Targeting aerosol delivery to regions of nasal-associated lymphoid tissue (NALT) in three dimensional models of human intranasal airways using the BiVax intranasal atomizer

• Published in: Frontiers in Drug Delivery 2024-11, Vol.4
• Main Authors: Laube, Beth L., Kesavan, Jana, Farias, Gonçalo, Karavas, Nektaria, Blondel, Mathilde, Suman, Julie
• Format: Article
• Language: English
• Subjects: 3D models of human intranasal airways; insertion angle; model age; model head position; nasal-associated lymphoid tissue (NALT); targeted aerosol delivery
• ISSN: 2674-0850; 2674-0850
• DOI: 10.3389/fddev.2024.1456538

IntroductionWell-organized nasal-associated lymphoid tissue (NALT) has been identified in the pharyngeal and tubal tonsils of both adults and children, and diffuse NALT has been identified in the superior, middle and inferior turbinate regions of children. However, it is not clear how to target these NALT sites with aerosolized vaccines. We explored whether head position and/or angle and distance of device insertion could be used to target fluorescein aerosol to NALT sites in three-dimensional printed models of the intranasal airways of an 18- and a 5-year-old (yo).MethodsThree head positions (upright [Up], tilted back 45° [45] and supine [Su]), two angles of insertion (30° and 45°) and two distances of insertion (6 mm and 9 mm) were tested. Fluorescein aerosol was generated by an Aptar Pharma BiVax 200 µL intranasal atomizer. Percent fluorescein deposition was quantified in the anterior nose, the upper horizontal third of the model (superior turbinate region), middle third (middle turbinate), lower third (inferior turbinate and nasopharynx combined) and exit filter.ResultsMean percent deposition in both models was 45 > Su (p = 0.03).DiscussionThese results suggest that, in individuals with similar nasal airway dimensions as our models: 1) supine and upright head positions might be used to target delivery of aerosolized vaccines generated by the BiVax intranasal atomizer to NALT sites in the middle turbinate and the inferior turbinate and nasopharynx combined, respectively; 2) delivery to the middle turbinate may be higher in children ≤5-yo; and 3) deposition in the anterior nose may be higher in adults, for all head positions. In vivo tests are needed to confirm these findings.