Bioactive films based on barley β-glucans and ZnO for wound healing applications

In this study, mixtures based on β-glucans and proteins are extracted from barley, in mild (MA) and high (HA) alkaline conditions, and employed with zinc oxide (ZnO) to prepare bioactive films for wound healing. Composition of extracts and properties of resulting films depend on pH extraction conditions. MA based samples show weak physical interactions among mixture components, whereas in HA films the extent of these interactions is larger. Consequently, their chemico-physical properties are significantly different, as demonstrated by FT-IR, thermal, mechanical and morphological analyses. ZnO with its bound water molecules acts as a slight plasticizer in MA, as shown by the lower T_g and the decrease of elastic modulus. In HA, this effect is evidenced up to ZnO 1%, and above this concentration an increase of strength at break is observed. Finally, MA and HA films show intrinsic antimicrobial properties, enhanced by ZnO, which make them exploitable as wound dressings.