Pullulan-based nanofiber membranes with antibacterial and anti-inflammatory properties for rhinosinusitis therapy

Rhinosinusitis is a common inflammatory condition of the nasal cavity that often requires antimicrobial and anti-inflammatory therapy. This study aimed to develop a noninvasive, multifunctional nanofiber platform for localized rhinosinusitis treatment. Pullulan-based nanofiber membranes co-loaded with ampicillin and clove oil were fabricated using the scalable Forcespinning® technique. The chemical composition, morphology, and thermo-physical properties of the developed membranes were characterized. Antibacterial activity was evaluated against Staphylococcus aureus using a Kirby – Bauer disk diffusion assay. Cytocompatibility and anti-inflammatory activity were assessed in RAW 264.7 macrophages, while mucus interaction and ex vivo mucosal permeation were evaluated using fluorescence-based methods. The optimized pullulan/ampicillin/clove oil nanofibers exhibited uniform, bead-free morphology with an average diameter of 530 ± 35 nm and adequate thermal stability. Composite nanofibers demonstrated significantly enhanced antibacterial activity compared to single-agent formulations. The nanofibers were non-cytotoxic up to 500 µg/mL and significantly reduced nitric oxide production in LPS-stimulated macrophages (p Chronic rhinosinusitis is a common condition in which the lining of the nasal passages and sinuses becomes inflamed and infected, often leading to congestion, facial pain, and reduced quality of life. Current treatments frequently rely on oral antibiotics or invasive procedures, which can cause unwanted side effects and may not effectively deliver medication to the site of infection. In this study, we developed a new, noninvasive treatment approach using very small fibers made from pullulan, a natural and biocompatible polymer. These nanofibers were designed to carry two therapeutic agents: ampicillin, an antibiotic used to treat bacterial infections, and clove oil, a natural compound known for its antibacterial and anti-inflammatory properties. We found that the nanofibers had a uniform structure and were able to evenly incorporate both therapeutic agents. Laboratory testing showed that the nanofibers strongly inhibited the growth of bacteria commonly associated with sinus infections and significantly reduced inflammation-related signaling in immune cells, without causing harm to healthy cells. Additional studies showed that the nanofibers could interact with and penetrate nasal mucus, suggesting they may effectively deliver medication within the nasal cavity. Overall, these findings indicate that pullulan-based nanofibers may be a safe and effective platform for localized treatment of sinus infections and inflammation, offering a promising alternative to systemic medications and invasive therapies.