Titanium Dioxide Nanoparticles as Radiosensitisers: An and Phantom-Based Study.

Radiosensitisation caused by titanium dioxide nanoparticles (TiO-NPs) is investigated using phantoms (PRESAGE dosimeters) and using two types of cell lines, cultured human keratinocyte (HaCaT) and prostate cancer (DU145) cells. Anatase TiO-NPs were synthesised, characterised and functionalised to allow dispersion in culture-medium for studies and halocarbons (PRESAGE chemical compositions). PRESAGE dosimeters were scanned with spectrophotometer to determine the radiation dose enhancement. Clonogenic and cell viability assays were employed to determine cells survival curves from which the dose enhancement levels "radiosensitisation" are deduced. Comparable levels of radiosensitisation were observed in both phantoms and cells at kilovoltage ranges of x-ray energies (slightly higher . Significant radiosensitisation (~67 %) of control was also noted in cells at megavoltage energies (commonly used in radiotherapy), compared to negligible levels detected by phantoms. This difference is attributed to biochemical effects, specifically the generation of reactive oxygen species (ROS) such as hydroxyl radicals (OH), which are only manifested in aqueous environments of cells and are non-existent in case of phantoms. This research shows that TiO-NPs improve the efficiency of dose delivery, which has implications for future radiotherapy treatments. Literature shows that TiO-NPs can be used as imaging agents hence with these findings renders these NPs as theranostic agents.