PHOTODYNAMIC EVALUATION OF METHYLENE VIOLET 3RAX: INSIGHTS INTO ITS INTERACTION WITH MELANOMA

Thais Soares de Oliveira; Mirella Boaro Kobal; Andre Satoshi Ferreira; Alexandre Mendes de Almeida Junior; KARINA ALVES DE TOLEDO; Sabrina Alessio Camacho; Pedro Aoki

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Trabalho

Título do Trabalho

PHOTODYNAMIC EVALUATION OF METHYLENE VIOLET 3RAX: INSIGHTS INTO ITS INTERACTION WITH MELANOMA

Autores

Thais Soares de Oliveira
Mirella Boaro Kobal
Andre Satoshi Ferreira
Alexandre Mendes de Almeida Junior
KARINA ALVES DE TOLEDO
Sabrina Alessio Camacho
Pedro Aoki

Modalidade

Pôster - resumo

Área temática

Materiais e biomateriais

Data de Publicação

27/05/2026

País da Publicação

Brasil

Idioma da Publicação

pt-BR

Página do Trabalho

https://www.even3.com.br/anais/workshop-do-ineo-2026/1459858-photodynamic-evaluation-of-methylene-violet-3rax--insights-into-its-interaction-with-melanoma

ISBN

978-65-272-2467-9

Palavras-Chave

Photodynamic therapy, Langmuir filme, Melanoma, methylene violet 3RAX

Resumo

Although melanoma is the least common form of skin cancer, it remains the most aggressive and lethal subtype, posing major therapeutic challenges¹. Photodynamic therapy (PDT) is an attractive alternative to conventional approaches because it is minimally invasive and can provide spatial and temporal selectivity². Here, we investigated the phenazine-derived photosensitizer methylene violet 3RAX (MV) as a PDT agent against the melanoma cell lines A375 and SH-4, combining in vitro assays with Langmuir monolayer studies as membrane models. MV showed negligible dark cytotoxicity, whereas photoactivation elicited a clear dose-dependent reduction in cell viability. Flow cytometry indicated late apoptosis as the predominant cell-death pathway under irradiation. To extend these two-dimensional findings toward a more physiologically relevant context, we will evaluate MV-mediated PDT in three-dimensional spheroids of both cell lines and compare responses between 2D and 3D systems. Langmuir isotherms revealed MV adsorption onto lipid monolayers and preferential interactions with anionic lipids. Moreover, irradiation promoted loss of monolayer material, consistent with lipid hydroperoxidation and subsequent chain cleavage, leading to membrane destabilization. Overall, these results support MV as a promising PDT photosensitizer, combining low dark toxicity with light-triggered cytotoxicity, apoptosis induction, and mechanistic evidence of membrane damage, warranting further validation in advanced biological models and informing its potential translation to therapeutic applications. References [1] F. Hoffmann-La Roche Ltd. Things you may not know about skin cancer. Published in 2020. Accessed February 20, 2021. https://www.roche.com/research_and_development/what_we_are_working_on/oncology/things-you-may-not-know-about-skin-cancer.html [2] Ochsner M. Photophysical and photobiological processes in photodynamic therapy of tumors. J Photochem Photobiol B Biol. 1997;39(1):1-18. doi:10.1016/S1011-1344(96)07428-3 Acknowledgments This work was supported by São Paulo Research Foundation (FAPESP, 2022/02189-2, 2023/17867-9, EMU 24/16714-7, EMU 2023/07375-1 and EMU 2023/16973-0) and National Council for Scientific and Technological Development (CNPq). T.S.O., M.B.K., A.M.A.Jr., A.S.F. and S.A.C. are thankful for her fellowships provided by FAPESP 2023/11785-0, 2021/14500-1, 2024/12714-2, 2024/11383-2, and 2024/15686-0, respectively. We thank the National Institute of Organic Electronics - INEO (FAPESP - process no. 2025/27044-5 and CNPq - process: 408449/2024-1)

Título do Evento: Workshop do INEO 2026
Cidade do Evento: Nazaré Paulista
Título dos Anais do Evento: Anais do Workshop do INEO 2026
Nome da Editora: Even3
Meio de Divulgação: Meio Digital

Como citar

OLIVEIRA, Thais Soares de et al.. PHOTODYNAMIC EVALUATION OF METHYLENE VIOLET 3RAX: INSIGHTS INTO ITS INTERACTION WITH MELANOMA.. In: Anais do Workshop do INEO 2026. Anais...Nazaré Paulista(SP) Hotel Estância Atibainha, 2026. Disponível em: https//www.even3.com.br/anais/workshop-do-ineo-2026/1459858-PHOTODYNAMIC-EVALUATION-OF-METHYLENE-VIOLET-3RAX--INSIGHTS-INTO-ITS-INTERACTION-WITH-MELANOMA. Acesso em: 10/08/2026