Advances in controlled drug delivery to the sinonasal mucosa

Controlled drug delivery is a valuable strategy for increasing local therapeutic concentrations in a sustained manner, particularly in locations that are difficult to access. One such target is the sinonasal mucosa, which can be chronically inflamed in patients with rhinitis or rhinosinusitis resulting in diminished quality of life, significant healthcare expenses, and multiple co-morbidities. While numerous medical therapies with daily administration are available, anatomical, physiological, and patient adherence barriers can limit their therapeutic efficacy. As such, there has been considerable development of biomaterial-based systems that can locally deliver anti-inflammatory, antibiotic, decongestant, and antihistamine medications over an extended duration. This review aims to highlight advances in such biomaterial-based systems for sinonasal delivery. Delivery vehicles including nasal packs, dressings, sinus stents, polymeric meshes, nanoparticles, microparticles, and in situ hydrogels are reviewed. Benefits of these vehicles are discussed, as well as their limitations, which, recently, has motivated the development of combination systems that leverage desirable properties of their individual components to enhance therapeutic delivery. Finally, discussion is provided on the potential of combination delivery vehicles, which can provide greater control of the duration of therapeutic release, as well as the ability to encapsulate multiple therapies, provide mechanical support, or conform to the mucosa. The future clinical use of controlled release systems with these attributes could have a transformative impact on improving treatment of difficult-to-control chronic diseases of the sinonasal mucosa.