Human neural progenitor cells retain viability, phenotype, proliferation, and lineage differentiation when labeled with a novel iron oxide nanoparticle, Molday ION Rhodamine B

Wei-Bin Shen,^1,2 Celine Plachez,^2,3 Amanda Chan,⁴ Deborah Yarnell,¹ Adam C Puche,³ Paul S Fishman,^1,5 Paul Yarowsky<sup>1,2

1</sup>Research Service, VA Maryland Health Care System, Baltimore, MD, USA; ²Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD, USA; ³Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, USA; ⁴Notre Dame of Maryland School of Pharmacy, Baltimore, MD, USA; ⁵Department of Neurology, University of Maryland School of Medicine, Baltimore, MD, USA

Abstract: Ultrasmall superparamagnetic iron-oxide particles (USPIOs) loaded into stem cells have been suggested as a way to track stem cell transplantation with magnetic resonance imaging, but the labeling, and post-labeling proliferation, viability, differentiation, and retention of USPIOs within the stem cells have yet to be determined for each type of stem cell and for each type of USPIO. Molday ION Rhodamine B™ (BioPAL, Worcester, MA, USA) (MIRB) has been shown to be a USPIO labeling agent for mesenchymal stem cells, glial progenitor cells, and stem cell lines. In this study, we have evaluated MIRB labeling in human neuroprogenitor cells and found that human neuroprogenitor cells are effectively labeled with MIRB without use of transfection reagents. Viability, proliferation, and differentiation properties are unchanged between MIRB-labeled neuroprogenitors cells and unlabeled cells. Moreover, MIRB-labeled human neuroprogenitor cells can be frozen, thawed, and replated without loss of MIRB or even without loss of their intrinsic biology. Overall, those results show that MIRB has advantageous properties that can be used for cell-based therapy.

Keywords: ferumoxides, USPIO, MION, neural stem cells, SC121 antibody, human, toxicology