Biofilm mitigation by drug (gentamicin)-loaded liposomes promoted by pulsed ultrasound

Abstract

The gentamicin-loaded nano-sized liposomes are shown to penetrate into alginate-based Ralstonia insidiosa bacterial biofilms by acoustic streaming generated by moderate pulsed ultrasound (frequency = 2.25 MHz, 10% duty cycle and spatially and temporally averaged intensity, ISATA ≈ 4.4 W/cm2). The liposomes are then burst by the scanned relatively high intensity ultrasound (frequency = 1.1 MHz, 10% duty cycle, the spatially and temporally averaged intensity ISATA ≈ 90 W/cm2) in situ, and the gentamicin solution is released from the liposomes resulting in 72% of Ralstonia insidiosa killing.