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Item Synthesis of iron oxide nanoparticles stabilized with sodium citrate and TMAOH(CDRR Editors) Cândido, Marcela Aparecida; Rost, Nathanne Cristina Vilela; Ferreira, Virginia Rezende; Raniero, Leandro JoséIron oxide nanoparticles (IONPs) represents a class of magnetic and biocompatible nanomaterials that have been widely used in research and medical applications, such as hyperthermia studies, as contrast agents for magnetic resonance imaging, biosensors, among others. However, their application depends on factors as surface properties, size, and morphology being appropriately balanced. IONPs can be obtained by different synthesis methods, however, chemical coprecipitation represents a simpler, easier and faster route, in which aqueous solutions of precursors containing iron (Fe3+) and ferrous (Fe2+) ions are alkalized under control of temperature and pH. This study proposes to synthesize iron oxide nanoparticles by the chemical coprecipitation methodand to stabilize them with sodium citrate (IONPs-CIT) and tetramethylammonium hydroxide (IONPs-TMAOH). Furthermore, to characterize the hydrodynamic diameter and the Zeta Potential of the samples by Dynamic Light Scattering. The cytotoxicity of IONPs-CIT in the MDA-MB-468 cell line was evaluated through the analysis of mitochondrial activity.Item Curcumin-coated iron oxide nanoparticles for photodynamic therapy of breast cancer(Springer Nature Link) Ferreira, Virginia Rezende; Ventura, Aveline; Candido, Marcela Aparecida; Ferreira-Strixino, Juliana; Raniero, Leandro JoséBreast cancer is the deadliest cancer among women and its treatment using traditional methods leads the patient to experience adverse effects. However, photodynamic therapy (PDT) is a non-invasive therapy modality that works through a photosensi- tizing agent, which treating activated by a suitable light source, releases reactive oxygen species capable of treating cancer. Furthermore, recent research indicates that combining PDT and nanoparticles can enhance therapeutic effects. In this way, the synthesis of IONPs (iron oxide nanoparticles) was carried out, and their subsequent coating was done with curcumin (IONPs@curcumin) so that they could act as therapeutic agents against breast cancer. Curcumin solubility tests were carried out to achieve the best results, with ethanol as a solvent, in different concentrations of ethanolic curcumin solution, with the optimal outcome observed at a concentration of 1 mM. Subsequently, the stability analysis was conducted by adjusting the pH of the medium, revealing that at pH 10, the IONPs@curcumin exhibited the best stability and dispersion conditions. Then, cytotoxicity tests of IONPs@curcumin were carried out on the MDA-MB-468 triple-negative breast cancer cell line, under experimental conditions without irradiation and subjected to PDT. The results revealed a viability greater than 70%, as it did not exhibit cytotoxicity for cells in the dark. After 1 h of incubation, the PDT associated with IONPs@curcumin showed 32% of cell viability at a concentration of 30 mg/mL.Item Tribocorrosion Susceptibility and Cell Viability Study of 316L Stainless Steel and Ti6Al4V Titanium Alloy with and without DLC Coatings(MDPI) Sene, Ana Claudia; Silva, Michely Glenda Pereira da; Macário, Paulo Fabrício; Vieira, Angela Aparecida; Leite, Priscila Maria Sarmeiro Correa Marciano; Silva, Newton Soares da; Marques, Francisco Das Chagas; Vieira, LúciaStainless steel (SS316L) and titanium alloy (Ti6Al4V) exhibit suitable properties for biomed- ical applications; however, the tribocorrosion of these materials, which is associated with metallosis, is still a significant concern. This work investigates the effectiveness of DLC smoothing coatings applied to the metals to reduce tribocorrosion and improve cell viability. The study was motivated by many reports of metallosis caused by metal debris in the soft tissues of the body. DLC coatings were produced using the plasma-enhanced chemical vapor deposition (PECVD) technique. The cytotoxicity, genotoxicity, and cell viability of metallic samples with and without DLC coatings were analyzed, considering the chemical composition of the coating and metallic components. The results show that the DLC coatings presented suitable interaction properties and no cytotoxicity or genotoxicity when exposed to the cellular environment, compared with the control group (p < 0.0001). They also demonstrated cell viability, low friction representing a reduction of 80%, and hardness 23–26 GPa, making them ideal for use on fixed implants. It is necessary to control the thickness and roughness of the coating to avoid pinholes and increase the corrosion protection of implants. These DLC coatings with low friction coefficients could facilitate the fixation of implantable pins and screws, including Kirschner wires.