Defect-Modified nano-BaTiO₃ as a Sonosensitizer for Rapid and High-Efficiency Sonodynamic Sterilization

Abstract

Multidrug-resistant bacteria caused by the unlimited overuse of antibiotics pose a great challenge to global health. An antibacterial method based on reactive oxygen species (ROS) is one of the effective strategies without inducing bacterial resistance. Owing to the ability of generating ROS, piezocatalytic material-mediated sonodynamic therapy (SDT) has drawn much attention. However, its major challenge is the low ROS generation efficiency in the piezocatalytic process due to the poor charge carrier concentration of piezoelectric materials. Vacancy engineering can regulate the charge density and largely promote ROS generation under ultrasound (US) irradiation. Herein, a US-responsive self-doped barium titanate with controlled oxygen vacancy (Vo) concentrations was successfully synthesized through a facile thermal reduction treatment at different temperatures (i.e., 350, 400, and 450 °C), and the corresponding samples were named as BTO-350, BTO-400, and BTO-450, respectively. Then, the effect of Vo concentrations on ROS generation efficiency during the piezocatalytic process was systematically studied. And BTO-400 was found to possess the highest piezocatalytic activity and excellent sonodynamic antibacterial performance against Escherichia coli and Staphylococcus aureus. Furthermore, its antibacterial mechanism was confirmed that the ROS generated under US could damage bacterial cell membrane and cause considerable leakage of cytoplasmic components and irreversible death of bacteria. Notably, the in vivo results illustrated that the BTO-400 could serve as an effective antibacterial agent and accelerate skin healing via SDT therapy. In all, the Vo defect-modified nano-BaTiO3 has a noticeable potential to induce a rapid and efficient sterilization as well as skin tissue repair by SDT.

Sonodynamic therapy-based nanoplatforms for combating bacterial infections

“…In another way, He et al designed a barium titanate with controlled oxygen vacancy (Vo-BTO) by thermal reduction treatment to enhance ROS generation ability [78] . Furthermore, Lei et al reported a novel nanoparticle with bacterial elimination activity based on sulfur-doped oxygen-defective BTO (SDBTO) for osteogenic therapy [79] .…”

An Injectable Black Phosphorus Hydrogel for Rapid Tooth Extraction Socket Healing

“…During the immediate postoperative period following tooth extraction, ROS are locally generated in the oral cavity and can enter the circulation . ROS, a battery of free radicals, such as singlet oxygen ( 1 O 2 ), , superoxide anion radical (•O 2 – ), , hydrogen peroxide (H 2 O 2 ), and hydroxyl radical (•OH). , The excess ROS existence in damaged sites may cause chronic healing, cell apoptosis and irreversible tissue injury . The production of ROS is a host defense mechanism of normal cell against bacterial pathogens .…”

Biocompatible Polymer-Grafted TiO2 Nanoparticle Sonosensitizers Prepared Using Phosphonic Acid-Functionalized RAFT Agent

“…For efficient SDTs, sonosensitizers are of great importance to initiate a sonochemical reaction when producing ROS. In the past, many sonosensitizers, such as TiO 2 [9,10], porphyrin and its derivatives [11][12][13][14], BaTiO 3 [15], and PtCu 3 [16,17] have been developed to enhance ROS generation and therapeutic effects. TiO 2 nanoparticles have the potential for targeted delivery to tumors through enhanced permeability and retentivity effects [18,19] owing to their nanometer size [5].…”