Fig 1.
Nanoparticles size and shape analysis (A) Representative micro-graphs (TEM) of Ag-NPs provided by the manufacturer (https://www.sigmaaldrich.com/PL/pl/product/aldrich/730785) and (B) computer-processed image for size measurements. (C) Histogram of size distribution function with size defined as an equivalent diameter. (D) Values of a maximum chord plotted against the equivalent diameter for individual particles. (E) Values of a perimeter plotted against the equivalent diameter for individual particles. Ag-NPs, silver nanoparticles.
Fig 2.
Metabolic activity of hMSCs incubated with Ag-NPs at a concentration of 0 μg/mL, 3.5 μg/mL, 7 μg/mL, and 14 μg/mL for (A) 10 min, (B) 60 min, and (C) 24 h. *P < 0.05, **P < 0.01, ***P < 0.001. Ag-NPs, silver nanoparticles.
Fig 3.
Representative images of hMSC cells stained with acridine orange and propidium iodide: all cells (A) (green); dead cells (red) (B) and overlap of both (C). hMSCs were fixed with MeOH, which caused cell death and membrane permeabilization.
Fig 4.
hMSCs incubated with Ag-NPs at a concertation of 14 μg/mL (A,B); 7 μg/mL (C,D); and 3.5 μg/mL (E,F) for the duration of 10 min. Green color—all cells (a,c,e); Red color—dead cells (b,d,f). Ag-NPs, silver nanoparticles.
Fig 5.
hMSCs incubated with Ag-NPs at a concertation of 14 μg/mL (A,B); 7 μg/mL (C,D); and 3.5 μg/mL (E,F) for the duration of 1 h. Green color—all cells (a,c,e); Red color—dead cells (b,d,f). Ag-NPs, silver nanoparticles.
Fig 6.
hMSCs incubated with Ag-NPs at a concertation of 14 μg/mL (A,B); 7 μg/mL (C,D); and 3.5 μg/mL (E,F) for the duration of 24 h. Green color—all cells (a,c,e); Red color—dead cells (b,d,f). Ag-NPs, silver nanoparticles.
Fig 7.
Antimicrobial activity of Ag-NPs against bacterial strains determined with the well-diffusion method. Bars represent the zones of inhibition of different concentrations of Ag-NPs for the tested bacterial strains. The data represent mean ± SD (n = 3). Ag-NPs, silver nanoparticles; MRSA, methicillin-resistant Staphylococcus aureus; MSSA, methicillin-susceptible Staphylococcus aureus.
Table 1.
MIC and MBC values (μg/mL) of Ag-NPs for different bacterial strains
| Drug-sensitive strains | Multidrug-resistant strains | |||||
|---|---|---|---|---|---|---|
| S. aureus MSSA | S. mutans | E. coli | L. acidophilus | S. aureus MRSA | S. haemolyticus | |
| MIC μg/mL | 5 | 10 | 5 | 5 | 5 | 5 |
| MBC μg/mL | 20 | 10 | 20 | 5 | 20 | 5 |
| MBC/MIC ratio | 4 | 1 | 4 | 1 | 4 | 1 |
[i] Ag-NPs, silver nanoparticles; MBC, minimum bactericidal concentration; MIC, minimum inhibitory concentration; MRSA, methicillin-resistant Staphylococcus aureus; MSSA, methicillin-susceptible Staphylococcus aureus.