Defined fetal bovine serum

The human monocytic cell line THP1 (kindly provided by V. Hornung, University of Bonn) derived from an acute monocytic leukemia patient was used to obtain macrophages. THP1 monocytes were cultured in medium containing RPMI (Gibco) supplemented with 10% defined fetal bovine serum (Gibco), 1% Penicillin-Streptomycin (Gibco), 1% L-glutamine (Gibco) and 1% sodium pyruvate (Gibco). Macrophage cultures were differentiated repeatedly from frozen stocks of THP1 cells. At least one week before experiment, THP1 monocytes were moved to THP1 differentiation medium containing RPMI with 1% Penicillin-Streptomycin, 1% L-glutamine, 1% sodium pyruvate plus 1% N2 supplement (Gibco) and 1% chicken serum (Gibco). To differentiate THP1 cells into a macrophage phenotype, the cells were treated in THP1 differentiation medium with 0.5 μg/ml phorbol-12-myristate-13-acetate (PMA, Sigma) for 3 hours. Afterwards, cells were washed 2 times with 37 °C warm medium and were kept in PMA-free THP1 differentiation medium for at least 24 hours. Then a serum free medium (THP1 differentiation medium without chicken serum) was applied to the macrophages.

The human Ramos [20 (link)] (Burkitt lymphoma) and Granta-519 [21 (link)] (mantle cell lymphoma) lines were obtained from American Type Culture Collection (ATCC; Bethesda, MD). All cells were maintained in RPMI 1640 medium (Gibco) supplemented with 10% defined fetal bovine serum (HyClone), penicillin (100 U/mL), and streptomycin (100 μg/mL) in a 5% carbon dioxide incubator. Cell viability was greater than 95% by trypan blue exclusion for all experiments described.

The human monocyte cell line THP1 derived from an acute monocytic leukemia patient was used to obtain macrophages (ATTC, USA). THP1 monocytes were cultured in medium containing RPMI (Gibco) supplemented with 10% defined fetal bovine serum (Gibco), 1% penicillin/streptomycin (Gibco), 1% l‐glutamine (Gibco), and 1% sodium pyruvate (Gibco). At least 1 week before the experiment, THP1 monocytes were moved to THP1 differentiation medium containing RPMI with 1% penicillin/streptomycin, 1% l‐glutamine, 1% sodium pyruvate plus 1% N2 supplement (Gibco), and 1% chicken serum (Gibco). To differentiate THP1 cells into a macrophage phenotype, the cells were treated in differentiation medium with 10 ng/ml phorbol‐12‐myristate‐13‐acetate (PMA; Sigma) for 48 h. Afterward, cells were washed two times with 37°C warm medium and were kept in PMA‐free differentiation medium for 48 h. For the experiments, serum‐free medium (differentiation medium without chicken serum) was applied to the macrophages.

Primary normal human bronchial epithelial (NHBE) cells were purchased from Lonza (Walkersville, MD, USA). We used NHBE cells from at least three different donors. NHBE cells were seeded in collagen-coated 24-well plates and were maintained in serum-free bronchial epithelial cell growth medium (BGEM, Lonza, Walkersville, MD, USA). Before stimulation, the NHBE cells were cultured in BEGM without hydrocortisone for 24 h. At confluency, submerged NHBE cells were stimulated with poly(I:C) (R&D Systems, Minneapolis, MN, USA), interferon (IFN)-γ (R&D Systems, Minneapolis, MN, USA), and interleukin (IL)-4 (R&D Systems, Minneapolis, MN, USA) for 24 h. Then, total RNA was isolated from the cells.
The Eol-1 human eosinophilic leukemic cell line was obtained from the Riken Cell Bank (Tsukuba, Japan). The cells were maintained in RPMI1640 medium (Gibco Laboratories, Grand Island, NY, USA) supplemented with 10% defined fetal bovine serum (Gibco) and 20 mM Hepes buffer (Gibco) in a humidified atmosphere with 5% CO₂ at 37 °C as described previously [23 (link)]. For the cytokine stimulation study, 5 × 10⁵ Eol-1 cells were incubated with a varying concentration of IL-5 (R&D Systems, Minneapolis, MN, USA) and IL-33 (R&D Systems, Minneapolis, MN, USA) for 24 h. Total RNA from the cultured Eol-1 cells was extracted, and single-strand cDNA was synthesized.

The MWNTs-OH (Nanjing XFNANO Materials TECH Co., Ltd.) was 20–40 nm in diameter with purity higher than 97%. The minimum essential medium (MEM), defined fetal bovine serum (FBS) (Gibco Co., USA), penicillin, streptomycin, trypsin (Sigma, Co., USA) were used for cell culture. Dimethyl formamide and eosin Y (EY) (J&K Chemical Ltd., China) were applied for electrode fabrication. 2,4-DCP (J&K Chemical Ltd., China) was used as the target compound. Phosphate-buffered solutions (PBS) were prepared by mixing stock solutions of 0.1 M Na₂HPO₄ and 0.1 M KH₂PO₄.