Green synthesis of MnO2 nanoparticles from Psidium guajava leaf extract: Morphological characterization, photocatalytic and DNA/BSA interaction studies.

In this work, a simple, efficient and eco-friendly green synthesis of manganese dioxide nanoparticles (MnO2NPs) by Psidium guajava leaf extract was described. Fourier-Transform infrared spectra results revealed that involvement of the plant extract functional groups in the formation of MnO2NPs. The UV-vis absorption spectra of the synthesized MnO2NPs exhibited absorption peaks at 374 nm, which were attributed to the band gap of the MnO2NPs. Crystal phase identification of the MnO2NPs were characterized by X-ray diffraction analysis and the formation of crystalline MnO2NPs have been confirmed. Furthermore, scanning electron microscopy analysis showed that the synthesized MnO2NPs have a spherical in shape. Interestingly, the prepared green synthesized MnO2NPs showed catalytic degradation activity for malachite green dye. Malachite green's photocatalytic degradation was detected spectrophotometrically in the wavelength range of 250-900 nm, and it was discovered to have a photodegradation efficiency of 75.5 % within 90 min when exposed to solar radiation. Green synthesized MnO2NPs are responsible for this higher activity. An interaction between synthesized NPs and biomolecules, including CT-DNA and BSA was also evaluated. The spectrophotometric and Fluoro spectroscopic analyses indicate a gradual reduction in peak intensities and shifts in wavelengths, indicating binding and affinity between the NPs and the biomolecules.

Iron oxide nanoparticle core-shell magnetic microspheres: Applications toward targeted drug delivery.

This study describes a sensitive reactive oxygen species (ROS)-responsive lecithin (LEC) incorporated iron oxide nanoparticle (Fe3O4 NP) system with potent anti-inflammatory properties and even more so when the antioxidant drug curcumin (CUR) is encapsulated in the PLGA hybrid magnetic microsphere system (Fe3O4@LEC-CUR-PLGA-MMS). The delivery system is responsive to ROS including an H2O2 environment to release the payload (CUR) drug. Greater cytotoxicity properties were observed in the presence of Fe3O4@LEC-CUR-PLGA-MMS against A549 and HeLa S3 cells with IC50 values after 24 h of 10 and 12 µg/mL and 10 and 20 µg/mL, respectively. The present Fe3O4@LEC-CUR-PLGA-MMS system demonstrated much better in vitro cytotoxicity, cellular morphological changes and moreover an ability to limit colony formation for A549 and HeLa S3 cancer cell lines than non-cancerous cells, and thus, should be further studied for a wide range of medical applications.