Iron 3 nitrate

Analytical grade metal precursors (silver nitrate (AgNO₃) 99% (molecular weight: 169.87 g/mol), iron (III) nitrate (Fe(NO₃)₃) 99%) (molecular weight 241.86 g/mol), were purchased from Sigma-Aldrich Co. (St Louis, MO, USA). H₂O₂ (10 mM; Merck, Darmstadt, Germany), ascorbic acid (500 mg/mL; Sigma Aldrich Co., St. Louis, MO, USA). C. auris strains (n = 25) procured from NICD, South Africa. All the reagents were used as received without performing any further purifications. All the metal precursors’ stock solutions were prepared in a clean environment using deionized, double distilled water as a solvent.

Iron(III) hydroxide suspensions were prepared by diluting 18 mM iron(III) nitrate (Sigma-Aldrich) in deionized water and subsequently neutralizing to pH 7 with 1 M NaOH, giving an iron concentration of 440 µM. Suspensions containing both 440 µM iron(III) and 440 µM aluminium(III) at pH 7 were created from 18 mM iron(III) nitrate, and 37 mM aluminium(III) nitrate (Perkin-Elmer) in a similar manner as described above, with aluminium(III) nitrate being added after the iron(III) nitrate. All suspensions were sonicated for 5 min prior to Aβ addition to encourage a homogeneous metal distribution.
Frozen Aβ(1–42) was thawed and dissolved in 0.1 M NaOH to create a 1 mg ml⁻¹ (220 µM) Aβ stock. This Aβ stock was allowed to sit for 30 min to ensure complete peptide dissolution before being added to the previously prepared metal suspensions. Aβ/metal suspensions were again neutralized to pH 7 following the addition of the Aβ stock, via the addition of 0.1 M hydrochloric acid (HCl). Final Aβ and metal concentrations were 35 and 370 µM, respectively. Amyloid-free iron suspensions were created in the same manner as above with the substitution of deionized water in place of Aβ. All Aβ/iron suspensions and amyloid-free controls were incubated at 37°C over a period of 144 h.

Iron (III) Nitrate (Fe(NO₃)₃·9 H₂O), Cobalt (II) Chloride hexahydrate (CoCl₂.6H₂O), Urea (CO(NH₂)₂) and Selenium Powder (Se) were purchased from Sigma-Aldrich. Potassium hydroxide, Sulfuric acid and Iso-propanol were of analytical grade and were used as received without any further purification. Preparation of Indian standard artificial sea water (ASW) and Dulbecco’s Phosphate-Buffered Saline (DPBS) is detailed in Supplementary note 1.

Methylamine, manganese II chloride (MnCl₂∙4H₂O), iron III chloride (FeCl₃∙6H₂O), iron III nitrate (Fe(NO₃)₃∙9H₂O), sodium oleate (SO), rhodamine, Dulbecco’s Modified Eagle Medium (DMEM), fetal bovine serum (FBS), trypsin-EDTA, Hoechst stain solution, and neutral red were purchased from Sigma Aldrich^® (St, Louis, MO, USA). Soy phosphatidylcholine (PC) was bought from Lipoid^® (Ludwigshafen, Germany). Paclitaxel (PTX) was acquired from LC Laboratories (United States). Penicillin/streptomycin was obtained from Gibco™ (Waltham, MA, USA). HPLC grade solvents were purchased from J.T. Baker (Radnor, PA, USA). B16F10 murine melanoma cells were provided by Banco de Células do Rio de Janeiro (BCRJ, Rio de Janeiro, Brazil). Ultrapure Milli-Q water was used throughout the experiments. All other reagents and solvents used were of analytical grade of superior.