Hyaluronic acid/tannic acid films for biomedical application

In this study thin films based on hyaluronic acid (HA) with tannic acid (TA) were investigated in three different weight ratios (80HA/20TA, 50HA/50TA, 20HA/80TA) for potential medical applications. Surface free energy as well as its roughness, mechanical properties, water vapor permeability rate, and antioxidant activity were determined. Moreover, the compatibility with blood and osteoblast cells was investigated. The irritation effect for hyaluronic acid/tannic acid films by in vitro method was also considered. The results showed that the films have low surface free energy (54-42 mJ/m 2 ), and rough surface (Ra 2.92-3.45 nm; Rq 3.84-4.21), and showed antioxidant activity (RSA 26% for 80HA/20TA; 93% for 20HA/80TA). All of the studied compositions of hyaluronic acid/tannic acid films are hemocompatible (hemolysis rate below 2%), however fully cytocompatible are only films based on 50HA/50TA. All films except 80HA/20TA showed appropriate mechanical properties in terms of potential implantation. All samples did not show the irritation effect during the studies using the reconstructed human epidermis.