RAPOSO, BRUNO L.SOUZA, SUEDEN O.SANTANA, GLEYCIANE S. deSARMENTO-NETO, JOSE F.SANTOS, BEATE S.RIBEIRO, MARTHA S.REBOUCAS, JULIO S.CABRAL FILHO, PAULO E.FONTES, ADRIANA2023-03-212023-03-21RAPOSO, BRUNO L.; SOUZA, SUEDEN O.; SANTANA, GLEYCIANE S. de; SARMENTO-NETO, JOSE F.; SANTOS, BEATE S.; RIBEIRO, MARTHA S.; REBOUCAS, JULIO S.; CABRAL FILHO, PAULO E.; FONTES, ADRIANA. Biophotonic strategy associated with hexyl zinc porphyrin for inactivation of Candida spp.. In: ANNUAL MEETING OF THE BRAZILIAN SOCIETY FOR BIOCHEMISTRY AND MOLECULAR BIOLOGY (SBBq), 51st; CONGRESS OF BRAZILIAN BIOPHYSICAL SOCIETY (SBBf)/LATIN AMERICAN FEDERATION OF BIOPHYSICAL SOCIETIES (Lafebs), 46th, September 5-8, 2022, Águas de Lindóia, SP. <b>Abstract...</b> São Paulo, SP: Sociedade Brasileira de Bioquímica e Biologia Molecular - SBBq, 2022. p. 271-271. Disponível em: http://repositorio.ipen.br/handle/123456789/33913.http://repositorio.ipen.br/handle/123456789/33913INTRODUCTION: The genus Candida is among the most frequent fungal pathogens worldwide. The indiscriminate use of antifungals enables the spread of resistant strains, which have been associated with high morbidity and mortality. Photodynamic inactivation (PDI) is a promising technology to treat resistant Candida spp. infections. PDI occurs when light excites a photosensitizer (PS) leading to the production of reactive oxygen species (ROS). Zn(II) porphyrins (ZnPs) present high efficiency for intracellular ROS generation and structural versatility for tailored lipophilicity and ionic character, modulating the bioavailability and interaction with cellular structures. OBJECTIVES: This study aimed to investigate the potential of ZnTnHex-2-PyP4+-mediated PDI to inactivate C. albicans and C. glabrata yeasts. MATERIALS AND METHODS: Candida yeasts (1×10^7 CFU/mL) were evaluated according to the groups: (i) control (without treatment); (ii) only ZnTnHex-2-PyP4+ (dark); (iii) only light (blue LED); and (iv) PDI (ZnP + light) using 10 min of pre-incubation. Different ZnP concentrations (0.15 to 1.25 μM) and light doses were firstly tested with C. albicans. Treated samples were diluted and seeded on Sabouraud agar for colony enumeration after incubation at 37 ºC for 24 h. DISCUSSION AND RESULTS: C. albicans viability decreased with increasing ZnP concentration, achieving complete eradication at 0.8 μM and 3 min of irradiation (24.1 mW/cm²). PDI with 1.25 μM and 1 min of irradiation resulted in a 2 log10 reduction only, demonstrating the importance of light dose in microbial photoinactivation. PDI parameters were subsequently adjusted for inactivation of C. glabrata. Complete C. glabrata eradication was achieved with ZnP at 0.8 μM, and 3 min of irradiation, however, at a higher irradiance (38.4 mW/cm²). Groups treated with either light or ZnP alone did not affect Candida spp. viability. CONCLUSION: These results suggest that the protocols used in this study were efficient for inactivating Candida spp. yeasts at sub-micromolar concentration ZnP and short irradiation times.271-271openAccessResumo de eventos científicos0000-0002-4203-1134https://orcid.org/0000-0002-4203-1134