A green approach for the synthesis of α-Fe2O3 nanoparticles from Gardenia resinifera plant and it's In vitro hyperthermia application.

The Gardenia, traditional medicinal plant used from ancient time to increase appetite and other medicinal uses has been employed for the synthesis of superparamagnetic α-Fe2O3 nanoparticles (NPs). The plant extracts unveiled its bifunctional nature through the reducing ferric ions by phenolic groups and capping nature through the -OH bonding over the NPs surface. The prepared NPs exhibits α-Fe2O3 phase among iron oxides and spherical morphology with an average size around 5 nm. The magnetic measurements proved the superparamagnetic behavior of NPs with non-saturating MS value of 8.5 emu/g at room temperature (300 K). Further, the hyperthermia study reveals, the NPs achieved a temperature of 40 °C and 43 °C within 6 min and reaches up to 43 °C and 45 °C within 10 min only for 5 µg/mL and 10 µg/mL concentrations respectively. Based on the heating profile of NPs, the SAR values (167.7 Oe, 300 MHz) calculated and are found to be around 62.75 W/g and 24.38 W/g for 5 µg/mL and 10 µg/mL NPs concentrations respectively. Subsequently, these have been used for toxicity assays, which presented enhanced cytotoxic effects on human mesenchymal cells lines proving them as a potential candidate for the biomedical applications.

Immobilization of invertase on chitosan coated γ-Fe2O3 magnetic nanoparticles to facilitate magnetic separation.

Industrially important invertase enzyme was immobilized on chitosan coated sol gel derived γ-Fe2O3 magnetic nanoparticles (MNPs) to enable it for repetitive use by magnetic separation. MNPs were characterized by X-ray diffraction (XRD), dynamic light scattering (DLS), field emission scanning electron microscope (FE-SEM), Fourier transform infrared (FTIR) spectrometer and magnetic measurements. FTIR studies confirmed successful immobilization of invertase on MNPs. The ability to convert sucrose into invert syrup was enhanced in immobilized invertase compared to that of free enzyme. Further it was found that invertase immobilized on MNPs (IIMNPs) were more stable at varying pH and temperature conditions. Magnetic separation technique was successfully employed for reuse of the IIMNPs for 20 times without significant loss of activity.