ADVANCING PHOTODYNAMIC THERAPY: COMPARATIVE STUDY OF BUTYL TOLUIDINE BLUE O AND CONVENTIONAL PHENOTHIAZINE PHOTOSENSITIZERS ON FIBROBLAST VIABILITY

Claudio Teruo Kassa; Aline Souza Silva; Rosani Tereza De Siqueira E Silva; Alessandra Lima da Silva Martins; Shirlene De Holanda lima; Valherya Silva Rodriguez; Giovanna Fontgalland Ferreira; Raquel Agnelli Mesquita Ferrari; Mark Wainwright; Renato Prates

Título del Trabajo

Autores

Claudio Teruo Kassa
Aline Souza Silva
Rosani Tereza De Siqueira E Silva
Alessandra Lima da Silva Martins
Shirlene De Holanda lima
Valherya Silva Rodriguez
Giovanna Fontgalland Ferreira
Raquel Agnelli Mesquita Ferrari
Mark Wainwright
Renato Prates

Modalidad

Investigación

Área temática

Medicina

Fecha de publicación

14/08/2026

País de publicación

Argentina | Argentina

Idioma de la Publicación

es-419

Página del Trabajo

https://www.even3.com.br/anais/ii-encuentro-biofotonica-597461/1253020-advancing-photodynamic-therapy--comparative-study-of-butyl-toluidine-blue-o-and-conventional-phenothiazine-photo

ISBN

978-65-272-2678-9

Palabras Clave

butyl toluidine blue O (BuTBO), antimicrobial photodynamic therapy (aPDT), L929

Resumen

Introduction: Antimicrobial photodynamic therapy (aPDT) has emerged as a promising alternative for infection control. This technique uses photosensitizers which, upon light activation, produce reactive oxygen species capable of inactivating microorganisms. While toluidine blue O (TBO) and methylene blue (MB) are commonly employed in aPDT, a novel derivative butyl toluidine blue O (BuTBO) has demonstrated potential to improve efficacy by minimizing photosensitizer dimerization. This study aims to evaluate the effects of BuTBO, TBO, and MB on fibroblasts viability, both in dark conditions and after light irradiation. Methods: Fibroblasts were exposed to BuTBO, MB, or TBO at concentrations ranging from 100 to 0.39 µM. Viability in the absence of light was assessed after a 5 min exposure. For aPDT experiments, cells were treated with 25 µM of each photosensitizer, incubated for 5 min, then irradiated with red LED light. Cell viability was assessed by MTT immediately after irradiation and, in a separate sample, after 24 h incubation. Crystal violet was used in parallel to quantify the total adherent cell biomass, providing complementary data independent of metabolic activity. Statistical analysis was conducted using one-way ANOVA followed by Bonferroni post hoc test. Results: In the dark, all photosensitizers showed no reduction in fibroblast viability; viability remained high at concentrations ≤ 25 µM. After aPDT at 25 µM, BuTBO caused a significantly greater reduction in viability compared to MB and TBO, as measured by MTT, indicating superior photodynamic efficacy. In contrast, crystal violet staining revealed no significant differences in optical density among groups, suggesting preservation of total adherent cell biomass. These data support that despite transient metabolic impairment post-aPDT, BuTBO maintains favorable cytocompatibility under the tested conditions. Conclusion: This pioneering in vitro study identifies BuTBO as an effective and biocompatible TBO-derived photosensitizer with strong potential for future clinical applications in antimicrobial photodynamic therapy.

Título del Evento: II Encuentro Latinoamericano de Investigación y Práctica en Biofotónica y I Seminario de Investigación de Posgrado en Salud
Ciudad del Evento: Buenos Aires
Título de las Actas del Evento: Actas II Encuentro Latinoamericano de Investigación y Práctica en Biofotónica y I Seminario de Investigación de Posgrado en Salud
Nombre de la Editora: Even3
Medio de Divulgación: Meio Digital

Como citar

KASSA, Claudio Teruo et al.. ADVANCING PHOTODYNAMIC THERAPY: COMPARATIVE STUDY OF BUTYL TOLUIDINE BLUE O AND CONVENTIONAL PHENOTHIAZINE PHOTOSENSITIZERS ON FIBROBLAST VIABILITY.. In: Actas II Encuentro Latinoamericano de Investigación y Práctica en Biofotónica y I Seminario de Investigación de Posgrado en Salud. Anais...Sao Paulo(SP) UNIMAIMONIDES, 2026. Disponible en: https//www.even3.com.br/anais/II-Encuentro-Biofotonica-597461/1253020-ADVANCING-PHOTODYNAMIC-THERAPY--COMPARATIVE-STUDY-OF-BUTYL-TOLUIDINE-BLUE-O-AND-CONVENTIONAL-PHENOTHIAZINE-PHOTO. Acceso en: 21/08/2026