Chitosan strips with controlled micro-porosity to improve buccal mucoadhesion

Objectives: Here, we propose the application of a novel film-like chitosan (CH) strips as oral patches to enhance wound healing and buccal drug delivery. The purpose is to improve mucoadhesion in the oral environment, exploiting the well-known bioadhesive properties of CH and the mechanical retention of strips, by means of their innovative highly oriented micropattern of porosity. Methods: CH strips were produced by cathode electrodeposition. Morphological and physical characterization was performed using Optic microscopy, Scanning Electron Microscope (SEM) and swelling degree analyses. Cytocompatibility with primary human gingival fibroblasts (HGF) was verified by means of MTT assay and SEM images. Mucoadhesion was tested using an ex vivo retention model, based on porcine buccal mucosa and DMA Q800 TA instrument. Results: CH strips displayed an oriented porosity, with pores of about 500 lm of diameter, and a random microporosity due to H2 bubble production during synthesis (20 lm). In PBS (pH7.4), structures displayed a excellent water uptake, in few minutes. High cytocompatibility, after primary HGF seeding onto oriented pores samples, was demonstrated. Interesting mucoadhesive properties were verified by ex vivo test. Conclusion(s): Morphological, physical and biological characterizations showed as CH strips are suitable bioadhesive device for buccal applications. Relevance: In perspective, these findings are relevant to produce drug delivery system for oral mucosa as well as to obtain mucoadhesive patches to enhance wound healing by mechanical protection.