Optimal Labeling Dose, Labeling Time, and Magnetic Resonance Imaging Detection Limits of Ultrasmall Superparamagnetic Iron-Oxide Nanoparticle Labeled Mesenchymal Stromal Cells

Table 2

Cellular iron content.

Group	Iron content per cell	𝑛	Multiple comparisons (Bonferroni corrected)
			Group A	Group B	Group C	Group D	Group E	Group F	Group G
(A) Unlabeled	0.48 ± 0.17 pg	44	—	ns	𝑃=0.02	𝑃<0.001	𝑃<0.001	𝑃<0.001	𝑃<0.001
(B) Half dose, 2 hours incubation	1.22 ± 0.52 pg	17	—	—	ns	ns	𝑃=0.001	𝑃<0.001	𝑃<0.001
(C) Full dose, 2 hours incubation	1.54 ± 0.83 pg	17	—	—	—	ns	𝑃=0.03	𝑃<0.001	𝑃<0.001
(D) Half dose, 6 hours incubation	2.36 ± 0.65 pg	17	—	—	—	—	ns	𝑃<0.001	𝑃<0.001
(E) Full dose, 6 hours incubation	2.71 ± 0.86 pg	21	—	—	—	—	—	𝑃<0.001	𝑃<0.001
(F) Half dose, 21 hours incubation	4.26 ± 1.59 pg	37	—	—	—	—	—	—	𝑃=0.002
(G) Full dose, 21 hours incubation	5.24 ± 1.50 pg	44	—	—	—	—	—	—	—

Values are shown ± SD.
USPIO: ultrasmall super-paramagnetic iron-oxide. USPIO dose—full = 10 𝜇g per 10⁵ cells. half = 5 𝜇g per 10⁵ cells, ns: nonsignificant.