Article Figures & Data
Figures
- FIG 1
(A) TEM photomicrographs of plain PLGA nanoparticles (NPs) and amphotericin B-loaded nanoparticles (AmB-NPs) at a ×20,000 or a ×50,000 magnification. (B) Percentage of AmB cumulative release from nanoparticles with and without sonication during 0 to 72 h of incubation. The double asterisks denote a significant difference (P < 0.01) between release with and without sonication. US, ultrasound.
- FIG 2
(A) Hemolysis of red blood cells following incubation with free AmB, AmB-NPs, and AmB-NPs with ultrasound preirradiated at an intensity of 0.30 W/cm2 for 15 min at final AmB concentrations of 0 to 32 μg/ml. (B) Toxicity analysis of macrophage viability following incubation with free AmB, AmB-NPs, and AmB-NPs with ultrasound preirradiated at an intensity of 0.30 W/cm2 for 15 min at the same AmB concentration of 4.0 μg/ml. **, P < 0.01 compared with the controls; *, P < 0.05 compared with AmB-NPs or AmB-NPs preirradiated by ultrasound treatment.
- FIG 3
Activity of biofilm (A) and biofilm biomass (B) are decreased significantly following treatment with a combination of ultrasound and AmB-NP compared with the control group. Ultrasonic irradiation parameters with a sound intensity of 0.30 W/cm2 for 15 min were chosen, and the final concentration of drug employed in the AmB group and AmB-NP group was 4.0 μg/ml. The double asterisks denote a significant difference (P < 0.01) compared with the control group.
- FIG 4
Living and dead fungal cells of the bottom biofilm layer of 3-D-reconstructed CLSM images of different treatment groups at a ×400 magnification (green, live cells; red [PI], dead cells).
- FIG 5
Proteolytic (A) and phospholipase (B) enzymatic activities of C. albicans biofilms of different treatment groups. Significant reductions in proteinase and phospholipase enzyme activities were observed with the combination treatment with 4.0 μg/ml AmB. The double asterisks denote a statistically significant difference (P < 0.01).
- FIG 6
Catheter fungal loading of C. albicans with different treatments after 24 h of incubation on plates (A) and fungal colony counts (log10 CFU) after 3- or 7-day treatments (B). The double asterisk denotes a significant difference (P < 0.01). Rectangles at the bottom of the panels, 1 cm.
- FIG 7
Morphological changes in catheter biofilm after seven consecutive days of treatment. C. albicans cells were stained with ConA and visualized by CLSM at a ×400 magnification. The control group of mature biofilms shows a dense structure on the catheter surface. In the group treated with ultrasound and AmB-NPs, only a single fungal colony remained on the catheter surface, and the biofilm was substantially eliminated. Bars, 50 μm.
- FIG 8
Scanning electron microscopy images of C. albicans biofilms on the surface of a rat subcutaneous catheter after 7-day treatments. The biofilm is attached to the catheter surface and has a complex structure with hyphae, yeast, and extracellular matrix in the control samples. The AmB-related treatments show deformed morphology of the biofilm, and treatment with ultrasound combined with AmB-NPs led to the complete inhibition of the biofilm, with cells remaining in the yeast form and being swollen and inactivated.
- FIG 9
Schematic illustration of low-frequency ultrasound irradiation in vitro (A) and in vivo (B).
Tables
- TABLE 1
Physical characteristics of nanoparticle formulationsa
Formulation Mean particle size (nm) ± SD Mean ZP (mV) ± SD PDI Mean LC% ± SD Mean EE% ± SD NPs 227.1 ± 5.06 −1.84 ± 0.25 0.223 AmB-NPs 287.8 ± 8.64 −10.9 ± 1.9 0.205 5.7 ± 0.12 85 ± 2.4 ↵a NPs, plain PLGA nanoparticles; AmB-NPs, amphotericin B-loaded PLGA nanoparticles; ZP, zeta potential; PDI, polydispersity index; LC, loading content; EE, entrapment efficiency.
- TABLE 2
COMSTAT analysis of structural parameters of C. albicans biofilm in different treatmentsa
Group Mean thickness (μm) ± SD Avg diffusion distance (μm) ± SD Mean textural entropy ± SD Mean areal porosity ± SD Control 30.56 ± 0.62 10.94 ± 0.18 4.40 ± 0.19 0.553 ± 0.037 US 29.38 ± 0.56 8.27 ± 0.15** 3.77 ± 0.12 0.697 ± 0.021 AmB 25.69 ± 0.13** 4.21 ± 0.03** 3.15 ± 0.07** 0.757 ± 0.023** US + AmB 20.51 ± 0.65** 2.82 ± 0.14** 2.22 ± 0.03** 0.897 ± 0.032** AmB-NPs 26.72 ± 0.24** 4.53 ± 0.11** 3.17 ± 0.06** 0.797 ± 0.015** US + AmB-NPs 11.56 ± 1.22**Δ 1.55 ± 0.11**Δ 1.60 ± 0.09**Δ 1.173 ± 0.067**Δ ↵a **, P < 0.01 compared to the control group; Δ, P < 0.01 compared to the AmB group. US, ultrasound; AmB, amphotericin B; AmB-NPs, amphotericin B-loaded PLGA nanoparticles.
