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Cell type-specific response to high intracellular loading of polyacrylic acid-coated magnetic nanoparticles.

Lojk J, Bregar VB, Rajh M, Miš K, Kreft ME, Pirkmajer S, Veranič P, Pavlin M - Int J Nanomedicine (2015)

Bottom Line: We compared the internalization pathway, intracellular trafficking, and intracellular fate of our NPs using fluorescence and transmission electron microscopy (TEM) as well as quantified NP uptake and analyzed uptake dynamics.The cell types differed in their uptake rate, the dynamics of intracellular trafficking, and the uptake capacity, as well as in their response to higher concentrations of internalized NPs.The observed differences in cell responses stress the importance of evaluation of NP-cell interactions on several different cell types for better prediction of possible toxic effects on different cell and tissue types in vivo.

View Article: PubMed Central - PubMed

Affiliation: Group for Nano and Biotechnological Applications, Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, Slovenia.

ABSTRACT
Magnetic nanoparticles (NPs) are a special type of NP with a ferromagnetic, electron-dense core that enables several applications such as cell tracking, hyperthermia, and magnetic separation, as well as multimodality. So far, superparamagnetic iron oxide NPs (SPIONs) are the only clinically approved type of metal oxide NPs, but cobalt ferrite NPs have properties suitable for biomedical applications as well. In this study, we analyzed the cellular responses to magnetic cobalt ferrite NPs coated with polyacrylic acid (PAA) in three cell types: Chinese Hamster Ovary (CHO), mouse melanoma (B16) cell line, and primary human myoblasts (MYO). We compared the internalization pathway, intracellular trafficking, and intracellular fate of our NPs using fluorescence and transmission electron microscopy (TEM) as well as quantified NP uptake and analyzed uptake dynamics. We determined cell viability after 24 or 96 hours' exposure to increasing concentrations of NPs, and quantified the generation of reactive oxygen species (ROS) upon 24 and 48 hours' exposure. Our NPs have been shown to readily enter and accumulate in cells in high quantities using the same two endocytic pathways; mostly by macropinocytosis and partially by clathrin-mediated endocytosis. The cell types differed in their uptake rate, the dynamics of intracellular trafficking, and the uptake capacity, as well as in their response to higher concentrations of internalized NPs. The observed differences in cell responses stress the importance of evaluation of NP-cell interactions on several different cell types for better prediction of possible toxic effects on different cell and tissue types in vivo.

No MeSH data available.


Related in: MedlinePlus

Time-dependent intracellular localization of PAA-coated Co-ferrite NPs in three observed cell types: (1) CHO cell line, (2) B16 cell line, and (3) MYO cells after 1 or 24 hours of incubation with RITC-labeled NPs.Notes: Figure shows cells under (A) phase contrast, (B) fluorescence of RITC-labeled NPs, (C) fluorescence of acidic organelles stained with LysoTracker® Blue, and (D) colocalization of RITC and LysoTracker® Blue signals. Scale bars correspond to 25 μm.Abbreviations: B16, mouse melanoma cell line; CHO, Chinese Hamster Ovary cell line; Co-ferrite, cobalt ferrite; NP, nanoparticle; MYO, primary human myoblasts; PAA, polyacrylic acid; RITC, rhodamine B isothiocyanate.
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f4-ijn-10-1449: Time-dependent intracellular localization of PAA-coated Co-ferrite NPs in three observed cell types: (1) CHO cell line, (2) B16 cell line, and (3) MYO cells after 1 or 24 hours of incubation with RITC-labeled NPs.Notes: Figure shows cells under (A) phase contrast, (B) fluorescence of RITC-labeled NPs, (C) fluorescence of acidic organelles stained with LysoTracker® Blue, and (D) colocalization of RITC and LysoTracker® Blue signals. Scale bars correspond to 25 μm.Abbreviations: B16, mouse melanoma cell line; CHO, Chinese Hamster Ovary cell line; Co-ferrite, cobalt ferrite; NP, nanoparticle; MYO, primary human myoblasts; PAA, polyacrylic acid; RITC, rhodamine B isothiocyanate.

Mentions: Fluorescence microscopy was performed on live cells after 1 and 24 hours of incubation with RITC-stained PAA NPs. LysoTracker® Blue was used to label acidic organelles. In agreement with TEM micrographs, NPs in the cytoplasm were restricted to localized spots, most likely representing vesicles containing NP aggregates (Figure 4, column B). With longer incubation time, the number of internalized NPs increased, and vesicles containing NPs increased in size and accumulated predominantly in the perinuclear region of the cell. At cell type-specific time intervals, NP fluorescence colocalized with LysoTracker® Blue (Figure 4D), confirming the presence of NPs in acidic organelles, such as late endosomes, amphisomes, and lysosomes. The majority of the NPs colocalized with acidic organelles 1 hour after incubation in CHO cells (Figure 4-1), and after 24 hours in the B16 cell line and MYO cells (Figures 4-2 and 4-3). After 24 hours, the NPs in the CHO cells were mostly no longer located in the acidic vesicles.


