# Photodynamic treatment in glioma: Metabolic and structural evaluation after therapy

## TL;DR

Photodynamic therapy using chlorin e6 effectively targets and kills gliosarcoma cells by damaging mitochondria and disrupting the cytoskeleton, primarily through apoptosis.

## Contribution

This study demonstrates that chlorin e6-based photodynamic therapy induces apoptosis and cytoskeletal damage in gliosarcoma cells, offering a novel therapeutic approach.

## Key findings

- PDT with chlorin e6 caused cytoskeletal disruption and reduced mitochondrial membrane potential in gliosarcoma cells.
- Cell death predominantly occurred via apoptosis, followed by necrosis, with effects varying by chlorin e6 concentration.
- Microscopy and flow cytometry confirmed morphological changes and mitochondrial damage in treated cells.

## Abstract

Gliomas are malignant tumors of the central nervous system, and one severe variant is called gliosarcoma. Photodynamic therapy (PDT) is a technique that stands out in the oncology area for minimizing side effects for the patient, triggering cell death at the site of irradiation, and can be used concomitantly with conventional treatments. This study aimed to evaluate the interaction of chlorine e6 with the cytoskeleton and mitochondria, as well as morphological changes and the death mechanism triggered after PDT. Chlorin e6 was used at concentrations of 200, 12.5, and 6.25 μg/mL, and cytoskeletal changes were analyzed by alpha‐tubulin staining and mitochondrial membrane potential (MMP) analysis by JC‐1 and Rhodamine 123 in flow cytometry. Surface features were examined using scanning electron microscopy, and the type of cell death mechanism was determined by flow cytometry with annexin and propidium iodide. Changes in the cytoskeleton were observed after PDT. Cytometry showed that cell death occurred predominantly via the apoptosis pathway, followed by the necrosis pathway. Chlorin e6 associated with PDT causes damage to gliosarcoma cells, regardless of concentration, showing cytoskeletal disruption, a decrease in MMP, and the percentage of cell death varies according to the concentration of PS.

PDT with chlorin e6 reduced mitochondrial membrane potential and induced gliosarcoma cell death, mainly via apoptosis and subsequently necrosis. Microscopy and flow cytometry confirmed cytoskeletal disorganization and morphological changes. These findings highlight PDT with Ce6 as a promising therapeutic alternative for gliosarcomas, showing strong cytotoxic and mitochondria‐targeted effects.