In liver resection surgery for the treatment of liver cancer and bile duct cancer, "bile leakage" is recognized as a serious complication. It involves the escape of bile into the body post-surgery. Since bile does not have coagulation functions like blood, hemostatic gels are used to prevent such leakage. However, existing products sometimes cannot sufficiently prevent leakage and may cause inflammatory reactions in liver tissue, creating demand for new materials.
A research group led by Research Associate Shohei Ishikawa and Professor Takamasa Sakai of the Graduate School of Engineering at the University of Tokyo has developed a new hydrogel to prevent bile leakage after liver resection. They utilized synthetic polymer "polyethylene glycol" as the base material, given its high biocompatibility and established usage in pharmaceuticals and cosmetics. The group devised a unique "time-delayed dual-stage reaction" in which the first stage instantly forms a gel to block bleeding and bile leakage, followed by a delayed second-stage reaction which chemically bonds the gel with amino groups (−NH2) on the surface of biological tissue. This results in long-term stable adhesion. In experiments with rats, hemostasis was achieved within 1 minute after liver resection, and no cases of bile leakage occurred during the proceeding one-month observation period. Furthermore, in the seven-day evaluation after surgery, almost no inflammation or liver damage was observed. Stable adhesion at the tissue interface was also confirmed.
This achievement balances both the blocking of bodily fluid leakage immediately after surgery and long-term stable adhesion. Its application is extendable to surgical challenges involving bodily fluid and gas leakage, such as pancreatic fluid leakage, air leakage after lung resection, and hemostasis at vascular injury sites. Furthermore, precisely designing the gelation time and its adhesion strength is expected to enable its expansion into fields such as drug delivery and scaffolds for regenerative medicine.
(Article: Masanori Nakajo)
