Ultrasound-responsive microbubbles in antibacterial therapy

Microbubbles(MBs)are gas-filled micrometer-scale spheres that are commonly formed by the gas core encapsulated with stabilizing shells,including polymers,surfactants,proteins,or liposomes shells.Clinically,MBs were originally used as contrast agents for enhanced ultrasound(US)imaging and diagnostics.Nowadays,MBs were given expectations that they can be alternative platforms for drug delivery owing to their unique acoustic properties.MBs can respond to the US by cavitation effect which refers to a series of complex dynamic processes,such as oscillation,expansion,contraction,and implosion[1].Drug molecules or therapeutic agents can be associated with the MB shells by means of van-der-Waals forces,electrostatic or hydrophobic interactions,or merely by physical encapsulation[2].Therefore,strategies are emerging which take advantages of US-mediated MBs drug delivery systems,mainly focusing on sonothrombolysis,cancer therapy and central nervous system(CNS)pathologies[3].Nevertheless,several researchers have apperceived the promising potential of US-responsive MBs in antibacterial therapy.Here,we aimed to paint an overview of the latest published papers on MBs for antibacterial therapy,hoping to help understand the perspectives that the field may offer emerging generations of antibacterial agents.