Fe 2 so4

To assess peroxidation-induced cell death, moDCs were stimulated with 1 µg/ml LPS. 25 µM deferoxamine (Sigma, St. Louis, USA), 100 μM α-tocopherol (Sigma, St. Louis, USA) or 100 μM freshly prepared Fe(II)SO₄ (Sigma, St. Louis, USA) was added and cells were subsequently cultured for 60 min at 37 °C and 5% CO₂ in serum-free RPMI-1640 (Gibco by Life Technologies, Kremsmünster, Austria). The medium was aspirated and cells were incubated for 1–4 hours with 0.5 mg/ml MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide). Finally, cells were lysed in 90% (v/v) iso-propanol, 40 mM HCl and 0.0125% (w/v) SDS. Absorbance at 595 nm was read as a measure for cell viability.

Oil palm empty fruit bunch (EFB) fibers were procured from Szetech Engineering Sdn Bhd (Selangor, Malaysia). These were milled and sieved to obtain fibers of diameters 106 to 500 µm. Fractionation of the oil palm EFB pulp was performed using 90% formic acid (Merck) and 30% hydrogen peroxide (Merck). Lignin content was determined using 98% sulfuric acid (Merck). With regards to the preparation of Fenton’s reagent and Fe(0) nanoparticles, a stock solution of Fe(II) was prepared from Fe₂SO₄ (Merck), with a small amount of 1 M hydrochloric acid (Merck) added to prevent sedimentation (~0.1 mL). The reducing agent here was sodium borohydride (Merck). Stock solutions of 5-fluorouracil (Merck) were prepared with reference to a standard calibration curve generated by a UV-Vis spectrophotometer equipped with a sipper and peltier (Spectrum SP-UV 300SRB) at a λ_max of 265 nm. Sodium acetate (Merck) was the buffer solution for this process. Graphene oxide (GO) was synthesized using graphite flakes (Ashbury, Inc. USA), phosphoric acid, 85% (Merck), potassium permanganate, 99.9% (Merck), hydrogen peroxide, 30% (Merck).

Oil palm EFB fibers were purchased from Szetech Engineering Sdn Bhd (Selangor, Malaysia) at desired sizes of 106 to 500 μm. The isolation of cellulose was done using formic acid, 90%, sodium hydroxide, hydrogen peroxide and H₂O₂ (Merck, Darmstadt, Germany) and was catalyzed by Fe(II) prepared from Fe₂SO₄ (Merck). The preparation of CaCO₃ nanoparticles was done using calcium chloride, CaCl₂, and sodium carbonate, Na₂CO₃ (Merck). The stock solution of 5-fluorouracil (Merck) was prepared at 100 ppm in sodium acetate solution (Merck) while the 10× concentrated phosphate-buffered saline, PBS (Merck), was diluted to a phosphate buffer and sodium chloride concentration of 0.01 and 0.154 M, respectively.