Characterization of silver nanoparticles (AgNPs) used in this study.

<p>A) Transmission electron micrograph of AgNPs functionalized with Polyvinylpyrrolidone (Vector-Vita Ltd., Russia), B) histogram of measured nanoparticles, C) High-angle annular dark-field imaging (HAADF) of AgNPs, D) Typical EDS analysis of particles along the trace indicated by a white line in (C).</p

The combined effect of silver nanoparticles (AgNPs) and fluconazole (FLC) in <i>C. albicans</i> reduces cell proliferation.

<p>Liquid cultures were exposed to the IC₅₀ of FLC and several combinations of AgNPs-FLC.</p

Cell density and concentrations of AgNPs and FLC used to determine the half–maximal inhibitory concentration (IC₅₀) of fluconazole (FLC) and AgNPs (silver) to inhibit <i>C. albicans.</i>

<p>The IC₅₀ for each cell concentration is underlined.</p><p>Cell density and concentrations of AgNPs and FLC used to determine the half–maximal inhibitory concentration (IC₅₀) of fluconazole (FLC) and AgNPs (silver) to inhibit <i>C. albicans.</i></p

TEM images showing interaction of silver nanoparticles with <i>C. albicans</i>.

<p>A, B) Sections of cells in which extracellular agglomeration of AgNPs coincided with the accumulation of smaller AgNPs in the cell wall and cytoplasm, C) Size distribution of intracellular AgNPs.</p

Subcultures of <i>C. albicans</i> in YPD agar plates after 24 h of incubation.

<p>A) Representative image of a culture to determine the IC₅₀ of AgNPs and FLC; B) subcultures of the combined effect of the IC₅₀ of AgNPs (18 µg/mL) and two concentrations of FLC; C) subcultures of the combined effect of the MIC of AgNPs (42 µg/mL) and two concentrations of FLC. In B–C the IC₅₀ of FLC (31 µg/mL) was used in the inoculations on the left side of the plate and 300 µg/mL of FLC on the right side.</p

Microscopic analysis of <i>C. albicans</i> from liquid cultures.

<p>A, B) Cells from control cultures observed under optical bright field microscopy and TEM, respectively; C, D) Cells exposed to silver nanoparticles were agglomerated and surrounded by AgNPs as seen by optical bright-field microscopy (C) and confirmed by TEM (D). Black arrows indicate <i>Candida</i> cells and white arrows indicate AgNPs aggregation.</p

Crystallographic analysis of intracellular nanoparticles in <i>C. albicans</i>.

<p>Silver nanoparticle shows (111) planes with 0.24 nm spacing.</p

Chemical characterization of <i>C. albicans</i> ultrathin sections.

<p>A, D) High-angle annular dark-field imaging (HAADF) of analyzed cells; (B, E) EDS analysis showing the absence of silver in (A) and the presence of silver in (D); (C, F) Lineal EDS spectrum of (A) and (D), respectively. Red line in A and D indicates the transect where chemical analysis was performed.</p

Minimum inhibitory concentration (MIC) of AgNPs for <i>C. albicans</i>, at different cell concentrations.

<p>Minimum inhibitory concentration (MIC) of AgNPs for <i>C. albicans</i>, at different cell concentrations.</p

Chemical characterization of intracellular nanoparticles.

<p>A) HAADF image in which analysis of internal AgNPs was carried out, B) Closer view of internal-external particles, C) Amplified image of analyzed internal particle, (D–F) Images of analyzed internal particle, G) EDS analysis showing the presence of silver, H) Variation of Ag and Os along a trace line at neighbor points near the particle indicated by a yellow arrow in Figs A to E; sampled points can be seen as black dots in D and E. Yellow arrows point out analyzed particle, red arrows point out extracellular AgNPs. Enclosed area in (F) indicates the zone where chemical analysis was conducted, and the image in the upper corner is the diffraction pattern of analyzed particle, confirming the presence of crystalline silver.</p