Objectives This study investigated the antibacterial action of photo-liberated nitric oxide (NO) from primary and tertiary S-nitrosothiol-modified mesoporous silica nanoparticles (1° RSNO-MSNs and 3° RSNO-MSNs, respectively) against planktonic periodontal pathogens and ex vivo subgingival periodontal biofilms.Materials and methods The antibacterial and antibiofilm efficacy of photo-liberated NO release from 1° RSNO-MSNs and 3° RSNO-MSNs was evaluated as a function of wavelength (405 and 455 nm), irradiance (400–1000 mW cm−2), and time (0–15 min) against Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and ex vivo subgingival biofilms. Time course, biofilm dispersion, and biofilm eradication assays were employed to evaluate the synergistic impact of antibacterial blue light therapy (aBLT) and photo-liberated NO.Results The addition of photo-initiated NO release with aBLT significantly improved antibiofilm activity, with irradiation of 405 nm at 1000 mW cm−2 demonstrating the most efficacious NO liberation from both 1° RSNO-MSNs and 3° RSNO-MSNs. While aBLT demonstrated antibacterial activity alone, the addition of NO was crucial for biofilm dispersal and eradication.Conclusions The in vitro and ex vivo results demonstrate, for the first time, the utility of a dual-action aBLT and NO-releasing system for treating periodontal pathogens and biofilms.
Johnson et al. (2026) studied this question.