Why are chitosans mucoadhesive?
Mucoadhesion is defined as the ability of materials to adhere to the soft mucosal surface that lines the gastrointestinal, tracheobronchial, reproductive, bladder, and ocular epithelia. The mucosa is comprised of a complex assortment of mucin glycoproteins that occur either in gel or solution state and that vary in detailed composition and thickness in the various tissues. The mucoadhesive properties of chitosans and chitosan-based biomaterials are widely known. The interaction between chitosans and porcine stomach mucin in the presence of different additives has shown that electrostatic interactions are complemented by hydrogen bonding and hydrophobic forces when chitosans and mucin are mixed in an aqueous environment.