Laser Disruption of Biofilm.
Laryngoscope. 118(7):1168-1173, July 2008.
Krespi, Yosef P. MD, FACS; Stoodley, Paul PhD; Hall-Stoodley, Luanne
PhD

Abstract: Objectives/Hypothesis: To demonstrate the capability of a
fiber-based Q-switched Nd:YAG laser (ARCLaser, Nuremberg, Germany and
Valam, Orangeburg, NY) to disrupt biofilm.

Study Design: Biofilms were grown in broth for 72 hours prior to the
experiment. A clinical otorrhea isolate from Pseudomonas aeruginosa
was used. Biofilms were placed in MatTek culture plates, on stainless
steel screws, tympanostomy tubes, and polyethylene terephthalate (PET)
sutures.

Methods: Culture plates, stainless steel screws, tympanostomy tubes,
and PET sutures were used for the laser disruption of biofilm
experiments. Q-switched Nd:YAG laser pulses were delivered on biofilms
using shockwave probes originally designed for cataract surgery. The
thin laser fiber tip was targeted against a titanium target, creating
the production of plasma and resulting in a shockwave effect.

Results: Biofilm areas were imaged before, during, and after laser
application using a confocal microscope. The biofilm was imaged
growing on the glass/plastic step of the plates, in the grooves of the
threads of the screws, over the tympanostomy tube, and on the PET
suture. During laser treatment, a time-lapse function was used to
capture the results. As a result of laser-generated shockwaves, the
biofilm was initially seen to oscillate and eventually break off with
individual pulses. Large and small pieces of biofilm were totally and
instantly removed from the surface to which they were attached in a
matter of a few seconds.

Conclusions: We were able to effectively disrupt Pseudomonas
aeruginosa biofilms in vitro using a miniature Q-switched Nd:YAG
laser, thin fibers, and special probes that generated plasma formation
and a resulting shockwave effect. This laser technology has the
ability to generate a powerful stress wave sufficient to disrupt
biofilm without any ill effect to the underlying host structure.
(C) The American Laryngological, Rhinological & Otological Society,
Inc.