The Antibiofilm efficacy of nitric oxide on soft contact lenses

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.

Prolonged Release Period of Nitric Oxide Gas for Treatment of Bacterial Keratitis by Amine-Rich Polymer Decoration of Nanoparticles

“…In severe cases of bacterial keratitis, it is urgent to inhibit infectious bacteria and heal the wounds at the same time. Untreated bacterial keratitis can cause complications that threaten vision, such as corneal opacity and perforation . Antibiotics are useful for killing the bacteria but not for wound healing.…”

“…Untreated bacterial keratitis can cause complications that threaten vision, such as corneal opacity and perforation. 27 Antibiotics are useful for killing the bacteria but not for wound healing. In this respect, the developed BPEI-surface modified NO-releasing Si NPs (BPEI-NO NPs) can be suggested as multifunctional nanotherapeutics for bacterial keratitis due to their antibacterial and wound repair functions with noncytotoxicity based on the sustained NO release.…”

Nitric oxide: an old drug but with new horizons in ophthalmology—a narrative review

“…NO can facilitate the dispersal of bacterial biofilm and NO can make bacteria more susceptible to other antibiotics ( 102 , 103 ). Kim et al ( 104 ) reported that biofilm formation on contact lens surface by Pseudomonas aeruginosa and Staphylococcus aureus was successfully inhibited by NO donor such as sodium nitrite. NO releasing contact lenses were also investigated with promising in vitro data ( 105 , 106 ).…”

The nitric oxide synthase gene negatively regulates biofilm formation in Staphylococcus epidermidis

“…It has been described that NO plays an important role in human host defense against pathogen infection and immune modulation ( Lee et al., 2017 ). Previous studies have demonstrated that NO can not only exert some essential biological functions in microorganisms but also regulate bacterial biofilm formation ( Kim et al., 2017 ) and drug resistance ( Gusarov et al., 2009 ). Additionally, endogenous bacterial NO can also contribute to protecting bacteria against oxidative stress, such as antibiotic-induced oxidative stress ( Holden et al., 2015 ), thus demonstrating that it may participate in bacterial resistance.…”