One-Pot Synthesis and Antifungal Activity of Nontoxic Silver-Loaded Hydroxyapatite Nanocomposites against Candida Species

Abstract

The impact of fungal diseases and the development of antimicrobial agents against pathogenic fungi have emerged as a main global healthcare challenge. In this study, the antifungal activity of silver-loaded hydroxyapatite (Ag/HAP) nanocomposites (NCs) with different Ag content synthesized by a one-pot microwave-assisted solvothermal method was evaluated against sensitive and resistant Candida species. The NCs’ composition and morphology were characterized by X-ray diffraction, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and high-resolution transmission electron microscopy analysis. Antifungal studies were conducted by a microdilution method according to a protocol from the Clinical and Laboratory Standards Institute. The main inhibitory effect was observed against Candida krusei, with a minimum inhibitory concentration (MIC) of 31.2 μg/mL, followed by Candida parapsilosis sensu stricto and Candida tropicalis (62.5 μg/mL) and Candida glabrata and Candida albicans (125 μg/mL). Furthermore, a toxicity assay was performed in the in vivo model Galleria mellonella by bathing or inoculating with the same NC concentration used in the previously mentioned microdilution experiments. For both approaches, all NC concentrations were not toxic in the in vivo model. The specific antifungal activity demonstrated that NCs act efficiently against species of Candida. These results show a potential antifungal application for well-designed nanostructured Ag/HAP composites.

Acinetobacter sp. mediated synthesis of AgNPs, its optimization, characterization and synergistic antifungal activity against C. albicans

“…Therefore, development of new broad spectrum drugs is necessary for control of Candida infections (Nett et al ; Yapar ). In our study, C. albicans showed dose dependent susceptibility towards AgNPs with MIC of 4 µ g ml −1 , which is lower than earlier reports (Panáček et al ; Kulatunga et al ; Gottardo et al ). It was suggested that anticandidal activity of AgNPs is due to the disruption of cell membrane integrity (Kim et al ).…”

“…Chemically synthesized AgNPs exhibits low MIC values along with high toxicity and low stability (Pal et al 2007;Kittler et al 2010;Pereira et al, 2014). Recently, anticandidal activity of rod-shaped silver loaded hydroxyapatite nanocomposites has been reported with MIC of 125 µg ml À1 against C. albicans (Gottardo et al 2019). However, it is important to note that, till date, there is only one report available on antifungal activity of bacteriogenic AgNPs against C. albicans (Lateef et al 2016).…”

Nanostructured Lipid Carriers Loaded with Lippia sidoides Essential Oil as a Strategy to Combat the Multidrug-Resistant Candida auris

“…Differences in resulting survival plots were evaluated using the Mantel-Cox test (Log-rank method) using the GraphPad Prism 5 software. The EO-loaded NLC formulations, at their respective concentrations tested, were considered toxic when they were able to kill at least 50% of larvae in a period of 5 days postinjection, following the protocol of Gottardo et al (2019) [36].…”

Size‐Controlled Facile Synthesis of Silver Nanoparticles by Chemical Reduction Method and Analysis of Their Antibacterial Performance

“…The impact of bacterial disease and the promotion of effective antibacterial agents to combat pathogenic diseases have appeared as a serious global healthcare challenge. [1] To overcome such a challenge, antibacterial agents have been invented, and efforts are being made to invent more new antibacterial agents. Parallel to their invention and development, researchers are attempting to confirm the effectiveness of existing agents.…”