Abstract
BackgroundTo investigate the antibiofilm efficacy of nitric oxide (NO) on soft contact lenses.MethodsNitrite (NO precursor) release from various concentrations (0–1000 μM) of sodium nitrite (NaNO2, NO donor) was measured by Griess Assay. Cell viability assay was performed using human corneal epithelial cell under various concentration (0–1000 μM) of NaNO2. Biofilm formation on soft contact lenses was achieved by adding Staphylococcus aureus or Pseudomonas aeruginosa to the culture media. Various concentrations of NaNO2 (0–1000 μM) were added to the culture media, each containing soft contact lens. After incubation in NaNO2 containing culture media for 1, 3, or 7 days, each contact lens was transferred to a fresh, bacteria-free media without NaNO2. The bacteria in the biofilm were dispersed in the culture media for planktonic growth. After reculturing the lenses in the fresh media for 24 h, optical density (OD) of media was measured at 600 nm and colony forming unit (CFU) was counted by spreading media on tryptic soy agar plate for additional 18 h.ResultsNitrite release from NaNO2 showed dose-dependent suppressive effect on biofilm formation. Most nitrite release from NaNO2 tended to occur within 30 min. The viability of human corneal epithelial cells was well maintained at tested NaNO2 concentrations. The bacterial CFU and OD showed dose-dependent decrease in the NaNO2 treated samples on days 1, 3 and 7 for both Staphylococcus aureus and Pseudomonas aeruginosa.ConclusionsNO successfully inhibited the biofilm formation by Staphylococcus aureus or Pseudomonas aeruginosa on soft contact lenses in dose-dependent manner.
Highlights
To investigate the antibiofilm efficacy of nitric oxide (NO) on soft contact lenses
Reculturing contact lenses with biofilm is a kind of indirect method for quantification of biofilm
After change of the environment, pathogens can release from the biofilm to culture media for planktonic growth
Summary
To investigate the antibiofilm efficacy of nitric oxide (NO) on soft contact lenses. Bacterial keratitis can cause sight-threatening complications, such as corneal opacity or perforation [1,2,3]. Corneal hypoxia and epithelial damage induced by wearing contact lenses enhances the bacterial adhesion and invasion [4]. Normal host defense mechanism against pathogen, such as tear and blinking can be significantly interfered by wearing contact lenses [5]. The adhesion of Nitric oxide (NO) is a one of well-known antibacterial mechanisms of mammalian host [11]. When generated locally with micromolar concentration, NO acts as a cytotoxic antimicrobial agent [11]. Previous studies have shown that NO could act as a key mediator for biofilm
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
