Objective An attractive cell source for stem cell-based therapy are WJ-MSCs. Hence, tracking WJ-MSCs using non-invasive imaging procedures (such as MRI) and contrast agents (Zn0.5Ni0.5Fe2O4, NFNPs) are required to evaluate cell distribution, migration, and differentiation. Results Results showed that the bare and dextrin-coated NFNPs were internalized inside the WJ-MSCs and had no effect on the cell viability, proliferation, apoptosis, karyotyping, and morphology of WJ-MSCs up to 125 mu g/mL. Besides, treated WJ-MSCs were differentiated into osteo/adipocyte-like cells. The expression of RUNX 2, SPP 1 (P < 0.05), and OCN (P > 0.05) genes in the WJ-MSCs treated with dextrin-coated NFNPs was higher than the untreated WJ-MSCs; and the expression of CFD, LPL, and PPAR-gamma genes was reduced in WJ-MSCs treated with both NFNPs in comparison with the untreated WJ-MSCs (P > 0.05). Conclusion Overall, results showed that dextrin-coated NFNPs had no adverse effect on the cellular characteristics, proliferation, and differentiation of WJ-MSCs, and suggesting their potential clinical efficacy.