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.

中文翻译：

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银纳米颗粒嵌入氮化碳：对白色念珠菌的抗真菌活性和对动物细胞的毒性


工程纳米材料的开发被认为是控制口腔感染的有前途的策略。在这项研究中，合成了银嵌入的氮化碳（Ag@g-CN）并针对白色念珠菌进行了测试，研究了它们在动物细胞中的抗真菌作用和生物相容性。 Ag@g-CN是通过简单的一锅热聚合技术合成的，并通过各种分析技术进行表征。 X 射线衍射 (XRD) 分析表明，掺入 Ag 后 g-CN 的晶体结构发生了轻微变化。傅里叶变换红外 (FT-IR) 光谱证实了 Ag-N 键的存在，表明银的成功掺入以及与 g-CN 氨基的潜在相互作用。紫外可见光谱表明，与 g-CN 相比，Ag@g-CN 的吸收边发生红移，这归因于银纳米粒子的表面等离子体共振效应。场发射扫描电子显微镜（FE-SEM）和透射电子显微镜（TEM）证实了两种材料的二维层状片状形态。 X 射线光电子能谱 (XPS) 中发现的 Ag 3d 峰证实了 Ag@g-CN 中存在金属 Ag ⁰ 纳米颗粒。 Ag@g-CN材料对白色念珠菌的参考菌株和口腔临床菌株表现出高抗真菌活性，最小抑菌浓度（MIC）范围在16-256 μg/mL之间。 Ag@g-CN 对白色念珠菌的作用机制归因于膜完整性的破坏和生物膜的扰动。此外，Ag@g-CN材料在成纤维细胞系和大蜡螟中表现出良好的生物相容性，在浓度高达1000 μg/mL时没有观察到明显的细胞毒性。 这些发现证明了Ag@g-CN材料作为治疗口腔真菌感染的有效且安全的抗真菌剂的潜力。