Sonodynamic Bacterial Inactivation Enhanced by an Actuator‐Integrated Mechanism

Abstract

Sonodynamic bacterial inactivation, a reactive oxygen species (ROS)empowered approach featuring high penetration depth and low health risk, is explored for antibiotic-free antibacterial treatment. However, the low yield and insufficient diffusion of ROS negatively affect the antibacterial efficacy of sonodynamic treatment, thus hindering its further development. Here an actuator-integrated mechanism is proposed for enhancing the sonodynamic efficacy of loaded sonosensitizers through motion-induced hydrodynamic effects, demonstrated by a porphyrin-decorated gold nanomotor, which can produce ROS for bacterial inactivation while performing multimodal motion via actuation using low-frequency ultrasound. Corroborated by numerical simulation, the experimental results show that the motor's stirring motion significantly increases the yield and diffusion of ROS through fluid flow and frequent interactions between the motor and bacterial targets, resulting in doubled antibacterial efficiency in comparison to a stationary motor. Furthermore, the flow-induced shear forces combined with the frequent interactions constitute a source of mechanical damage and can form a synergy with the antibacterial properties of ROS, enabling an efficient biofilm eradication that is inaccessible by freely suspended porphyrin. In conclusion, this study reports a motion-based strategy to enhance sonodynamic efficacy and provides proof of concept using a sonodynamic gold nanomotor powered by ultrasound.

Sonodynamic therapy-based nanoplatforms for combating bacterial infections

“…The fluorescence imaging of infected mice indicated that the MAPC with pH-responsive Ce6-releasing properties showed an excellent antibacterial effect upon additional US treatment. Another study took the advantages of Au and organic sonosensitizers, Sun et al developed by Au nanorod coated thiol-poly (N, N-diethylacrylamide) for meso -tetrakis(4-sulfonatophenyl) porphyrin (TPPS@Au) loading [59] . TPPS@Au presented SDT antibacterial performance and performed multimodal motion via US propulsion.…”

An Overview of Stimuli-Responsive Intelligent Antibacterial Nanomaterials

“…As shown in Figure 9 a, Sun et al proposed the use of ultrasound-driven micro/nanomotors to enhance sono-dynamic antibacterial efficiency [ 116 ]. Specifically, they presented meso-tetra(4-sulfonatophenyl) porphyrin (TPPS)-modified gold nanorod (Au NR) motors as an illustrative example.…”

“… ( a ) Schematic illustration of an ultrasound-propelled sonodynamic nanomotor for enhanced bacterial inactivation [ 116 ], Copyright 2023 Wiley-VCH. ( b ) Schematic illustration of Na + inserted metal–organic framework for rapid therapy of infected bacteria [ 114 ], Copyright 2021 Elsevier.…”

Ultrasound-responsive gallium protoporphyrin and oxygen loaded perfluoropentane nanodroplets for effective sonodynamic therapy of implant infections

“…SDT has low invasiveness, high penetration depth, and can respond to US to produce ROS for sterilization, thereby avoiding the issue of antibiotic resistance. 11,12 SDT has shown great promise for treating infections and has gained increasing attention. [13][14][15] However, several issues still greatly limit the therapeutic efficacy of SDT for bacterial biofilms.…”