Biocompatibility and nanostructured materials: applications in nanomedicine.

There has been huge interest in applications of nanomaterials in biomedical science, including diagnosis, drug delivery, and development of human organs. Number of these nanomaterials has been already studied in human or at pre-clinical trial. There is a growing concern on potential toxicity and adverse effects of nanomaterials on human health, including lack of standard method of assessment of toxicology of these materials. Our investigation indicated that the bare and small nanoparticle have higher toxicity than modified and bulk materials, respectively. In addition, spherical nanoparticles have less toxicity than rod nanoparticles due to immune response of body.

Megavoltage X-ray Dose Enhancement with Gold Nanoparticles in Tumor Bearing Mice.

One of the applications of gold nanoparticles (GNPs) in medicine is radiation dose-enhancing effect. Although there are many simulations, in vitro and in vivo evidence that GNPs can enhance significantly the radiation dose effect of orthovoltage beams. These beams compared with megavoltage (MV) beams, have limited applications in radiotherapy. In order to evaluate GNPs radiosensitization performance with MV beams in-vivo, we used two most clinically used X-ray beams (6 and 18 MV) with the dose of 20 Gy for each mouse. Intratumoral injection of 50 nm GNPs with the concentration of 5 mg ml(-1) was applied to melanoma tumor growing in the left leg of 7 to 8 mice in 4 control and treatment groups of C57BL/6 mice. Albeit, using 10 cm plexiglass jig phantom in the beam path improved the radiation - treatments, the statistical differences between groups were not significant. According to the results, it is concluded that mice can be treated with smaller tumors and higher concentrations of GNPs in MV radiation beams.