CFU values (/mL) for <i>S</i>. <i>mutans</i> isolated from biofilms that were either exposed to bare, positively charged or negatively charged SPIONs or were incubated in the absence of SPIONs.

<p>CFU values (/mL) for <i>S</i>. <i>mutans</i> isolated from biofilms that were either exposed to bare, positively charged or negatively charged SPIONs or were incubated in the absence of SPIONs.</p

Zeta potential values of the SPIONs determined before and after incubation with the biofilm.

<p>Zeta potential values of the SPIONs determined before and after incubation with the biofilm.</p

Structure of the charged SPIONs.

<p>The amine and carboxyl functional groups are attached to the silica shell on the surface of the SPIONs.</p

Induced lysosomes and ROS level in various cell lines upon interaction with (a) PEG- and (b) APTES-coated SPIONs.

<p>Induced lysosomes and ROS level in various cell lines upon interaction with (a) PEG- and (b) APTES-coated SPIONs.</p

Description of the cell lines used in MTT and XTT studies (DMEM: Dulbecco's modified Eagle's medium; Ham's: Nutrient Mixture F-10; FBS: fetal bovine serum; RPMI-1640 (Roswell Park Memorial Institute)).

<p>Description of the cell lines used in MTT and XTT studies (DMEM: Dulbecco's modified Eagle's medium; Ham's: Nutrient Mixture F-10; FBS: fetal bovine serum; RPMI-1640 (Roswell Park Memorial Institute)).</p

Induced lysosomes in (a) Capan-2, (b) Panc-1, (c) HeLa, and (d) Jurkat cells were obtained upon interaction with CES-coated SPIONs.

<p>In live lysosomes assay, the lysosomes and nuclei are seen as red and blue fluorescence, respectively. Induced ROS level in (e) Capan-2, (f) Panc-1, (g) HeLa, and (h) Jurkat cells were obtained upon interaction with SPIONs. In intracellular ROS assay, the ROS level and nuclei are seen as green and blue fluorescence, respectively; (i) fluorescence intensities of induced lysosomes and ROS for all cell lines.</p

Figure 1

<p>(a) TEM image of monodisperse iron oxide nanocrystals; Inset at the top left illustrates the selected area diffraction pattern of the SPIONs. (b) FTIR spectra of bare and coated-SPIONs with various polymers; and cell viabilities of the conventional (c) MTT- and XTT-assay and (d) modified MTT- and XTT-methods after treatment with various concentrations of CES-grafted SPIONs. Differences between obtained cell viabilities confirm the importance of toxicity method modifications of conventional methods for NPs.</p

Time course variations of the hydrodynamic size of various NPs (400 µL with concentrations of 2 mM), while interacting with cell medium (1 mL of DMEM+FBS 10%).

<p>Time course variations of the hydrodynamic size of various NPs (400 µL with concentrations of 2 mM), while interacting with cell medium (1 mL of DMEM+FBS 10%).</p

Comparison of the different SPIONs used in this research. Sizes and zeta potentials are presented as mean ± SD (n = 4).

<p>Comparison of the different SPIONs used in this research. Sizes and zeta potentials are presented as mean ± SD (n = 4).</p

(a) and (b) fluorescence intensities of induced lysosomes and ROS for all cell lines after treatment with PEG- and APTES-coated SPIONs.

<p>(a) and (b) fluorescence intensities of induced lysosomes and ROS for all cell lines after treatment with PEG- and APTES-coated SPIONs.</p