Serbay Özkan, Charlotte Trot, Patricia Murray
Cerrahpaşa Medical Journal - 2025;49(1):1-8
Objective: This study evaluated the labeling efficiency of human adipose-derived mesenchymal stem/stro-mal cells (MSCs) with ProMag superparamagnetic iron oxide nanoparticles (SPIONs) under adherent and suspension conditions, aiming to define practical parameters for translational use. Methods: The MSCs were labeled with 3 ProMag SPION concentrations (10-40 µg/mL) under adherent culture. Labeling efficiency and viability were assessed by Prussian blue staining and an adenosine triphos-phate-based viability assay . The MSC identity (CD44, CD90) and hematopoietic markers (CD34, CD45) were analyzed by flow cytometry . Nanoparticle uptake mechanisms were probed using a low-temperature endocytosis inhibition assay . Comparative experiments examined labeling efficiency between adherent cul-tures and suspension protocols using Eppendorf tubes and Petri dishes. Results: A concentration of 20 µg/mL achieved an optimal balance between labeling efficiency (79%) and viability (73%) and was used in subsequent assays. The MSC identity was preserved, with >95% CD44/CD90 expression, though slight increases in CD34 (4.10%) and CD45 (8.55%) were observed after labeling. Uptake occurred predominantly via active endocytosis. Adherent conditions yielded significantly higher labeling efficiency than suspension in Eppendorf tubes (P = .002). Suspension in Petri dishes showed mod-erately improved uptake but did not reach significance (P = .062). Conclusion: ProMag SPIONs effectively label adipose-derived MSCs, though efficiency is strongly influ-enced by the suspension environment. Optimized suspension-based strategies, considering vessel geometry and defined concentration parameters, may enable rapid labeling approaches suitable for real-time mag-netic particle imaging in regenerative therapies.
