Chitosan cryogels reinforced with nanocellulose–chitosome hybrid systems for enhanced mucoadhesive properties

The objective of this study was to produce chitosan cryogels and investigate the effect of the incorporation of nanocellulose, liposome or chitosome hybrid systems loaded with propolis extract (PE) on their physicochemical properties and in vitro mucoadhesivenes. PE was loaded in liposomes uncoated (L) or coated with chitosan without (chitosomes – Ch) or with crosslinking by using sodium tripolyphosphate (TPPCh). Soybean pod nanocelluloses (CNs) were produced and added to the hybrid particles, obtaining CN-L, CN-Ch and CN-TPPCh. Cryogels containing 3 wt% nanocellulose and TPP-crosslinked chitosomes displayed a mucoadhesive force of 0.2 ± 0.1 N, 1.6-fold higher than controls. Cryogel pore sizes ranged from 10 to 100 µm, larger in liposome-only samples, explaining their higher fragility, being unsuitable for further characterizations. Nanocellulose addition exhibited smaller pores due to fiber network formation and lower wettability for L samples (water contact angle - WCA = 84.1° at 15 s). TPPCh showed pores more filled, influenced by ionic gelation, and have shown a higher WCA (up to 110° at 15 s). The addition of Ch and TPPCh has significantly improved the hydrophobicity of the chitosan-based cryogels. However, only CN-L and CN-TPPCh revealed enhanced properties of mucoadhesiviness, highlighting the importance of the incorporation of nanocellulsoes into these matrices. Therefore, hybrid systems composed of nanocelluloses and TPP-chitosomes emerge as interesting particles to improve cryogel properties for bioactive delivery applications. • Chitosan cryogels were reinforced with nanocellulose and hybrid bioactive systems. • Nanocelluloses (CN) reduced pore size and improved cryogel structural stability. • TPP-crosslinked chitosomes increased cryogel hydrophobicity and pore filling. • CN-L and CN-TPPCh cryogels showed enhanced mucoadhesion for bioactive delivery.