Procedures
NPS, Ondine
Photodynamic treatment was performed using the CE-marked Steriwave™ Nasal Photodisinfection System (NPS, SW4000, Ondine Biomedical Inc, Vancouver, BC, Canada). This is a Class II Medical Device that includes a power source, a Nasal Light Illuminator (NLI) and a methylene blue formulation (MBF) approved in Canada and Europe for the decolonization of the anterior nasal passages. The topically applied MBF binds microbial components, and the illuminating red light is absorbed by the photosensitizer molecules, producing reactive oxygen species responsible for the lethal microbial disruption. Selectivity is produced by electrostatic differentiation of the cationic photosensitizer to microbes versus generally zwitterionic host tissues.Nasopharyngeal (NP) swabs were performed before treatment and on days 3 and 7. NP specimens were collected in Universal Transport Media (Vircell) and used for RNA extraction (TANBeadThe procedure was initiated by swabbing the MBF inside the patient’s anterior nares, including nostrils and nasal passages. The dual-channel NLI was connected to the power source and inserted into the patient’s nostrils. A 4-minute illumination cycle was applied three times using new MBF after each cycle. This 4 min x 3 scheme was repeated on day 2 and 3. In total, each patient was treated for 36 min. NLI channels were labelled with “L” and “R” for the left/right nostril and a a new set of NLI was used each day to avoid self-contamination.