Polyethylenimine-modified curcumin-loaded mesoporus silica nanoparticle (MCM-41) induces cell death in MCF-7 cell line.

Breast cancer accounts for the first highest mortality rate in India and second in world. Though current treatment strategies are effectively killing cancer cells, they also end in causing severe side effects and drug resistance. Curcumin is a nutraceutical with multipotent activity but its insolubility in water limits its therapeutic potential as an anti-cancer drug. The hydrophilicity of curcumin could be increased by nanoformulation or changing its functional groups. In this study, curcumin is loaded on mesoporous silica nanoparticle and its anti-cancer activity is elucidated with MCF-7 cell death. Structural characteristics of Mobil Composition of Matter - 41(MCM-41) as determined by high-resolution transmission electron microscopy (HR-TEM) shows that MCM-41 size ranges from 100 to 200 nm diameters with pore size 2-10 nm for drug adsorption. The authors found 80-90% of curcumin is loaded on MCM-41 and curcumin is released efficiently at pH 3.0. The 50 µM curcumin-loaded MCM-41 induced 50% mortality of MCF-7 cells. Altogether, their results suggested that increased curcumin loading and sustained release from MCM-41 effectively decreased cell survival of MCF-7 cells in vitro.

Oxidative stress-mediated cytotoxicity and apoptosis induction by TiO2 nanofibers in HeLa cells.

Titanium dioxide nanoparticles are increasingly being used in pharmaceutical and cosmetic products. The high aspect ratio of fibrous nanomaterials, such as carbon nanotubes and TiO(2) nanofibers (TiO(2)NFs), similar to the one used in this study makes them an attractive structural material and has attracted a lot of attention due to their possible negative health effects as suggested by their morphological similarities with asbestos. In the present study, therefore, toxicity of TiO(2)NFs was evaluated in human cervical adenocarcinoma HeLa cells. The TEM and XRD analyses showed that TiO(2)NFs used in this study are pure with uniform diameter of around 200 nm, and their length to width aspect ratio ranged between 5 and 15. Exposure of HeLa cells to TiO(2)NFs induced significant cytotoxicity even at doses as low as 2 µg/ml. The intracellular uptake of TiO(2)NFs in cells was shown by Alizarin Red S (ARS) labeled nanofibers. The mechanism of toxicity is mainly due to the induction of cellular oxidative stress, as revealed by elevated ROS levels, reduced antioxidant levels, and increased lipid peroxidation leading to apoptosis. The cell cycle analysis indicated G(2)/M cell cycle arrest in the cells exposed to TiO(2)NF. TiO(2)NFs treatment to HeLa cells resulted in increased expression of proapoptotic proteins Bax with an increase in cytosolic Cytochrome-C and inhibition of anti-apoptotic protein Bcl-2. Our results revealed the potential mechanism of cellular effects of TiO(2)NFs.