Determination of the intracellular localization of bacteriochlorin-derived photosensitizers for photodynamic therapies.

• Grant number: 25/03409-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2025
• End date: June 30, 2026
• Field of knowledge: Physical Sciences and Mathematics - Physics
• Principal Investigator: Sebastião Pratavieira
• Grantee: Julia Bernardes Coelho
• Host Institution: Instituto de Física de São Carlos (IFSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil

Abstract

Cancer remains one of the leading causes of global mortality, exacerbated by increased longevity, exposure to carcinogenic agents, and disparities in access to treatment. Traditional therapies, such as surgery and chemotherapy, while effective, are often associated with significant side effects, driving the demand for more selective and less invasive methods. Among innovative approaches, photodynamic therapy (PDT) stands out, utilizing reactive oxygen species (ROS) to eliminate tumor cells. The study of PDT has become even more relevant with the advancement of third-generation photosensitizers (PS), such as bacteriochlorins, which offer greater tumor selectivity, reduced side effects, and high efficacy in treating deep-seated tumors due to their absorption in the near-infrared region (740-780 nm). This project proposes a detailed comparison between pigmented metastatic melanoma cells (SH4) and healthy fibroblasts to evaluate the selectivity and efficiency of PS. To achieve this, confocal fluorescence microscopy will be employed to map the intracellular localization of PS in different organelles, including the endoplasmic reticulum, cytoskeleton, mitochondria, lysosomes, nucleus, and glycoproteins. After identifying the intracellular localization of PS, cell death will be analyzed to determine whether it occurs via apoptosis or necrosis. This approach will contribute to a deeper understanding of the therapeutic mechanisms involved, with the potential for developing more effective and safer treatments. (AU)