Crosslinker Effects on Properties of Hydroxyethylacryl Chitosan/Sodium Alginate Hydrogel Films

Abstract

SummaryThe aim of this research is to investigate the effects of Ca2+ and Zn2+ ions on the swelling behavior, mechanical property and antibacterial activity of hydroxyethylacryl chitosan (HC)/ sodium alginate (SA) hydrogel films. The hydrogel films composed of HC and SA in different proportions (75:25, 50:50 and 25:75 w/w) were prepared by dipping method using calcium chloride as a single crosslinking agent and both calcium chloride and zinc sulfate as a couple crosslinking agent. The structures of the films were characterized by infrared spectroscopy (FT‐IR). It was found that Ca2+ ions could only crosslink with SA through the formation of ionic bonds while Zn2+ ions could crosslink both HC through the formation of coordinate bonds and SA through the formation of partially ionic or coordinate bonds. The swelling behaviors of the films in phosphate buffered saline (PBS) were investigated. The results showed relatively high stability for the crosslinked films with the couple crosslinking agent. The mechanical properties of the hydrogel films were also tested. It was found that the mechanical properties of the calcium‐zinc crosslinked films were greater than calcium crosslinked films. The values of tensile strength and elongation at break of the calcium‐zinc crosslinked films in the fully hydrated state were up to 12.9 MPa and 67%, respectively. Additionally, the calcium‐zinc crosslinked films evidenced better antibacterial activity to Staphylococcus aureus than calcium crosslinked films. Moreover, all of prepared hydrogel films exhibited no cytotoxicity for Vero cells. The comprehensive results suggest their potential as a wound dressing.