Reduction of Pseudomonas aeruginosa biofilm formation through the application of nanoscale vibration.

Bacterial biofilms pose a significant burden in both healthcare and industrial environments. With the limited effectiveness of current biofilm control strategies, novel or adjunctive methods in biofilm control are being actively pursued. Reported here, is the first evidence of the application of nanovibrational stimulation (nanokicking) to reduce the biofilm formation of Pseudomonas aeruginosa. Nanoscale vertical displacements (approximately 60 nm) were imposed on P. aeruginosa cultures, with a significant reduction in biomass formation observed at frequencies between 200 and 4000 Hz at 24 h. The optimal reduction of biofilm formation was observed at 1 kHz, with changes in the physical morphology of the biofilms. Scanning electron microscope imaging of control and biofilms formed under nanovibrational stimulation gave indication of a reduction in extracellular matrix (ECM). Quantification of the carbohydrate and protein components of the ECM was performed and showed a significant reduction at 24 h at 1 kHz frequency. To model the forces being exerted by nanovibrational stimulation, laser interferometry was performed to measure the amplitudes produced across the Petri dish surfaces. Estimated peak forces on each cell, associated with the nanovibrational stimulation technique, were calculated to be in the order of 10 pN during initial biofilm formation. This represents a potential method of controlling microbial biofilm formation in a number of important settings in industry and medical related processes.