The synthesis and detailed physicochemical characterization of Pluronic F-127-modified MNCb and MNCl have been previously described [38, 39].
As expected, MNCl core diameter was larger than those of MNCb and MNRd and the differences between hD were even more profound due to IONPs geometry.
The XRD measurements of MNCb, MNRd, and MNCl showed that all samples can be attributed to magnetite phase [Fe.sub.3][O.sub.4] (a = 8.396 [Angstrom], ICDD no.
To further confirm IONPs biocompatibility cells were stained with H2DCFDA and nuclear green after exposure to the highest concentration of MNCb, MNRd, and MNCl (200 [micro]g/mL).
MNCb, MNRd, and MNCl delivery efficiency for all tumor types was 3.79% ID, 2.94% ID, and 1.21% ID, respectively (two-way ANOVA, p > 0.05).
Next MRI studies were performed to evaluate MNCb, MNRd, and MNCl contrast properties in vivo.
Among studied IONPs, MNCl demonstrated the best MRI-contrast properties (Table 2).
The most profound tumor contrasting corresponded to 6-24 hours after MNCb and MNCl injection, whereas MNRd accumulation in malignancies reached its maximum within first 30 minutes upon i.v.
As a result, MNCl can exhibit increased values of saturation magnetization and relaxivity compared with individual nanoparticles [9, 10, 30].
However, MNCl overperformed MNCb in contrasting malignant tissues.
Thus, 24 h after treatment with MNCb, MNRd, and MNCl, liver accumulated 74 [+ or -] 12% ID, 50 [+ or -] 9% ID, and 70 [+ or -] 6% ID and spleen 20 [+ or -] 3% ID, 11 [+ or -] 3% ID, and 21 [+ or -] 4% ID, respectively.
Probably, due to increased half-lives, MNCb and MNCl gradually accumulated in most tumors up to 24 h, resulting in better uptake rates and MRI performance compared with MNRd.