Presentation
13 March 2024 Evaluating photodynamic therapy with protoporphyrin IX in the context of mitochondrial bioenergetics
Author Affiliations +
Abstract
Protoporphyrin IX (PPIX) is an endogenous photosensitizer synthesized inside mitochondria by administering 5-aminolevulinic acid (ALA). With that in mind, it is important to understand the effects and mechanisms of PDT with PPIX directly on mitochondria at the bioenergetic level. This study evaluated mitochondrial respiration and swelling after in vitro PDT treatment at 635 nm in isolated mice liver mitochondria. Overall, respiration after PDT treatment showed an increase in mitochondria proton leak, reducing the respiratory control ratio (RCR) and coupling efficiency, and promoting a partial loss of cytochrome c, proportionally higher as the PPIX concentration or light dose increased. Besides, it also promoted mitochondrial swelling due to the opening of the mitochondrial permeability transition pore. These results indicate that PDT using PPIX as a photosensitizer probably causes damage to mitochondrial membranes, impairing respiration, which can contribute to cell death afterward.
Conference Presentation
© (2024) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Natasha F. Mezzacappo, Natalia M. Inada, and Vanderlei S. Bagnato "Evaluating photodynamic therapy with protoporphyrin IX in the context of mitochondrial bioenergetics", Proc. SPIE PC12823, Optical Methods for Tumor Treatment and Detection: Mechanisms and Techniques in Photodynamic Therapy XXXII, PC1282306 (13 March 2024); https://doi.org/10.1117/12.3003911
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KEYWORDS
Mitochondria

Photodynamic therapy

Bioenergetics

Cell death

Diseases and disorders

Dose control

Liver

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