A "Janus" Zwitterionic Hydrogel Patch for Tissue Repair and Prevention of Post-Operative Adhesions.

Anti-peritoneal adhesions (PA) are very important after abdominal surgery for that PA often leads to other medical problems and imposes a huge financial burden on the national healthcare system. In this work, a "Janus" zwitterionic hydrogel patch where one side can adhere firmly to the tissue, while the other side has anti-fouling properties and has little interaction with the surrounding tissue has been developed. The "Janus" hydrogel patch is prepared by in situ formation of a bonding polymer layer poly(acrylic-co-N-hydroxysuccinimide acrylate) on one side of zwitterionic hydrogel. The mechanical, swelling, adhesion, biodegradability and biocompatibility tests are performed to study the function of "Janus" hydrogel patch to prevent wound adhesion and rapid repair. It is found that the adhesive side of the hydrogel patch has stable adhesion to tissues, avoiding the slippage faced by many commercial anti-adhesion gels in the body. The other zwitterionic side can resist proteins and fibroblasts and prevent external interactions or adhesion with other tissues. This convenient and effective method provides a new idea for the design of postoperative anti-adhesion materials and broadens the application of hydrogels in the biomedical field.