A robustly injectable hydrogel bioadhesive for sutureless repair of large colonic defects

Despite recent advances in surgical adhesives as promising alternatives to sutures or staplers for colonic defects and gastrointestinal management, significant challenges persist regarding to excellent biocompatibility, injectability operation, robust tissue adhesion and durable stability in colon environments due to the growing popularity of minimally invasive laparoscopy. In this work, we reported an in situ injectable hydrogel bioadhesive (OSG) consisting of FDA-approved Octa-armed poly (ethylene glycol) succinimidyl glutarate (Octa-PEG-SG) and Octa-armed poly (ethylene glycol) amine (Octa-PEG-NH2) polymers for sutureless repair of large colonic defects. The OSG hydrogel was advantageous to rapid injection to cover the whole irregular surfaces via the formation of uniform networks and chemical interface binding, and capable of instant adhesion, high burst pressure, secure sutureless closure and durable compliance in the ex vivo porcine colonic injury models, thus enabling robust wet adhesion interfaces even in direct contact with intestinal fluids and constant colonic peristalsis. In terms of excellent biocompatibility and suitable degradability after a comprehensive evaluation from in vivo and in vitro studies, OSG hydrogel was validated with efficient sutureless colonic repair in a rat-injured model without causing postoperative adhesion, long-term inflammatory response and colonic transcriptome and microbiome interference. Innovatively, we further established large-size (3 cm) of porcine colonic defect models by minimally invasive technique, and verified its therapeutic effect under laparoscopic technology. Overall, the proposed OSG bioadhesive offers a promising clinical alternative to sutures for the treatment of colonic defects.