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Photodynamic therapy (PDT) is a promising alternative to conventional cancer treatment methods. Nonetheless, improvement of in vivo light penetration and cancer cell-targeting efficiency remain major challenges in clinical photodynamic therapy. This study aimed to develop multifunctional magnetic nanoparticles conjugated with a photosensitizer (PS) and cancer-targeting molecules via a simple surface modification process for PDT. To selectively target cancer cells and PDT functionality, core magnetic (Fe3O4) nanoparticles were covalently bound with chlorin e6 (Ce6) as a PS and folic acid (FA). When irradiated with a 660-nm long-wavelength light source, the Fe3O4-Ce6-FA nanoparticles with good biocompatibility exerted marked anticancer effects via apoptosis, as confirmed by analyzing the translocation of the plasma membrane, nuclear fragmentation, activities of caspase-3/7 in prostate (PC-3) and breast (MCF-7) cancer cells. Ce6, used herein as a PS, is thus more useful for PDT because of its ability to produce a high singlet oxygen quantum yield, which is owed to deep penetration by virtue of its long-wavelength absorption band; however, further in vivo studies are required to verify its biological effects for clinical applications.

We report a novel zinc oxide (ZnO) nanoparticle with antioxidant properties, prepared by immobilizing the antioxidant 3-(3,4-dihydroxyphenyl)-2-propenoic acid (caffeic acid, CA) on the surfaces of micro-dielectric barrier discharge (DBD) plasma-treated ZnO nanoparticles. The microstructure and physical properties of ZnO@CA nanoparticles were characterized by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), infrared spectroscopy, and steady state spectroscopic methods. The antioxidant activity of ZnO@CA nanoparticles was evaluated using an ABTS (3-ethyl-benzothiazoline-6-sulfonic acid) radical cation decolorization assay. ZnO@CA nanoparticles exhibited robust antioxidant activity. Moreover, ZnO@CA nanoparticles showed strong antibacterial activity against Gram-positive bacteria (Staphylococcus aureus) including resistant bacteria such as methicillin-resistant S. aureus and against Gram-negative bacteria (Escherichia coli). Although Gram-negative bacteria appeared to be more resistant to ZnO@CA nanoparticles than Gram-positive bacteria, the antibacterial activity of ZnO@CA nanoparticles was dependent on particle concentration. The antioxidant and antibacterial activity of ZnO@CA may be useful for various biomedical and nanoindustrial applications.

Regular nanosized structures are considered to be promising materials for magnetic information storage media with high density of information. Recently attention was paid to static and dynamic magnetic properties arising from dimensional confinement in such nanostructures. Here we present an investigation of permalloy antidot arrays of different thicknesses. Thin permalloy films of thickness ranging from 10to500nm were deposited on nanoporous Al2O3 membranes with a pore size of 100nm. It was found that additional ferromagnetic resonance peaks appear for film thicknesses below 100nm, while films with larger thicknesses show resonance properties similar to continuous films. A comparison between the films deposited onto Si wafers and porous media was done. An evolution of the domain structures observed in MFM experiments was confirmed by micromagnetic calculations.