Purpose: Although magnetite nanoparticles (MNPs) are promising agents for hyperthermia therapy, insufficient drug encapsulation efficacies inhibit their application as nanocarriers in the targeted drug delivery systems. In this study, porous magnetite nanoparticles (PMNPs) were synthesized and coated with a thermosensitive polymeric shell to obtain a synergistic effect of hyperthermia and chemotherapy. Materials and methods: PMNPs were produced using cetyltrimethyl ammonium bromide template and then coated by a polyethylene glycol layer with molecular weight of 1500 Da (PEG1500) and phase transition temperature of 48 ± 2 °C to endow a thermosensitive behavior. The profile of drug release from the nanostructure was studied at various hyperthermia conditions generated by waterbath, magnetic resonance-guided focused ultrasound (MRgFUS), and alternating magnetic field (AMF). The in vitro cytotoxicity and hyperthermia efficacy of the doxorubicin-loaded nanoparticles (DOX-PEG1500-PMNPs) were assessed using human lung adenocarcinoma (A549) cells. Results: Heat treatment of DOX-PEG1500-PMNPs containing 235 ± 26 mg·g⁻¹ DOX at 48 °C by waterbath, MRgFUS, and AMF, respectively led to 71 ± 4%, 48 ± 3%, and 74 ± 5% drug release. Hyperthermia treatment of the A549 cells using DOX-PEG1500-PMNPs led to 77% decrease in the cell viability due to the synergistic effects of magnetic hyperthermia and chemotherapy. Conclusion: The large pores generated in the PMNPs structure could provide a sufficient space for encapsulation of the chemotherapeutics as well as fast drug encapsulation and release kinetics, which together with thermosensitive characteristics of the PEG1500 shell, make DOX-PEG1500-PMNPs promising adjuvants to the magnetic hyperthermia modality.

Hybrid reinforcement’s novel composite (Al-Fe₃O₄-SiC) via powder metallurgy method was successfully fabricated. In this study, the aim was to define the influence of SiC-Fe₃O₄ nanoparticles on microstructure, mechanical, tribology, and corrosion properties of the composite. Various researchers confirmed that aluminum matrix composite (AMC) is an excellent multifunctional lightweight material with remarkable properties. However, to improve the wear resistance in high-performance tribological application, hardening and developing corrosion resistance was needed; thus, an optimized hybrid reinforcement of particulates (SiC-Fe₃O₄) into an aluminum matrix was explored. Based on obtained results, the density and hardness were 2.69 g/cm³, 91 HV for Al-30Fe₃O₄-20SiC, after the sintering process. Coefficient of friction (COF) was decreased after adding Fe₃O₄ and SiC hybrid composite in tribology behaviors, and the lowest COF was 0.412 for Al-30Fe₃O₄-20SiC. The corrosion protection efficiency increased from 88.07%, 90.91%, and 99.83% for Al-30Fe₃O₄, Al-15Fe₃O₄-30SiC, and Al-30Fe₃O₄-20SiC samples, respectively. Hence, the addition of this reinforcement (Al-Fe₃O₄-SiC) to the composite shows a positive outcome toward corrosion resistance (lower corrosion rate), in order to increase the durability and life span of material during operation. The accomplished results indicated that, by increasing the weight percentage of SiC-Fe₃O₄, it had improved the mechanical properties, tribology, and corrosion resistance in aluminum matrix. After comparing all samples, we then selected Al-30Fe₃O₄-20SiC as an optimized composite.

Self-assembled nanotubular arrays on Ti alloys could be used for more effective implantable devices in various medical approaches. In the present work, the adhesion of TiO2 nanotubes (TiO2 NTs) on Ti-6Al-4V (Ti64) was investigated by laser spallation and scratch test techniques. At first, electrochemical anodization was performed in an ammonium fluoride solution dissolved in a 90:10 ethane-1,2-diol (ethylene glycol) and water solvent mixture. This process was performed at room temperature (23?C) at a steady potential of 60 V for 1 h. Next, the TiO2 nanotubes layer was heat-treated to improve the adhesion of the coating. The formation of selforganized TiO2 nanotubes as well as the microstructural evolution, are strongly dependent on the processing parameters and subsequent annealing. From microscopic analysis, highly oriented arrays of TiO2 nanotubes were grown by thermal treatment for 90min at 500?C. Further heat treatment above 500?C led to the detachment of the nanotubes and the complete destruction of the nanotubes occurred at temperature above 700?C. Scratch test analysis over a constant scratch length (1000 ?m) indicated that the failure point was shifted from 247.4 to 557.9 ?m while the adhesion strength was increased from ~862 to ~1814mN after annealing at 500?C. The adhesion measurement determined by laser spallation technique provided an intrinsic adhesion strength of 51.4MPa for the TiO2 nanotubes on the Ti64 substrate.