The study of magnetism in materials without partially filled d or f bands has gained much attention in the past years. Even though it has challenged the understanding of traditional magnetism, there is a wide range of studies debating the nature of magnetism in such materials. Theories on whether the exhibited ferromagnetic behavior is due to sample impurities or intrinsic structural defects have been published throughout the years. Materials such as hexaborides, non-magnetic oxides, and carbon nanostructures have been of great interest due to their potential applications. For a better understanding, herein, we present a literature review combining past and up-to-date studies on these materials.

Even today, breast cancer remains a global public problem, with a high mortality rate among women. Nanoparticle (NP) based systems are developed to enhance drug delivery, reducing the toxic effect of medicine molecules. By using iron oxide nanoparticles for cancer treatment, several advantages were highlighted: the ability to target specific locations derived from their magnetic properties and reduced side effects. The aim of this study was to examine on breast cancer cell line the anticancer potential of γ-Fe₂O₃ NPs loaded with doxorubicin (DOX) and stabilized with carboxymethylcellulose sodium (CMCNa). The γ-Fe₂O₃ NPs were synthesized by laser pyrolysis technique and their nanometric size and crystallinity were confirmed by X-ray diffraction and transmission electron microscopy. The loading efficiency was estimated by using absorption and fluorescence spectroscopy. The DOX conjugated//CMCNa coated γ-Fe₂O₃ NPs proved through the biological studies to have a good anticancer effect through the inhibition of tumoral cell proliferation, disruption of the cellular membrane, induction of cell death and reduced effects on normal breast cells. Our data showed that DOX cytotoxicity increases significantly when conjugated with ɣ-Fe₂O₃ and ɣ-Fe₂O₃_CMCNa, a 50% reduction of cancer cell viability was obtained with a concentration around 0.1 µg/mL.

The purpose of this study was to investigate the effectiveness in photodynamic therapy of iron oxide nanoparticles (γ-Fe₂O₃ NPs), synthesized by laser pyrolysis technique, functionalized with 5,10,15,20-(Tetra-4-sulfonatophenyl) porphyrin tetraammonium (TPPS) on human cutaneous melanoma cells, after only 1 min blue light exposure. The efficiency of porphyrin loading on the iron oxide nanocarriers was estimated by using absorption and FTIR spectroscopy. The singlet oxygen yield was determined via transient characteristics of singlet oxygen phosphorescence at 1270 nm both for porphyrin functionalized nanoparticles and rose bengal used as standard. The irradiation was performed with a LED (405 nm, 1 mW/cm²) for 1 min after melanoma cells were treated with TPPS functionalized iron oxide nanoparticles (γ-Fe₂O₃ NPs_TPPS) and incubated for 24 h. Biological tests revealed a high anticancer effect of γ-Fe₂O₃ NPs_TPPS complexes indi-cated by the inhibition of tumor cell proliferation, reduction of cell adhesion, and induction of cell death through ROS generated by TPPS under light exposure. The biological assays were combined with the pharmacokinetic prediction of the porphyrin.

In order to find solutions to current worldwide environmental problems, it is crucial to develop sustainable nanomaterials, ideally with multifunctional properties. Considering this, novel TiO₂-SnO₂@NMs (noble metals: Au and Ag) composites, for use as sustainable nanomaterials, were successfully prepared via a two-step synthesis process consisting of laser pyrolysis followed by the chemical impregnation of the collected materials with noble metals. The addition of SnO₂ favors the transformation of TiO₂ from a mixture with a majority Anatase phase to one with a Rutile phase majority. With consideration for their level of environmental toxicity, the features of the synthesized nanomaterials were structurally, morphologically, and optically described and assessed for environmental protection applications as gas sensors and photocatalysts. In the case of the Surface Acoustic Wave sensor, based on a pure TiO₂ nanopowder, a notable difference in the frequency shift was detected in comparison to the other examined sensors. All sensors responded to the CH₄ concentrations tested (0.02–0.1%). On the other hand, when methyl orange was photodegraded under visible light, the results obtained using NMs for decoration revealed that the photocatalytic activity of TiO₂-SnO₂@NMs was significantly improved compared to the TiO₂-SnO₂ binary composite, which already has an enhanced photocatalytic activity, compared to pure TiO₂. Overall, this work produces nanoparticles that exhibit better sensory and photocatalytic features, as well as higher levels of biocompatibility with skin cells, for use as eco-friendly nanomaterials for a sustainable future.

The specific roles played by both support and noble metals in light absorption, charge separation, and the formation of ·OH and O₂⁻ (ROS) are analyzed for light-triggered oxidation of phenol (Ph) over pristine and over noble metal (Ag, Au, Pt) -loaded TiO₂. Experiments show that the supported noble metals act as a light visible absorber, assist the separation of photo-charges and reduction of O₂ to O₂⁻. The O₂⁻ oxidizes mildly Ph to oxygenated products (hydroquinone, benzoquinone, and 1,2-dihydroxibenzene). In a parallel process, ·OH radicals, yielded by TiO₂, mineralize Ph to CO₂ by fast reaction sequences. Radical quenching and photo electrochemical measurements (surface photovoltage) confirm independently that the production of ·OH and O₂⁻ scale with oxidative conversion of Ph. The selectivity to CO₂ and mild oxidation products is the result of the interplay between catalyst activity for ·OH and for O₂⁻ production.