100 cx tem

The toxic effects of AgNO₃, D-SNPs, and N-SNPs on C. albicans morphology were assessed by TEM. Briefly, C. albicans cells treated or not with 1.5 mg/mL of each of the three treatments for 24 h at 30 °C were collected by centrifugation at 3500 rpm for 10 min. The resultant pellets were rinsed in PBS at least three times to remove any excess nanoparticles, fixed in ice-cold 4F1G (a mixture of 4% formaldehyde and 1% glutaraldehyde) in PBS for 2 h, stained with 1% osmium tetroxide (OsO₄) for 2 h at ambient temperature, washed with PBS to eliminate excess OsO₄, and dehydrated by immersion in 25%, 50%, 75%, 95%, and 100% ethanol. The dehydrated samples were infiltrated with propylene oxide and embedded in an Araldite Epon mixture. The specimens were cut into ultrathin (70 nm) sections on a LKB Ultramicrotome using a glass knife, double-stained with 2% uranyl acetate and lead citrate, and loaded onto 200-mesh copper grids for visualization under a JEOL 100 CX TEM (JEOL, Tokyo, Japan) operating at 80 kV [40 (link)]. The C. albicans cell size (before and after the treatment with the three silver agents) and NP size distribution in at least 10 TEM images were measured using the ImageJ software.

The phase of as-synthesized Fe₃O₄ NPs was characterized by X-ray powder diffraction on a Bruker D8 Advanced Diffractometer System (Bruker AXS, Inc., Madison, WI, USA) equipped with Cu/Kα radiation in the 2θ range from 20° to 80° (λ = 1.5418 Å). The size and morphology of samples were characterized using a JEOL 100CX transmission electron microscope (TEM; JEOL Ltd., Akishima-shi, Japan). The mean particle size was obtained from TEM images by counting more than 100 particles. The structure of the particles was characterized using a high-resolution TEM (HRTEM) and selected area electron diffraction (SAED) on a JEOL100CX TEM. Dynamic light scattering (DLS) measurements were performed in a Malvern Zetasizer Nano-ZS device (Malvern, WR, UK) to determine the hydrodynamic size of Fe₃O₄ NPs before and after coating HLC in a colloidal suspension. The zeta-potential of the suspensions was measured at 25°C. UV-vis absorption spectra were taken using a Shimadzu UV-1601 UV-visible spectrophotometer (Shimadzu, Kyoto, Japan). Magnetic properties of the samples were characterized by a LakeShore Model 7407 vibrating sample magnetometer (VSM; Lake Shore Cryotonics Inc., Wersterville, OH, USA).

C. albicans were incubated in with EG-AgNPs (50 μg/mL). Cells were fixed with 2.5% glutaraldehyde in sodium cacodylate buffer, and post-fixed in the same buffer with 1% osmium tetroxide for 2 h. The pellets were embedded in Spurr resin after dehydration by ethanol gradient (70–100%). Then, 0.25% toluidine blue was used to stain the semi-thin cuts (300 nm) for observation in an optical microscope (Axiophot Zeiss, with plan achromat objective), followed by ultra-thin cuts (70 nm) using a Porter Blum MT-2 ultra-microtome (Sorval, Liverpool, NY, USA). Samples were imaged in JEOL 100CX TEM (JEOL USA Inc., Peabody, MA, USA).