Magnetochemistry

Sepsis-induced acute lung injury (SALI) is characterized by dysregulated inflammation with limited therapeutic options. Although Anemoside B4 (AB4) exhibits anti-inflammatory properties, its clinical application is hindered by poor bioavailability. To address this limitation, we developed magnetically guided gelatin microrobots (MG-AB4) for targeted AB4 delivery. The MG-AB4 system consists of a Fe₃O₄-loaded gelatin shell for enabling precise magnetic navigation (velocity: 110 μm/s), an AB4 core for rapid drug release which is advantageous for acute inflammatory responses, and surface modifications to enhance cellular uptake. Compared with free AB4, MG-AB4 significantly suppressed key inflammatory cytokines (Interleukin-6 (IL-6), Interleukin-1 beta (IL-1β), Tumor necrosis factor-alpha (TNF-α); p < 0.01), inhibited NF-κB activation (p < 0.01), and improved cell viability in an inflammatory model (p < 0.05). This study demonstrates that magnetically guided AB4 delivery using rapidly releasing microrobots is a promising strategy for SALI treatment, wherein the synergy of targeted delivery and potent anti-inflammatory action may effectively mitigate disease progression.

Herein, we address the challenge of high core losses in soft magnetic composites (SMCs) at high frequencies by developing a FeSiAl/WS₂ composite system processed under a transverse magnetic field (TMF). In this study, 200- and 600-mesh FeSiAl powders were used as base materials and combined with 2.25 wt.% two-dimensional tungsten disulfide (WS₂; an insulating agent) to prepare FeSiAl/2.25 wt.%WS₂ soft magnetic composites via ultrasonic mixing. The evolution of soft magnetic properties under a transverse magnetic field (TMF) was systematically investigated. The novelty of this work lies in the synergistic combination of fine FeSiAl particles and WS₂ nanosheets as an interparticle insulator and the application of a TMF to simultaneously suppress eddy current and hysteresis losses—a challenge that is difficult to address using conventional approaches. Morphological analysis confirmed a uniform and continuous organic coating of WS₂ nanosheets on FeSiAl particle surfaces. Permeability measurements revealed a slight decrease in effective permeability after the TMF treatment; however, the high-frequency performance was markedly enhanced. Magnetic loss analysis revealed a substantial reduction in the hysteresis loss and an increase in the quality factor under the TMF. Notably, the FeSiAl (600 mesh)/2.25 wt.% WS₂ composite achieved a total magnetic loss of 234 kW/m³ under a TMF of 140 kA/m, magnetic induction of 20 mT, and frequency of 1 MHz, representing a 69% reduction compared with conventional SMCs. These results not only validate the effectiveness of the proposed synergistic approach but also highlight the potential of FeSiAl (600 mesh)/2.25 wt.% WS₂ for use in high-power, high-frequency magnetic devices, with improved energy efficiency and thermal performance.

In this work, we present the first report on the synthesis via the sol–gel method of a high-entropy (Fe_0.2Co_0.2Cu_0.2Ni_0.2Mn_0.2)Nb₂O₆ with columbite–orthorhombic structure. Polyvinylpyrrolidone (PVP), ammonium niobium oxalate, and equimolar amounts of Fe, Co, Cu, Ni, and Mn ions were used. The refinement of the XRD pattern showed the presence of niobate crystallites with an average size of 48.4 nm and a fraction of 7.6 wt% of a spinel-like phase. At temperatures below 5 K, the DC and AC magnetometry results revealed the presence of a ferromagnetic-like phase due to the niobate phase. The Mössbauer spectrum at 300 K showed a paramagnetic and two magnetically ordered components corresponding to the niobate and the spinel-like phases, respectively. The spectral components were typical of Fe³⁺, indicating the presence of cation vacancies. The elemental mapping obtained from EDS measurements showed compositional homogeneity. The XRF measurements confirmed a composition consistent with nominal values. These results confirm the feasibility of synthesizing entropy-stabilized columbite oxides via the sol–gel route, opening new opportunities for the design of multifunctional ceramics with tunable structural and magnetic properties for high-performance thermal barrier coatings and energy conversion applications.