Rapid Gelation from Lipoic Acid/Trometamol Binary Assembling for Realizing 3D Printing in Poly(Lipoic Acid)-based Hydrogel Bandages Production

Developing a strongly adhesive, easily removable and robust bandage is valuable in trauma emergencies. Poly(lipoic acid) (PLA)-based adhesives have been well-developed, however, the additive manufacturing and depolymerization of which remains a challenge. Herein, LA and trometamol are found to rapidly gel into a supramolecular hydrogel at room temperature with injectability and 3D printing potential. Meanwhile, the synthesized LA-grafted hyaluronic acid (HALA) and cellulose nanocrystals (CNC) are involved not only to optimize 3D printing, but also to be the macromolecular covalent crosslinker and giant physical crosslinker to co-polymerize with LA after printing to effectively promote fidelity and prevent the inverse closed-loop depolymerization of PLA in water. The hydrogel bandage exhibits strong adhesion (the adhesion strength was ~ 10 times higher than FibrinGlu) and enhanced elastic modulus and toughness, as well as immediate self-healing ability. Meanwhile, the hydrogel bandage can be removed with no residue by water flushing, showing protection to neo-tissue during dressing replacement. The in vivo healing of the incision and full-layer wounds confirms that the application of the hydrogel bandage significantly promoted wound healing by closing the wound, forming a physical barrier and providing an anti-inflammatory effect, showing great potential in future clinical applications.