Investigation of ROS-Driven Cytotoxic Mechanisms in WO3:Ag Heterostructures Supported on Carbon Against Bladder Cancer
Authors:   Center for Development of Functional Materials, Federal University of São Carlos, Fragelli Bruna , Almeida Rodolpho Joice Margareth de ,   Federal University Of São Carlos, de Godoy Krissia Frando ,   Federal University Of São Carlos, Líbero Laura Ordonho ,   Center for Development of Functional Materials, Federal University of São Carlos, Granone Luis Ignácio ,   Chemistry Departament, (IFIMAR), CONICET, Universidad Nacional de Mar del Plata, Churio Maria Sandra ,   Chemistry Departament, (IFIMAR), CONICET, Universidad Nacional de Mar del Plata, Muniz Rennó Ana Claudia ,   Department of Biosciences, Federal University of São Paulo, Freitas Anibal Fernanda de ,   Federal University Of São Carlos, Longo Elson ,   Center for Development of Functional Materials, Federal University of São Carlos, Assis Marcelo ,   Department of Biosciences, Federal University of São Paulo
Published: December 2024

Bladder cancer presents a significant health challenge due to its high malignancy and rising incidence rates. Silver-based materials are well-known for their cytotoxic effects on various cell types. This study not only aimed to synthesize and characterize carbon-supported WO3:Ag heterostructures but also to evaluate their biological and physicochemical properties. The material was synthesized through the synergistic thermal decomposition of α-Ag2WO4 dispersed in chitosan, followed by WO3:Ag heterostructure formation on a carbon support, yielding samples with varying α-Ag2WO4 concentrations (SC, SC1, SC2, and SC4, for 0, 10, 20 and 40% of α-Ag2WO4 for chitosan). Characterization confirmed the successful formation of carbon-supported heterostructures with controlled ionic release and enhanced ROS generation. In vitro assays were conducted to assess the viability of non-tumor (3T3 fibroblasts) and tumor (bladder carcinoma MB49) cells using MTT salt and neutral red dye. Additional analyses included autophagy detection by correlating data from viability assays, nitric oxide and ROS quantification using the Griess reaction and fluorescent probes, and Caspase-3 activity measured with a fluorescent antibody. The results indicated that SC1 and SC2 samples were more effective against both cell types, with SC2 showing heightened effectiveness against the tumor lineage by inducing greater oxidative stress in MB49 cells compared to 3T3 fibroblasts. Additionally, the materials exhibited low ionic release (<0.01%), reducing potential adverse effects. Mechanistic analysis showed that the carbon support and synergistic interactions between WO₃ and Ag modulated ⦁OH radical production, even without light, enhancing the material's cytotoxic efficiency. These findings highlight the therapeutic potential of WO₃:Ag heterostructures as a safe and effective approach for treating aggressive cancers like bladder carcinoma, emphasizing the importance of further development in advanced biofunctional materials. This study also highlights the therapeutic potential of carbon-supported WO3:Ag heterostructures in bladder cancer treatment and underscores the importance of continued research in the development of novel anticancer strategies.