Dunaliella salina microalgae aqueous extract-based magnetic nanoparticles (Fe3 O4-NPs): Green synthesis, characterization and in vitro anticancer investigations

In the current study, a facile, rapid, and eco-friendly method was provided for green synthesizing of magnetic Fe3O4-NPs with enhanced stability and biocompatibility using different weight concentrations (1 %, 3 %, and 5 %) of aqueous extract of Dunaliella salina (D. salina) microalgae. The properties of the green-synthesized magnetic nanoparticles (GMNPs-ex1%, GMNPs-ex3%, and GMNPs-ex5%) were compared with chemically-synthesized ones (CMNPs) via XRD, TEM, FESEM, VSM, DLS, ZP, FTIR, hemolysis, cell viability, DAPI staining, and apoptosis analyses. TEM imaging revealed mean sizes of 11.21 +/- 2.63 nm and 14.08 +/- 3.24 nm for GMNPs-ex5% and CMNPs, respectively, with better dispersity for GMNPs-ex5%, as confirmed with their polydispersity index (PDI = 0.24 for GMNPs-ex5% and 0.58 for CMNPs). These sizes were consistent with the crystallite size of pure magnetite phase nanoparticles obtained from XRD. FESEM images confirmed spherical shape for the majority of nanoparticles. FTIR spectra confirmed the involvement of functional groups from the extract in GMNPs, contributing to their stability (ZP of GMNPs-ex5% = -34 mV). The saturation magnetization decreased with increasing the extract ratio (from 62.41 to 8.94 emu/g), attributed to the non-magnetic nature of the extract coating. GMNPs-ex5% exhibited a negligible hemolysis rate (< 2 %) compared to CMNPs. Furthermore, IC50 values of GMNPs and extract against HFF-2 and A549 cells were higher than those of CMNPs, indicating the biocompatibility of green-synthesized nanoparticles. In the DAPI staining method, GMNPs-ex5%, similar to the extract, caused less DNA damage to HFF-2 cells. Additionally, the apoptosis assay using annexin V/PI staining kit indicated that green-synthesized nanoparticles induced lower apoptosis in normal cells. Overall, this study highlights the potential of green-synthesized Fe3O4-NPs for various biomedical applications, showcasing their enhanced properties and biocompatibility compared to conventionally synthesized counterparts.