Speaker
Description
Microwave hyperthermia (MWH) is an application using mild heat at a temperature range of 40-42°C to treat cancers. The source of local mild heat is emitted from the friction forces of oscillated dipole actions of water molecules in tissues. The local mild heat attracts temperature-sensitive anticancer drugs which allows efficient chemotherapy and reduce side effects. Unfortunately, studies which link MWH with the production of reactive oxygen species (ROS) are still lacking. Therefore, in this study, the aim is to screen and evaluate ROS production of dual-sensitizer loaded nanodroplets under MWH exposure in cell-free solution. This study will act as an alternative intervention to ultrasound. Two types of phantoms were used namely agar phantom (AP) and gelatine-based tumour mimicking phantom (TMP) which acted as tissue barrier models. An ROS assay, potassium iodide (KI) was used to detect and quantify ROS production mainly hydrogen peroxide upon UV light absorbance at 350nm. Experiments were run in dark. Based on results, ROS mainly hydrogen peroxide was clearly produced only when sensitizers were encapsulated in nanodroplets under MWH exposure. There were no significant differences in ROS productions between the dual and single-sensitizer loaded nanodroplets under MWH exposure in each phantom (p>0.05). However, significant differences in ROS productions were recorded where a higher ROS production was obtained in the dual-sensitizer loaded nanodroplets compared to their corresponding unencapsulated form under MWH exposure in AP (p<0.01) and TMP (p<0.05). Significant differences in ROS production did not clearly occur between the dual and
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single-sensitizer loaded nanodroplets but developed between dual-sensitizer loaded nanodroplets and their corresponding unencapsulated sensitizer form under MWH exposure in each phantom. Therefore, nanodroplets may play a role in promoting significant ROS production through the influence of MWH exposure, similarly to outcomes found with ultrasound exposure. However, further studies should be performed to elucidate underlying mechanisms which stimulate sensitizers to generate ROS under MWH exposure.
