Chitosan based-asymmetric membranes for wound healing: A review

The wound healing process involves highly complex and dynamic events that allow the re-establishment of skin's structural integrity. To further improve or to overcome the drawbacks associated with this process, researchers have been focused on the development of new therapeutics. Among them, asymmetric membranes are currently one of the most promising approaches to be used in wound healing due to its structural similarities with the epidermal and dermal layers of the native skin. The outer layer of asymmetric membranes provides a barrier that protects the wound from external damages (e.g. microorganisms and chemical agents), whereas the interior porous layer acts as template for supporting cell adhesion, migration and proliferation. Among the different materials used to produce these distinct layers, the chitosan arises as one of the preeminent materials due to its inherent biocompatibility, antibacterial, hemostatic, and healing properties. Therefore, in this review, it is provided an overview of the different chitosan-based asymmetric membranes developed for wound dressing applications. Further, the chitosan modifications to enhance its bioactivity as well as the asymmetric membranes general properties and production techniques are also described.