Mussel-inspired adhesive hydrogels based on biomass-derived xylan and tannic acid cross-linked with acrylic acid with antioxidant and antibacterial properties

Inspired by mussel chemistry, adhesive hydrogels represented by polydopamine (PDA) have been widely studied in many fields such as biomedical applications and bioelectronics. However, the process of producing PDA from dopamine often requires specific conditions, which oxidize some of the effective groups and reduce the adhesion effect. So it is important to develop a simple and effective method for fabrication and application of adhesive hydrogels. In this work, an adhesive hydrogel composed of xylan, polyacrylic acid (PAA) and tannic acid (TA) was developed using a facile approach, which exhibited excellent mechanical and adhesion properties. The xylan and TA both from plants could endow the hydrogels with unique properties such as biocompatibility and biodegradability. Surprisingly, the resultant hydrogels exhibited excellent stretchability (extension ratio up to 4600%) and adhesive strength (up to 25 kPa). Besides, the synthesized hydrogels displayed excellent antioxidant and antibacterial properties, while the scavenging rate of 2, 2-Diphenyl-1-picrylhydrazyl (DPPH) radical reached to 94.12%. This study provides a new insight for the design of hydrogels with stretchable, adhesive, antioxidant and antibacterial abilities.