Main > Journal of Innovative Optical Health >  Volume 11 >  Issue 5 >  Page 1850029 > Article
Journal of Innovative Optical Health, Vol. 11, Issue 5, 1850029 (2018)

The bactericidal effect of continuous wave laser with strongly absorbing coating at the fiber tip

Vadim Elagin1,2,*, Anton Smirnov2, Vladimir Yusupov3, Alexey Kirillov4, Nadezhda Ignatova1, Olga Streltsova5, Evgeniy Grebenkin5, and Vladislav Kamensky2

Author Affiliations

  • 1Institute of Biomedical Technologies Privolzhsky Research Medical University 10/1 Minina Square, Nizhny Novgorod 603005, Russia
  • 2Laboratory of Laser Nanomodification of Materials Institute of Applied Physics Russian Academy of Sciences 46 Ulyanova Street, Nizhny Novgorod 603950, Russia
  • 3Institute of Photon Technologies of Federal Scientific Research Centre "Crystallography and Photonics" of the Russian Academy of Sciences 2 Pionerskaya Street, Moscow, Troitsk 108840, Russia
  • 4Department of Innovative Program Institute of Applied Physics Russian Academy of Sciences 46 Ulyanova Street, Nizhny Novgorod 603950, Russia
  • 5Department of Urology Privolzhsky Research Medical University 10/1 Minina Square, Nizhny Novgorod 603005, Russia

Abstract

The bactericidal effect of laser radiation with a quartz fiber-based transmission system with a strong absorption coating converter against bacteria associated with urological stones has been studied. Gram-negative rod Escherichia coli and the Gram-positive coccus Staphylococcus epidermidis, Staphylococcus aureus, Enterococcus faecalis and Enterococcus faecium were used in this study. Each bacterial species was treated by continuous-wave near infrared laser coupled with bare fiber tip or strongly absorption coating fiber tip. After treatment, the temperature of bacterial suspension was measured. In addition, the temperature distribution was analyzed. It has been shown that using laser with a strongly absorption coating fiber tip results in significant bactericidal effect. The decrease of the amount of E. coli and S. epidermidis was 100% after treatment with an output power of 6W of radiation at a wavelength of 0.97 _m for 40 s. Number of S. aureus and Ent. faecium colony-forming unit was reduced to 70% after same exposure. The peak temperature of bacterial suspension was 86_C after treatment by laser with a strongly absorption coating fiber tip. Laser with a strongly absorption coating fiber tip provides large-scale hydrodynamic flows directed away from the fiber tip. The laser with a strongly absorption coating fiber tip has bactericidal effect. The main role is associated with the effect of high temperature, which, in the form of flow in a liquid medium, affects bacteria.

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