Mucoadhesive properties of sulphated polysaccharides carrageenans from red seaweed families Gigartinaceae and Tichocarpaceae.

The mucoadhesive properties of different types of carrageenan (kappa-, kappa/beta-, iota/kappa- and lambda-CRGs) isolated from red seaweed families Gigartinaceae and Tichocarpaceae collected on the Pacific coast were studied. We examined the interaction between CRGs and pig stomach mucin in dilute aqueous solutions using a set of methods. Measurements of the dynamic light scattering of mucin in the presence of CRG showed that the polysaccharides cause aggregation of mucin particles, as confirmed by microscopy data. The addition of CRGs to solutions of mucin resulted in the formation of a mixture that changed the charge of mucin, especially in the case of kappa- and kappa/beta-CRGs. The interaction between CRG and porcine gastric mucin in the presence of various additives confirmed that hydrogen bonds and electrostatic interactions are complemented when CRG and mucin are mixed in an aqueous medium, which is also confirmed by in vitro methods based on measurements of work of adhesion and shear stress. Kappa- and kappa/beta-CRGs that contain 3,6-anhydro-α-d-galactopyranose chains (DA) have high molecular weight and exhibit a high density of available hydrogen bonding groups able to interact more strongly with mucin glycoproteins.