The responses of immune cells to iron oxide nanoparticles

• Published in: Journal of applied toxicology 2016-04, Vol.36 (4), p.543-553
• Main Authors: Xu, Yaolin, Sherwood, Jennifer A., Lackey, Kimberly H., Qin, Ying, Bao, Yuping
• Format: Article
• Language: English
• Subjects: Biocompatibility; Cell Line, Tumor; Cell Survival - drug effects; Cells; Cellular; cellular uptake and toxicity; Charging; Coatings; Ferric Compounds - chemistry; Ferric Compounds - toxicity; Humans; immune response; Immunity, Innate - drug effects; Immunology; Iron; iron oxide nanoparticles; Iron oxides; monocytes; Monocytes - cytology; Monocytes - drug effects; Monocytes - metabolism; Nanoparticles; Nanoparticles - chemistry; Nanoparticles - toxicity; Polyethylene Glycols - chemistry; Protective coatings; Surface Properties; surface-dependent effects; Toll-Like Receptor 2 - genetics; Toll-Like Receptor 2 - metabolism; Toxicity; Tumor Necrosis Factor-alpha - genetics; Tumor Necrosis Factor-alpha - metabolism; Viability
• ISSN: 0260-437X; 1099-1263
• DOI: 10.1002/jat.3282

Immune cells play an important role in recognizing and removing foreign objects, such as nanoparticles. Among various parameters, surface coatings of nanoparticles are the first contact with biological system, which critically affect nanoparticle interactions. Here, surface coating effects on nanoparticle cellular uptake, toxicity and ability to trigger immune response were evaluated on a human monocyte cell line using iron oxide nanoparticles. The cells were treated with nanoparticles of three types of coatings (negatively charged polyacrylic acid, positively charged polyethylenimine and neutral polyethylene glycol). The cells were treated at various nanoparticle concentrations (5, 10, 20, 30, 50 μg ml−1 or 2, 4, 8, 12, 20 μg cm−2) with 6 h incubation or treated at a nanoparticle concentration of 50 μg ml−1 (20 μg cm−2) at different incubation times (6, 12, 24, 48 or 72 h). Cell viability over 80% was observed for all nanoparticle treatment experiments, regardless of surface coatings, nanoparticle concentrations and incubation times. The much lower cell viability for cells treated with free ligands (e.g. ~10% for polyethylenimine) suggested that the surface coatings were tightly attached to the nanoparticle surfaces. The immune responses of cells to nanoparticles were evaluated by quantifying the expression of toll‐like receptor 2 and tumor necrosis factor‐α. The expression of tumor necrosis factor‐α and toll‐like receptor 2 were not significant in any case of the surface coatings, nanoparticle concentrations and incubation times. These results provide useful information to select nanoparticle surface coatings for biological and biomedical applications. Copyright © 2016 John Wiley & Sons, Ltd. Surface coating effects on nanoparticle cellular uptake, toxicity, and ability to trigger immune response were evaluated on human monocyte cell line using iron oxide nanoparticles. The cells were treated with nanoparticles of three types of coatings (negatively charged polyacrylic acid‐PAA, positively charged polyethylenimine‐PEI, and neutral polyethylene glycol‐PEG). Cell viability and the expression of TNF‐α and TLR2 were used to quantify the toxicity and immune response.