Silver Nanoparticle-Embedded Carbon Nitride: Antifungal Activity on Candida albicans and Toxicity toward Animal Cells

• Published in: ACS applied materials & interfaces 2024-05, Vol.16 (20), p.25727-25739
• Main Authors: Arumugam, Ganeshkumar, Durairaj, Sivaraj, Gonçale, Juliana Caparroz, Fonseca do Carmo, Paulo Henrique, Terra Garcia, Maíra, Soares da Silva, Newton, Borges, Bruno Montanari, Loures, Flavio Vieira, Ghosh, Deepa, Vivanco, Juan F., Junqueira, Juliana Campos
• Format: Article
• Language: English
• Subjects: Biological and Medical Applications of Materials and Interfaces
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.4c02694

The development of engineered nanomaterials has been considered a promising strategy to control oral infections. In this study, silver-embedded carbon nitrides (Ag@g-CN) were synthesized and tested against Candida albicans, investigating their antifungal action and biocompatibility in animal cells. Ag@g-CN was synthesized by a simple one-pot thermal polymerization technique and characterized by various analytical techniques. X-ray diffraction (XRD) analysis revealed slight alterations in the crystal structure of g-CN upon the incorporation of Ag. Fourier transform infrared (FT-IR) spectroscopy confirmed the presence of Ag–N bonds, indicating successful silver incorporation and potential interactions with g-CN’s amino groups. UV–vis spectroscopy demonstrated a red shift in the absorption edge of Ag@g-CN compared with g-CN, attributed to the surface plasmon resonance effect of silver nanoparticles. Field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) confirmed the 2D layered sheet like morphology of both materials. The Ag 3d peaks found in X-ray photoelectron spectroscopy (XPS) confirmed the presence of metallic Ag0 nanoparticles in Ag@g-CN. The Ag@g-CN materials exhibited high antifungal activity against reference and oral clinical strains of C. albicans, with minimal inhibitory concentration (MIC) ranges between 16–256 μg/mL. The mechanism of Ag@g-CN on C. albicans was attributed to the disruption of the membrane integrity and disturbance of the biofilm. In addition, the Ag@g-CN material showed good biocompatibility in the fibroblastic cell line and in Galleria mellonella, with no apparent cytotoxicity observed at a concentration up to 1000 μg/mL. These findings demonstrate the potential of the Ag@g-CN material as an effective and safe antifungal agent for the treatment of oral fungal infections.