Millex gs filter of 0.22 m

IONP@Zn-cit was synthesized by combining 25 mg FeCl₃, 25 mg ZnCl₂, 58.5 mg citrate trisodium (selected as a coating to ensure colloidal stability), and 0.5 mL hydrazine hydrate in H₂O milliQ at a final volume of 5 mL. Immediately, the mixture was subjected to very fast ramping (1 min) to 100 °C under stirring with microwave irradiation at 240 W (MW; CEM) for 10 min, and a final cooling step with N₂ gas until 55 °C was achieved (Figure 7). Subsequently, 6 mL of IONP@Zn-cit was purified by gel filtration using PD-10 desalting columns (Sephadex G-25 Medium; Cytvia) in water. The concentrations of incorporated Fe and Zn were determined by ICP-MS. For the in vitro studies (colloidal stability, cytotoxicity, and clonogenic assays), nanoparticle suspension medium was exchanged by ultrafiltration (Amicon Ultra-15, membrane PLTK Ultracel-PL, 30 kDa; Merck Millipore) at 1520× g for 3 min. After that, the cell culture medium was added to resuspend the nanoparticles, and the centrifugation step was repeated twice until the medium was adjusted to the initial volume to maintain concentrations. Finally, the NPs were sterilized using a vented Millex-GS filter of 0.22 µm (Merck Millipore).

IONP@Zn-cit was synthesized by combining 25 mg FeCl₃, 25 mg ZnCl₂, 58.5 mg citrate trisodium (selected as a coating to ensure colloidal stability), and 0.5 mL hydrazine hydrate in H₂O milliQ at a final volume of 5 mL. Immediately, the mixture was subjected to very fast ramping (1 min) to 100 °C under stirring with microwave irradiation at 240 W (MW; CEM) for 10 min, and a final cooling step with N₂ gas until 55 °C was achieved (Figure 7). Subsequently, 6 mL of IONP@Zn-cit was purified by gel filtration using PD-10 desalting columns (Sephadex G-25 Medium; Cytvia) in water. The concentrations of incorporated Fe and Zn were determined by ICP-MS. For the in vitro studies (colloidal stability, cytotoxicity, and clonogenic assays), nanoparticle suspension medium was exchanged by ultrafiltration (Amicon Ultra-15, membrane PLTK Ultracel-PL, 30 kDa; Merck Millipore) at 1520× g for 3 min. After that, the cell culture medium was added to resuspend the nanoparticles, and the centrifugation step was repeated twice until the medium was adjusted to the initial volume to maintain concentrations. Finally, the NPs were sterilized using a vented Millex-GS filter of 0.22 µm (Merck Millipore).