Rita Barros

Photodynamic therapy (PDT) is a non-invasive cancer treatment that uses light-activated photosensitisers to generate reactive oxygen species (ROS) and kill tumour cells. This project aims to evaluate the PDT potential of graphitic carbon nitride nanoparticles (GCN- NPs) in melanoma and to expand their applicability to deeper tissues using up-converting nanoparticles (UCNPs). GCN-NPs are promising due to their strong ROS-generating capacity under visible light. Since visible light penetrates only a few millimetres into tissue, in the first phase of this project, I will study GCN’s ability to generate ROS and induce apoptosis in melanoma cells (skin cancer), using stable cell lines that express genetically encoded sensors for ROS (HyPer7) and apoptosis (SCAT3). Experiments will be performed in standard 2D monolayers and in physiologically relevant 3D tumour spheroids, which better reproduce tumour architecture and microenvironmental gradients. In parallel, I will address the key limitation of visible light activation by conjugating GCN- NPs to UCNPs. These UCNPS absorb tissue-penetrating near-infrared (NIR) light and convert it into visible light, enabling GCN-NPS activation in deeper tissues and expanding their therapeutic potential beyond superficial cancers.