Comparison of Transfection Agents in Forming Complexes with Ferumoxides, Cell Labeling Efficiency, and Cellular Viability

Abstract

By complexing ferumoxides or superparamagnetic iron oxide (SPIO) to transfection agents (TAs), it is possible to magnetically label mammalian cells. There has been no systematic study comparing TAs complexed to SPIO as far as cell labeling efficiency and viability. This study investigates the toxicity and labeling efficiency at various doses of FEs complexed to different TAs in mammalian cells. Different classes of TAs were used, such as polycationic amines, dendrimers, and lipid-based agents. Cellular toxicity was measured using doses of TAs from 1 to 50 microg/mL in incubation media. Iron incorporation efficiency was measured by combining various amounts of FEs and different doses of TAs. Lipofectamine2000 showed toxicity at lowest dose (1 microg/mL), whereas FuGENE6 and low molecular weight poly-L-lysine (PLL) showed the least toxicity. SPIO labeling efficiency was similar with high-molecular-weight PLL (388.1 kDa) and superfect, whereas FuGENE6 and low-molecular-weight PLL were inefficient in labeling cells. Concentrations of 25 to 50 microg/mL of FEs complexed to TAs in media resulted in sufficient endocytosis of the SPIO into endosomes to detect cells on cellular magnetic resonance imaging.

In vivo magnetic resonance imaging of injected mesenchymal stem cells in rat myocardial infarction; simultaneous cell tracking and left ventricular function measurement

“…Protamine sulfate is a naturally occurring peptide used clinically worldwide as an antidote for heparin-induced anticoagulation and is well-tolerated by cells and, thus, has a high therapeutic window [18]. Arbab AS et al reported that magnetic labeling of cells with ferumoxides-protamine sulfate complexes is comparable or superior to other methods and that the addition of heparin to cell washes after labeling can completely dissolve surface-bound particles of ferumoxides-protamine sulfate complexes through competition; therefore, very clean labeling is possible with minimum extracellular iron complex formation [12,13]. In our study, we determined that cell labeling with this ferumoxides-protamine sulfate method was very efficient and clean, with almost no residual extracellular iron complexes.…”

“…To label the MSCs, we used ferumoxides (Feridex)(Berlex Laboratories, Wayne, NJ) combined with protamine sulfate (American Pharmaceuticals Partner, Schaumburg, IL) as a transfection agent [12,13]. Feridex (50 lg/ml) and protamine sulfate (9 lg/ml) were added to the standard culture medium and, then, mixed for 10 min with intermittent hand shaking.…”

Negatively Charged Magnetite Nanoparticle Clusters as Efficient MRI Probes for Dendritic Cell Labeling and In Vivo Tracking

“…[ 2c , 5 ] Formed complexes tend to aggregate onto the negatively charged cellular membrane by electrostatic interaction, hence facilitating internalization. However, these agents showed obvious cytotoxicity to cells, [ 6 ] resulting in differentiation inhibition, [ 7 ] apoptosis, or even death. Furthermore, these probes tend to electrostatically adsorption on the surface of cells rather than internalization.…”

Nanoparticles and clinically applicable cell tracking

“…115 However, several studies did show negative effects on cellular function following labelling with iron oxide particles at lower doses, including negative effects on multilineage differentiation capacity, 116 migratory capacity, 104 altered cytokine production 117 or cell survival. 118 In a review by Singh et al, 114 the various mechanisms by which iron oxide agents can exert adverse effects on cell function have been discussed, and include effects on membrane integrity, mitochondrial function, generation of reactive oxygen species and DNA damage. In many cases, the toxic effects are dose dependent and related to specific nanoparticle composition aspects.…”