Biological characteristics of adipose tissue-derived stem cells labeled with amine-surface-modified superparamagnetic iron oxide nanoparticles

Superparamagnetic Iron Oxide Nanoparticles: Cytotoxicity, Metabolism, and Cellular Behavior in Biomedicine Applications

Superparamagnetic iron oxide nanoparticles (SPIONs) have been widely investigated and applied in the field of biomedicine due to their excellent superparamagnetic properties and reliable traceability. However, with the optimization of core composition, shell types and transfection agents, the cytotoxicity and metabolism of different SPIONs have great differences, and the labeled cells also show different cellular behaviors. Therefore, a holistic review of the construction and application of SPIONs is desired. This review focuses the advances of SPIONs in the field of biomedicine in recent years. After summarizing the toxicity of different SPIONs, the uptake, distribution and metabolism of SPIONs in vitro were discussed. Then, the regulation of labeled-cells behavior is outlined. Furthermore, the major challenges in the optimization process of SPIONs and insights on its future developments are proposed.

Effects of labeling human mesenchymal stem cells with superparamagnetic zinc-nickel ferrite nanoparticles on cellular characteristics and adipogenesis/osteogenesis differentiation

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 µg/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-γ 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.

Superparamagnetic Iron Oxide Particles (VSOPs) Show Genotoxic Effects but No Functional Impact on Human Adipose Tissue-Derived Stromal Cells (ASCs)

Adipose tissue-derived stromal cells (ASCs) represent a capable source for cell-based therapeutic approaches. For monitoring a cell-based application in vivo, magnetic resonance imaging (MRI) of cells labeled with iron oxide particles is a common method. It is the aim of the present study to analyze potential DNA damage, cytotoxicity and impairment of functional properties of human (h)ASCs after labeling with citrate-coated very small superparamagnetic iron oxide particles (VSOPs). Cytotoxic as well as genotoxic effects of the labeling procedure were measured in labeled and unlabeled hASCs using the MTT assay, comet assay and chromosomal aberration test. Trilineage differentiation was performed to evaluate an impairment of the differentiation potential due to the particles. Proliferation as well as migration capability were analyzed after the labeling procedure. Furthermore, the labeling of the hASCs was confirmed by Prussian blue staining, transmission electron microscopy (TEM) and high-resolution MRI. Below the concentration of 0.6 mM, which was used for the procedure, no evidence of genotoxic effects was found. At 0.6 mM, 1 mM as well as 1.5 mM, an increase in the number of chromosomal aberrations was determined. Cytotoxic effects were not observed at any concentration. Proliferation, migration capability and differentiation potential were also not affected by the procedure. Labeling with VSOPs is a useful labeling method for hASCs that does not affect their proliferation, migration and differentiation potential. Despite the absence of cytotoxicity, however, indications of genotoxic effects have been demonstrated.

New Insights into Biocompatible Iron Oxide Nanoparticles: A Potential Booster of Gene Delivery to Stem Cells

Gene delivery to stem cells is a critical issue of stem cells-based therapies, still facing ongoing challenges regarding efficiency and safety. Recent advances in the controlled synthesis of biocompatible magnetic iron oxide nanoparticles (IONPs) have provided a powerful nanotool for assisting gene delivery to stem cells. However, this field is still at an early stage, with well-designed and scalable IONPs synthesis highly desired. Furthermore, the potential risks or bioeffects of IONPs on stem cells are not completely figured out. Therefore, in this review, the updated researches focused on the gene delivery to stem cells using various designed IONPs are highlighted. Additionally, the impacts of the physicochemical properties of IONPs, as well as the magnetofection systems on the gene delivery performance and biocompatibility are summarized. Finally, challenges attributed to the potential impacts of IONPs on the biologic behaviors of stem cells and the large-scale productions of uniform IONPs are emphasized. The principles and challenges summarized in this review provide a general guidance for the rational design of IONPs-assisted gene delivery to stem cells.

Toxicity and Functional Impairment in Human Adipose Tissue-Derived Stromal Cells (hASCs) Following Long-Term Exposure to Very Small Iron Oxide Particles (VSOPs)

Magnetic nanoparticles (NPs), such as very small iron oxide NPs (VSOPs) can be used for targeted drug delivery, cancer treatment or tissue engineering. Another important field of application is the labelling of mesenchymal stem cells to allow in vivo tracking and visualization of transplanted cells using magnetic resonance imaging (MRI). For these NPs, however, various toxic effects, as well as functional impairment of the exposed cells, are described. The present study evaluates the influence of VSOPs on the multilineage differentiation ability and cytokine secretion of human adipose tissue derived stromal cells (hASCs) after long-term exposure. Human ASCs were labelled with VSOPs, and the efficacy of the labelling was documented over 4 weeks in vitro cultivation of the labelled cells. Unlabelled hASCs served as negative controls. Four weeks after labelling, adipogenic and osteogenic differentiation was histologically evaluated and quantified by polymerase chain reaction (PCR). Changes in gene expression of IL-6, IL-8, VEGF and caspase 3 were determined over 4 weeks. Four weeks after the labelling procedure, labelled and unlabelled hASCs did not differ in the gene expression of IL-6, IL-8, VEGF and caspase 3. Furthermore, the labelling procedure had no influence on the multidifferentiation ability of hASC. The percentage of labelled cells decreased during in vitro expansion over 4 weeks. Labelling with VSOPs and long-term intracellular disposition probably have no influence on the physiological functions of hASCs. This could be important for the future in vivo use of iron oxide NPs.

