MNCb and MNRd provided detectable tumor signaling in 73% and 63% tumors, respectively (Figures 4-6).
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.
All studied IONPs had a similar crystallite size of 10-20 nm; however, hD ranged from 65 nm for MNCb to 120 nm for MNRd.
Among the three IONPs, MNCb exhibited the highest relaxivity rates in vitro and the best delivery efficiency to tumor site.
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.
In the current work, 2.94% of injected MNCl and 3.79% of injected MNCb ended up in studied tumors, and for B16 melanoma, uptake rates were even higher (4.8% and 6.6% ID, respectively).
To ensure the safety of studied MNCb, MNRd, and MNCl, we carried on cytotoxicity studies on mice fibroblasts.
MNCb and MNCl high r2-relaxivity and delivery to malignant tissues resulted in efficient MR contrasting of multiple tumors in mice.
Histograms of MNCb (a), MNRd (b), and MNCl (c) size distribution (associated with Figure 1A) Supplementary figure S2.