Cell type-specific response to high intracellular loading of polyacrylic acid-coated magnetic nanoparticles.

Lojk J, Bregar VB, Rajh M, Miš K, Kreft ME, Pirkmajer S, Veranič P, Pavlin M - Int J Nanomedicine (2015)

Time-dependent intracellular localization of PAA-coated Co-ferrite NPs in three observed cell types: (1) CHO cell line, (2) B16 cell line, and (3) MYO cells after 1 or 24 hours of incubation with RITC-labeled NPs.Notes: Figure shows cells under (A) phase contrast, (B) fluorescence of RITC-labeled NPs, (C) fluorescence of acidic organelles stained with LysoTracker® Blue, and (D) colocalization of RITC and LysoTracker® Blue signals. Scale bars correspond to 25 μm.Abbreviations: B16, mouse melanoma cell line; CHO, Chinese Hamster Ovary cell line; Co-ferrite, cobalt ferrite; NP, nanoparticle; MYO, primary human myoblasts; PAA, polyacrylic acid; RITC, rhodamine B isothiocyanate.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4340463&req=5

f4-ijn-10-1449: Time-dependent intracellular localization of PAA-coated Co-ferrite NPs in three observed cell types: (1) CHO cell line, (2) B16 cell line, and (3) MYO cells after 1 or 24 hours of incubation with RITC-labeled NPs.Notes: Figure shows cells under (A) phase contrast, (B) fluorescence of RITC-labeled NPs, (C) fluorescence of acidic organelles stained with LysoTracker® Blue, and (D) colocalization of RITC and LysoTracker® Blue signals. Scale bars correspond to 25 μm.Abbreviations: B16, mouse melanoma cell line; CHO, Chinese Hamster Ovary cell line; Co-ferrite, cobalt ferrite; NP, nanoparticle; MYO, primary human myoblasts; PAA, polyacrylic acid; RITC, rhodamine B isothiocyanate.
Mentions: Fluorescence microscopy was performed on live cells after 1 and 24 hours of incubation with RITC-stained PAA NPs. LysoTracker® Blue was used to label acidic organelles. In agreement with TEM micrographs, NPs in the cytoplasm were restricted to localized spots, most likely representing vesicles containing NP aggregates (Figure 4, column B). With longer incubation time, the number of internalized NPs increased, and vesicles containing NPs increased in size and accumulated predominantly in the perinuclear region of the cell. At cell type-specific time intervals, NP fluorescence colocalized with LysoTracker® Blue (Figure 4D), confirming the presence of NPs in acidic organelles, such as late endosomes, amphisomes, and lysosomes. The majority of the NPs colocalized with acidic organelles 1 hour after incubation in CHO cells (Figure 4-1), and after 24 hours in the B16 cell line and MYO cells (Figures 4-2 and 4-3). After 24 hours, the NPs in the CHO cells were mostly no longer located in the acidic vesicles.

Bottom Line: We compared the internalization pathway, intracellular trafficking, and intracellular fate of our NPs using fluorescence and transmission electron microscopy (TEM) as well as quantified NP uptake and analyzed uptake dynamics.The cell types differed in their uptake rate, the dynamics of intracellular trafficking, and the uptake capacity, as well as in their response to higher concentrations of internalized NPs.The observed differences in cell responses stress the importance of evaluation of NP-cell interactions on several different cell types for better prediction of possible toxic effects on different cell and tissue types in vivo.

View Article: PubMed Central - PubMed

Affiliation: Group for Nano and Biotechnological Applications, Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, Slovenia.

ABSTRACT
Magnetic nanoparticles (NPs) are a special type of NP with a ferromagnetic, electron-dense core that enables several applications such as cell tracking, hyperthermia, and magnetic separation, as well as multimodality. So far, superparamagnetic iron oxide NPs (SPIONs) are the only clinically approved type of metal oxide NPs, but cobalt ferrite NPs have properties suitable for biomedical applications as well. In this study, we analyzed the cellular responses to magnetic cobalt ferrite NPs coated with polyacrylic acid (PAA) in three cell types: Chinese Hamster Ovary (CHO), mouse melanoma (B16) cell line, and primary human myoblasts (MYO). We compared the internalization pathway, intracellular trafficking, and intracellular fate of our NPs using fluorescence and transmission electron microscopy (TEM) as well as quantified NP uptake and analyzed uptake dynamics. We determined cell viability after 24 or 96 hours' exposure to increasing concentrations of NPs, and quantified the generation of reactive oxygen species (ROS) upon 24 and 48 hours' exposure. Our NPs have been shown to readily enter and accumulate in cells in high quantities using the same two endocytic pathways; mostly by macropinocytosis and partially by clathrin-mediated endocytosis. The cell types differed in their uptake rate, the dynamics of intracellular trafficking, and the uptake capacity, as well as in their response to higher concentrations of internalized NPs. The observed differences in cell responses stress the importance of evaluation of NP-cell interactions on several different cell types for better prediction of possible toxic effects on different cell and tissue types in vivo.

No MeSH data available.


Related in: MedlinePlus