Design of a 3D printed nanocellulose based moisturizer for wound dressing applications

The skin grafts are difficult to heal on concave body surfaces. Also the wound healing depends significantly on many factors such as the patient`s health condition, wound location, etc. The current treatment method relies on the absorption of wound exudate thanks to the Hydrofiber technology. This could create problems since the wound exudate remains in contact with the wound bed increasing the risk of infection. Here, to solve this problem we propose a new concept of a 3D printed wound dressing consisting of four separated modules. One of these modules is the moisturizing layer which has a direct contact with the skin We design a 3D module that provides a moist environment during the healing process of the wound (around 7 days), removes the excess fluid produced from the wound, is mechanically stable under moderate compression and shear force and retains the shape of the dressing. The purpose of the work is to use completely sustainable materials, especially microfibrillated nanocellulose (MFC) and develop a 3D prototype which covers the concave armpit surface. The work is divided in; designing of CAD 3D structure with channels to allow the extraction of the fluid through capillarity forces; designing the bioink suitable for the application and printing and testing the final structure for the dressing prototype. The printability and rheological properties of bioinks were tested and it was shown that they are suitable for 3D printing of wound dressing. The quality of the 3D printed dressings was characterized by performing the water retention tests, shrinking analysis, rheological, compression test and simulate wound fluid (SWF) extraction test.