The mechanical properties and bactericidal degradation effectiveness of tannic acid-based thin films for wound care.

The surface area is the most important aspect when considering the interactions between a material and the surrounding environment. Chitosan (CTS) and tannic acid (TA) were previously successfully tested by us to obtain thin films to serve as wound dressings or food packaging materials. However, surface properties as well as the antimicrobial activity of the material were not considered. They are important if the material is likely to find application in biomedical or food packaging application. Thereby, this study is a further investigation of chitosan/tannic acid films surface properties. The results showed that higher content of tannic acid increases the surface free energy and roughness, which is beneficial when considering the application of the materials as wound dressings. However, higher content of chitosan provides better antibacterial properties. Hence, the most optimal complex of chitosan and tannic acid for proposed application is the ratio 80/20.