Magnetic Nanoparticle Labeling of Human Platelets from Platelet Concentrates for Recovery and Survival Studies

Platelets are the smallest blood cells and important for hemostasis. Platelet concentrates (PC) are medicinal products transfused to prevent or treat bleeding. Typically, platelets in PCs are assessed by in vitro tests for their function. However, in vivo testing of these platelets is highly desirable. To distinguish transfused platelets from patients or probands own cells after PC transfusions within the scope of clinical studies, platelets need to be efficiently labeled with minimal preactivation prior to transfusion. Here we report on a method for improved cell uptake of ferucarbotran magnetic nanoparticles contained in Resovist, an FDA-approved MRI contrast agent, by modifying the nanoparticle shell with human serum albumin (HSA). Both HSA-ferucarbotran nanoparticles and magnetically labeled platelets were produced according to EU-GMP guidelines. Platelet function after labeling was evaluated by light transmission aggregometry and by determination of expression of CD62P as platelet activation marker. Magnetic labeling does not impair platelet function and platelets showed reasonable activation response to agonists. Platelet survival studies in NOD/SCID-mice resulted in comparable survival behavior of magnetically labeled and nonlabeled platelets. Additionally, labeled platelets can be recovered from whole blood by magnetic separation.

Biological Characteristics of Fluorescent Superparamagnetic Iron Oxide Labeled Human Dental Pulp Stem Cells

Tracking transplanted stem cells is necessary to clarify cellular properties and improve transplantation success. In this study, we investigate the effects of fluorescent superparamagnetic iron oxide particles (SPIO) (Molday ION Rhodamine-B™, MIRB) on biological properties of human dental pulp stem cells (hDPSCs) and monitor hDPSCs in vitro and in vivo using magnetic resonance imaging (MRI). Morphological analysis showed that intracellular MIRB particles were distributed in the cytoplasm surrounding the nuclei of hDPSCs. 12.5–100 μg/mL MIRB all resulted in 100% labeling efficiency. MTT showed that 12.5–50 μg/mL MIRB could promote cell proliferation and MIRB over 100 μg/mL exhibited toxic effect on hDPSCs. In vitro MRI showed that 1 × 10⁶ cells labeled with various concentrations of MIRB (12.5–100 μg/mL) could be visualized. In vivo MRI showed that transplanted cells could be clearly visualized up to 60 days after transplantation. These results suggest that 12.5–50 μg/mL MIRB is a safe range for labeling hDPSCs. MIRB labeled hDPSCs cell can be visualized by MRI in vitro and in vivo. These data demonstrate that MIRB is a promising candidate for hDPSCs tracking in hDPSCs based dental pulp regeneration therapy.

Potential role of tracing stem cell transplantation and effects on the immune cell function of ferumoxytol combining with heparin and protamine in vivo/in vitro

Cell labeling and tracing have played an increasingly important role in the field of stem cell transplantation. Nanocomplexes combining three Food and Drug Administration (FDA)-approved drugs: heparin (H), protamine (P), and ferumoxytol (F) (HPF nanocomplexes) display high labeling efficiency in human adipose tissue-derived stem cells (hADSCs), but their biological safety has not been determined. In this study, we tested the labeling efficiency of HPF in hADSCs through in vitro cytotoxicity studies and in vivo murine preclinical studies using HPF-labeled hADSCs. The labeling process did not cause cell apoptosis and had little effect on cell proliferation. In vivo magnetic resonance imaging (MRI) showed that the HPF-labeled cells produced a hypointense signal that did not affect liver and kidney functions. However, after injection of HPF-labeled cells into mice, lymphocyte transformation testing showed that T and B lymphocyte proliferation was significantly increased. These findings suggest that extensive safety testing of HPF nanocomplexes is necessary; the process to evaluate HPF as an investigative new drug application could therefore be postponed.

Self-assembled dual-modality contrast agents for non-invasive stem cell tracking via near-infrared fluorescence and magnetic resonance imaging

Stem cells hold great promise for treating various diseases. However, one of the main drawbacks of stem cell therapy is the lack of non-invasive image-tracking technologies. Although magnetic resonance imaging (MRI) and near-infrared fluorescence (NIRF) imaging have been employed to analyse cellular and subcellular events via the assistance of contrast agents, the sensitivity and temporal resolution of MRI and the spatial resolution of NIRF are still shortcomings. In this study, superparamagnetic iron oxide nanocrystals and IR-780 dyes were co-encapsulated in stearic acid-modified polyethylenimine to form a dual-modality contrast agent with nano-size and positive charge. These resulting agents efficiently labelled stem cells and did not influence the cellular viability and differentiation. Moreover, the labelled cells showed the advantages of dual-modality imaging in vivo.