The water treatment system for hemodialysis (HD) is used to treat multiple patients requiring HD simultaneously. This system requires a large amount of purified reverse osmosis (RO) water. However, a major drawback of this method is the formation of biofilms in dialysate pathways. The purpose of this study was to investigate the efficacy of NOC 18, a nitric oxide (NO) donor that can be used at neutral pH, in disinfecting the RO water pathway. Silicone tubes were obtained from the terminal sites of two different HD units. The biofilm coverage and mean biofilm thickness on the tube lumen were evaluated by scanning electron microscopy. The results demonstrated that treatment with NOC 18 alone and in conjunction with sodium hypochlorite reduced biofilm coverage and mean biofilm thickness. Thus, NO donor is a potential disinfectant that enhances bacterial dispersion from biofilms formed on the silicone tube lumen and reduces biofilm coverage and thickness on the RO water pathway at neutral pH. Furthermore, combined disinfection with the NO donor and sodium hypochlorite might enhance biofilmremoval efficacy in clinical practice.

  • NO donor reduces microbial in the RO water pathway for hemodialysis.

  • NOC 18 reduces biofilm coverage and thickness under neutral pH conditions.

  • Disinfection ability of NO donor alone is weak.

  • NO donor and sodium hypochlorite together increase biofilm removal.

  • The cleaning method using NOC 18 is environmentally friendly.

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