Interfacial Mo, W-Conjugated Polarization, and Oxygen Vacancies of MoO₂/WO₃ in Enhanced Microwave Therapy for MRSA-Induced Osteomyelitis

Abstract

Deep tissue infection, such as osteomyelitis, caused by methicillin-resistant Staphylococcus aureus (MRSA) infection, poses a serious threat to public health and cannot be effectively treated by antibiotics. In this study, we report a microwave (MW)-responsive MoO 2 /WO 3 heterojunction that can be utilized to effectively treat MRSA-infected osteomyelitis under MW irradiation because of the enhanced MW thermal effect and MW catalysis of the composite. The underlying mechanism is as follows: A myriad of oxygen vacancies forms on the surface of MoO 2 and WO 3 by deoxidization effect with hydrogen from the decomposition of sodium borohydride, which induces a mass of free electrons on the surface of the composite and consequently promotes a localized surface plasmon resonance effect (LSPR) under MW irradiation. Furthermore, the conjugation of Mo and W at the interface enhances the LSPR effect. Thus, the LSPR effect not only induces the formation of radical oxygen species, thereby enhancing MW catalysis, but also results in the formation of an interfacial electrical field, which strengthens dipole polarization through synergistic action with oxygen vacancies and contributes to better MW thermal effects. The characteristics of MoO 2 /WO 3 prove to be promising for the treatment of deep-tissue infections under MW irradiation.

Multistage coupling of interface and core–shell engineering of a cobalt-based heterostructure for integration of multiple electromagnetic absorption

“…5a, it can be seen that the total DOS of N-PC@IC/Co/rGO was mainly occupied by Co, and the metallic conductivity was proved by the electronic state occupying the Fermi surface. 28 Simultaneously, the outstanding conductivity could be demonstrated by the high delocalization near the Fermi level, 25 which corresponded to the conductivity results. To further explore the electronic migration, the work function was utilized (Fig.…”

Lattice Strain Engineering of Ti3C2 Narrows Band Gap for Realizing Extraordinary Sonocatalytic Bacterial Killing

“…47 DCFH could be then oxidized to fluorescing 2′,7′-dichlorofluorescein (DCF) by ROS, and the fluorescence intensity of DCF can directly reflect the oxidative stress. 48 The MRSA cells in the LS-Ti 3 C 2 group showed the highest fluorescence intensity (Figure 5G galactopyranoside (ONPG) intensity of the LS-Ti 3 C 2 group was the highest among the groups (Figure 5H), 49 which indicated that US-triggered ROS in the LS-Ti 3 C 2 group led to the enhancement of bacterial membrane permeability. Also, the LS-Ti 3 C 2 nanosheets caused enhancement of protein leakage and significant reduction of adenosine triphosphate (ATP) activity of MRSA owing to highly efficient SDT (Figure 5I,J).…”

“…Subsequently, 2′,7′-dichlorodihydrofluorescein diacetate (DCFH-DA) was applied to discover intracellular ROS, which is hydrolyzed into dichlorofluorescin (DCFH) after it enters the bacteria . DCFH could be then oxidized to fluorescing 2′,7′-dichlorofluorescein (DCF) by ROS, and the fluorescence intensity of DCF can directly reflect the oxidative stress . The MRSA cells in the LS-Ti 3 C 2 group showed the highest fluorescence intensity (Figure G and Figure S13), indicating that the US-triggered extraordinary ROS release caused fatal oxidative stress to the MRSA bacteria.…”

Exploring the role of oxygen vacancies on the magnetic and electromagnetic absorption properties of La3+-modified M-type hexaferrite with Al3+ doping

“…All the samples have more than one semicircle, suggesting that multiple dielectric relaxation is present, contributing to the dielectric loss, which is consistent with peaks observed in the real and imaginary parts of complex permittivity. The presence of defects and oxygen vacancies also leads to the accumulation of charges at the interfaces of grain boundaries, causing interfacial polarization and dielectric relaxation, which can also enhance the dielectric loss of the materials [66]. Furthermore, a partial linear behaviour is noticed between ϵ ′ (ω) and ϵ ′ ′ (ω) for all the samples.…”