Bacterial biofilm disruption using laser generated shockwaves

Abstract

A system was built to test the efficacy of bacterial biofilm disruption using laser generated shockwaves. The system is based on a Q-switched, ND:YAG pulsed laser operating at a rep rate of 10 Hz with 1500 mJ pulses centered at 1064 nm. The laser pulses were used to create shockwave pulses in Al coated polycarbonate substrates and a resulting peak stress of greater than 50 MPa was measured. These stress pulses were coupled to bacteria grown to confluence on agar plates and cell death as a result of shockwave stress was assessed. The results show a 55% reduction in the number living bacteria between shocked and control samples. This type of biofilm disruption method could prove useful in the treatment of infected wounds where standard treatment methods such as debridement and topical antibiotics have proven to be ineffectual or harmful.

Laser-generated shockwaves enhance antibacterial activity against biofilmsin vitro

“…LGS is a novel, minimally invasive modality for biofilm disruption which involves generation of mechanical shockwaves from laser irradiation of a coupled substrate . Unlike standard laser technologies, there is no direct contact of thermal energy from the laser system to the tissue being treated.…”

“…Laser‐generated shockwave (LGS) therapy is a novel, minimally invasive, and non‐thermal method for the removal of bacterial biofilms . LGS utilizes compressive stress waves generated by laser ablation of a thin titanium film to mechanically disrupt the biofilm, without damaging the underlying tissue (Fig.…”

“…). Previously, it has been shown that LGS therapy can remove bacterial biofilm grown in a polystyrene dish, and the treatment resulted in an immediate 55% reduction in colony‐forming unit (CFU) count of bacterial cultures grown on agar . Furthermore, work by Nigri et al demonstrated that LGS therapy in combination with vancomycin therapy can reduce S. epidermidis CFU count on vascular prosthetic grafts .…”

In‐depth analysis of antibacterial mechanisms of laser generated shockwave treatment

“…A novel proposed method for biofilm disruption is laser generated shockwaves (LGS) . LGS involves laser ablation of a metallic layer deposited on a flexible substrate and causing thermal expansion of the metal, thereby producing a compressive stress shockwave with a minimal tensile component.…”

Analysis of flexible substrates for clinical translation of laser-generated shockwave therapy

“…LGS have recently been adapted as a potential solution to safe, efficient biofilm removal [13]. These shockwaves are generated using a short-pulsed laser incident on absorptive metal films deposited onto a carrier substrate.…”