Investigating the role of calcium and biological trace elements in hypericin photodynamic therapy induced tumor cell death using nuclear microscopy

This study involves the analysis of human NPC xenograft tumors in murine models using the National University of Singapore nuclear microscope. PDT was carried out using the photosensitiser hypericin under various conditions. The microbeam techniques of particle induced X-ray emission, Rutherford backscattering spectrometry and scanning transmission ion microscopy were used to quantify elemental concentrations in cryo-fixed sections of tumor tissue. Preliminary results are presented as well as their implications for the mechanisms underlying photodynamic cell killing.