Tannic acid-thioctic acid hydrogel: a novel injectable supramolecular adhesive gel for wound healing

Skin tissue defects represent a major threat to human health. It is of vital importance for researchers to develop novel ideal adhesives with strong adhesion, good biocompatibility, low cost, and simple production approaches. Inspired by the phenomenon of free-radical scavenging by polyphenols, as well as the fact that polyphenols improve the mechanical properties of flour products, a tannic acid-thioctic acid (TATA) supramolecular hydrogel was synthesized via the ring-opening polymerization of thioctic acid and thiyl radical-polyphenol Michael addition. The synthetic procedure was robust, facile, time-saving, and low-cost, and thus in accordance with the rules of green chemistry. Successful intermolecular crosslinking was confirmed using X-ray photoelectron spectroscopy (XPS). The multiple hydrogen bonds formed between the polyphenol residues and carboxyl groups endowed the hydrogel with self-healing and injectable properties. Additionally, the TATA hydrogel was used as an adhesive for skin wound healing, and it exhibited decreased therapeutic time and an enhanced regeneration effect compared with suture treatment. This hydrogel also showed antibacterial activity against Methicillin-resistant Staphylococcus aureus in a burn wound infection model. Based on the above features, the TATA hydrogel exhibits potential as a surgical antibacterial bioadhesive for a broad range of medical applications.