbed dose was found to be directly proportional to the increase in the square field size and inversely proportional to the increase in depth. Moreover, the solid phantom demonstrated more absorbed doses as compared to the water phantom.