Endoscope-assisted magnetic helical micromachine delivery for biofilm eradication in tympanostomy tube.

Occlusion of the T-tube (tympanostomy tube) is a common postoperative sequela related to bacterial biofilms. Confronting biofilm-related infections of T-tubes, maneuverable and effective treatments are still challenging presently. Here, we propose an endoscopy-assisted treatment procedure based on the wobbling Fe 2 O 3 helical micromachine (HMM) with peroxidase-mimicking activity. Different from the ideal corkscrew motion, the Fe 2 O 3 HMM applies a wobbling motion in the tube, inducing stronger mechanical force and fluid convections, which not only damages the biofilm occlusion into debris quickly but also enhances the catalytic generation and diffusion of reactive oxygen species (ROS) for killing bacteria cells. Moreover, the treatment procedure, which integrated the delivery, actuation, and retrieval of Fe 2 O 3 HMM, was validated in the T-tube implanted in a human cadaver ex vivo. It enables the visual operation with ease and is gentle to the tympanic membrane and ossicles, which is promising in the clinical application.