A Wet Adhesive Biological Glue for Tissue Patch Fixation

Although biological glue showed considerable potential for assisting patches in sealing tissue defects, its limited wet adhesion resulted in unreliable sealing or even detachment. Herein, we developed a wet adhesive Fe@LA glue by heating a mixed solution of ethyl lactate containing α-lipoic acid (LA) with ferric ion (Fe3+) to assist tissue patches in sealing defects. After being applied to the patch surface, the Fe@LA glue gradually cured upon contact with water. The strong hydrophobicity of the cured glue disrupted the hydration layer, allowing the carboxyl groups in its network to form interfacial bonds with tissues, which enabled the ReDura membrane (RM) patch to firmly adhere to wet bovine pericardium and achieve an adhesive strength of 54.3 kPa while withstanding a burst pressure of 37.0 kPa. Biosafety evaluations (cytotoxicity, hemolysis, acute systemic toxicity, subacute systemic toxicity, subcutaneous implantation, and skin irritation) confirmed its biocompatibility when the coating amount was ≤2 mg/cm2. In both porcine gastric defect sealing and rat liver hemostasis models, the patches with Fe@LA glue showed effective sealing and hemostasis, highlighting its promise for suture-free sealing of tissue defects.