2D Piezoelectric Bi₂MoO₆ Nanoribbons for GSH‐Enhanced Sonodynamic Therapy

Abstract

Reducing the scavenging capacity of reactive oxygen species (ROS) and elevating ROS production are two primary goals of developing novel sonosensitizers for sonodynamic therapy (SDT). Hence, ultrathin 2D Bi2MoO6–poly(ethylene glycol) nanoribbons (BMO NRs) are designed as piezoelectric sonosensitizers for glutathione (GSH)‐enhanced SDT. In cancer cells, BMO NRs can consume endogenous GSH to disrupt redox homeostasis, and the GSH‐activated BMO NRs (GBMO) exhibit an oxygen‐deficient structure, which can promote the separation of electron–hole pairs, thereby enhancing the efficiency of ROS production in SDT. The ultrathin GBMO NRs are piezoelectric, in which ultrasonic waves introduce mechanical strain to the nanoribbons, resulting in piezoelectric polarization and band tilting, thus accelerating toxic ROS production. The as‐synthesized BMO NRs enable excellent computed tomography imaging of tumors and significant tumor suppression in vitro and in vivo. A piezoelectric Bi2MoO6 sonosensitizer‐mediated two‐step enhancement SDT process, which is activated by endogenous GSH and amplified by exogenous ultrasound, is proposed. This process not only provides new options for improving SDT but also broadens the application of 2D piezoelectric materials as sonosensitizers in SDT.

A Calcium Fluoride Nanozyme for Ultrasound‐Amplified and Ca2+‐Overload‐Enhanced Catalytic Tumor Nanotherapy

“…Apart from the enzymatic assays, electron spin resonance (ESR) spectroscopy was exploited to detect to qualitatively analyze the generation of •OH species by using a spin trapper 5,5-dimethyl-1-pyrroline N-oxide (DMPO). [22] Different from control, US, H 2 O 2 , and US + H 2 O 2 groups with ignorable peaks, the characteristic quartet signal (1:2:2:1) emerged in both weak acid environment (pH = 5.4) and neutral medium condition (pH = 7.4) in the presence of CaF 2 and H 2 O 2 , which echoes the solution-level results. It is noted that the introduction of US elevated the generation rate of •OH as revealed by the enhanced ESR signal intensity, further evidencing that such an exogenous US stimulus (Figure S5, Supporting Information) with the intrinsic cavitation effect can release energy to accelerate the reaction rate and enhance the reaction degree for assisting the production of more ROS, finally contributing to amplified therapeutic performance (Figure 2i).…”

Dual-Signaling Photoelectrochemical Biosensor Based on Biocatalysis-Induced Vulcanization of Bi2MoO6 Nanosheets

“…29 Analogously, apart from the two typical peaks of Mo 3d located at 235.28 eV (Mo 3d3/2) and 232.12 eV (Mo 3d5/2), two new asymmetric peaks could be found at 234.16 and 231.18 eV, indicating the conversion of Mo 6+ to Mo 5+ (Figure 1F). 30 Moreover, the O 1s spectra could be reasonably deconvolved into three component peaks, which are assigned as lattice oxygen (529.64 eV), oxygen vacancies (530.73 eV), and hydroxyl oxygen (531.95 eV), respectively (Figure 1G). 31 It has been widely recognized that oxygen vacancies can significantly improve the faster charge transport kinetics, thus strongly enhancing the PEC activity of the target electrode matrix.…”

Recent developments of sonodynamic therapy in antibacterial application

“…Piezoelectric materials have a broad scientific potential as a new type of sonosensitizers attributed to the fact that the rupture of bubbles during SDT causes local high pressure (1 × 10 8 Pa). 99 However, at the present time, research on piezoelectric materials in antibacterial SDT is insufficient, and further attention to this sector is needed.…”