6 In vivo PDT studies with fullerenes

During PDT the PS concentrates specifically within the malignant tissue so when the light is directly focused on the lesion, it causes reactive oxygen species (ROS) to be generated resulting in cellular destruction at the region of interest. There is a report of regressions after PDT in a mouse tumor model, which correlates to the fact that fullerenols are potential antioxidants and have anti-tumor and anti-metastasis effects by reducing tumor vascularization [176]. This is also consistent with recent reports showing that reactive oxygen intermediates the increase of VEGF expression in vitro and in vivo [177–179] and that antioxidants inhibit VEGF expression [180, 181] and prevent neovascularization [181, 182].