Introduction: Fe 3 O 4 nanoparticles (Fe 3 O 4 NPs) with multiple functionalities are intriguing candidates for various biomedical applications. Materials and Methods: This study introduced a simple and green synthesis of Fe 3 O 4 NPs using a low-cost stabilizer of plant waste extract rich in polyphenols content with a well-known antioxidant property as well as anticancer ability to eliminate colon cancer cells. Herein, Fe 3 O 4 NPs were fabricated via a facile co-precipitation method using the crude extract of Garcinia mangostana fruit peel as a green stabilizer at different weight percentages (1, 2, 5, and 10 wt.%). The samples were analyzed for magnetic hyperthermia and then in vitro cytotoxicity assay was performed. Results: The XRD planes of the samples were corresponding to the standard magnetite Fe 3 O 4 with high crystallinity. From TEM analysis, the green synthesized NPs were spherical with an average size of 13.42±1.58 nm and displayed diffraction rings of the Fe 3 O 4 phase, which was in good agreement with the obtained XRD results. FESEM images showed that the extract covered the surface of the Fe 3 O 4 NPs well. The magnetization values for the magnetite samples were ranging from 49.80 emu/g to 69.42 emu/g. FTIR analysis verified the functional groups of the extract compounds and their interactions with the NPs. Based on DLS results, the hydrodynamic sizes of the Fe 3 O 4 nanofluids were below 177 nm. Furthermore, the nanofluids indicated the zeta potential values up to −34.92±1.26 mV and remained stable during four weeks of storage, showing that the extract favorably improved the colloidal stability of the Fe 3 O 4 NPs. In the hyperthermia experiment, the magnetic nanofluids showed the acceptable specific absorption rate (SAR) values and thermosensitive performances under exposure of various alternating magnetic fields. From results of in vitro cytotoxicity assay, the killing effects of the synthesized samples against HCT116 colon cancer cells were mostly higher compared to those against CCD112 colon normal cells. Remarkably, the Fe 3 O 4 NPs containing 10 wt.% of the extract showed a lower IC 50 value (99.80 µg/mL) in HCT116 colon cancer cell line than in CCD112 colon normal cell line (140.80 µg/mL). Discussion: This research, therefore, introduced a new stabilizer of Garcinia mangostana fruit peel extract for the biosynthesis of Fe 3 O 4 NPs with desirable physiochemical properties for potential magnetic hyperthermia and colon cancer treatment.

The overwhelming request for nanodevices and heat flow developments has led to consider magnetic Fe3O4 nanoparticles as a new dawn to the sophisticated nanotechnology in a sustainable manner. This research presented a facile production of Fe3O4 nanoparticles using co-precipitation method and the extract of Garcinia Mangostana fruit peel waste as a green stabilizer and capping agent. The X-ray powder diffraction (XRD) planes of the synthesized nanoparticles showed the formation of magnetite Fe3O4 nanoparticles with good crystallinity. Based on the image of field emission scanning electron microscope (FESEM), the diameter of the nanoparticles was estimated to be 69.14±2.87 nm as was coated by the extract. The Fe3O4 nanoparticles presented an acceptable magnetization value of 51.17 emu/g. From the analysis of Fourier-transform infrared spectroscopy (FTIR), the phenolic compounds and other functional groups of the extract had interactions with the Fe ions to successfully synthesize the nanoparticles. The green synthesized Fe3O4 nanofluids showed small hydrodynamic size of 145.80±3.14 and high zeta potential value of -30.5±1.82 mV. This study, thus, showed that the extract of Garcinia Mangostana fruit peel waste can serve as a bio-stabilizer and capping agent to enhance physiochemical properties and colloidal stability of the Fe3O4 nanofluids with an environmentally-friendly manner and low cost for modern applications.