Opportunities offered by chitosan-based nanotechnology in mucosal/skin drug delivery

Chitosan (CS) based nanocarriers have been extensively studied starting from early 90s. The unique properties of CS and in particular its capability to interact with various epithelia and its mucoadhesion potential have attracted many researchers. The mild preparation conditions of CS nanosystems offer the opportunities to load stress sensitive hydrophilic macromolecules such as proteins and genetic materials. Moreover CS nanosystems are able to protect their cargo from the environment (pH, enzymes). The safety issues related to this polymer seem in part overcome at least for CS as polymeric solution. For this reason skin and mucosae, in particular buccal and vaginal ones, seem the more promising administration routes with lower technical and regulatory challenges. Even if several papers focused on CS nanocarriers for skin and mucosal (buccal and vaginal) administration have been published, other work should be done aiming at optimizing CS nanocarriers in view of clinical applications.